Abstract A multilevel inverter (MLI) is a popular inverter for solar based high power applications. The drawback of conventional H-bridge inverter is non-sinusoidal output voltage, which reduces the output quality of inverter. Later, the drawback of conventional H-bridge was overcome by conventional MLI. But, conventional MLI needs maximum number of diodes and switches. In order to overcome this drawback proposed MLI topology with level shifting sinusoidal pulse width modulation (SPWM) technique can be employed. Proposed MLI contain fewer number of switches and diodes, which helps in optimizing the circuit layout, reducing gate driver circuit for those switches. SPWM technique uses multicarrier waveforms with level shifting ensuring the reduction in total harmonics distortion (THD). In this Paper level shifting SPWM technique has been incorporated in which 5 kHz carrier wave is compare with 50Hz of sinusoidal wave with a modulation index of 0.8. THD of proposed 9-level inverter is 17.27% without filter and 4.29% with LC filter. Simulation of proposed inverter is carried out in MATLAB/SIMULINK. Key Words: Solar, 9-level inverter, Level shifting SPWM, Power diodes and switches, Total Harmonics Distortion (THD)
Comparison of symmetrical and asymmetrical cascaded current source multilevel...eSAT Journals
Abstract This paper presents symmetrical and asymmetrical cascaded multilevel inverter approach for high power output applications. It is based on the cascade connection of the H-bridge inverter cells. Comparison of symmetrical and asymmetrical current source multi level inverter is shown using 2 H-bridge inverter cells with cascade connection. Now ever by the supplies which are in GP with different ratios like 2,3,etc. Structural and operational characteristics are discussed and their inherent advantages are shown. Simulation using Matlab Simulink is done to verify the performance. Simulation and results for this proposed scheme are presented in this paper. Index Terms: Asymmetrical cascaded multilevel inverter, Current source multi level inverter, MATLAB Simulink, Optimization angle control, Symmetrical multi level inverter, Total harmonic distortion (THD).
This paper presents the analysis study between multilevel inverters that are often classified into multilevel voltage source and multilevel current source inverters. For multilevel voltage source inverter (MVSI), the specific topology studied for this work is the Cascaded H-Bridge MVSI. Whereas, the multilevel current source inverter (MCSI) is based on Paralleled Inductor Configuration MCSI. For this study, the analysis between these converters are done with respect to the number of components, the advantages and disadvantages of each converters during performing inverter operation. In term of output voltage and current quality, the percentage of the Total Harmonic Distortion (THD) are measured and compared for both topologies. MATLAB/Simulink software has been used in this research to design and simulate in order to study the performances of both inverters.
Usage of high power and medium voltage applications in domestic and industrial purpose has been increased in the recent years. Also, the penetration of renewable energy sources is increasing rapidly. To make use the renewable energy sources there is a need of using inverters. The basic inverter is conventional two level inverter which produces the square wave output voltage. The major drawback of conventional inverter is it contains more harmonics. Therefore, multilevel inverters have been introduced with staircase output voltage waveform. Lot of multilevel inverter topologies have been developed and cascaded H bridge type is the more frequently used. But, it requires more number of switches for higher output voltage level. In this paper, a novel 7 level asymmetrical multilevel inverter topology is proposed with less number of switches. This proposed topology is compared with already existing topology. The simulation of circuit and result analysis of the circuit is carried out by using Matlab/simulink software. The comparison between existing topology and proposed topology is given. The results are discussed and presented.
Comparison of Multilevel Inverter Topologies for STATCOM ApplicationsIJERA Editor
In this paper is to present an comparison of four different STATCOM multilevel inverter topologies which are suitable to be connected to the un-linear loads and unbalancing loads. The majority of power consumption has been drawn in reactive loads. These loads are drawn in low power factor and therefore give rise to reactive power burden in the power system. So that STATCOM controller is used to compensate reactive power, correction of power factor and elimination of current harmonics. This paper mainly focuses the analysis issues of the Cascade H-bridge, Incremental cascade H-bridge, Incremental cascade I–bridge and Incremental – reduction cascade H-bridge multilevel topologies with PWM technique for STATCOM applications; Inverter operation play a vital in STATCOM, presenting a methods for best suitable in the point of low THD, better output, cost and efficiency. MATLAB/SIMULINK results are present in this paper of multilevel inverter four topologies for STATCOM applications with Instantaneous p – q theory controller implemented.
Generally, PV cell converts sunlight into electricity in the form of dc. Integration of PV system with the existing grid requires dc-ac conversion. This conversion is possible with the help of a dc-ac converter known as an inverter. Among all types of the inverter, multilevel inverters (MLIs) are playing a major role with all their major privileges like High power quality, low distortion, less blocking voltages for switching devices. Conventional multilevel inverter topologies such as diode clamped, flying capacitor and cascaded MLIs are having so many disadvantages. One of the common disadvantage among all the conventional MLIs is the requirement of more number of power electronic components as the level of the output voltage increase. To reduce the power electronic components this paper proposes a multilevel inverter topology in symmetrical and asymmetrical configuration. The proposed MLI uses 12 switches and 19 diodes which are very less compared to conventional MLI topologies for generates nine and thirteen level output voltages. Comparison between presented MLI topology and conventional MLI topologies is presented in this paper. Finally, the proposed MLI whose input is fed from the PV system is integrated into the grid. The proposed concept is validated by using the MATLAB/SIMULINK software and the appropriate results are presented in this paper.
Comparison of symmetrical and asymmetrical cascaded current source multilevel...eSAT Journals
Abstract This paper presents symmetrical and asymmetrical cascaded multilevel inverter approach for high power output applications. It is based on the cascade connection of the H-bridge inverter cells. Comparison of symmetrical and asymmetrical current source multi level inverter is shown using 2 H-bridge inverter cells with cascade connection. Now ever by the supplies which are in GP with different ratios like 2,3,etc. Structural and operational characteristics are discussed and their inherent advantages are shown. Simulation using Matlab Simulink is done to verify the performance. Simulation and results for this proposed scheme are presented in this paper. Index Terms: Asymmetrical cascaded multilevel inverter, Current source multi level inverter, MATLAB Simulink, Optimization angle control, Symmetrical multi level inverter, Total harmonic distortion (THD).
This paper presents the analysis study between multilevel inverters that are often classified into multilevel voltage source and multilevel current source inverters. For multilevel voltage source inverter (MVSI), the specific topology studied for this work is the Cascaded H-Bridge MVSI. Whereas, the multilevel current source inverter (MCSI) is based on Paralleled Inductor Configuration MCSI. For this study, the analysis between these converters are done with respect to the number of components, the advantages and disadvantages of each converters during performing inverter operation. In term of output voltage and current quality, the percentage of the Total Harmonic Distortion (THD) are measured and compared for both topologies. MATLAB/Simulink software has been used in this research to design and simulate in order to study the performances of both inverters.
Usage of high power and medium voltage applications in domestic and industrial purpose has been increased in the recent years. Also, the penetration of renewable energy sources is increasing rapidly. To make use the renewable energy sources there is a need of using inverters. The basic inverter is conventional two level inverter which produces the square wave output voltage. The major drawback of conventional inverter is it contains more harmonics. Therefore, multilevel inverters have been introduced with staircase output voltage waveform. Lot of multilevel inverter topologies have been developed and cascaded H bridge type is the more frequently used. But, it requires more number of switches for higher output voltage level. In this paper, a novel 7 level asymmetrical multilevel inverter topology is proposed with less number of switches. This proposed topology is compared with already existing topology. The simulation of circuit and result analysis of the circuit is carried out by using Matlab/simulink software. The comparison between existing topology and proposed topology is given. The results are discussed and presented.
Comparison of Multilevel Inverter Topologies for STATCOM ApplicationsIJERA Editor
In this paper is to present an comparison of four different STATCOM multilevel inverter topologies which are suitable to be connected to the un-linear loads and unbalancing loads. The majority of power consumption has been drawn in reactive loads. These loads are drawn in low power factor and therefore give rise to reactive power burden in the power system. So that STATCOM controller is used to compensate reactive power, correction of power factor and elimination of current harmonics. This paper mainly focuses the analysis issues of the Cascade H-bridge, Incremental cascade H-bridge, Incremental cascade I–bridge and Incremental – reduction cascade H-bridge multilevel topologies with PWM technique for STATCOM applications; Inverter operation play a vital in STATCOM, presenting a methods for best suitable in the point of low THD, better output, cost and efficiency. MATLAB/SIMULINK results are present in this paper of multilevel inverter four topologies for STATCOM applications with Instantaneous p – q theory controller implemented.
Generally, PV cell converts sunlight into electricity in the form of dc. Integration of PV system with the existing grid requires dc-ac conversion. This conversion is possible with the help of a dc-ac converter known as an inverter. Among all types of the inverter, multilevel inverters (MLIs) are playing a major role with all their major privileges like High power quality, low distortion, less blocking voltages for switching devices. Conventional multilevel inverter topologies such as diode clamped, flying capacitor and cascaded MLIs are having so many disadvantages. One of the common disadvantage among all the conventional MLIs is the requirement of more number of power electronic components as the level of the output voltage increase. To reduce the power electronic components this paper proposes a multilevel inverter topology in symmetrical and asymmetrical configuration. The proposed MLI uses 12 switches and 19 diodes which are very less compared to conventional MLI topologies for generates nine and thirteen level output voltages. Comparison between presented MLI topology and conventional MLI topologies is presented in this paper. Finally, the proposed MLI whose input is fed from the PV system is integrated into the grid. The proposed concept is validated by using the MATLAB/SIMULINK software and the appropriate results are presented in this paper.
Active power and current control for a modular multilevel converter (mmc) bas...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
A Single-Phase Multilevel Current-Source Converter using H-Bridge and DC Curr...IJPEDS-IAES
This paper presents a different topology of H-bridge based multilevel current-source inverter (CSI). In this new inverter configuration, an H-bridge CSI is connected with a single or more current modules to generate a multilevel output current waveform with lower di/dt, and less distortion. Using the proposed multilevel CSI, the number of the power switching devices, and isolated gate drive circuits can be reduced. Moreover, chopper based DC current sources are presented to reduce the inductor size effectively to be in micro-Henry order, and to ensure the balance of the intermediate current levels. The proposed topology is inherently able to reduce the inductor conduction losses if compared with the conventional multilevel CSIs and the H-bridge CSI. Seven-level PWM inverter configurations with non-isolated DC current sources and with a single DC power source are verified through computer simulations. Furthermore, laboratory prototypes of seven-level CSI is setup and tested. The results show that the inverter circuit works properly to generate the multilevel output current waveform with low harmonics currents, small inductors and with less conduction losses which proves feasibility of the proposed multilevel CSI.
