This document compares the performance of a photovoltaic powered embedded Z-source inverter (EZSI) feeding an induction motor drive using either sine pulse width modulation (PWM) or space vector modulation (SVM). An EZSI provides single-stage power conversion from a DC source and can boost the output voltage above the input DC voltage. The document designs, models and simulates a PV-powered EZSI induction motor system in MATLAB/Simulink. The results show this drive system has advantages like voltage boosting ability and reduced harmonic content compared to a traditional voltage source inverter.
Design and Control of Switched-Inductor Quasi-Z-Source Inverter for Photovolt...irjes
The conventional Z-Source Inverter (ZSI) used for photovoltaic applications has certain
shortcomings such as high stress across the passive components and low boost factor. This paper presents the
design and analysis of three phase switched inductor quasi Z-source inverter (SL-QZSI) for photovoltaic (PV)
applications. The wide voltage gain and the compensation for dead time effect of SL-QZSI with the help of
shoot-through states makes it suitable for PV application. Modulation strategies such as Simple boost,
Maximum boost and Constant maximum boost control methods are investigated for the operation and control
of SL-QZSI. PV source is modeled in MATLAB and incremental & conductance MPPT algorithm is
implemented .Simulation of the SL-QZSI circuit powered by PV source is carried out by implementing
maximum boost control method and the performance parameters are discussed.
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.
Space Vector of Three Phase Three level Neutral Point Clamped Quasi Z Source ...IJTET Journal
Space vector of three phase three level neutral point clamped quasi z source inverter is proposed in this paper. Space vector modulation is the pulse width modulation consists of number of switching states. Space vector pulse width modulation technique utilizes 15% more power from DC source. Harmonics are reduced by the presence of switching states. Quasi Z-source inverter is advanced topologies which performs both boost and buck operation of a converter. The proposed inverter obtains continuous input current and the boost converter is not needed. So, maximum voltage can be obtained in the load and system complexity is reduced. Maximum power can be obtained from the solar panel by using MPPT. The implementation of MPPT is to operate a PV array under constant voltage and power reference to modify the duty cycle of the inverter.The simulation of proposed topology is done in MATLAB/SIMULINK software.
Analysis of Impedance Source Inverter Topologies for Grid Integration of PV I...IJPEDS-IAES
In this paper, the performance of different Impedance Source Inverter (ZSI)
topologies in implementing single stage power conversion for grid
ingetertion of PV power converters is discussed. Unlike the traditional
inverters, ZSI employs a distinctive impedance network, there by making
shoot-through state is possible. The independent control variables are shootthrough
duty ratio and modulation index. Simple Boost Control pulse width
modulation technique was used in this work to vary the modulation index.
Here the basic operation, simple boost control method, characteristics,
requirements and harmonic analysis of the classical Z-Source Inverter (ZSI),
TZ-Source Inverter (TZSI), Trans-Z-Source Inverter (Trans-ZSI) and
Improved ZSI (IMZSI) topologies were compared for interfacing the wide
range variable input energy to utility supply system. The performances were
compared based on its MATLAB/SIMULINK simulation model and featured
results are shown to confirm its validity.
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.
Design and Control of Switched-Inductor Quasi-Z-Source Inverter for Photovolt...irjes
The conventional Z-Source Inverter (ZSI) used for photovoltaic applications has certain
shortcomings such as high stress across the passive components and low boost factor. This paper presents the
design and analysis of three phase switched inductor quasi Z-source inverter (SL-QZSI) for photovoltaic (PV)
applications. The wide voltage gain and the compensation for dead time effect of SL-QZSI with the help of
shoot-through states makes it suitable for PV application. Modulation strategies such as Simple boost,
Maximum boost and Constant maximum boost control methods are investigated for the operation and control
of SL-QZSI. PV source is modeled in MATLAB and incremental & conductance MPPT algorithm is
implemented .Simulation of the SL-QZSI circuit powered by PV source is carried out by implementing
maximum boost control method and the performance parameters are discussed.
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.
