IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Comparative Steady State Analysis of Boost and Cascaded Boost Converter with ...IAES-IJPEDS
In this paper, an overall comparison between the Boost Converter (BC) &
Cascaded Converter/ Cascaded Boost Converter (CBC) has been depicted in
terms of ideal condition, as well as with the consideration of Equivalent
Series Resistance (ESR) of inductor(s). The loss comparison in the two
converters due to the ESR is also included in this paper. It can be seen that in
CBC, voltage gain is more but the power loss due to ESR is also more
compared to BC. The parameters of the converters are derived with a
consideration of per unit ripple quantity of inductor current and capacitor
voltage. A boundary condition between the continuous conduction mode
(CCM) & discontinuous conduction mode (DCM) of the inductor current is
also shown. The behaviour of the capacitor current for the converters is
discussed during ON and OFF condition of the switch(es) during DCM. At
the end, the simulation results of both the converters are given for a
20V/100V, 100 W output. The analysis and simulation results are presented
in this paper for the verification of the feasibility.
Modeling and Simulation of Closed Loop Controlled Parallel Cascaded Buck Boos...IJPEDS-IAES
This Work deals with design, modeling and simulation of parallel cascaded
buck boost converter inverter based closed loop controlled solar system. Two
buck boost converters are cascaded in parallel to reduce the ripple in DC
output. The DC from the solar cell is stepped up using boost converter. The
output of the boost converter is converted to 50Hz AC using single phase full
bridge inverter. The simulation results of open loop and closed loop systems
are compared. This paper has presented a simulink model for closed loop
controlled solar system. Parallel cascaded buck boost converter is proposed
for solar system.
A Novel Approach of Position Estimation and Power Factor Corrector Converter ...IJPEDS-IAES
This paper proposes a Power factor Corrected (PFC) Bridgeless Buck-Boost converter fed BLDC motor drive. The Bridgeless configuration eliminates the Diode Bridge Rectifier in order to reduce the number of components and the conduction loss. The position sensors used in BLDC drives have drawbacks of additional cost, mechanical alignment problems. These bottle necks results in sensorless technique. The Sensorless technique mostly relies on measurement of Back EMF to determine relative positions of stator and rotor for the correct coil energising sequence can be implemented. This paper introduces the offline Finite Element method for sensorless operation. The proposed sensorless scheme estimates the motor position at standstill and running condition. The obtained Power Factor is within the acceptable limits IEC 61000-3-2. The proposed drive is simulated in MATLAB/Simulink the obtained results are validated experimentally on a developed prototype of the drive.
Comparative Evaluation of Generalized Multicell Impedance Source Inverter for...IJPEDS-IAES
Voltage-Source Inverter is limited by its only voltage step-down operation. In adding with extra boosting the flexibility is kept active for the number of semiconductors which is unchanged, voltage-type Z-source inverter was earlier proposed. This new class of inverter is generally less sensitive to electromagnetic noises. However, their boosting capabilities are anyhow less with high component stresses and poorer spectral performances caused by low modulation index ratios. Their boosting gains are, therefore, restricted in practice. To overcome these we use the generalized switched-inductor Z- source inverter is proposed, By comparing with PWM technique and SPWM technique, whose extra boosting abilities and other advantages have been verified in simulation analysis and experiment.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Comparative Steady State Analysis of Boost and Cascaded Boost Converter with ...IAES-IJPEDS
In this paper, an overall comparison between the Boost Converter (BC) &
Cascaded Converter/ Cascaded Boost Converter (CBC) has been depicted in
terms of ideal condition, as well as with the consideration of Equivalent
Series Resistance (ESR) of inductor(s). The loss comparison in the two
converters due to the ESR is also included in this paper. It can be seen that in
CBC, voltage gain is more but the power loss due to ESR is also more
compared to BC. The parameters of the converters are derived with a
consideration of per unit ripple quantity of inductor current and capacitor
voltage. A boundary condition between the continuous conduction mode
(CCM) & discontinuous conduction mode (DCM) of the inductor current is
also shown. The behaviour of the capacitor current for the converters is
discussed during ON and OFF condition of the switch(es) during DCM. At
the end, the simulation results of both the converters are given for a
20V/100V, 100 W output. The analysis and simulation results are presented
in this paper for the verification of the feasibility.
Modeling and Simulation of Closed Loop Controlled Parallel Cascaded Buck Boos...IJPEDS-IAES
This Work deals with design, modeling and simulation of parallel cascaded
buck boost converter inverter based closed loop controlled solar system. Two
buck boost converters are cascaded in parallel to reduce the ripple in DC
output. The DC from the solar cell is stepped up using boost converter. The
output of the boost converter is converted to 50Hz AC using single phase full
bridge inverter. The simulation results of open loop and closed loop systems
are compared. This paper has presented a simulink model for closed loop
controlled solar system. Parallel cascaded buck boost converter is proposed
for solar system.
A Novel Approach of Position Estimation and Power Factor Corrector Converter ...IJPEDS-IAES
This paper proposes a Power factor Corrected (PFC) Bridgeless Buck-Boost converter fed BLDC motor drive. The Bridgeless configuration eliminates the Diode Bridge Rectifier in order to reduce the number of components and the conduction loss. The position sensors used in BLDC drives have drawbacks of additional cost, mechanical alignment problems. These bottle necks results in sensorless technique. The Sensorless technique mostly relies on measurement of Back EMF to determine relative positions of stator and rotor for the correct coil energising sequence can be implemented. This paper introduces the offline Finite Element method for sensorless operation. The proposed sensorless scheme estimates the motor position at standstill and running condition. The obtained Power Factor is within the acceptable limits IEC 61000-3-2. The proposed drive is simulated in MATLAB/Simulink the obtained results are validated experimentally on a developed prototype of the drive.
Comparative Evaluation of Generalized Multicell Impedance Source Inverter for...IJPEDS-IAES
Voltage-Source Inverter is limited by its only voltage step-down operation. In adding with extra boosting the flexibility is kept active for the number of semiconductors which is unchanged, voltage-type Z-source inverter was earlier proposed. This new class of inverter is generally less sensitive to electromagnetic noises. However, their boosting capabilities are anyhow less with high component stresses and poorer spectral performances caused by low modulation index ratios. Their boosting gains are, therefore, restricted in practice. To overcome these we use the generalized switched-inductor Z- source inverter is proposed, By comparing with PWM technique and SPWM technique, whose extra boosting abilities and other advantages have been verified in simulation analysis and experiment.
An Enhanced Flying Capacitor Multilevel Inverter fed Induction Motor DriveIDES Editor
This paper focused on the development of
capacitor voltage balancing methods in a flying capacitor
multilevel inverter (FCMLI) fed induction motor drive.