Multilevel Inverter (MLI) has attracted a great attention by different researchers and industries due to its capability in handling high power application and minimizing the harmonics contents in the output. This study propose three different topologies of MLI (5-level) which are Cascaded H-Bridge Multilevel Inverter (CHMLI) ,Diode Clamped Multilevel Inverter and Flying Capacitor Multilevel Inverter (FCMLI) .These three topologies have been modelled in MATLAB/SIMULINK and compared in terms of THD and number of components used. Sinusoidal Pulse Width Modulation is utilized to control both of the topologies with same DC source. The results showed that ,CHMLI is superior compared to DCMLI and FCMLI in which the CHMLI produce 26.29% THD while DCMLI and FCMLI produce 29.14% and 33.53% respectively .Moreover less components and switching losses is obtained when using the CHMLI.
Control of inverters to support bidirectional power flow in grid connected sy...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
In this paper both DC-DC Converter and multilevel inverter have been proposed. The proposed multilevel inverter with appropriate gate signals generates seven level AC output voltage. Also, with the implementation of Low Pass Filter, the output voltage’s Total Harmonic Distortion is reduced. Not only switching losses but also voltage stress of switches can be reduced. With the help of Sinusoidal Pulse-Width Modulation (SPWM) switches of the inverters are controlled. Finally, a laboratory prototype has been implemented and from experimental results, the seven level output of implemented inverter can be inferred.
3. simulation of 11 level hybrid cascade stack (hcs) inverter with reduced nu...EditorJST
This paper presents a new multilevel topology based on cascaded hybrid multi-level (HCS)
inverter. There are different topologies for cascaded inverters for reducing the switches, power loss. The output
voltage is increased and the number of switches is reduced with the HCS inverter. Due to this reduction in
number of on-state switches, power loss and voltage drop is reduced. Simulation results for 11 level symmetric
form of converter is described.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Analysis of dc capacitor voltage balance method for h bridge inverter based p...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A novel p q control algorithm for combined active front end converter and shu...eSAT Journals
Abstract
This paper presents a combined active front-end converter and shunt active filter (AFE+SAF) controlled by p-q theory control
algorithm. The Combined AFE+SAF is able to compensate reactive power, harmonic power and unbalanced power produced by
unbalanced linear, non linear and at the same time three phase AC to DC power conversion AFE+SAF will not pollute the source
currents. The p-q theory control algorithm is able to meat the target of load compensation and three phase AC to DC (for drives)
conversion. the AFE+SAF verified by simulation for different cases as unbalanced linear load, non linear load, unbalanced linear
and non linear load, unbalanced linear non linear and drive load. The whole simulation has been carried out on the mat lab/ simulink
software.
Keywords:- active front-end converter, shunt active power filter, p-q theory, power quality, harmonics, reactive power
A Comparison Analysis of Unipolar and Bipolar Switching modulated Cascade H-B...IJERA Editor
This paper discusses controlling of cascaded H-bridge multi inverter with sinusoidal modulation based PWM methods. Multi-level inverters are used to reduce the THD in the output wave form without reduction in power output of inverter. Increase in voltage level in the output voltage of an inverter increases numbers of components to be used in inverter configuration. This in turn increases the switching loss. But results in good harmonic distortion and provide better quality fundamental wave. Carrier based PWM schemes are used for control of switching operation of multi-level inverters. Many kinds of PWM schemes are available to control inverter switches. In this paper uniploar carrier based PWM, bipolar carrier based PWM schemes are considered for generation of carrier signals. The carrier signals thus generated are compared with sinusoidal and third harmonic based sinusoidal modulating signals for production of switching Pulses. Switching schemes are designed for a 3 Phase 3, 5, 7, 9 and 11 Level inverters. The proposed switching schemes are applied to Cascaded H-Bridge Multi Level inverters. The circuit is simulated with MATLAB Simulink environment for verification of total harmonic distortion.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
In this paper, both symmetric and asymmetric operations for an optimized cascaded multilevel power inverter (MLI) are thoroughly examined. While symmetric configurations are more suitable for AC drives due to their equal power sharing among the various levels, the asymmetric topologies fulfill the higher number of power source combinations under the same power semiconductor switch count. Additionally, particular attention was put on the design of this optimized topology in terms of both reliability and power efficiency by managing redundant states and minimizing the number of power switch commutations. Furthermore, a fundamental switching frequency modulation (FSFM) is thoroughly described in C MEX programming language and then the resulting gating signals are fed into the power circuit designed with PSPICE. By applying this co-simulation approach, the control design task is greatly simplified while achieving advanced analyses with more realistic electronic devices.
Performance enhancement of DC/DC converters for solar powered EV IJECEIAES
The paper initially presents the essential drive arrangement required for electric vehicle. It requests high power bidirectional stream ability, with wide info voltage range, and yield voltage of vitality stockpiling gadgets, for example, super capacitors or batteries shift with the adjustment in stack. At that point the tenacity and outline of previously mentioned converter is proposed in this paper. The converter which relates a half extension topology, has high power stream ability and least gadget focuses on that can appropriately interface a super capacitor with the drive prepare of a crossover electric vehicle. Besides, by contrasting the fundamental qualities and applications with some ordinary bidirectional DC/DC converter, the proposed converter has low gadget rating and can be controlled by obligation cycle and stage move. Finally, the most essential attributes of this converter is that it utilizes the transformer spillage inductance as the essential vitality exchange component and control parameters, Simulation waveforms in light of MATLAB recreation are given to exhibit the integrity of this novel topology, and this converter is additionally reasonable for high power application, specifically to control the charge-release of super capacitors or batteries that can be utilized as a part of cross breed solar based electric vehicle.
Cascaded H-BRIDGE Converter for Domestic ApplicationsIJTET Journal
Multilevel inverters have recently found its way in to the high power applications in both domestic and industrial fields with its ability of low switching frequency. Out of all the topologies of a multilevel inverter, the cascaded H-bridge inverter is most commonly used due to its modular topology. This paper presents a five level cascaded multilevel inverter whose dc voltage source is charged by a solar panel. The switching is done by PIC microcontroller. The programming of the microcontroller is done using MPLAB programmer. Topology is designed with minimum size, weight & reduced power losses. The simulation work is done using MATLAB and experimental results have been presented to validate the theory.
Design & characterization of high speed power efficient cmos comparatorIAEME Publication
In this paper authors have design the High Speed Power Efficient CMOS Voltage
Comparator which can be realized in A/D Converters. The simulation is carried out in 130nm
and 90nm technologies. The supply voltage for this comparator is 1v and 0.9v for 130nm and
90nm respectively. The Characterization of comparator is done in terms of offset, ICMR,
propagation delay, power dissipation in both the technologies and the result has been
compared for both the technologies. The simulation results shows that the speed of 1.92GHz
and 2.44GHz with the power dissipation of 9.19µW and 7.45µW was achieved in 130nm and
90nm technologies respectively.
WebTecz.com is one of the IT service provider company in India. WebTecz provide Digital marketing, web development & designing, ecommrece development, app development and ISP services at best price. IT consulting services in India.
Active power and current control for a modular multilevel converter (mmc) bas...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
A Single-Phase Multilevel Current-Source Converter using H-Bridge and DC Curr...IJPEDS-IAES
This paper presents a different topology of H-bridge based multilevel current-source inverter (CSI). In this new inverter configuration, an H-bridge CSI is connected with a single or more current modules to generate a multilevel output current waveform with lower di/dt, and less distortion. Using the proposed multilevel CSI, the number of the power switching devices, and isolated gate drive circuits can be reduced. Moreover, chopper based DC current sources are presented to reduce the inductor size effectively to be in micro-Henry order, and to ensure the balance of the intermediate current levels. The proposed topology is inherently able to reduce the inductor conduction losses if compared with the conventional multilevel CSIs and the H-bridge CSI. Seven-level PWM inverter configurations with non-isolated DC current sources and with a single DC power source are verified through computer simulations. Furthermore, laboratory prototypes of seven-level CSI is setup and tested. The results show that the inverter circuit works properly to generate the multilevel output current waveform with low harmonics currents, small inductors and with less conduction losses which proves feasibility of the proposed multilevel CSI.
Multilevel Inverter (MLI) has attracted a great attention by different researchers and industries due to its capability in handling high power application and minimizing the harmonics contents in the output. This study propose three different topologies of MLI (5-level) which are Cascaded H-Bridge Multilevel Inverter (CHMLI) ,Diode Clamped Multilevel Inverter and Flying Capacitor Multilevel Inverter (FCMLI) .These three topologies have been modelled in MATLAB/SIMULINK and compared in terms of THD and number of components used. Sinusoidal Pulse Width Modulation is utilized to control both of the topologies with same DC source. The results showed that ,CHMLI is superior compared to DCMLI and FCMLI in which the CHMLI produce 26.29% THD while DCMLI and FCMLI produce 29.14% and 33.53% respectively .Moreover less components and switching losses is obtained when using the CHMLI.
Control of inverters to support bidirectional power flow in grid connected sy...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
In this paper both DC-DC Converter and multilevel inverter have been proposed. The proposed multilevel inverter with appropriate gate signals generates seven level AC output voltage. Also, with the implementation of Low Pass Filter, the output voltage’s Total Harmonic Distortion is reduced. Not only switching losses but also voltage stress of switches can be reduced. With the help of Sinusoidal Pulse-Width Modulation (SPWM) switches of the inverters are controlled. Finally, a laboratory prototype has been implemented and from experimental results, the seven level output of implemented inverter can be inferred.