Space Vector of Three Phase Three level Neutral Point Clamped Quasi Z Source ...IJTET Journal
Space vector of three phase three level neutral point clamped quasi z source inverter is proposed in this paper. Space vector modulation is the pulse width modulation consists of number of switching states. Space vector pulse width modulation technique utilizes 15% more power from DC source. Harmonics are reduced by the presence of switching states. Quasi Z-source inverter is advanced topologies which performs both boost and buck operation of a converter. The proposed inverter obtains continuous input current and the boost converter is not needed. So, maximum voltage can be obtained in the load and system complexity is reduced. Maximum power can be obtained from the solar panel by using MPPT. The implementation of MPPT is to operate a PV array under constant voltage and power reference to modify the duty cycle of the inverter.The simulation of proposed topology is done in MATLAB/SIMULINK software.
Analysis of Impedance Source Inverter Topologies for Grid Integration of PV I...IJPEDS-IAES
In this paper, the performance of different Impedance Source Inverter (ZSI)
topologies in implementing single stage power conversion for grid
ingetertion of PV power converters is discussed. Unlike the traditional
inverters, ZSI employs a distinctive impedance network, there by making
shoot-through state is possible. The independent control variables are shootthrough
duty ratio and modulation index. Simple Boost Control pulse width
modulation technique was used in this work to vary the modulation index.
Here the basic operation, simple boost control method, characteristics,
requirements and harmonic analysis of the classical Z-Source Inverter (ZSI),
TZ-Source Inverter (TZSI), Trans-Z-Source Inverter (Trans-ZSI) and
Improved ZSI (IMZSI) topologies were compared for interfacing the wide
range variable input energy to utility supply system. The performances were
compared based on its MATLAB/SIMULINK simulation model and featured
results are shown to confirm its validity.
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.
Improved Trans-Z-source Inverter for Automobile ApplicationIJTET Journal
In this paper a new technology is proposed with a replacement of conventional voltage source/current
source inverter with Improved Trans-Z-source inverter in automobile applications. The improved Trans-Z-source
inverter has a high boost inversion capability and continues input current. Also this new inverter can suppress the
resonant current at the startup; this resonant current in the startup may lead the device to permanent damage. In
improved Trans-Z-source inverter a couple inductor is needed, instead of this coupled inductor a transformer is used.
By using a transformer with sufficient turns ratio the size can be reduced. The turn’s ratio of the transformer decides
the input voltage of the inverter. In this paper operating principle, comparison with conventional inverters, working
with automobiles simulation results, THD analysis, Hardware implementation using ATMEGA 328 P are included.
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.
SIMULATION AND ASSESSMENT OF SINGLE PHASE SEMI-Z-SOURCE INVERTER (S-ZSI)IAEME Publication
The present investigation is a step towards the development of a single phase semi-Z-source inverter (s-ZSI) with photovoltaic, its topology and the assessment with respect to the voltage and current output. The proposed semi-Z-source inverter use only two active switches to achieve a desired output. The simulation was carried out using MATLAB and the results are discussed in various waveforms.
Simulation of Z-Source Inverter Fed Three Phase Induction Motor DriveIJSRD
This paper presents performance characteristics of Z-source inverter (ZSI) fed Induction Motor (IM) drives. Z-Source inverter is a single stage converter which performs both buck-boost energy conversions using the LC impedance network. This reduces the voltage range of the capacitors used and also the cost of the proposed topology which is in turn used to control the speed of an induction motor which is used in many valuable industrial applications. The Z Source inverter is a combined inverter with an additional buck-boost feature and the proposed topology increases the efficiency of the circuit by reducing the voltage stress across the capacitors. The z-source inverter is very advantageous over traditional inverters and we can be employed all ac and dc power conversion applications. Z-source inverter can boost dc input voltage with no requirement of dc to dc boost converter or step up transformer hence overcoming output voltage limitation of voltage source inverter as well as lower cost. A comparison among conventional PWM inverter dc to dc boost PWM inverter and control circuit cost which are the main a power electronics system.
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.
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.
Performance and Analysis of Hybrid Multilevel Inverter fed Induction Motor Drivernvsubbarao koppineni
This paper presents the Five level inverter with single DC source which is used to generate a five level output with two bridges and six switches and performance of three phase induction motor is analyzed when connected to PV array For this two identical dc sources of 50V each for two bridges in five levels using Multi level inverter and five level output is obtained by using a single DC source of 100V with six switches. A virtual DC source (charged capacitor acts as virtual DC source) is used for getting the output. The same technique is implemented for three-phase circuit i.e. by using single DC source. An asynchronous motor (three-phase) is connected as load and its performance characteristics are analyzed. And further the DC source is replaced by a renewable resource such as solar panels, fuel cell etc. and DC voltage is obtained. Performance characteristics of three-phase asynchronous motor are analyzed with PV array connected. The method can be easily extended to an m-level inverter.