For improving the performance of flying capacitor
multilevel inverter, a switching pattern selection scheme
is implemented. The proposed method has been designed
a nine -level flying capacitor multilevel inverter by using
sinusoidal pulse width modulation technique. The selected
pattern has been exposed to give superior performance in
load voltage, total harmonics distortion and capacitor
voltage fluctuation. The performance of proposed
strategies is confirmed through simulation investigations.
This paper proposed a new sparce matrix converter with Z-source network to provide unity voltage transfer ratio. It is an ac-to-ac converter with diode-IGBT bidirectional switches. The limitations of existing matrix converter like higher current THD and less voltage transfer ratio issues are overcome by this proposed matrix converter by inserting a Z-source. Due to this Z-source current harmonics are totally removed. The simulation is performed for different frequencies. The simulation results are presented to verify the THD and voltage transfer ratio and compared with the existing virtual AC/DC/AC matrix converter. The experimental output voltage amplitude can be varied with the variable frequencies.
This paper presents a new simplified cascade multiphase DC-DC buck power converter suitable for low voltage and large current applications. Cascade connection enables very low voltage ratio without using very small duty cycles nor transformers. Large current with very low ripple content is achieved by using the multiphase technique. The proposed converter needs smaller number of components compared to conventional cascade multiphase DC-DC buck power converters. This paper also presents useful analysis of the proposed DC-DC buck power converter with a method to optimize the phase and cascade number. Simulation and experimental results are included to verify the basic performance of the proposed DC-DC buck power converter.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
With the purpose of rein in the high voltage of flexible power systems, renovation and
amendment of multi-level structures aimed at acquisition of high quality voltage is certainly required. In this
regard, robust topology must be occupied that encompass the maximum output voltage levels along with
minimum of switch number, of course, with taking into account of Peak Inverse Voltage (PIV). In this
paper, a neoteric high-performance multilevel cascaded inverter is suggested up to the problem of
repetitive output levels to be unraveled and also number of output voltage levels to be maximized. It has
been constructed by series-connected multilevel inverters blocks and three-level inverter. The simulation
results along with experimental results extracted by manufactured prototype have transparently approved
high efficiency of proposed inverter as well as its feasibility. Apart from above, new mathematical approach
has been presented to calculate and define the DC voltage sources magnitudes in asymmetric converter.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This paper presents the simulation design of dc/dc interleaved boost converter with zero-voltage switching (ZVS). By employin the interleaved structure, the input current stresses to switching devices were reduced and this signified to a switching conduction loss reduction. All the parameters had been calculated theoretically. The proposed converter circuit was simulated by using MATLAB/Simulink and PSpice software programmes. The converter circuit model, with specifications of output power of 200 W, input voltage range from 10~60 V, and operates at 100 kHz switching frequency was simulated to validate the designed parameters. The results showed that the main switches of the model converter circuit achieved ZVS conditions during the interleaving operation. Consequently, the switching losses in the main switching devices were reduced. Thus, the proposed converter circuit model offers advantages of input current stress and switching loss reductions. Hence, based on the designed parameters and results, the converter model can be extended for hardware implementation.
Analysis of 7-Level Cascaded & MLDCLI with Sinusoidal PWM & Modified Referenc...IJMTST Journal
Multilevel inverter offers several advantages compare to the conventional three phase bridge inverter in terms of lower dv/dt stresses, lower electromagnetic compatibility and better THD features. The primary use of DC to AC conversion & speed control of machines also voltage controller and reduce the harmonics in the levels of inverter by using cascade multilevel inverter. This paper presents a comparison of cascaded and multilevel dc link inverter (MLDCLI) Using only a DC power source and capacitors. A MLDCLI can be constructed by the series connection half and full bridge cells each having its own DC source .A multilevel voltage source inverter can be formed by connecting an MLDCL with a single bridge inverter. The MLDCL provides a DC voltage with the shape of a staircase with or without pulse width modulation (PWM) to the bridge inverter, which in turn alternates the polarity to produce an AC voltage. compared with the cascaded multilevel inverter, The MLDCLI can significantly reduce the switch count as the number of voltage levels increases beyond five for a given number of voltage levels , m , the required number of active switches is 2(m -1) for the existing multilevel inverter but is m+3 for the MLDCL inverters.
This paper presents the performance of a seven level cascaded multilevel inverter &MLDCLI Based on a sinusoidalPWM and modified Reference PWM control techniques. Performance analysis is made based on the results of simulation study conducted on the operation of the cascaded & MLDCLI using MATLAB/SIMULINK. The performance parameters chosen in the work include the waveform pattern harmonic spectrum, fundamental value & total harmonic distortion (THD) of the three phase cascaded H-Bridge MLI & MLDCLI.
SIMULATION ANALYSIS OF CLOSED LOOP DUAL INDUCTOR CURRENT-FED PUSH-PULL CONVER...Journal For Research
The current electronic devices require DC power source, which is taken from a battery or DC power supply. DC-DC converter is utilized to get regulated dc voltage from unregulated one. Switched mode power supply (SMPS) are commonly used in industrial applications, because of more advantages compared to linear power supply. In SMPS we have isolated and non-isolated converters, where isolated converters are frequently used, in order to get more voltage with multiple outputs. So among different isolated converters, push-pull converter is chosen for micro converter applications to obtain high voltage conversion ratio by using HF transformer, due to their better utilization of transformer. New methodology of control is implemented for making ZVS and ZCS at same time and to reduce the number of switches in the secondary side of dual inductor CFPP converter, which is a voltage doubler circuit. This becomes the solution for problem identification. Thus this converter with soft-switching reduces the switching losses.The current-fed push-pull converters are used in many applications like photo-voltaic (PV) power converters for boosting the output voltage. Push-pull converter is chosen for micro converter applications, to obtain high voltage conversion ratio by using high frequency (HF) transformer, due to their better utilization of transformer. This deals with the design of dual inductor CFPP converter, where zero voltage switching (ZVS) and zero current switching (ZCS) is achieved for the primary side of the converter by using secondary switches. Primary side switches are controlled by closed loop control topology. The secondary side is made with voltage doubler to obtain high voltage. Open loop and closed loop control of dual inductor current fed push pull converter simulation is finished by MATLAB/SIMULINK and their outcomes are analyzed.
An Active Input Current Waveshaping with Zero Switching Losses for Three-Phas...IDES Editor
In this paper a zero voltage switched active network
(Fig. 1) which can be used in conjunction with single-phase or
three-phase ac to dc diode rectifiers is presented. It is shown
that application of the proposed switching network in threephase
ac to dc boost converter yields zero switching losses
while maintaining a unity input power factor. Active network
capacitor, Cs, diodes D7, and D8, maintain a zero voltage during
turn-off of Q1, and Q2, Capacitor, Cs, discharges through
the boost inductors of the circuit thus limiting the rate of rise
of current during turn-on. Moreover, the advantage of the
proposed active network is that it can maintain a zero voltage
switching over the entire range of the duty cycle of the operation.