3. simulation of 11 level hybrid cascade stack (hcs) inverter with reduced nu...EditorJST
This paper presents a new multilevel topology based on cascaded hybrid multi-level (HCS)
inverter. There are different topologies for cascaded inverters for reducing the switches, power loss. The output
voltage is increased and the number of switches is reduced with the HCS inverter. Due to this reduction in
number of on-state switches, power loss and voltage drop is reduced. Simulation results for 11 level symmetric
form of converter is described.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Analysis of dc capacitor voltage balance method for h bridge inverter based p...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A novel p q control algorithm for combined active front end converter and shu...eSAT Journals
Abstract
This paper presents a combined active front-end converter and shunt active filter (AFE+SAF) controlled by p-q theory control
algorithm. The Combined AFE+SAF is able to compensate reactive power, harmonic power and unbalanced power produced by
unbalanced linear, non linear and at the same time three phase AC to DC power conversion AFE+SAF will not pollute the source
currents. The p-q theory control algorithm is able to meat the target of load compensation and three phase AC to DC (for drives)
conversion. the AFE+SAF verified by simulation for different cases as unbalanced linear load, non linear load, unbalanced linear
and non linear load, unbalanced linear non linear and drive load. The whole simulation has been carried out on the mat lab/ simulink
software.
Keywords:- active front-end converter, shunt active power filter, p-q theory, power quality, harmonics, reactive power
A Comparison Analysis of Unipolar and Bipolar Switching modulated Cascade H-B...IJERA Editor
This paper discusses controlling of cascaded H-bridge multi inverter with sinusoidal modulation based PWM methods. Multi-level inverters are used to reduce the THD in the output wave form without reduction in power output of inverter. Increase in voltage level in the output voltage of an inverter increases numbers of components to be used in inverter configuration. This in turn increases the switching loss. But results in good harmonic distortion and provide better quality fundamental wave. Carrier based PWM schemes are used for control of switching operation of multi-level inverters. Many kinds of PWM schemes are available to control inverter switches. In this paper uniploar carrier based PWM, bipolar carrier based PWM schemes are considered for generation of carrier signals. The carrier signals thus generated are compared with sinusoidal and third harmonic based sinusoidal modulating signals for production of switching Pulses. Switching schemes are designed for a 3 Phase 3, 5, 7, 9 and 11 Level inverters. The proposed switching schemes are applied to Cascaded H-Bridge Multi Level inverters. The circuit is simulated with MATLAB Simulink environment for verification of total harmonic distortion.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
In this paper, both symmetric and asymmetric operations for an optimized cascaded multilevel power inverter (MLI) are thoroughly examined. While symmetric configurations are more suitable for AC drives due to their equal power sharing among the various levels, the asymmetric topologies fulfill the higher number of power source combinations under the same power semiconductor switch count. Additionally, particular attention was put on the design of this optimized topology in terms of both reliability and power efficiency by managing redundant states and minimizing the number of power switch commutations. Furthermore, a fundamental switching frequency modulation (FSFM) is thoroughly described in C MEX programming language and then the resulting gating signals are fed into the power circuit designed with PSPICE. By applying this co-simulation approach, the control design task is greatly simplified while achieving advanced analyses with more realistic electronic devices.
Performance enhancement of DC/DC converters for solar powered EV IJECEIAES
The paper initially presents the essential drive arrangement required for electric vehicle. It requests high power bidirectional stream ability, with wide info voltage range, and yield voltage of vitality stockpiling gadgets, for example, super capacitors or batteries shift with the adjustment in stack. At that point the tenacity and outline of previously mentioned converter is proposed in this paper. The converter which relates a half extension topology, has high power stream ability and least gadget focuses on that can appropriately interface a super capacitor with the drive prepare of a crossover electric vehicle. Besides, by contrasting the fundamental qualities and applications with some ordinary bidirectional DC/DC converter, the proposed converter has low gadget rating and can be controlled by obligation cycle and stage move. Finally, the most essential attributes of this converter is that it utilizes the transformer spillage inductance as the essential vitality exchange component and control parameters, Simulation waveforms in light of MATLAB recreation are given to exhibit the integrity of this novel topology, and this converter is additionally reasonable for high power application, specifically to control the charge-release of super capacitors or batteries that can be utilized as a part of cross breed solar based electric vehicle.
Cascaded H-BRIDGE Converter for Domestic ApplicationsIJTET Journal
Multilevel inverters have recently found its way in to the high power applications in both domestic and industrial fields with its ability of low switching frequency. Out of all the topologies of a multilevel inverter, the cascaded H-bridge inverter is most commonly used due to its modular topology. This paper presents a five level cascaded multilevel inverter whose dc voltage source is charged by a solar panel. The switching is done by PIC microcontroller. The programming of the microcontroller is done using MPLAB programmer. Topology is designed with minimum size, weight & reduced power losses. The simulation work is done using MATLAB and experimental results have been presented to validate the theory.
Design & characterization of high speed power efficient cmos comparatorIAEME Publication
In this paper authors have design the High Speed Power Efficient CMOS Voltage
Comparator which can be realized in A/D Converters. The simulation is carried out in 130nm
and 90nm technologies. The supply voltage for this comparator is 1v and 0.9v for 130nm and
90nm respectively. The Characterization of comparator is done in terms of offset, ICMR,
propagation delay, power dissipation in both the technologies and the result has been
compared for both the technologies. The simulation results shows that the speed of 1.92GHz
and 2.44GHz with the power dissipation of 9.19µW and 7.45µW was achieved in 130nm and
90nm technologies respectively.
WebTecz.com is one of the IT service provider company in India. WebTecz provide Digital marketing, web development & designing, ecommrece development, app development and ISP services at best price. IT consulting services in India.
A SCEPP desenvolve projetos de alta complexidade para sistemas de controle e proteção para geração e distribuição de energia além de montar e fornecer painéis e cubículos de baixa e média tensão.
Painel 4 – Energia Hidrocinética no Norte do BrasilUKinBrazilNetwork
Apresentação ministrada pelo Srs. Geraldo Lúcio Tiago Filho, Diretor Executivo, Júlio Souza, Pesquisador, e Antônio Botan, Pesquisador, todos do Centro Nacional de Referência em Pequenas Centrais Hidrelétricas (CERPCH) da Universidade Federal de Itajubá, exibida durante o Seminário Hidrocinética no Norte do Brasil. O evento foi realizado em Brasília, no dia 27 de abril 2016, no Auditório da Eletronorte.
FUZZY LOGIC CONTROL BASED GRID INTEGRATION OF PHOTOVOLTAIC POWER SYSTEM USING...IAEME Publication
This paper discourse about design and modeling of distributed Photovoltaic power system using a 11 Level Cascaded H-Bridge Inverter for the purpose of grid integration. The MOSFET switches helps in power quality improvement by decreasing the Total Harmonic Distortion using multilevel inverter. The proposed grid connected Power System has been designed and analyzed in MATLAB Simulink environment. Fuzzy Logic based Intelligent Controller has been implemented for voltage regulation at Point of Common Coupling of Grid connected PV Power System. Obtained results from Simulation model and compared with IEEE Standard 1547 for endorsing the effectiveness of the proposed system.
Control rápido de hemorragia y contaminación, cierre temporal, resucitación y restauración de la fisiología normal en UCI y subsecuente reexploración y reparo definitivo
Reduce la mortalidad a 50%
Презентація на Urban Cafe Day, яка відбулась в рамках конференції на Майстерні "Партисипативні практики в урбаністиці, бюджетуванні, культурі". Організатори: Інститут міста (Львів) та Аналітичний центр CEDOS (Київ) за підтримки Представництва Фонду імені Гайнріха Бьолля в Україні, Фундації Чарльза Стюарта Мотта та Німецького товариства міжнародного співробітництва GIZ.
http://www.maisterniamista.org.ua/2016/06/21/partysypatyvna-konferentsiya/
A Prototype model of Field Programmable Gate Array (FPGA) Based Nine Level Cascaded Multilevel Inverter is to be designed and Implemented to produce AC output voltage of desired magnitude and frequency.
Comparison of thd reduction for asymmetrical cascaded h bridge invertereSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Cascaded h bridge multilevel inverter in a three phase eleven leveleSAT Journals
Abstract
This paper essentially concentrates on the design and implementation of a unique topology for a three phase eleven level
cascaded H-bridge multilevel cluverter by employing different kinds of switching schemes. The basic purpose of this paper is to
enhance the number of voltage level at the output without addition of any complexity to power circuit.
The main advantages of this proposed topology is to scale down the THD and reducing electromagnetic interface EMI generation
and high voltage with very close to sine waveform. In this paper, severel kinds of carrier pulse width modulation techniques are
proposed as which scale down the total harmonic distortion and improve the out voltage from the proposed topology and POD
modulation techniques reduce the THD. A number of H-bridge arranged in cascaded to increase the voltage level with the
different switching schemes analyzed in this paper. It is observed that this new topology can be recommended to three phase
eleven level cascaded H-bridge inverter for the best and optimum performance over the conventional methods. This performance
in optimized in the eleven level of inverter.
Improving the fundamental waveforms and reducing the total harmonic distortion by using 60 IGBTs and switching is arranged
by a topology in cascaded manners.
The simulation model is produced by MATLAB2009 software version.
Key Words: Cascaded H-bridge multilevel inverter, different phase pulse width modulation, total harmonic
distortionTHD, EMI
A Novel Three Phase Multilevel Inverter with Single DC Link for Induction Mot...IJECEIAES
All industrial drives need a controlled output and it can be achieved by controlling the input supply. In this regard, the inverter circuit plays an important role in the applications of industrial drives. The industrial drives are operated at high rated power and the conventional inverters cannot be applicable for high power demands because of the large dV/dt (rate of change of voltage) and more switching losses. Therefore, multilevel inverters are introduced for high power-medium voltage applications. For all AC drives the MLIs are reliable in operation. This MLI topology also reduces the harmonics and bearings stress of a motor with low dV/dt. In most applications multilevel inverters are used because we can get more number of voltage levels. To increase the number of voltage levels, circuit needs to have more switches. But, we have to optimize the switch count and switching operations. The power level of the inverter is limited due to high currents and stress. In this paper, we proposed a new circuit topology which enables the switches to be active at different voltage levels, causes reduction of the switching losses and also increases the efficiency of the inverter. In this we have presented two configurations for an eleven level MLI for three phase induction motor drive application. In this an individual DC source is connected for each bridge circuit of each phase in one configuration and only one common DC link is used for three phases in another configuration. With this the size, cost and complexity could be decreased. In both the configurations the controlled output of the inverter is connected to the induction motor drive. The circuits are modeled using Matlab/simulink software and corresponding output waveforms are analyzed for both configurations.