An intrinsic problem with neutral point clamped (NPC) multilevel inverters (MLI) is unbalance of capacitor voltage. There are many mitigation techniques well established in the literature to balance the neutral point voltage for 3-level inverter. These techniques employ either Carrier based pulse width modulation (CBPWM), Space vector pulse width modulation (SVPWM) or hybrid of both the PWM techniques. Balancing becomes complicated as the level of the inverter increases due to addition of capacitor junctions. The imbalance in capacitor voltages may cause uneven voltage distribution among switching devices and sometimes may cause failure. It also increases harmonic content in its output waveform. This paper develops new modulation scheme for balancing capacitor voltages for Five-level inverter .The scheme is a hybrid PWM which is a combination of both CBPWM and SVPWM techniques. As per this scheme CBPWM is applied to meet the load demand and at the zero crossings of the reference signal, CBPWM is blocked and for one carrier cycle. During this SVPWM is applied with appropriate switching state selection to neutralize the imbalance in capacitor voltage.
Implementation of Cascaded H Bridge Control Scheme for SSSC using Zero Sequen...ijtsrd
This paper focuses on a control scheme of cascaded H bridge scheme implemented in SSSC for enhance the three phase power systems. Cascaded H bridge based SSSC has offer low switching losses and less total harmonics distortion, and reduces the number of circuit components. Each H bridge cell has isolated dc capacitors which is exist balanced capacitor voltages. Since SSSC is often requested to operate under asymmetrical condition by power system faults such as one line grounding or two line short circuit and it can be the control output current almost freely. Cascaded H bridge based SSSC needs wide range of margin of dc voltage for operates in large unbalanced voltage power system. This proposed system focused on to avoids wide range of margin of dc voltage by exclusively using the two methods such has zero sequence voltage and negative sequence current. By this scheme, the SSSC is allowed to operate under asymmetrical condition by power system faults. The validity is examined by digital simulation under one line and two line fault in power system. M. Subalakshmi | A. Rathinam ""Implementation of Cascaded H-Bridge Control Scheme for SSSC using Zero Sequence Voltage and Negative Sequence Current"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-2 , February 2020,
URL: https://www.ijtsrd.com/papers/ijtsrd30063.pdf
Paper Url : https://www.ijtsrd.com/engineering/electrical-engineering/30063/implementation-of-cascaded-h-bridge-control-scheme-for-sssc-using-zero-sequence-voltage-and-negative-sequence-current/m-subalakshmi
A Single Phase Eleven Level Cascaded H-Bridge Multilevel Inverter for Photovo...IJMER
Abstract: A Cascaded H-Bridge Multilevel Inverter is a power electronic converter built to synthesize a desired ac voltage
from several levels of dc voltages with better harmonic spectrum. Such inverters are suitable for high voltage and high
power applications and have been an important development in recent years. This paper presents the performance of a
eleven level cascaded H-Bridge multilevel inverter topology with multicarrier pulse width modulation technique for
photovoltaic cell. This inverter is capable of producing eleven levels of output voltage from the dc supply voltage. This
topology magnifies the fundamental output voltage with reduction in total harmonic distortion . The output is drawn near the
sine wave because of more levels. It can also be easily extended to an m-level inverter. The performance of the proposed
PWM strategy in terms of output voltage and THD is shown using MATLAB/Simulink.
Keywords: Multilevel inverter, Cascaded H-Bridge multilevel inverter, Multicarrier pulse width modulation, PV cell, Total
harmonic distortion.
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 proposes the use of Embedded EZ-source
inverter system (EZSI) as a single stage power conversion
concept for adjustable speed drives (ASD) in photovoltaic
applications. Open loop and closed loop control strategy of
EZSI system are proposed. EZSI produces the same voltage
gain as Z-source inverter (ZSI) but due to the DC sources
embedded within the X- shaped impedance network, it has
the added advantage of inherent source filtering capability
and also reduced capacitor sizing. This is attained without
any extra passive filters. By controlling the shoot-through
duty ratio and modulation index, EZSI system can produce
any desired AC output voltage even greater than DC rail
voltage and it also provides ride-through capability under
voltage sag. These advantages are more significant for
adjustable speed drive (ASD) applications in order to regulate
the speed. The operational analysis, control strategy and
simulation results exemplify that an EZSI is the most
promising technique for renewable energy applications in
order to reduce the overall system complexity and thereby
improving the inverter efficiency.