Consequently, boost stage can be used directly to control
the dc bus voltage by varying the duty cycle at Constant switching
frequency. The resulting advantages include higher
switching frequencies, and better efficiency. Finally the operation
of the active switching network is verified experimentally
on a prototype three-phase ac to dc converter.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Microcontroller Based Novel Dc-to-Ac Grid Connected Inverter TopologyIDES Editor
The conventional line commutated ac-to-dc
converters/ inverters have square-shaped line current which
contains higher-order harmonics. Moreover, it requires a
costly and bulky dc inductor or choke. The line current with
the high harmonic contents generates EMI and therefore it
causes more heating of the core of distribution or power
transformers. Alternatively, PWM based inverters using
MOSFET/IGBT switches can be used for the above purpose.
However, apart from higher switching losses, the power
handling capability and reliability of these devices are quite
low in comparison to thyristors/ SCR. A thyristor based forced
commutated inverters are not suitable for PWM applications
due to the problems of commutation circuits. A pure sinusoidal
voltage output or waveform with low harmonic contents is
most desirable in the conversion from dc to ac. In the present
work, a novel two pulse line commutated inverter is been
proposed with control signal generated from PIC 16F 877A. It
improves the wave shape hence it reduces the total harmonic
distortion (THD) of the grid interactive-inverter. The
simulation of the circuit is done using SIMULINK. Moreover,
the performance of the proposed circuitry is far better than
the conventional line-commutated inverter. It reduces THD,
number of thyristors and dispenses with the bulky dc inductor/
choke. A prototype model is developed for discontinuous line
current mode. The results are also compared with the
simulation results in SIMULINK/ MATLAB.
Application of PWM Control Strategy on Z-Source Isolated Dual active bridge D...IJMER
This project presents a Z-source with bidirectional dc–dc converter. The switching count is
reduced by adding a passive element. Thus, we are improving the output voltage level. The voltage
regulation range of proposed converter is better than that of the traditional bidirectional dc–dc
converter. The fully bridge symmetrical circuit configuration, is neither a high-voltage side nor a lowvoltage
side in the circuit structure, and the sources connected to the dc side of each H-bridge circuit
with voltage sources and current sources. This method can reduce current stress and improves the
system efficiency.
In this paper we are presenting a dual active bridge (DAB) dc–dc converter is also known as
Bidirectional DC-DC converter. Both simulation results are shown by using MATLAB software.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Development of Switch Mode Dc Converter Using MATLAB/ dSPACEIDES Editor
In this paper with the help of Matlab/Simulink and
dSPACE, the Switch-Mode DC Converter is built in real-time
to control the output voltage of the controller using PWM
algorithm. First, the Simulink model of Switch-Mode DC
Converter (i.e. Single-Pole and Two-Pole Converter Model)
is built and, after verifying the results, it is implemented in
real-time. Next, a DC motor is connected to the output
terminals (i.e. Phase A1 and Phase B1) of the Power Electronics
Board such that a variable voltage is applied to the terminals
of DC motor. Now, by changing the magnitude of the applied
voltage, the speed of the motor is varied. This is also referred
to as an open-loop voltage control of DC motor. The purpose
of the real-time implementation is obtaining variable voltage
at the output of the power converter, while controlling its
amplitude with a dSPACE DS1104-based user interface.
An Enhanced Flying Capacitor Multilevel Inverter fed Induction Motor DriveIDES Editor
This paper focused on the development of
capacitor voltage balancing methods in a flying capacitor
multilevel inverter (FCMLI) fed induction motor drive.
For improving the performance of flying capacitor
multilevel inverter, a switching pattern selection scheme
is implemented. The proposed method has been designed
a nine -level flying capacitor multilevel inverter by using
sinusoidal pulse width modulation technique. The selected
pattern has been exposed to give superior performance in
load voltage, total harmonics distortion and capacitor
voltage fluctuation. The performance of proposed
strategies is confirmed through simulation investigations.
This paper proposed a new sparce matrix converter with Z-source network to provide unity voltage transfer ratio. It is an ac-to-ac converter with diode-IGBT bidirectional switches. The limitations of existing matrix converter like higher current THD and less voltage transfer ratio issues are overcome by this proposed matrix converter by inserting a Z-source. Due to this Z-source current harmonics are totally removed. The simulation is performed for different frequencies. The simulation results are presented to verify the THD and voltage transfer ratio and compared with the existing virtual AC/DC/AC matrix converter. The experimental output voltage amplitude can be varied with the variable frequencies.
This paper presents a new simplified cascade multiphase DC-DC buck power converter suitable for low voltage and large current applications. Cascade connection enables very low voltage ratio without using very small duty cycles nor transformers. Large current with very low ripple content is achieved by using the multiphase technique. The proposed converter needs smaller number of components compared to conventional cascade multiphase DC-DC buck power converters. This paper also presents useful analysis of the proposed DC-DC buck power converter with a method to optimize the phase and cascade number. Simulation and experimental results are included to verify the basic performance of the proposed DC-DC buck power converter.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
With the purpose of rein in the high voltage of flexible power systems, renovation and
amendment of multi-level structures aimed at acquisition of high quality voltage is certainly required. In this
regard, robust topology must be occupied that encompass the maximum output voltage levels along with
minimum of switch number, of course, with taking into account of Peak Inverse Voltage (PIV). In this
paper, a neoteric high-performance multilevel cascaded inverter is suggested up to the problem of
repetitive output levels to be unraveled and also number of output voltage levels to be maximized. It has
been constructed by series-connected multilevel inverters blocks and three-level inverter. The simulation
results along with experimental results extracted by manufactured prototype have transparently approved
high efficiency of proposed inverter as well as its feasibility. Apart from above, new mathematical approach
has been presented to calculate and define the DC voltage sources magnitudes in asymmetric converter.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This paper presents the simulation design of dc/dc interleaved boost converter with zero-voltage switching (ZVS). By employin the interleaved structure, the input current stresses to switching devices were reduced and this signified to a switching conduction loss reduction. All the parameters had been calculated theoretically. The proposed converter circuit was simulated by using MATLAB/Simulink and PSpice software programmes. The converter circuit model, with specifications of output power of 200 W, input voltage range from 10~60 V, and operates at 100 kHz switching frequency was simulated to validate the designed parameters. The results showed that the main switches of the model converter circuit achieved ZVS conditions during the interleaving operation. Consequently, the switching losses in the main switching devices were reduced. Thus, the proposed converter circuit model offers advantages of input current stress and switching loss reductions. Hence, based on the designed parameters and results, the converter model can be extended for hardware implementation.