A New Multilevel Inverter with Reduced Number of SwitchesIAES-IJPEDS
In recent day’s Multilevel inverter (MLI) technologies become a incredibly main choice in the area of high power medium voltage energy control. Though multilevel inverter has a number of advantages it has drawbacks in the vein of higher levels because of using more number of semiconductor switches. This may leads to vast size and price of the inverter is very high. So in order to overcome this problem the new multilevel inverter is proposed with reduced number of switches. The proposed method is well suited for a high power application and it built with three Dc sources and six Switches. Multi carrier pwm technique is used for sine wave generation. The results are validated through the harmonic spectrum of the FFT window by using Matlab/simulink. The result of the proposed MLI is compared with the conventional MLI and other seven level existing topologies.
Multilevel inverters offers less distortion and less electro-magnetic interference compared with other conventional inverters and hence, it can be used in many industrial and commercial applications. This paper analyze the performance of the modified single phase seven level symmetrical inverter using minimum number of switches. The proposed topology consists of six switches and two dc sources, and produces seven level output voltage waveform during symmetric operation. The cost and size of the propsoed inverter minimum as it uses minimum number of components, The performance of the proposed multilevel inverter is analysed for different switching angles and the corresponding simulation results are presented. The simulation of the proposed inverter is carried out using MATLAB/Simulink software.
Multilevel inverter fed induction motor driveseSAT Journals
Abstract Induction motor drive is used in almost all industries including oil and gas sectors, production plants and process industries. Speed control of induction motor is a major concern. The proposed technology implements a better speed control for induction motor drives using a multilevel inverter. The switching sequences are generated by optimized pre-calculated angles for controlling induction motor. And also with the use of a multi-level inverter there is lower distortion of output voltages and Total Harmonic Distortion (THD) of machine currents under steady state operating conditions can be minimized. THD can be further reduced by optimizing the switching angles. This technology can be extended to higher levels of output voltages by using an n state multilevel inverter. In this paper, a seven level multilevel inverter is proposed, its simulation is done in MATLAB/Simulink and the results were verified by experimenting on a hardware prototype. This could be extended to higher levels of voltage waveform and can be used in photovoltaics. A multilevel inverter could be a better choice as a dc-dc converter in solar power circuits. Keywords: Multilevel inverter, optimal pulse with modulation, total harmonic d1istortion.
Hardware Implementation of SPWM Based Diode Clamped Multilevel Invertrrahulmonikasharma
This paper present three phase three level diode clamped multi level inverter. The control technique used here is sine pulse width modulation. The inverter can reduce the harmonic components compared with that of traditional full-bridge inverter under the condition of identical supply DC voltage and switching frequency. Here this paper presents a operational principles and switching functions are analyzed. The proposed inverter improves the dynamic performances Inverter is simulated using MATLAB/SIMULINK FFT analysis has been done. Proto type hardware is developed in laboratory and simulation results are compared with experimental results. Voltage to frequency control in open loop for three phase induction motor has also been done.
Multilevel inverters have become popular among high power converters for the past few years due to their high quality output waveform and low total harmonic distortions (THD). In addition, the filter size also reduces significantly to achieve a pure sine wave output. Cascaded H-Bridge topology has been recognized as the most promising among various classical topologies for multi-level inverters on the basis of its modular form and ease of design, troubleshooting, packaging and high power capabilities. However, a large number of switches are required in cascaded H-Bridge multilevel inverter that leads to larger system losses and an increase in cost. In this paper the modified cascaded topology is proposed to reduce the number of controlled switches without affecting the resolution of output waveform or the number of voltage levels. We achieved this by replacing some of the high cost controlled transistor switches with diodes, in the cascaded H-Bridges. Furthermore, equal voltage source sharing is also possible by using the proposed topology. Hence the proposed inverter is a type of cascaded multilevel inverter with reduced switches, better modular structure, low cost and high efficiency. The inverter design is validated using simulations and tested on hardware prototype.
FPGA Based Design and Validation of Asymmetrical Reduced Switch Multilevel In...IJPEDS-IAES
This paper proposes a new Asymmetrical multilevel inverter topology with
reduced number of switches. This topology is superior to the existing
multilevel inverter (MLI) configurations in terms of lower total harmonic
distortion (THD) value and lower cost. The idea incorporates a new module
setup comprising of four different voltage sources having voltage output
levels in a specific ratio. The proposed topology uses a novel pulse width
modulation (PWM) technique (as presented) to control the gating pulses. The
operation is simulated using MATLAB/SIMULINK and its results are
validated through FPGA Spartan 3 based hardware prototype inverter (using
three voltage sources to produce a 7 level output, which may be extended to
15 level). The circuit complexity is drastically reduced and it is suitable for
medium and high power applications. THD for the output is quite low when
compared with the conventional inverter.This paper proposes a new Asymmetrical multilevel inverter topology with
reduced number of switches. This topology is superior to the existing
multilevel inverter (MLI) configurations in terms of lower total harmonic
distortion (THD) value and lower cost. The idea incorporates a new module
setup comprising of four different voltage sources having voltage output
levels in a specific ratio. The proposed topology uses a novel pulse width
modulation (PWM) technique (as presented) to control the gating pulses. The
operation is simulated using MATLAB/SIMULINK and its results are
validated through FPGA Spartan 3 based hardware prototype inverter (using
three voltage sources to produce a 7 level output, which may be extended to
15 level). The circuit complexity is drastically reduced and it is suitable for
medium and high power applications. THD for the output is quite low when
compared with the conventional inverter.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
A new cascaded multilevel inverter with less no of switcheseSAT Journals
Abstract In this paper proposed a new topology for cascaded multi level inverters. This structure consists of series connection of proposed basic unit blocks which are built with both unidirectional and bidirectional switches. The proposed structure has some advantages including: reduction in the number of switches and driver circuits, cost and installation area. Three algorithms for determination of dc voltages sources’ magnitudes have also been proposed. The algorithms can produce all odd and even levels at the output voltage the proposed structure also has fewer dc voltage sources variety and less maximum blocking voltage of switches compared to conventional inverters. The capability of proposed structure This paper propose a new topology for cascaded multilevel in producing all odd and even output voltage levels is proved by simulation result for a 21-level inverter. Keywords: Multilevel inverters, symmetric multilevel, asymmetric multilevel
Optimization techniques for harmonics minimization in cascaded hybrid multile...eSAT Journals
Abstract
Recent advancements in the field of power electronics have made possible the worldwide application of converters in dc power source utilization, uninterruptible power supplies, electric motor speed control, switched mode power supplies, flexible alternating current transmission systems devices including static synchronous compensator and their controls. Power semiconductor devices such as converters have been emerged as powerful devices in the power industries. As such, harmonics free output of inverters is assuming extreme importance. Over the past decades, depending upon the topologies and control strategies, numerous optimization techniques have been proposed for desired output waveform. This paper presents a review of optimization techniques used for multilevel inverters. The pros and cons of optimization techniques are discussed. The objective of these optimization techniques is to find out the optimum firing angles of multilevel inverters, which results in minimum harmonics. As a preferred option for proposed work, reduction of total harmonic distortion with the aid of particle swarm optimization technique to multilevel inverters is suggested.
Keywords: Power Converters, Multilevel Inverters (MLI), Cascaded Hybrid Bridge (CHB), Modulation, Switching Frequency, Harmonic Distortions.
Study and Simulation of Seven Level - Ten Switch Inverter TopologyMohd Esa
Compared to conventional two-level inverter, multilevel inverter
performance is high because of their reduced harmonic distortion, less
electromagnetic interference, reduced common mode voltage and higher dc link
voltages. However complex pulse width modulation control, balancing of
capacitor voltages & increased number of switches are main drawbacks of
multilevel inverter.This paper focuses on study and simulation of single phase
seven level inverter topology using only ten switches. This paper also presents
two different control techniques for seven level-ten switch inverter topology.Rload
is connected to inverter and simulation is performed using
MATLAB/Simulink Software.
In recent research, there has been an extensive increase in interest to multilevel power
conversion. The introduction of new inverter topologies & unique modulation
techniques was involved in recent research studies. However, the most commonly
used multi-level inverter topologies are multi-cell inverter [1], diode clamped inverter
[2]-[5] and capacitor clamped inverter [6]. Some applications for these inverters
include industrial drives, flexible ac transmission systems [7], traction applications in
the transport industry and grid integration of non-conventional energy sources.
The seven level-ten switch topology is a symmetrical topology since the values of
all voltage sources are the same. However, there are several asymmetrical topologies
that need voltage sources of different values. This asymmetry results in the need of dc
voltage sources having a specific relation between them and also the difference in
rating of the semiconductor switches. This paper, presents study and simulation of a
new multilevel inverter topology named reversing voltage (RV) [8]. This topology
requires less number of components compared to conventional topologies. It is also
more efficient since the inverter has a component which operates the switching power
devices at line frequency. Therefore, there is no need for all switches to work in high
frequency which leads to simpler and more reliable control of the inverter. Two
different control techniques are used in this paper to drive the inverter .The simulation
results of the seven level-ten switch inverter topology are presented.
Multilevel inverter offers many benefits for high power application compavered to conventional cascaded Multilevel Inverter topology.This paper presents Symmetric CMLI using variable frequency carrier based pulse width modulation techniques. The proposed topology reduces total harmonic distortion and reduced switching losses for seven level inverter. The simulation study of the proposed topology has been carried out in MATLAB/SIMULINK. The main objective of this paper is to achieve number of levels of MLI with reduced number of switches and DC power sources compared to conventional topology.
Comparative Analysis and Simulation of Diode Clamped & Cascaded H-Bridge Mult...IJERA Editor
Multilevel inverters have become more popular over the years in high power medium voltage applications without the use of a transformer and with promise of less disturbance & reduced harmonic distortion. In this paper, two types of multilevel converter in three phase configuration, cascaded H-Bridge multilevel inverter (CMLI) and diode clamped multilevel inverter (DCMLI) of 5 and 7-level are modelled and compared in the case of feeding of a three phase squirrel cage induction motor. Here, carrier based sinusoidal pulse width modulation (SPWM) technique is used as the modulation strategy. These modulation strategy include phase disposition technique (PD), phase opposition disposition technique (POD), and an alternative phase opposition disposition technique (APOD). A detailed study of the modulation technique has been carried out through MATLAB/SIMULINK for both multilevel converters and a comparative evaluation between DCMLI and CMLI using SPWM technique in terms of THD%.