A DC Inrush Current Minimisation Method using Modified Z-Source Inverter in A...IAES-IJPEDS
The adjustable speed drives employ PWM converter-inverter system in order
to obtain unity power factor. The DC inrush current in DC link capacitors of
the rectifier limits the operation of power devices. Hence, this paper proposes
a new approach to reduce the DC inrush current by employing modified
Z-source inverter in a Adjustable Speed Drive system. The operating
principles, design procedure and simulation results are shown and compared
with the conventional Z-Source inverter.
Improved Trans-Z-source Inverter for Automobile ApplicationIJTET Journal
In this paper a new technology is proposed with a replacement of conventional voltage source/current
source inverter with Improved Trans-Z-source inverter in automobile applications. The improved Trans-Z-source
inverter has a high boost inversion capability and continues input current. Also this new inverter can suppress the
resonant current at the startup; this resonant current in the startup may lead the device to permanent damage. In
improved Trans-Z-source inverter a couple inductor is needed, instead of this coupled inductor a transformer is used.
By using a transformer with sufficient turns ratio the size can be reduced. The turn’s ratio of the transformer decides
the input voltage of the inverter. In this paper operating principle, comparison with conventional inverters, working
with automobiles simulation results, THD analysis, Hardware implementation using ATMEGA 328 P are included.
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.
SIMULATION AND ASSESSMENT OF SINGLE PHASE SEMI-Z-SOURCE INVERTER (S-ZSI)IAEME Publication
The present investigation is a step towards the development of a single phase semi-Z-source inverter (s-ZSI) with photovoltaic, its topology and the assessment with respect to the voltage and current output. The proposed semi-Z-source inverter use only two active switches to achieve a desired output. The simulation was carried out using MATLAB and the results are discussed in various waveforms.
Simulation of Z-Source Inverter Fed Three Phase Induction Motor DriveIJSRD
This paper presents performance characteristics of Z-source inverter (ZSI) fed Induction Motor (IM) drives. Z-Source inverter is a single stage converter which performs both buck-boost energy conversions using the LC impedance network. This reduces the voltage range of the capacitors used and also the cost of the proposed topology which is in turn used to control the speed of an induction motor which is used in many valuable industrial applications. The Z Source inverter is a combined inverter with an additional buck-boost feature and the proposed topology increases the efficiency of the circuit by reducing the voltage stress across the capacitors. The z-source inverter is very advantageous over traditional inverters and we can be employed all ac and dc power conversion applications. Z-source inverter can boost dc input voltage with no requirement of dc to dc boost converter or step up transformer hence overcoming output voltage limitation of voltage source inverter as well as lower cost. A comparison among conventional PWM inverter dc to dc boost PWM inverter and control circuit cost which are the main a power electronics system.
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.
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.
Performance and Analysis of Hybrid Multilevel Inverter fed Induction Motor Drivernvsubbarao koppineni
This paper presents the Five level inverter with single DC source which is used to generate a five level output with two bridges and six switches and performance of three phase induction motor is analyzed when connected to PV array For this two identical dc sources of 50V each for two bridges in five levels using Multi level inverter and five level output is obtained by using a single DC source of 100V with six switches. A virtual DC source (charged capacitor acts as virtual DC source) is used for getting the output. The same technique is implemented for three-phase circuit i.e. by using single DC source. An asynchronous motor (three-phase) is connected as load and its performance characteristics are analyzed. And further the DC source is replaced by a renewable resource such as solar panels, fuel cell etc. and DC voltage is obtained. Performance characteristics of three-phase asynchronous motor are analyzed with PV array connected. The method can be easily extended to an m-level inverter.