Analysis of 7-Level Cascaded & MLDCLI with Sinusoidal PWM & Modified Referenc...IJMTST Journal
Multilevel inverter offers several advantages compare to the conventional three phase bridge inverter in terms of lower dv/dt stresses, lower electromagnetic compatibility and better THD features. The primary use of DC to AC conversion & speed control of machines also voltage controller and reduce the harmonics in the levels of inverter by using cascade multilevel inverter. This paper presents a comparison of cascaded and multilevel dc link inverter (MLDCLI) Using only a DC power source and capacitors. A MLDCLI can be constructed by the series connection half and full bridge cells each having its own DC source .A multilevel voltage source inverter can be formed by connecting an MLDCL with a single bridge inverter. The MLDCL provides a DC voltage with the shape of a staircase with or without pulse width modulation (PWM) to the bridge inverter, which in turn alternates the polarity to produce an AC voltage. compared with the cascaded multilevel inverter, The MLDCLI can significantly reduce the switch count as the number of voltage levels increases beyond five for a given number of voltage levels , m , the required number of active switches is 2(m -1) for the existing multilevel inverter but is m+3 for the MLDCL inverters.
This paper presents the performance of a seven level cascaded multilevel inverter &MLDCLI Based on a sinusoidalPWM and modified Reference PWM control techniques. Performance analysis is made based on the results of simulation study conducted on the operation of the cascaded & MLDCLI using MATLAB/SIMULINK. The performance parameters chosen in the work include the waveform pattern harmonic spectrum, fundamental value & total harmonic distortion (THD) of the three phase cascaded H-Bridge MLI & MLDCLI.
SIMULATION ANALYSIS OF CLOSED LOOP DUAL INDUCTOR CURRENT-FED PUSH-PULL CONVER...Journal For Research
The current electronic devices require DC power source, which is taken from a battery or DC power supply. DC-DC converter is utilized to get regulated dc voltage from unregulated one. Switched mode power supply (SMPS) are commonly used in industrial applications, because of more advantages compared to linear power supply. In SMPS we have isolated and non-isolated converters, where isolated converters are frequently used, in order to get more voltage with multiple outputs. So among different isolated converters, push-pull converter is chosen for micro converter applications to obtain high voltage conversion ratio by using HF transformer, due to their better utilization of transformer. New methodology of control is implemented for making ZVS and ZCS at same time and to reduce the number of switches in the secondary side of dual inductor CFPP converter, which is a voltage doubler circuit. This becomes the solution for problem identification. Thus this converter with soft-switching reduces the switching losses.The current-fed push-pull converters are used in many applications like photo-voltaic (PV) power converters for boosting the output voltage. Push-pull converter is chosen for micro converter applications, to obtain high voltage conversion ratio by using high frequency (HF) transformer, due to their better utilization of transformer. This deals with the design of dual inductor CFPP converter, where zero voltage switching (ZVS) and zero current switching (ZCS) is achieved for the primary side of the converter by using secondary switches. Primary side switches are controlled by closed loop control topology. The secondary side is made with voltage doubler to obtain high voltage. Open loop and closed loop control of dual inductor current fed push pull converter simulation is finished by MATLAB/SIMULINK and their outcomes are analyzed.
An Active Input Current Waveshaping with Zero Switching Losses for Three-Phas...IDES Editor
In this paper a zero voltage switched active network
(Fig. 1) which can be used in conjunction with single-phase or
three-phase ac to dc diode rectifiers is presented. It is shown
that application of the proposed switching network in threephase
ac to dc boost converter yields zero switching losses
while maintaining a unity input power factor. Active network
capacitor, Cs, diodes D7, and D8, maintain a zero voltage during
turn-off of Q1, and Q2, Capacitor, Cs, discharges through
the boost inductors of the circuit thus limiting the rate of rise
of current during turn-on. Moreover, the advantage of the
proposed active network is that it can maintain a zero voltage
switching over the entire range of the duty cycle of the operation.
Consequently, boost stage can be used directly to control
the dc bus voltage by varying the duty cycle at Constant switching
frequency. The resulting advantages include higher
switching frequencies, and better efficiency. Finally the operation
of the active switching network is verified experimentally
on a prototype three-phase ac to dc converter.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Microcontroller Based Novel Dc-to-Ac Grid Connected Inverter TopologyIDES Editor
The conventional line commutated ac-to-dc
converters/ inverters have square-shaped line current which
contains higher-order harmonics. Moreover, it requires a
costly and bulky dc inductor or choke. The line current with
the high harmonic contents generates EMI and therefore it
causes more heating of the core of distribution or power
transformers. Alternatively, PWM based inverters using
MOSFET/IGBT switches can be used for the above purpose.
However, apart from higher switching losses, the power
handling capability and reliability of these devices are quite
low in comparison to thyristors/ SCR. A thyristor based forced
commutated inverters are not suitable for PWM applications
due to the problems of commutation circuits. A pure sinusoidal
voltage output or waveform with low harmonic contents is
most desirable in the conversion from dc to ac. In the present
work, a novel two pulse line commutated inverter is been
proposed with control signal generated from PIC 16F 877A. It
improves the wave shape hence it reduces the total harmonic
distortion (THD) of the grid interactive-inverter. The
simulation of the circuit is done using SIMULINK. Moreover,
the performance of the proposed circuitry is far better than
the conventional line-commutated inverter. It reduces THD,
number of thyristors and dispenses with the bulky dc inductor/
choke. A prototype model is developed for discontinuous line
current mode. The results are also compared with the
simulation results in SIMULINK/ MATLAB.
Application of PWM Control Strategy on Z-Source Isolated Dual active bridge D...IJMER
This project presents a Z-source with bidirectional dc–dc converter. The switching count is
reduced by adding a passive element. Thus, we are improving the output voltage level. The voltage
regulation range of proposed converter is better than that of the traditional bidirectional dc–dc
converter. The fully bridge symmetrical circuit configuration, is neither a high-voltage side nor a lowvoltage
side in the circuit structure, and the sources connected to the dc side of each H-bridge circuit
with voltage sources and current sources. This method can reduce current stress and improves the
system efficiency.