Simulation of Five Level Diode Clamped Multilevel Inverterrahulmonikasharma
The power electronics device which converts DC power to AC power at required output voltage and frequency level is known as inverter. The voltage source inverters produce an output voltage or a current with levels either 0 or +ve or-ve V dc. They are known as two-level inverters. Multilevel inverter is to synthesize a near sinusoidal voltage from several levels of dc voltages. Multilevel inverter has advantage like minimum harmonic distortion. Multi-level inverters are emerging as the new breed of power converter options for high power applications. They typically synthesize the stair-case voltage waveform (from several dc sources) which has reduced harmonic content. Multi-level inverters have many attractive features, high voltage capability, reduced common mode voltages near sinusoidal outputs, low dv/dt, and smaller or even no output filter; sometimes no transformer is required at the input side, called the transformer-less solution, making them suitable for high power applications In this paper a 5-level Diode clamped multilevel inverter is developed by IGBTS using Simulink. Gating signals for these IGBTS have been generated by designing comparators. In order to maintain the different voltage levels at appropriate intervals, the conduction time intervals of IGBT have been maintained by controlling the pulse width of gating pulses[6] (by varying the reference signals magnitude of the comparator). The simulation results for 5-level and THD for the output have been identified by MATLAB/SIMULINK.
Similar to Ijret20150410062 doi link not opening (20)
Mechanical properties of hybrid fiber reinforced concrete for pavementseSAT Journals
Abstract
The effect of addition of mono fibers and hybrid fibers on the mechanical properties of concrete mixture is studied in the present
investigation. Steel fibers of 1% and polypropylene fibers 0.036% were added individually to the concrete mixture as mono fibers and
then they were added together to form a hybrid fiber reinforced concrete. Mechanical properties such as compressive, split tensile and
flexural strength were determined. The results show that hybrid fibers improve the compressive strength marginally as compared to
mono fibers. Whereas, hybridization improves split tensile strength and flexural strength noticeably.
Keywords:-Hybridization, mono fibers, steel fiber, polypropylene fiber, Improvement in mechanical properties.
Material management in construction – a case studyeSAT Journals
Abstract
The objective of the present study is to understand about all the problems occurring in the company because of improper application
of material management. In construction project operation, often there is a project cost variance in terms of the material, equipments,
manpower, subcontractor, overhead cost, and general condition. Material is the main component in construction projects. Therefore,
if the material management is not properly managed it will create a project cost variance. Project cost can be controlled by taking
corrective actions towards the cost variance. Therefore a methodology is used to diagnose and evaluate the procurement process
involved in material management and launch a continuous improvement was developed and applied. A thorough study was carried
out along with study of cases, surveys and interviews to professionals involved in this area. As a result, a methodology for diagnosis
and improvement was proposed and tested in selected projects. The results obtained show that the main problem of procurement is
related to schedule delays and lack of specified quality for the project. To prevent this situation it is often necessary to dedicate
important resources like money, personnel, time, etc. To monitor and control the process. A great potential for improvement was
detected if state of the art technologies such as, electronic mail, electronic data interchange (EDI), and analysis were applied to the
procurement process. These helped to eliminate the root causes for many types of problems that were detected.
Managing drought short term strategies in semi arid regions a case studyeSAT Journals
Abstract
Drought management needs multidisciplinary action. Interdisciplinary efforts among the experts in various fields of the droughts
prone areas are helpful to achieve tangible and permanent solution for this recurring problem. The Gulbarga district having the total
area around 16, 240 sq.km, and accounts 8.45 per cent of the Karnataka state area. The district has been situated with latitude 17º 19'
60" North and longitude of 76 º 49' 60" east. The district is situated entirely on the Deccan plateau positioned at a height of 300 to
750 m above MSL. Sub-tropical, semi-arid type is one among the drought prone districts of Karnataka State. The drought
management is very important for a district like Gulbarga. In this paper various short term strategies are discussed to mitigate the
drought condition in the district.
Keywords: Drought, South-West monsoon, Semi-Arid, Rainfall, Strategies etc.
Life cycle cost analysis of overlay for an urban road in bangaloreeSAT Journals
Abstract
Pavements are subjected to severe condition of stresses and weathering effects from the day they are constructed and opened to traffic
mainly due to its fatigue behavior and environmental effects. Therefore, pavement rehabilitation is one of the most important
components of entire road systems. This paper highlights the design of concrete pavement with added mono fibers like polypropylene,
steel and hybrid fibres for a widened portion of existing concrete pavement and various overlay alternatives for an existing
bituminous pavement in an urban road in Bangalore. Along with this, Life cycle cost analyses at these sections are done by Net
Present Value (NPV) method to identify the most feasible option. The results show that though the initial cost of construction of
concrete overlay is high, over a period of time it prove to be better than the bituminous overlay considering the whole life cycle cost.
The economic analysis also indicates that, out of the three fibre options, hybrid reinforced concrete would be economical without
compromising the performance of the pavement.
Keywords: - Fatigue, Life cycle cost analysis, Net Present Value method, Overlay, Rehabilitation
Laboratory studies of dense bituminous mixes ii with reclaimed asphalt materialseSAT Journals
Abstract
The issue of growing demand on our nation’s roadways over that past couple of decades, decreasing budgetary funds, and the need to
provide a safe, efficient, and cost effective roadway system has led to a dramatic increase in the need to rehabilitate our existing
pavements and the issue of building sustainable road infrastructure in India. With these emergency of the mentioned needs and this
are today’s burning issue and has become the purpose of the study.
In the present study, the samples of existing bituminous layer materials were collected from NH-48(Devahalli to Hassan) site.The
mixtures were designed by Marshall Method as per Asphalt institute (MS-II) at 20% and 30% Reclaimed Asphalt Pavement (RAP).
RAP material was blended with virgin aggregate such that all specimens tested for the, Dense Bituminous Macadam-II (DBM-II)
gradation as per Ministry of Roads, Transport, and Highways (MoRT&H) and cost analysis were carried out to know the economics.
Laboratory results and analysis showed the use of recycled materials showed significant variability in Marshall Stability, and the
variability increased with the increase in RAP content. The saving can be realized from utilization of recycled materials as per the
methodology, the reduction in the total cost is 19%, 30%, comparing with the virgin mixes.
Keywords: Reclaimed Asphalt Pavement, Marshall Stability, MS-II, Dense Bituminous Macadam-II
Laboratory investigation of expansive soil stabilized with natural inorganic ...eSAT Journals
Abstract
Soil stabilization has proven to be one of the oldest techniques to improve the soil properties. Literature review conducted revealed
that uses of natural inorganic stabilizers are found to be one of the best options for soil stabilization. In this regard an attempt has
been made to evaluate the influence of RBI-81 stabilizer on properties of black cotton soil through laboratory investigations. Black
cotton soil with varying percentages of RBI-81 viz., 0, 0.5, 1, 1.5, 2, and 2.5 percent were studied for moisture density relationships
and strength behaviour of soils. Also the effect of curing period was evaluated as literature review clearly emphasized the strength
gain of soils stabilized with RBI-81 over a period of time. The results obtained shows that the unconfined compressive strength of
specimens treated with RBI-81 increased approximately by 250% for a curing period of 28 days as compared to virgin soil. Further
the CBR value improved approximately by 400%. The studies indicated an increasing trend for soil strength behaviour with
increasing percentage of RBI-81 suggesting its potential applications in soil stabilization.
Influence of reinforcement on the behavior of hollow concrete block masonry p...eSAT Journals
Abstract
Reinforced masonry was developed to exploit the strength potential of masonry and to solve its lack of tensile strength. Experimental
and analytical studies have been carried out to investigate the effect of reinforcement on the behavior of hollow concrete block
masonry prisms under compression and to predict ultimate failure compressive strength. In the numerical program, three dimensional
non-linear finite elements (FE) model based on the micro-modeling approach is developed for both unreinforced and reinforced
masonry prisms using ANSYS (14.5). The proposed FE model uses multi-linear stress-strain relationships to model the non-linear
behavior of hollow concrete block, mortar, and grout. Willam-Warnke’s five parameter failure theory has been adopted to model the
failure of masonry materials. The comparison of the numerical and experimental results indicates that the FE models can successfully
capture the highly nonlinear behavior of the physical specimens and accurately predict their strength and failure mechanisms.
Keywords: Structural masonry, Hollow concrete block prism, grout, Compression failure, Finite element method,
Numerical modeling.
Influence of compaction energy on soil stabilized with chemical stabilizereSAT Journals
Abstract
Increase in traffic along with heavier magnitude of wheel loads cause rapid deterioration in pavements. There is a need to improve
density, strength of soil subgrade and other pavement layers. In this study an attempt is made to improve the properties of locally
available loamy soil using twin approaches viz., i) increasing the compaction of soil and ii) treating the soil with chemical stabilizer.
Laboratory studies are carried out on both untreated and treated soil samples compacted by different compaction efforts. Studies
show that increase in compaction effort results in increase in density of soil. However in soil treated with chemical stabilizer, rate of
increase in density is not significant. The soil treated with chemical stabilizer exhibits improvement in both strength and performance
properties.
Keywords: compaction, density, subgradestabilization, resilient modulus
Geographical information system (gis) for water resources managementeSAT Journals
Abstract
Water resources projects are inherited with overlapping and at times conflicting objectives. These projects are often of varied sizes
ranging from major projects with command areas of millions of hectares to very small projects implemented at the local level. Thus,
in all these projects there is seldom proper coordination which is essential for ensuring collective sustainability.
Integrated watershed development and management is the accepted answer but in turn requires a comprehensive framework that can
enable planning process involving all the stakeholders at different levels and scales is compulsory. Such a unified hydrological
framework is essential to evaluate the cause and effect of all the proposed actions within the drainage basins.
The present paper describes a hydrological framework developed in the form of a Hydrologic Information System (HIS) which is
intended to meet the specific information needs of the various line departments of a typical State connected with water related aspects.
The HIS consist of a hydrologic information database coupled with tools for collating primary and secondary data and tools for
analyzing and visualizing the data and information. The HIS also incorporates hydrological model base for indirect assessment of
various entities of water balance in space and time. The framework would be maintained and updated to reflect fully the most
accurate ground truth data and the infrastructure requirements for planning and management.