An intrinsic problem with neutral point clamped (NPC) multilevel inverters (MLI) is unbalance of capacitor voltage. There are many mitigation techniques well established in the literature to balance the neutral point voltage for 3-level inverter. These techniques employ either Carrier based pulse width modulation (CBPWM), Space vector pulse width modulation (SVPWM) or hybrid of both the PWM techniques. Balancing becomes complicated as the level of the inverter increases due to addition of capacitor junctions. The imbalance in capacitor voltages may cause uneven voltage distribution among switching devices and sometimes may cause failure. It also increases harmonic content in its output waveform. This paper develops new modulation scheme for balancing capacitor voltages for Five-level inverter .The scheme is a hybrid PWM which is a combination of both CBPWM and SVPWM techniques. As per this scheme CBPWM is applied to meet the load demand and at the zero crossings of the reference signal, CBPWM is blocked and for one carrier cycle. During this SVPWM is applied with appropriate switching state selection to neutralize the imbalance in capacitor voltage.
Implementation of Cascaded H Bridge Control Scheme for SSSC using Zero Sequen...ijtsrd
This paper focuses on a control scheme of cascaded H bridge scheme implemented in SSSC for enhance the three phase power systems. Cascaded H bridge based SSSC has offer low switching losses and less total harmonics distortion, and reduces the number of circuit components. Each H bridge cell has isolated dc capacitors which is exist balanced capacitor voltages. Since SSSC is often requested to operate under asymmetrical condition by power system faults such as one line grounding or two line short circuit and it can be the control output current almost freely. Cascaded H bridge based SSSC needs wide range of margin of dc voltage for operates in large unbalanced voltage power system. This proposed system focused on to avoids wide range of margin of dc voltage by exclusively using the two methods such has zero sequence voltage and negative sequence current. By this scheme, the SSSC is allowed to operate under asymmetrical condition by power system faults. The validity is examined by digital simulation under one line and two line fault in power system. M. Subalakshmi | A. Rathinam ""Implementation of Cascaded H-Bridge Control Scheme for SSSC using Zero Sequence Voltage and Negative Sequence Current"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-2 , February 2020,
URL: https://www.ijtsrd.com/papers/ijtsrd30063.pdf
Paper Url : https://www.ijtsrd.com/engineering/electrical-engineering/30063/implementation-of-cascaded-h-bridge-control-scheme-for-sssc-using-zero-sequence-voltage-and-negative-sequence-current/m-subalakshmi
A Single Phase Eleven Level Cascaded H-Bridge Multilevel Inverter for Photovo...IJMER
Abstract: A Cascaded H-Bridge Multilevel Inverter is a power electronic converter built to synthesize a desired ac voltage
from several levels of dc voltages with better harmonic spectrum. Such inverters are suitable for high voltage and high
power applications and have been an important development in recent years. This paper presents the performance of a
eleven level cascaded H-Bridge multilevel inverter topology with multicarrier pulse width modulation technique for
photovoltaic cell. This inverter is capable of producing eleven levels of output voltage from the dc supply voltage. This
topology magnifies the fundamental output voltage with reduction in total harmonic distortion . The output is drawn near the
sine wave because of more levels. It can also be easily extended to an m-level inverter. The performance of the proposed
PWM strategy in terms of output voltage and THD is shown using MATLAB/Simulink.
Keywords: Multilevel inverter, Cascaded H-Bridge multilevel inverter, Multicarrier pulse width modulation, PV cell, Total
harmonic distortion.
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 proposes the use of Embedded EZ-source
inverter system (EZSI) as a single stage power conversion
concept for adjustable speed drives (ASD) in photovoltaic
applications. Open loop and closed loop control strategy of
EZSI system are proposed. EZSI produces the same voltage
gain as Z-source inverter (ZSI) but due to the DC sources
embedded within the X- shaped impedance network, it has
the added advantage of inherent source filtering capability
and also reduced capacitor sizing. This is attained without
any extra passive filters. By controlling the shoot-through
duty ratio and modulation index, EZSI system can produce
any desired AC output voltage even greater than DC rail
voltage and it also provides ride-through capability under
voltage sag. These advantages are more significant for
adjustable speed drive (ASD) applications in order to regulate
the speed. The operational analysis, control strategy and
simulation results exemplify that an EZSI is the most
promising technique for renewable energy applications in
order to reduce the overall system complexity and thereby
improving the inverter efficiency.