In this paper we are presenting a dual active bridge (DAB) dc–dc converter is also known as
Bidirectional DC-DC converter. Both simulation results are shown by using MATLAB software.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Development of Switch Mode Dc Converter Using MATLAB/ dSPACEIDES Editor
In this paper with the help of Matlab/Simulink and
dSPACE, the Switch-Mode DC Converter is built in real-time
to control the output voltage of the controller using PWM
algorithm. First, the Simulink model of Switch-Mode DC
Converter (i.e. Single-Pole and Two-Pole Converter Model)
is built and, after verifying the results, it is implemented in
real-time. Next, a DC motor is connected to the output
terminals (i.e. Phase A1 and Phase B1) of the Power Electronics
Board such that a variable voltage is applied to the terminals
of DC motor. Now, by changing the magnitude of the applied
voltage, the speed of the motor is varied. This is also referred
to as an open-loop voltage control of DC motor. The purpose
of the real-time implementation is obtaining variable voltage
at the output of the power converter, while controlling its
amplitude with a dSPACE DS1104-based user interface.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Analysis and hardware implementation of five level cascaded H Bridge inverterIJERA Editor
The cascaded multilevel inverter (CMLI) has gained much attention in recent years due to its advantages in high
voltage and high power with low harmonics applications. A standard cascaded multilevel inverter requires n DC
sources for 2n+1levels at the output, where n is the number of inverter stages. This paper presents a topology to
control cascaded multilevel inverter that is implemented with multiple DC sources to get 2"+1_ 1 levels. Without
using Pulse Width Modulation (PWM) technique, the firing circuit can be implemented using Microcontroller
which greatly reduces the Total Harmonic Distortion (THD) and switching losses. To develop the model of a
cascaded hybrid multilevel inverter, a simulation is done based on MATLAB/SIMULINK software and
hardware implementation was also done. Their integration makes the design and analysis of a hybrid multilevel
inverter more complete and detailed.
Design and Development of Power Electronic Controller for Grid-connected PV A...IJAPEJOURNAL
Design and simulation of a simple power electronic interface for grid-connected PV array has been proposed using boost converter and line-commutated inverter with maximum power point tracking (MPPT) controller. The output of PV array varies with irradiation, and hence the duty cycle of the PI controller is adjusted automatically to supply a constant DC voltage to the inverter circuit, the output of which is directly connected to the grid. The MPPT controller extracts maximum power from the solar array and feeds it to the single-phase utility grid. The proposed scheme has been modeled in the MATLAB 7.1 software and the complete system has been simulated for open loop and closed loop configurations. The active power fed to the grid is taken for different firing angles in open loop mode and the firing angle for maximum power has been determined. This is compared with the firing angle obtained from the closed loop mode and found that both results agree with each other.
Fuzzy Logic Controller Based High Frequency Link AC-AC Converter For Voltage ...IJTET Journal
Abstract—In this paper, an advanced high frequency link AC-AC Push-pull cycloconverter for the voltage compensation is proposed in order to maintain the power quality in electric grid. The proposed methodology can be achieve arbitrary output voltage without using large energy storage elements. So that the system is more steadfast and less costly compared with the conventional inverter topology. Additionally, the proposed converter does not contain any line frequency transformer, which reduces the cost further. The control scheme for the push pull cycloconverter employs the fuzzy logic controller based sinusoidal pulse width modulation (SPWM) to accomplish better performance on voltage compensation, like unbalanced voltage harmonics elimination. The simulation results are given to show the effectiveness of the proposed high frequency link AC-AC converter and fuzzy logic controller based SPWM technology
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
AC-DC converters are widely used in industrial and domestic applications. Input AC voltage is rectified and
filtered using filtering circuit which consists of large electrolytic capacitors. These capacitors draw a large
amount of current and the efficiency of the converter system decreases drastically. large ripple factor have made the converter system inefficient .This paper
analyses about different converter topology and proposes a different design which is based on converting Ac signal to specified Dc signal of about 5V by which ripple factor can be reduced to make the system enough efficient. The implification of this project is for charging or operating semiconductor devices .The results of respective topologies are shown through P-simulation program with integrated circuit emphasis (PSPICE) simulation and their
parameters are calculated. Three parameters are considered for the comparison of these topologies
NON-ISOLATED SOFT SWITCHING DC-DC CONVERTER AND LOAD AT FULL RANGE OF ZVS IAEME Publication
A non isolated soft switching DC–DC converter and load at full range of zero-voltage
switching (ZVS) characteristic is proposed. The proposed converter consists of an auxiliary circuit,
an inductor, two switches, and 2 diodes to achieving high efficiency at full range of load. At low
and heavy loads, ZVS of switching device is achieved by energy storing component. The inductor
energy stored varies with load and hence results in minimizes conduction loss. This leads to
switching of device for full range of load. The proposed DC - DC converter achieves high
efficiency as switching loss is reduced due to soft switching and ZVS operation which severe to
reduce conduction loss. The efficiency is improved about 4% in boost mode (2.5% in buck mode) at
full range of load. To verify the performance of the proposed converter, experimental results
prototype are presented.
A Review to AC Modeling and Transfer Function of DCDC ConvertersRadita Apriana
In this paper, AC modeling and small signal transfer function for DC-DC converters are
represented. The fundamentals governing the formulas are also reviewed. In DC-DC converters, the
output voltage must be kept constant, regardless of changes in the input voltage or in the effective load
resistance. Transfer function is the necessary knowledge to design a proper feedback control such as PID
control to regulate the output voltage as linear PID and PI controllers are usually designed for DC-DC
converters using standard frequency response techniques based on the small signal model of the
converter.
This paper introduces a new topology of multilevel inverter, which is able to operate at high performance. This proposed circuit achieves requirements of reduced number of switches, gate-drive circuits, and high design flexibility. In most cases fifteen-level inverters need at least twelve switches. The proposed topology has only ten switches. The inverter has a quasi-sine output voltage, which is formed by level generator and polarity changer to produce the desired voltage and current waveforms. The detailed operation of the proposed inverter is explained. The theoretical analysis and design procedure are given. Simulation results are presented to confirm the analytical approach of the proposed circuit. A 15-level and 31-level multilevel inverters were designed and tested at 50 Hz.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC ConvertersIAES-IJPEDS
This paper proposes a transfomerless switched capacitor buck boost converter model, which provides higher voltage gain and higher efficiency when compared to the conventional buck boost converter. The averaged model based on state- space description is analyzed in the paper. The simulation results are presented to confirm the capability of the converter to generate high voltage ratios. The comparison between the proposed model and the traditional model is also provided to reveal the improvement. The proposed converter is suitable for for a wide application which requires high step-up DC-DC converters such as DC micro-grids and solar electrical energy.
Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC Converters
Eo24881888
1. P.N.V. Revan Kumar, B. Dastagiri Reddy, V. Nagabhaskar Reddy / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.881-888
Analysis Of Non-Linear Robust Control Strategies Of Switch
Mode Dc To Ac Inverter With Reactive Load
*P.N.V. REVAN KUMAR,**B. DASTAGIRI REDDY,
***V. NAGABHASKAR REDDY
*P.G.Student Dept. of EEE, RGMCET, Nandyal
** Research Scholar, NIT Tiruchirappalli.
***Associate Professor, Dept. of EEE, RGMCET
Abstract- Control strategies are having Compared to the bridge-type inverter,
necessity to remain the output voltage stable for the inverter using a dc-to-dc converter
large disturbances at input as well as at output . configuration has several advantages. Only one
A dc-to-ac inverter, which gives the nearer switch operates at
sinusoidal output by using nonlinear robust high frequency and, as a result, switching losses
control based on the dc-to-dc converter will be significantly less. The conduction loss will
topology. Computer simulation results show the be slightly higher because of one extra switch to
robustness and fast dynamical response of the the bridge configuration. The overall losses will be
control system. Then the nonlinear control law less, thereby increasing efficiency. In addition,
has been extended to a bidirectional inverter to the output filtering capacitors in the dc-to-dc
overcome some of the drawbacks. The stability converters can be a dc-type capacitor.
analysis of the control system is presented. The
closed loop control system under P control, Pl II. PRINCIPLE OF OPERATION
control, PD control and PID control of the The principle of operation of this type of
voltage loop for different types of loads are inverter is illustrated in fig 1, where the dc-to-dc
investigated. The results show that the PD converter is of buck configuration. The average
control is the best choice. All the work is carried output voltage of this buck converter, Vo, is the
out in MATLAB simulation environment and product of duty ratio and the input voltage i.e., if
the results are presented. the input voltage is constant and the duty ratio is
varied slowly, relative to the switching frequency,
I. INTRODUCTION in the form of a fully rectified sinusoidal wave, the
Nowadays switch–mode dc-to-ac inverters output will naturally be a fully rectified sine wave.
are used in various types of applications, such as Through a bridge circuit, which is synchronized
uninterruptible power supplies, communication with the fully rectified sine waveform of the duty
ring generators, aerospace power systems, and ratio of the dc-dc converter, the output is
variable-speed ac machine drives where the “unfolded” into a sinusoidal waveform as shown in
objective is to produce a sinusoidal ac output fig 2. In which both the magnitude and frequency
whose magnitude and frequency can be controlled. of the output are controlled by the dc-dc converter,
The loads in the aforementioned applications are based on the magnitude and frequency of the
either critical or sensitive. A good steady state and reference signal.
dynamic performance of the switch-mode dc-to-ac
inverter is desirable for these applications.
Usually a bridge configuration is employed
for the switch-mode dc-to-ac inverters. If the input
to switch-mode inverters is a dc voltage source
then they are referred to as voltage source inverters
(VSI). The other types of inverters which are used
for high power ac motor drives are current source
inverters (CSI), where the dc input to the inverter is
a dc current source.
Recently, switch-mode dc-to-ac inverters
using a dc-to-dc converter topology have been
developed. Using the dc-dc converter, controlled dc
Fig. 1 Buck converter with duty ratio varying in
output in the form of a fully rectified sinusoidal
theform of a fully rectified sine wave.
wave is generated which becomes the input for the
controlled bridge which then outputs a pure sine
voltage waveform.
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2. P.N.V. Revan Kumar, B. Dastagiri Reddy, V. Nagabhaskar Reddy / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.881-888
A switch-mode dc-to-dc converter is shown in fig 4.This model is valid only for
generally composed of two basic parts. One is the continuous conduction mode operation.
power stage, or the switching converter, the other is In this averaged-circuit model, the active
the control circuit, as shown in fig 3.where V r is the switch is modeled by a controlled current source
reference voltage, y denotes the combination of the with its value equal to the average current flowing
feedbacks, and α is the duty ratio. through it over one switching cycle, i.e., is = αiL for
the buck converter, where “iL” is the averaged
inductor current and α is the duty ratio. The
average output voltage
Fig.2 A bridge synchronizer following the buck
converter . Fig. 4. Averaged model of the buck converter.
across the diode over one switching cycle is
modeled as a controlled voltage source with its
value equal to Vd = αVs for the buck converter.
From fig 5, the output voltage can be expressed as
Vo = αpVs-VL (1)
Where VL is the averaged value of the
indicator voltage and αp is the duty ratio required
for the switching converter. This αp can be
expressed as
αp = (Vo+VL)/Vs (2)
equation(2) defines the duty ratio required
by the buck converter at a specific operating point
Fig. 3 General Block diagram of switching of Vo, VL and Vs.
converter The control circuit can now be constructed
to generate the duty ratio. Let the input and output
The power stage controls the power relation of the control circuit be formulated as
absorbed from the unregulated supply voltage and αc = [K(Vr – Vo) + VL]/Vs (3)
provides a regulated constant output voltage at the Where Vr is the reference voltage, K is the
load. The main purpose of the control circuit is to gain of the proportional error amplifier, and αc
generate a proper duty ratio according to the denotes the duty ratio generated by the control
conditions of the circuit so that the variation of the circuit. The implementation is shown in fig 5(a).
output voltage is reduced as much as possible when The proposed dc-to-ac inverter using nonlinear
the supply voltage or load current changes. For robust control system.
different control laws, the effect of such
disturbance is different.
In order to achieve robust control of the
output voltage, i.e., to eliminate the effect of the
supply voltage or load current disturbance, the
control strategy should be particularly constructed
and feedbacks should be properly selected so that
the control circuit can provide the exact duty ratio
required by the power stage. This implies that the
closed loop output voltage should be independent
of either the supply voltage or the load current and
should be determined only by the reference
voltage. Fig. 5(a).The diagram of the proposed inverter.
A nonlinear control strategy can be Practically the output of the control circuit
applied to the buck-type dc-to-dc converter to is connected to the gate of the active switch in the
realize the above objective. The low-frequency power stage, making αp = αc. Therefore, the closed-
averaged equivalent model of a buck converter is loop characteristic can be obtained as
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3. P.N.V. Revan Kumar, B. Dastagiri Reddy, V. Nagabhaskar Reddy / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.881-888
(Vo+VL)/Vs = [K(Vr-Vo) + VL]/Vs (4) supply voltage. Nonlinear control law combined
From the output voltage can be found as with the inherent nonlinear buck converter has
Vo = [K/(K+1)]Vr (5) resulted, in this case, in a linear closed loop system.