Keywords: Hydrological Information System (HIS); WebGIS; Data Model; Web Mapping Services
Forest type mapping of bidar forest division, karnataka using geoinformatics ...eSAT Journals
Abstract
The study demonstrate the potentiality of satellite remote sensing technique for the generation of baseline information on forest types
including tree plantation details in Bidar forest division, Karnataka covering an area of 5814.60Sq.Kms. The Total Area of Bidar
forest division is 5814Sq.Kms analysis of the satellite data in the study area reveals that about 84% of the total area is Covered by
crop land, 1.778% of the area is covered by dry deciduous forest, 1.38 % of mixed plantation, which is very threatening to the
environmental stability of the forest, future plantation site has been mapped. With the use of latest Geo-informatics technology proper
and exact condition of the trees can be observed and necessary precautions can be taken for future plantation works in an appropriate
manner
Keywords:-RS, GIS, GPS, Forest Type, Tree Plantation
Factors influencing compressive strength of geopolymer concreteeSAT Journals
Abstract
To study effects of several factors on the properties of fly ash based geopolymer concrete on the compressive strength and also the
cost comparison with the normal concrete. The test variables were molarities of sodium hydroxide(NaOH) 8M,14M and 16M, ratio of
NaOH to sodium silicate (Na2SiO3) 1, 1.5, 2 and 2.5, alkaline liquid to fly ash ratio 0.35 and 0.40 and replacement of water in
Na2SiO3 solution by 10%, 20% and 30% were used in the present study. The test results indicated that the highest compressive
strength 54 MPa was observed for 16M of NaOH, ratio of NaOH to Na2SiO3 2.5 and alkaline liquid to fly ash ratio of 0.35. Lowest
compressive strength of 27 MPa was observed for 8M of NaOH, ratio of NaOH to Na2SiO3 is 1 and alkaline liquid to fly ash ratio of
0.40. Alkaline liquid to fly ash ratio of 0.35, water replacement of 10% and 30% for 8 and 16 molarity of NaOH and has resulted in
compressive strength of 36 MPa and 20 MPa respectively. Superplasticiser dosage of 2 % by weight of fly ash has given higher
strength in all cases.
Keywords: compressive strength, alkaline liquid, fly ash
Experimental investigation on circular hollow steel columns in filled with li...eSAT Journals
Abstract
Composite Circular hollow Steel tubes with and without GFRP infill for three different grades of Light weight concrete are tested for
ultimate load capacity and axial shortening , under Cyclic loading. Steel tubes are compared for different lengths, cross sections and
thickness. Specimens were tested separately after adopting Taguchi’s L9 (Latin Squares) Orthogonal array in order to save the initial
experimental cost on number of specimens and experimental duration. Analysis was carried out using ANN (Artificial Neural
Network) technique with the assistance of Mini Tab- a statistical soft tool. Comparison for predicted, experimental & ANN output is
obtained from linear regression plots. From this research study, it can be concluded that *Cross sectional area of steel tube has most
significant effect on ultimate load carrying capacity, *as length of steel tube increased- load carrying capacity decreased & *ANN
modeling predicted acceptable results. Thus ANN tool can be utilized for predicting ultimate load carrying capacity for composite
columns.
Keywords: Light weight concrete, GFRP, Artificial Neural Network, Linear Regression, Back propagation, orthogonal
Array, Latin Squares
Experimental behavior of circular hsscfrc filled steel tubular columns under ...eSAT Journals
Abstract
This paper presents an outlook on experimental behavior and a comparison with predicted formula on the behaviour of circular
concentrically loaded self-consolidating fibre reinforced concrete filled steel tube columns (HSSCFRC). Forty-five specimens were
tested. The main parameters varied in the tests are: (1) percentage of fiber (2) tube diameter or width to wall thickness ratio (D/t
from 15 to 25) (3) L/d ratio from 2.97 to 7.04 the results from these predictions were compared with the experimental data. The
experimental results) were also validated in this study.
Keywords: Self-compacting concrete; Concrete-filled steel tube; axial load behavior; Ultimate capacity.
Evaluation of punching shear in flat slabseSAT Journals
Abstract
Flat-slab construction has been widely used in construction today because of many advantages that it offers. The basic philosophy in
the design of flat slab is to consider only gravity forces; this method ignores the effect of punching shear due to unbalanced moments
at the slab column junction which is critical. An attempt has been made to generate generalized design sheets which accounts both
punching shear due to gravity loads and unbalanced moments for cases (a) interior column; (b) edge column (bending perpendicular
to shorter edge); (c) edge column (bending parallel to shorter edge); (d) corner column. These design sheets are prepared as per
codal provisions of IS 456-2000. These design sheets will be helpful in calculating the shear reinforcement to be provided at the
critical section which is ignored in many design offices. Apart from its usefulness in evaluating punching shear and the necessary
shear reinforcement, the design sheets developed will enable the designer to fix the depth of flat slab during the initial phase of the
design.
Keywords: Flat slabs, punching shear, unbalanced moment.
Evaluation of performance of intake tower dam for recent earthquake in indiaeSAT Journals
Abstract
Intake towers are typically tall, hollow, reinforced concrete structures and form entrance to reservoir outlet works. A parametric
study on dynamic behavior of circular cylindrical towers can be carried out to study the effect of depth of submergence, wall thickness
and slenderness ratio, and also effect on tower considering dynamic analysis for time history function of different soil condition and
by Goyal and Chopra accounting interaction effects of added hydrodynamic mass of surrounding and inside water in intake tower of
dam
Key words: Hydrodynamic mass, Depth of submergence, Reservoir, Time history analysis,
Evaluation of operational efficiency of urban road network using travel time ...eSAT Journals
Abstract
Efficiency of the road network system is analyzed by travel time reliability measures. The study overlooks on an important measure of
travel time reliability and prioritizing Tiruchirappalli road network. Traffic volume and travel time were collected using license plate
matching method. Travel time measures were estimated from average travel time and 95th travel time. Effect of non-motorized vehicle
on efficiency of road system was evaluated. Relation between buffer time index and traffic volume was created. Travel time model has
been developed and travel time measure was validated. Then service quality of road sections in network were graded based on
travel time reliability measures.
Keywords: Buffer Time Index (BTI); Average Travel Time (ATT); Travel Time Reliability (TTR); Buffer Time (BT).
Estimation of surface runoff in nallur amanikere watershed using scs cn methodeSAT Journals
Abstract
The development of watershed aims at productive utilization of all the available natural resources in the entire area extending from
ridge line to stream outlet. The per capita availability of land for cultivation has been decreasing over the years. Therefore, water and
the related land resources must be developed, utilized and managed in an integrated and comprehensive manner. Remote sensing and
GIS techniques are being increasingly used for planning, management and development of natural resources. The study area, Nallur
Amanikere watershed geographically lies between 110 38’ and 110 52’ N latitude and 760 30’ and 760 50’ E longitude with an area of
415.68 Sq. km. The thematic layers such as land use/land cover and soil maps were derived from remotely sensed data and overlayed
through ArcGIS software to assign the curve number on polygon wise. The daily rainfall data of six rain gauge stations in and around
the watershed (2001-2011) was used to estimate the daily runoff from the watershed using Soil Conservation Service - Curve Number
(SCS-CN) method. The runoff estimated from the SCS-CN model was then used to know the variation of runoff potential with different
land use/land cover and with different soil conditions.
Keywords: Watershed, Nallur watershed, Surface runoff, Rainfall-Runoff, SCS-CN, Remote Sensing, GIS.
Estimation of morphometric parameters and runoff using rs & gis techniqueseSAT Journals
Abstract
Land and water are the two vital natural resources, the optimal management of these resources with minimum adverse environmental
impact are essential not only for sustainable development but also for human survival. Satellite remote sensing with geographic
information system has a pragmatic approach to map and generate spatial input layers of predicting response behavior and yield of
watershed. Hence, in the present study an attempt has been made to understand the hydrological process of the catchment at the
watershed level by drawing the inferences from moprhometric analysis and runoff. The study area chosen for the present study is
Yagachi catchment situated in Chickamaglur and Hassan district lies geographically at a longitude 75⁰52’08.77”E and
13⁰10’50.77”N latitude. It covers an area of 559.493 Sq.km. Morphometric analysis is carried out to estimate morphometric
parameters at Micro-watershed to understand the hydrological response of the catchment at the Micro-watershed level. Daily runoff
is estimated using USDA SCS curve number model for a period of 10 years from 2001 to 2010. The rainfall runoff relationship of the
study shows there is a positive correlation.
Keywords: morphometric analysis, runoff, remote sensing and GIS, SCS - method
-
Effect of variation of plastic hinge length on the results of non linear anal...eSAT Journals
Abstract The nonlinear Static procedure also well known as pushover analysis is method where in monotonically increasing loads are applied to the structure till the structure is unable to resist any further load. It is a popular tool for seismic performance evaluation of existing and new structures. In literature lot of research has been carried out on conventional pushover analysis and after knowing deficiency efforts have been made to improve it. But actual test results to verify the analytically obtained pushover results are rarely available. It has been found that some amount of variation is always expected to exist in seismic demand prediction of pushover analysis. Initial study is carried out by considering user defined hinge properties and default hinge length. Attempt is being made to assess the variation of pushover analysis results by considering user defined hinge properties and various hinge length formulations available in literature and results compared with experimentally obtained results based on test carried out on a G+2 storied RCC framed structure. For the present study two geometric models viz bare frame and rigid frame model is considered and it is found that the results of pushover analysis are very sensitive to geometric model and hinge length adopted. Keywords: Pushover analysis, Base shear, Displacement, hinge length, moment curvature analysis
Effect of use of recycled materials on indirect tensile strength of asphalt c...eSAT Journals
Abstract
Depletion of natural resources and aggregate quarries for the road construction is a serious problem to procure materials. Hence
recycling or reuse of material is beneficial. On emphasizing development in sustainable construction in the present era, recycling of
asphalt pavements is one of the effective and proven rehabilitation processes. For the laboratory investigations reclaimed asphalt
pavement (RAP) from NH-4 and crumb rubber modified binder (CRMB-55) was used. Foundry waste was used as a replacement to
conventional filler. Laboratory tests were conducted on asphalt concrete mixes with 30, 40, 50, and 60 percent replacement with RAP.
These test results were compared with conventional mixes and asphalt concrete mixes with complete binder extracted RAP
aggregates. Mix design was carried out by Marshall Method. The Marshall Tests indicated highest stability values for asphalt
concrete (AC) mixes with 60% RAP. The optimum binder content (OBC) decreased with increased in RAP in AC mixes. The Indirect
Tensile Strength (ITS) for AC mixes with RAP also was found to be higher when compared to conventional AC mixes at 300C.