A DC Inrush Current Minimisation Method using Modified Z-Source Inverter in A...IAES-IJPEDS
The adjustable speed drives employ PWM converter-inverter system in order
to obtain unity power factor. The DC inrush current in DC link capacitors of
the rectifier limits the operation of power devices. Hence, this paper proposes
a new approach to reduce the DC inrush current by employing modified
Z-source inverter in a Adjustable Speed Drive system. The operating
principles, design procedure and simulation results are shown and compared
with the conventional Z-Source inverter.
Filter Based Solar Power Generation System with a Seven Level InverterIJMTST Journal
This paper proposes a new solar power generation system, which is composed of a DC/DC power converter and a new seven-level inverter. The DC/DC power converter integrates a DC-DC boost converter and a transformer to convert the output voltage of the solar cell array into two independent voltage sources with multiple relationships. This new seven-level inverter is configured using a capacitor selection circuit and a full-bridge power converter, connected in cascade. The capacitor selection circuit converts the two output voltage sources of DC-DC power converter into a three-level DC voltage and the full- bridge power converter further converts this three- level DC voltage into a seven-level AC voltage. In this way, the proposed solar power generation system generates a sinusoidal output current that is in phase with the utility voltage and is fed into the utility. The salient features of the proposed seven-level inverter are that only six power electronic switches are used and only one power electronic switch is switched at high frequency at any time. A prototype is developed and tested to verify the performance of this proposed solar power generation system.
In this paper, three different impedance source inverters: Z-source inverter, EZ- source inverter, TZ-Source for wind energy conversion system (WECS) were investigated. Total output power and THD of each of these systems are calculated. The proposed system can boost the output voltage effectively when the low output voltage of the generator is available at low wind speed. This system has higher performance, less components, increased efficiency and reduced cost. These features make the proposed TZSI based system suitable for the wind conversion systems. MATLAB simulink model for wind generator system is developed and simulation studies are successfully performed. The simulation is done using MATLAB and the simulation results are presented. This comparison shows that the TZ-source inverter is very promising for wind energy conversion system.
This paper addresses the approach to improve the efficiency of the quasi Z-source inverter. In order to increase the efficiency the reduction of conduction losses is one way to approach. Sequentially to decrease the conduction losses in the quasi z-source inverter the replacement of diode is replacing with switches is proposed which is also called as synchronous rectification. The paper represents basics of the approach, analysis and comparison of the power losses of the traditional and proposed designs of the grid connected PV-system with quasi z-source inverter system. The proposed approach validated on the computer simulations in the MATLAB environment.
Hysteresis SVM for Coupled Inductor Z Source Diode Clamped 3-Level Inverter B...IAES-IJPEDS
Due to its advantages such as it can defeat problems such as leakage current
and insertion of DC in the grid and provides low stress on power devices,
Diode-clamped three-level inverter (DCTLI) is habitually used in
transformerless photovoltaic (PV) connected to grid network. But it still has
a problem of shoot-through which dwells in its legs, so its operation not
reliable. Z source network is employed to permit operation without shoot
through risk and improve its reliability. Coupled inductors are replaced the
line transformers in to attain lower cost, reduced size, and improved its
reliability and efficiency. Coupled inductor which avoids leakage current
problem and losses. It employs coupled inductor z source diode clamped
three level inverter (CI-Z-DC-TLI) to boost the voltage and further progress
the consistency of the proposed system by avoiding the shoot through the
problem. The proposed system assures that common-mode voltage
and shoot-through risk is avoided. Moreover, controlling DC-TLI with
Hysteresis SVM algorithm which improves output voltage and current
control. Simulation and experimental results of this proposed system were
analyzed using MATLAB environment and FPGA hardware.