The averaged closed loop output voltage is
It is to be noted that the output voltage Vo proportional to the reference voltage.
at the left side is rms value, Vr is also rms value When the supply voltage changes, the duty
and K is gain of the proportional error amplifier. ratio will react immediately and change
Vo = [K/(K+1)]Vr|sinωot| (6) accordingly to such an extent that it can cancel the
and represents a fully rectified sinusoidal effect of the supply voltage disturbance. Thus the
waveform having the same frequency as the output voltage keeps unchanged.
references signal Vr. The feedback of the averaged inductor
The bridge-type synchronizer composed voltage is used to correct the disturbance of the
of T1 – T4, as shown in fig .6 is used to generate a load current. The inductor voltage is proportional
sinusoidal ac voltage waveform for which input is to the rate of change of inductor current, which is
the buck converter output Vo given by above the sum of the load current and the capacitor
equation. In this synchronizer, the switching cycle current as shown in fig 5. i.e., VL = L di/dt and I =
of the diagonal pair of switches, (T 1, T4) or (T2, T3) ic + io. As soon as there is a tendency for the load
is synchronized with that of the reference signal Vr. current to change, i.e., even before the load current
For example, T1 and T4 are turned on at 0, T, 2T has actually changed, the correction action of the
etc., and T2 and T3 are turned on at (T/2), (3T/2) control circuit begins. The generated duty ratio is
etc., as shown in fig 3.4 Therefore, the fully accurate enough so that the low frequency averaged
rectified sinusoidal voltage Vo can be unfolded into output voltage does not change.
a sinusoidal output voltage Vac. This sinusoidal The block diagram of the Function
output voltage Vac is immune to disturbances in the Controlled Buck converter is shown in fig 7. The
input voltage or output current. The proposed low frequency component of the inductor voltage is
closed-loop control system of the switch-mode dc- retrieved and is added with the output of the
to-ac inverter using the buck converter topology is controller to formulate the numerator of the control
illustrated in fig 5(b). law (3). The controller specified here can be of P,
The output equation shows that by the PI, PD, etc. type. Finally the duty ratio is generated
control law (3), the closed loop averaged output by
voltage is forced to be proportional to a reference dividing Vn by Vs as defined in fig 6.
voltage.
This result means that the closed loop
output voltage is independent of supply voltage and
the load current. In other words, the averaged
output voltage remains unchanged even when there
is disturbance from either the supply voltage or
load current. Zero voltage regulation or robust
control of output voltage is, therefore, achieved.
Various waveforms of the proposed dc-to-ac Fig. 6. Block Diagram of function control.
inverter. The major drawback of the proposed circuit
is that it can only work for resistive load but will
not work efficiently for reactive load. In the switch-
mode dc-to-ac inverter, the load can be resistive,
inductive, or capacitive. Therefore the energy flows
bidirectionally. As a remedy to this a bidirectional
power stage of the Buck converter is considered, as
shown in fig 7.
Fig.5(b).The sinusoidal output voltage is
obtained by the bridge-type synchronizer.
The control law (3) is nonlinear. The duty
ratio is proportional to the sum of the averaged
Fig. 7 Bidirectional buck converter.
inductor voltage and the output of the error
In this bidirectional power stage, the
amplifier and is inversely proportional to the
switches Q1 and Q2 are triggered complementarily.
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4. P.N.V. Revan Kumar, B. Dastagiri Reddy, V. Nagabhaskar Reddy / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.881-888
When energy flows from input to output, Q1 and
D2 are active. The power stage functions like a
Buck Converter. When energy flows from output to
input, Q2 and D1 are active. The power stage
functions like a Boost converter. As a result, the
inductor current is always continuous, even at a no
load condition. The low-frequency averaged circuit
model for the bidirectional converter is shown in
fig 8, which is a combination of a Buck Converter
and a Boost converter. Fig. 10 Low-Frequency average circuit model for
stability analysis.
The average voltage of the inductor is
indispensable in the construction of the control
circuit. However, the actual inductor voltage is a
high-frequency rectangular wave. It consists of a
low-frequency component and a series of high-
frequency components, which are multiples of the
switching frequency. A switching average low-pass
filter discussed in the last section is used to retrieve
the useful low-frequency component and suppress
Fig. 8 Averaged model of the bidirectional buck greatly the high-frequency components.
converter Approximately the low-frequency component of
According to Kirchhoff’s current and the inductor voltage at the output of the filter
voltage law, the circuit model shown in fig 8, can delays the actual one by one switching period.
be simplified to a simpler model, shown in fig 9. First, the resistive load is considered for
Obviously this circuit model is the same as that the stability analysis. The parameters of the power
shown in fig. 4. This paves a way to extend the stage are: fs = 10 KHz, L = 5mH, C = 10e–6F, R =
aforementioned nonlinear robust control to the 30 Ohm and RL = 0.05 Ohm; RC = 0.01 Ohm.
switch-mode dc-to-ac inverter.
A) PROPORTIONAL CONTROL
The dynamic response of the closed-loop
system to the disturbances in line and load are
investigated and the results are presented as
follows.
Fig 11 shows the root locus of the closed
control system when the proportional gain of the
error amplifier of feedback loop Kp varies from Kp
= 1 to Kp = 100. The control system is unstable for
Fig. 9 Simplified averaged model of the the given parameters because two roots are in the
bidirectional buck converter. right half s-plane.
III. STABILITY ANALYSIS
In order to ensure that the dc-to-ac
inverter using the nonlinear robust control will
generate the desirable output voltage, irrespective
of disturbances such as variations in the input
voltage and perturbations in the load current, the
closed control system needs to be carefully studied.
The low-frequency averaged circuit
equivalent circuit model shown in fig 4 is used to
perform the stability analysis. As the winding
resistance of the inductor, RL, and equivalent series
resistance (ESR) of the filtering capacitor RC,
should be included, the equivalent circuit is
Fig. 11 Root locus plot of the control system with P
redrawn and shown in fig 10.
control (Kp 1 to 100)
B) PROPORTIONAL-PLUS-INTEGRAL
CONTROL
The root loci of the closed-loop system
where the feedback loop of output voltage is under
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5. P.N.V. Revan Kumar, B. Dastagiri Reddy, V. Nagabhaskar Reddy / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.881-888
PI control are shown in fig 12(a), (b) and (c). The Root locus analysis is performed for the
diagrams shown in fig 13(a) and (b) describe the closed-loop control system with PD control. Fig
root loci when the proportional gain varies from Kp 13(a) and (b) gives the root loci of the closed-loop
= 1 to control system.