Keywords: Reclaimed asphalt pavement, Foundry waste, Recycling, Marshall Stability, Indirect tensile strength.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Quality defects in TMT Bars, Possible causes and Potential Solutions.
Ijret20150410062 doi link not opening
1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 10 | Oct-2015, Available @ http://www.ijret.org 379
MULTILEVEL INVERTER WITH LEVEL SHIFTING SPWM TECHNIQUE USING
FEWER NUMBER OF SWITCHES FOR SOLAR APPLICATIONS
Mahajan Sagar Bhaskar Ranjana1
, Pandav Kiran Maroti2
, Ruchita Maheshwari3
, Pachagade Ruchi M.4
1,2,3,4
Department of Electrical and Electronics Engineering Marathwada Institute of Technology (MIT), Aurangabad,
INDIA- 431028
sagar25.mahajan@gmail.com1
, kiranpandav88@yahoo.co.in2
, rchitadahad@gmail.com3
, ruchi.pachagade@gmail.com4
Abstract
A multilevel inverter (MLI) is a popular inverter for solar based high power applications. The drawback of conventional H-bridge
inverter is non-sinusoidal output voltage, which reduces the output quality of inverter. Later, the drawback of conventional H-
bridge was overcome by conventional MLI. But, conventional MLI needs maximum number of diodes and switches. In order to
overcome this drawback proposed MLI topology with level shifting sinusoidal pulse width modulation (SPWM) technique can be
employed. Proposed MLI contain fewer number of switches and diodes, which helps in optimizing the circuit layout, reducing gate
driver circuit for those switches. SPWM technique uses multicarrier waveforms with level shifting ensuring the reduction in total
harmonics distortion (THD). In this Paper level shifting SPWM technique has been incorporated in which 5 kHz carrier wave is
compare with 50Hz of sinusoidal wave with a modulation index of 0.8. THD of proposed 9-level inverter is 17.27% without filter
and 4.29% with LC filter. Simulation of proposed inverter is carried out in MATLAB/SIMULINK.
Key Words: Solar, 9-level inverter, Level shifting SPWM, Power diodes and switches, Total Harmonics Distortion (THD)
--------------------------------------------------------------------***----------------------------------------------------------------------
1. INTRODUCTION
Renewable energy sources have gained wide importance due
to the depletion of fossil fuels. Also the problem of pollution
caused by fossil fuels can be solved by using clean and
freely available renewable energy. Solar energy is one of the
renewable energy in which most of the researchers are
showing interests as it can be responsible for green energy
concept.
In case of solar energy system, voltage generated from solar
array is needed to be converted into ac signal for high power
AC application. Conventional H-bridge inverter is not a
practical solution for DC-AC conversion because of large
harmonics distortion and switching losses. Later, the
drawbacks of conventional inverter are overcome by
multilevel inverter (MLI) [1]-[2]. The increased number of
level reduces the harmonic content and brings the output
voltage waveform closer to sinusoidal. Conventional MLI
include diode clamped, flying capacitors and cascaded H-
bridge. In diode clamped MLI, diodes are used in majority
and number of diode increases with increase in levels. In
flying capacitor MLI, number of capacitor is increases with
increase in levels. In cascaded MLI, as the cascade stage
increases, certainly the number of switches and sources also
increases [3]-[6]. In Fig.1 (a), cascaded MLI for N-stages is
shown. But, these conventional MLI‟s requires large number
of power devices to generate maximum number of levels.
Further, this drawback is overcome by modifying the
conventional MLI‟s circuits. Diode clamped MLI has been
discussed with lesser number of diodes in [7]. Modified
flying capacitor topology is discussed in [8]. In [9], cascade
MLI topology with reduced number of switches is
discussed. In [10]-[12], 7-level inverter using 7 switches and
9 switches has been discussed. In Fig.1 (b) and Fig.1 (c), 7-
level with 9-switches and 7-level with 7-switches are shown
respectively. In [13], 7-level with 6-switches MLI is
explained. In Fig.1 (d), the schematic of 7-level with 6-
switches MLI is shown. In [13], though the number of
switches is less; but the number of diodes increases with
number of levels. The above discussed MLI‟s gives more
number of levels as compared to conventional MLI using
minimum number of switches. In the above topology, the
emphasis is on minimizing the number of switches but it
still requires large number of voltage sources. This
drawback is overcome by advanced MLI [14] and
asymmetrical MLI. Single phase MLI with single PV source
and less number of switches is proposed in [15]. The
drawback of advance MLI is that it requires inductor and a
switch operating at high frequency. The cost and design
complexity of advance MLI is increased due to the use of
inductor.
Generally, asymmetrical multilevel inverters are used to
increase the number of levels. In [16], 25-level
asymmetrical inverter with 12 switches for renewable power
grid applications is proposed. In [17], 25-level asymmetrical
inverter with 10 switches for solar application is proposed.
In [18], modified cascaded H-bridge inverter is proposed
with three different algorithms to generate 9, 13 and 17
levels. It is observed that THD for 9-level, 13-level and 17-
level inverter without filter is 17.22%, 10.74% and 7.76%
respectively. Also the THD for 9-level, 13-level and 17-
level inverter with filter is 5.86%, 5.18% and 4.71%
respectively.
2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 04 Issue: 10 | Oct-2015, Available @ http://www.ijret.org 380
Asymmetric multilevel inverter is more advantageous than
symmetric multilevel inverter in obtaining more number of
output levels using same number of voltage sources. But the
main drawback of asymmetrical inverter is that it increases
the complexity of gate triggering pulses. The other
drawback is that the required rating of the power devices is
not same. Due to complexity of gate triggering pulses
asymmetrical MLI‟s are not beneficial to use. The proposed
MLI requires fewer number of power devices and nearly
removes all major above discussed drawbacks. In this paper,
a novel 9-level MLI with 7-switches is proposed. The
SPWM technique is used to reduce the THD and improve
the quality of output voltage.
2. PROPOSED TOPOLOGY
The proposed MLI is designed for 9-level using 7 switches
as shown below in Fig. 2. This topology is modification of
conventional H-bridge inverter where number of levels can
be increased by stacking specific combination of diode,
switch and voltage source. Switches S1, S5, S6 and S7
represent H-bridge in which S1, S5 are used for generating
negative voltage levels whereas S6, S7 are used for positive
voltage levels. In addition switches S2, S3 and S4 are used to
increase the number of levels. The proposed scheme 9-level
inverter requires 7-switches, 3-diodes and 4-voltage sources.
Fig. 3 shows circuit diagram of N-level proposed MLI.
Fig.2 Circuit diagram of proposed 9- level inverter.
Fig.3 N-level proposed MLI.
The relationship between number of output levels, switches,
diodes and voltage sources is stated in TABLE-I. It can be
depicted that this topology is suitable only for odd number
of output levels. (N+5)/2 switches with anti-parallel diodes,
(N-3)/2 clamping diodes and (N-1)/2 sources are needed to
design N-Level proposed inverter.
Table-I Relationship between number of output levels,
switches, diodes and voltage sources
No. of
levels
No. of
switches
No. of
clamping diodes
No. of
sources
3 4 0 1
5 5 1 2
7 6 2 3
9 7 3 4
N (N+5)/2 (N-3)/2 (N-1)/2
3. OPERATION OF PROPOSED TOPOLOGY
The operation for 9-level MLI with 7-switches as shown in
Fig. 2 is discussed below. Switches S1 and S5, S6 and S7 are
complementary to each other. S1, S5 are turned „ON‟ to
generate negative output levels and S6, S7 are turned „ON‟ to
generate positive output levels. The switches S2, S3 and S4
(a) Conventional Cascaded MLI (b) 7-level with 7-switches (c) 7-level with 9-switches (d) 7-level with 6-switches
Fig.1 (a)-(d) Existing multilevel Inverter
Fig.1 (a)-(d) Existing multilevel Inverter
3. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 04 Issue: 10 | Oct-2015, Available @ http://www.ijret.org 381
are turned „ON‟ and turned „OFF‟ accordingly to increase
the number of output levels.
Table-II Switching states with corresponding voltage levels
Switches S2, S3, and S4 are turned „ON‟ when maximum
positive and negative output level is required and are turned
„OFF‟ with corresponding levels as shown in TABLE-II.
The current flow direction through the circuit for positive
and negative voltage levels is shown in Fig.4 (a)-(d) and
Fig.5 (a)-(d) respectively.
3. SPWM TECHNIQUE FOR PROPOSED TOPOLOGY
Sinusoidal pulse width modulation (SPWM) technique is
used for pulse generation where reference wave is sinusoidal
and carrier wave is high frequency triangular wave. The
comparison of both these waves gives rise to the pulses to
trigger the switches. Level shifting SPWM technique is
employed in order to reduce THD. Multiple carrier waves
are compared with single reference wave with 0.8
modulation index. Three schemes of level shifting SPWM
involve phase disposition, phase opposition disposition and
alternate phase opposition disposition. In this paper phase
disposition has been used for the pulse generation for the
proposed MLI.
Fig.6 (a) shows the internal circuitry of SPWM pulse logic
block for 9-level proposed MLI. The internal circuitry of
SPWM block contains bias, relational operator, followed by
logic operators. The inputs for SPWM logic block are
sinusoidal waveform and triangular waveform. Pulses are
generated according to switching logic and amplitude
modulation index. The methodology of generating pulses for
9-level MLI is shown in Fig.6 (b). Phase opposition
disposition and alternate phase opposition disposition
SPWM techniques are also suitable for proposed converter.
The modulation index for SPWM Technique is the ratio of
Amplitude of reference wave (AR) to the product of number
of positive or negative level and amplitude of carrier wave
(AC).
R
C
A
Modulation Index =
N-1
A
2
(1)
(a) Vout = Vdc4+Vdc3+Vdc2+Vdc1
(b) Vout = Vdc3+Vdc2+Vdc1
(c) Vout = Vdc2+Vdc1
(d) Vout = Vdc1
Fig.4 (a)-(d) positive levels current direction
Voltage Levels S1 S2 S3 S4 S5 S6 S7
Vdc4+Vdc3+Vdc2+Vdc1 0 1 1 1 0 1 1
Vdc3+Vdc2+Vdc1 0 1 1 0 0 1 1
Vdc2+Vdc1 0 1 0 0 0 1 1
Vdc1 0 0 0 0 0 1 1
0 0 0 0 0 0 0 0
-Vdc1 1 0 0 0 1 0 0
-Vdc2-Vdc1 1 1 0 0 1 0 0
-Vdc3-Vdc2-Vdc1 1 1 1 0 1 0 0
-Vdc4-Vdc3-Vdc2-Vdc1 1 1 1 1 1 0 0
4. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 04 Issue: 10 | Oct-2015, Available @ http://www.ijret.org 382
(a) Vout = -Vdc1
(b) Vout = -Vdc2-Vdc1
(c) Vout = -Vdc3-Vdc2-Vdc1
(d) Vout = -Vdc4-Vdc3-Vdc2-Vdc1
Fig.5 (a)-(d) Negative levels current direction
(a) SPWM pulse logic block
(b) methodology
Fig.6 (a)-(b) methodology for generation of pulses.
4. SIMULATION RESULTS
The proposed MLI has been designed for 2kW, 9-level
output voltage using 7-switches for solar application. Four
input voltage sources are used and each voltage source is
equal to 60V. Phase disposition level shifting SPWM
technique is used with 50 Hz reference sinusoidal wave and
5 KHz carrier wave with modulation index 0.8. The
proposed 9-level inverter is designed with or without filter
LC Filter. LC filter has been used with inductance of 0.5mH
and capacitance of 15µF to reduce higher order harmonics.
The simulation has been performed in
MATLAB/SIMULINK. The switching pulse generation for
switches S1 and S5, S2, S3, S4, S6 and S7 has been shown in
Fig.7 to Fig.11 respectively. It is observed that switches S2,
S3 and S4 required two carrier waveforms to obtain
switching pulses whereas S1, S5, S6 and S7 required single
carrier waveform. 9-level output voltage and output current
waveforms without LC filter are shown in Fig.12. It is
observed that 4 positive, 4 negative and 1 zero level is
obtained with amplitude of each level is 60V. The highest
positive level is 240V which is the positive addition of all
input voltage sources. The highest negative level is -240V
which is the negative addition of all input voltage sources.
Fig.13 shows the output voltage and output current
sinusoidal.
5. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 04 Issue: 10 | Oct-2015, Available @ http://www.ijret.org 383
Fig.7 Pulse generation for switch S1 and S5
Fig.8 Pulse generation for switch S2
Fig.9 Pulse generation for switch S3
The voltage stress across each switch is shown in Fig.14. It
is observed that the voltage stress across switches S1, S5, S6
and S7 is 240V which is equal to the addition of all input
voltage source. The voltage stress across switches S2, S3
and S4 is 60V which is equal to single input voltage source.
The THD of output voltage without filter is 17.27% which is
calculated by using Fast Fourier Transform (FFT) analysis
window shown in Fig.15. Afterwards, higher order
harmonics are eliminated by using LC filter. Fig.16 shows
the THD of filtered output is 4.29%.
Fig.10 Pulse generation for switch S4
Fig.11 Pulse generation for switch S6 and S7
Fig.12 Output Voltage and Output Current Waveform
without filter
Fig.13 Output Voltage and Output Current Waveform with
filter
6. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 04 Issue: 10 | Oct-2015, Available @ http://www.ijret.org 384
Fig.14 Voltage stress across switches
Fig.15 THD of proposed topology without filter
Fig.16 THD of proposed topology with filter
5. COMPARISON OF PROPOSED MLI WITH
CONVENTIONAL AND EXISTING MLI
Conventional MLI includes diode clamped, flying capacitors
and cascaded MLI. Diode clamped MLI required more
number of diodes and switches. Flying capacitor MLI
required more number of clamping capacitors and switches.
Cascaded MLI required separate DC source and more
number of switches. Later the above discussed drawback is
overcome by modifying conventional MLI. The proposed
modified H-bridge cascaded MLI consists of fewer diodes
than diode clamped MLI, fewer capacitors than flying
capacitor MLI, fewer switches than conventional cascaded
MLI. TABLE-III shows the comparison between diode
clamped, flying capacitance, cascaded H-bridge MLI and
proposed MLI, where N is the level generated by single
phase MLI.
Table-III COMPARISON BETWEEN SINGLE PHASE MLI
MLI
Types
Switches
clamping and
anti- parallel
diodes
capacitor source
Diode
clamped
2 N 1
2
N 1
2
N 1
2
1
Flying
Capacitor
2 N 1
2 N 1
2
N 1
4
1
Cascaded
H-Bridge
2 N 1
2 N 1
N 1
2
N 1
2
Proposed
MLI
N+5
2
N+1
N-1
2
N-1
2
Fig.17 Graphs between numbers of power devices versus
number of Levels
7. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 10 | Oct-2015, Available @ http://www.ijret.org 385
Fig.17 shows the graphs between required number of
switches, diodes, capacitors and sources versus number of
levels for proposed and conventional MLI. Proposed MLI
reduces the complexity of circuit design and cost because
less number of power devices required for designing the
proposed MLI.
6. CONCLUSION
In this paper, a new topology of Multilevel Inverter (MLI)
with fewer number of switches is designed for solar
applications which overcomes the drawbacks of
conventional multilevel inverter. (N+5)/2 switches with anti-
parallel diodes, (N-3)/2 clamping diodes and (N-1)/2
sources are needed to design N-Level proposed inverter. The
proposed MLI advantages include fewer number of switches
which in turn reduced the corresponding gate driving
circuitry, made the circuit compact in size. Due to which
optimization of circuit layout is possible. The proposed MLI
is designed for 9-level with power 2kW and In-Phase level
shifting SPWM technique is used for the generate switching
pulses for switches of the MLI. It is observed that output
voltage total harmonics distortion (THD) of 9 level
proposed MLI without filter is 17.27% whereas with filter is
4.29%. The simulation results and pulse generation using
SPWM technique also discussed. The simulation results
show that proposed MLI has the characteristics which are
desirable for solar based high power applications.
REFERENCES
[1] J.S. Lai and F.Z. Peng, “Multilevel Converters- A new
breed of power converters” IEEE transactions on
industrial applications, Vol.32,pp.509-517, May-
June1996.
[2] Rodriguez. J; J. S. Lai; F. Z. Peng; “Multilevel
Inverters: A Survey of Topologies, Controls and
Applications” IEEE transactions on Industrial
Electronics, Vol.49, No.4, August 2002.
[3] Malinowski. M; Gopakumar. K; Rodriguez. J; Perez,
M. A; “A survey on cascaded multilevel inverters”,
IEEE, Transactions on industrial electronics, Vol.57,
2009.
[4] Wei Zhao; Hyuntae Choi; G. Konstantinou; M.
Ciobotaru; and V.G. Agelidis “Cascaded H-bridge
Multilevel Converter for Large-scale PV Grid-
Integration with Isolated DC-DC stage” PEDG, IEEE
2012.
[5] S. Rivera; S. Kouro; B. Wu; J. I. Leon; J. Rodriguez;
and L. G. Franquelo "Cascaded H-bridge multilevel
converter multistring topology for large scale
photovoltaic systems," IEEE, ISIE 2011, pp.1837-1844.
[6] B. Singh; N. Mittal; and K. S. Verma “Multi-Level
Inverter: A Literature Survey On Topologies And
Control Strategies”, International Journal of Reviews in
Computing, Vol. 10, July 2012, pp. 1-16
[7] Zhiguo pan; F. Z. Peng; Victor Stefanoic and Mickey
Leuthen “A Diode-Clamped Multilevel Converter with
Reduced Number of Clamping Diodes.” IEEE 2004.
[8] N. Maheshkumar; V. Maheskumar; and M. Divya “The
New Topology In Flying Capacitor Multilevel Inverter”
International Conference on Computer Communication
and Informatics, IEEE-2013.
[9] Ebrahim. Babaei “A Cascade Multilevel Converter
Topology with Reduced Number of Switches” IEEE
Transaction on Power Electronics, Vol. 23,issue 6, pp.
2657-2664, 2008.
[10]T.v.v.s Lakshmi; Noby George; Umashankar. S and
Kothari .D. P “Cascaded seven level inverter with
reduced number of switches using level shifting PWM
technique” ICPEC, IEEE 2013.
[11]K.Gobinath, S.Mahendran, I.Gnanambal, “Novel
cascaded H-Bridge Multilevel Inverter with harmonic
elimination”, IEEE International Conference on Green
High Performance Computing ICGHPC, March 2013.
[12]J. J. Nedumgatt; Vijayakumar; Kirubakarann. A; and
Umashankar S; “A Multilevel Inverter with Reduced
Number of Switches” Conference on Electrical,
Electronics and Computer Science,IEEE 2012.
[13]Nurul Aisyah Yusof; Norazliani Md Sapari; Hazlie
Mokhlis; Jeyraj Selvaraj “A Comparative Study of 5-
level and 7-level Multilevel Inverter Connected to the
Grid” international conference on power and energy,
IEEE, PEcon, 2012.
[14]Mahajan Sagar Bhaskar Ranjana, Nandyala Sreeramula
Reddy, Repalle Kusala Pavan Kumar “A novel single
phase advanced multilevel inverter with adjustable
amplitude of voltage levels” IEEE International
Conference on Circuit, Power and Computing
Technologies, ICCPCT 2014, nagarcoil,
[15]Mahajan Sagar Bhaskar Ranjana; Pandav Kiran Maroti;
B. Sri Revathi; “A Novel Single Phase Multilevel
Inverter with Single Photovoltaic Source and Less
Number of switches” IEEE, International Conference
On Devices, Circuits And Systems – ICDCS 2014,
Coimbatore.
[16]Mahajan Sagar Bhaskar; Kaustubh P. Draxe; Kiran M.
Pandav “A Novel Asymmetric Multilevel Inverter with
Minimum Number of Switches in Renewable Power
Grid Applications” IEEE, International conference on
Green Computing, Communication and Conservation of
Energy, ICGCE-2013.
[17]Kaustubh P. Draxe; Mahajan Sagar Bhaskar Ranjana;
Kiran M. Pandav “A Cascaded Asymmetric Multilevel
Inverter with Minimum Number of Switches for Solar
Applications” IEEE, International Conference on Power
and Energy Systems: Towards Sustainable Energy,
PESTSE 2014, Bangalore.
[18]Mahajan Sagar Bhaskar Ranjana; Prasad S Wankhade;
Niraj D Gondhalekar; “A Modified Cascaded H-Bridge
Multilevel Inverter For Solar Applications” IEEE,
International Conference on Green Computing,
Communication and Conservation of Electrical Energy
ICGCCEE‟14.