Kp = 100 under the condition that the integral gain The derivative gain Kd is fixed at Kd =
KI is fixed at KI = 1 and KI = 20, respectively. It 0.01 and Kd = 0.1, respectively while the
can be seen that two categories segments of the proportional gain Kp is being varied from 1 to 100.
roots lie in the right half s-plane in both diagrams. All the roots are in the left half of s plane. For each
Fig 4.3(c) shows two roots in the right half s-plane value of Kd there are three segments. One segment
when KI changes from KI = 0.1 to KI = 50 and Kp = is on the real axis and becomes the dominant root
1 is kept. Obviously, the closed-loop control and the other two segments are conjugate and lie
system using PI control is unstable for the given far away left from the real root. Fig 13(c) gives the
parameters. root loci of the PD control for Kp = 10 while the Kd
is varied from 0 to 0.01. It can be seen that as the
Kd value is increased,
the two conjugate roots move into the left half of
s-plane. Thus, from the analysis it is seen that for
the given parameters, the system can be stabilized
when the gain Kd is proper.
Fig. 12(a). Root locus plot of the control system
with PI control (Kp 1 – 100 ,KI=1)
Fig. 13(a). Root locus plot of the control system
with PD control (Kp 1-100 ,Kd=0.03)
Fig. 12(b). Root locus plot of the control system
with PI control (Kp 1 – 100 ,KI=20)
Fig. 13(b). Root locus plot of the control system
with PD control (Kp 1-100 ,Kd=0.1)
D) PROPORTIONAL-PLUS-INTEGRAL-
PLUS-DERIVATIVE CONTROL
PID control for the output voltage
feedback loop is also analyzed. The effect of the
gains, Kp, KI and Kd on the stability of the system
is investigated. From the analysis we can say that if
Fig. 12(c). Root locus plot of the control system the gains are selected properly, the system can be
with PI control (Kp 1,KI=0.1-50) stable. However, if the gains are not properly
C) PROPORTIONAL-PLUS-DERIVATIVE selected, the system cannot be stable.
CONTROL
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6. P.N.V. Revan Kumar, B. Dastagiri Reddy, V. Nagabhaskar Reddy / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.881-888
Comparing with PD control, in both cases
where Kd = 0.01 is kept, PID control adds one real
root between the root of PD control and the origin.
It is this root that is dominant. As a result, PID
control has slower dynamic response or is more
oscillating that PD control. The reason is that the
PD control can be made stable and Pl control is not
stable. The integral part in the PID control moves
the roots of the PD control system toward the right
half s-plane. Therefore, the performance of the
system with PID control is worse that PD control.
The closed-loop control systems for
inductive load with P control, PI control, PD
control and PID control for the output voltage .
feedback loop Fig. 14 output voltage (in volts) of the
switch-mode inverter for R load.
B) EFFECT OF SUPPLY VOLTAGE
DISTURBANCE
The simulated result is shown in fig 15.
This result shows that, when the supply voltage
variations are in the between 150 and 250 V, the
output voltage of the inverter does not change.
Fig. 13(c). Root locus plot of the control system
with PD control (Kp 10 ,Kd=0-0.01).
have been investigated. The root loci are similar to
those for resistive load, except for an additional
small segment on real axis around (-314, 0). This
Fig:15 Effect of the input voltage step changes on
additional root is caused by the sLo + Ro. Because
the output voltage.
this root is on the negative real axis and is confined
C) EFFECT OF THE OUTPUT LOAD STEP
within a tiny range around (-314, 0), it will not
CHANGES ON THE OUTPUT
affect the stability.
VOLTAGE
As a result of the stability analysis, PD
The response of the control system to a
control is selected for the output voltage feedback
large disturbance in the load is also studied by
loop.
simulation. The result is illustrated in fig 16. The
output current is plotted along with the voltage.
IV. COMPUTER SIMULATION The output current suddenly changes from 5 to 7.5
RESULTS amps (peak – peak) in magnitude in response to a
A) RESISTIVE LOAD load disturbance. To get a clear idea of the load
The switch-mode dc-to-ac inverter using a disturbance scaled output current along with
dc-dc converter topology with the nonlinear robust voltage is plotted in fig 17. The simulation result
control strategy with resistive load as shown in fig reveals that the output voltage of the inverter under
5 is simulated using MATLAB. The simulation the proposed control technique is not affected by
details are enclosed in the appendix. the deviations in the load.
The parameters of the inverter are as follows.
Input voltage 200 V dc
Buck filtering inductor 5mH.
Buck filtering capacitor 10e-6F.
Reference voltage = 25* sin(2*pi*50*t) Volts (pp).
Switching frequency = 10 KHz,
PD control is used in the voltage loop
886 | P a g e
7. P.N.V. Revan Kumar, B. Dastagiri Reddy, V. Nagabhaskar Reddy / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.881-888
peak) in magnitude in response to a load
disturbance. Output voltage along with scaled
output current is plotted. This result confirms that
the proposed model works well for both resistive
and reactive loads.
Fig.16 Effect of the load disturbance on the output
voltage.
Fig.19 Inverter output voltage for inductive load.
Fig. 17 Effect of the load disturbance on the output
voltage with scaled current.
D) RESPONSE TO A STEP CHANGE OF
Fig.20 Effect of the load disturbance on the output
THE REFERENCE SIGNAL
voltage with scaled current.
Finally, the response of the control system
to a step change in the reference signal is
simulated. The result shown in fig 18 demonstrates V. CONCLUSIONS
that this control system has fast dynamic response. The bidirectional inverter with dc-dc
The response is plotted for a step change in converter topology has been simulated using
reference signal from 20 to 30 V in magnitude. MATLAB. The simulation results confirm that the
nonlinear robust control, which has been employed,
provides dynamical stabilization of the output
voltage of the inverter thus achieving zero voltage
regulation. Also with dc-dc converter topology for
the inverter pure sinusoidal output has been
generated. Also the inverter has high efficiency. By
the extension of this novel nonlinear control
strategy the bidirectional inverter has also been
simulated which works both for resistive and
reactive loads. Stability analysis of the control
system under P control, PI control, PD control and
PID control of the output voltage feedback loop is
carried out. The root loci reveal that PD control is
Fig.18 Response for step change in reference the best among the four control schemes.
signal.
REFERENCES
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load is plotted as shown in fig 19 and fig 20 shows Robbins, Power Electronics, Converters,
the effect of inductive load disturbance. The output
current suddenly changes from 5 to 7 amps (peak-
887 | P a g e
8. P.N.V. Revan Kumar, B. Dastagiri Reddy, V. Nagabhaskar Reddy / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.881-888
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P.N.V. REVAN KUMAR was
born in anantapur, india,
received the B.Tech (Electrical
and Electronics Engineering)
degree from the Jawaharlal
Nehru Technological
University, Hyderabad in 2010
. Currently pursuing M-Tech
in the Dept. Electrical and Electronics
Engineering, Rajeev Gandhi Memorial College
of Engg. & Tech, Nandyal.E-
mail:revankumarp245@gmail.com.
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