Proposed impedance network also has more degrees of freedom for varying its voltage gain, and hence, improving the versatility of the inverter. A switching algorithm is applied to this topology to control the charging time and discharging interval of inverter inductor. Methods/Statistical Analysis: On the basis of the conventional Z-source inverter[ZSI], this paper offer a novel on new type impedance source inverter which only contains one capacitor with tightly coupled three winding transformer, whose obtained voltage gain is presently not matched by existing networks operated at small duty ratio. The inverter can increase the boost factor through adjusting shoot-through duty ratio and varying the number of turns in the three winding transformer. Findings: The proposed impedance network also has more degrees of freedom for varying its voltage gain, and hence, improving the versatility of the inverter. A switching algorithm is applied to this topology to control the charging time and discharging interval of inverter inductor. A simple control strategy is applied to this configuration which is responsible for regulating the transfer power to the maximum amount and also to justify the amount of Total Harmonic Dissortion (THD) in minimum point. The working principle of the proposed Y-Source Inverter has been demonstrated by mathematical analysis in detail. The MATLAB/Simulink Simulation results are conducted to validate the
Digital Implementation of DSVPWM Control for EV fed through Impedance Source ...IAES-IJPEDS
In this paper, a new space vector modulation technique is proposed for speed
control of Induction Motor using Z-source inverter powered by a low voltage
DC source. The zero states of conventional space vector modulation are used
for boosting the DC-link voltage to the required level. The proposed SVM
technique estimates the required shoot through period of the Z-source
inverter to maintain the DC-link voltage constant at the desired level through
capacitor voltage control. A 32 bit DSP (TMS320F28335) is used to
implement the proposed space vector modulation method. The power
structure and the modulation technique is well suited for electric vehicle
application.
Simulation and Implementation of Quasi-Z-Source Based Single-stage Buck/boost...IJPEDS-IAES
Renewable power systems as distributed generation units often experience big changes in the inverter input voltage due to fluctuations of energy resources. Z-source inverter (ZSI) is known as a single-stage buck/boost inverter. The ZSI achieves voltage buck/boost in single stage, without additional switches. Triggering on state enables energy to be stored in inductors, which is released when at non-shoot-through state, followed by the voltage boost feature. The voltage-fed Z-source inverter/quasi-Z-source inverter (QZSI) has been presented suitable for photovoltaic (PV) applications mainly because of its single-stage buck and boost capability and the improved reliability.
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.
Comparative Evaluation of Three Phase Three Level Neutral Point Clamped Z-So...NAGARAJARAOS
The Z-impedance network coThree-level Z-source inverters are recent single-stage topological solutions
proposed for buck-boost energy conversion with all favorable advantages of
three-level switching retained. Despite their effectiveness in achieving voltage
buck-boost conversion, existing three-level Z-source inverters use two
impedance networks and two isolated dc sources, which can significantly
increase the overall system cost and require a more complex modulator for
balancing the network inductive voltage boosting. Offering a number of less
costly alternatives, this paper presents the design and control of two threelevel Z-source inverters, whose output voltage can be stepped down or up
using only a single impedance network connected between the dc input source
and either a neutral-point-clamped (NPC) or dc-link cascaded inverter
circuitry.
This paper investigates the carrier based modulation schemes (SPWM and
Modified SVPWM) of three-level three phase Z-source inverters with either
two Z-source networks or single Z-source network connected between the dc
sources and inverter circuitry. With the proper offset added for achieving both
optimized harmonic performance and fundamental output voltage, the
proposed modulation schemes of three-level Z-source inverters can satisfy the
expected boost operation under unbalanced modulation conditions. The
Simulation has been performed through Matlab/Simulink and relative
simulation results with conventional method have been presented to validate
the proposed methodnsists of L and C components connected in an X fashion.
The firing control of the Z-source inverter includes the shoot through states. The Zsource inverter advantageously utilizes the shoot-through state to boost the DC bus
voltage by gating on both the upper and lower switches of a phase leg. Three-level
neutral-point-clamped (NPC) inverters, having many inherent advantages, are
commonly used as the preferred topology for medium voltage ac drives [1], and have
recently been explored for other low-voltage applications including grid-interfacing
power converters and high-speed drive converters [2], [3]. Despite their generally
favorable output performance, NPC inverters are constrained by their ability to
perform only voltage-buck operation with buck-boost energy conversion, usually
achieved by connecting various dc-dc boost converters to the front ends of the dc-ac
inverters. These two-stage solutions are usually more costly and can be harder to
control, since they involve more active and passive components. Offering a singlestage solution, [4], [5] propose the buck-boost Z-source NPC inverter, whose
topology is illustrated in Fig. 1 (can be viewed as an extension from the two-level Zsource inverter proposed in [6]).
Proposed Method for Shoot-Through in Three Phase ZSI and Comparison of Differ...IAES-IJPEDS
This paper presented the new methodology for different control techniques applied to three phase Z-source inverter for minimisation of switching losses. The procedure for proposed control techniques and its effects on the performance of operation of three phase Z-source inverter are analyzed. The graphs for voltage gain and voltage stress are drawn for different control methods. The flow-chart for the symmetrical and unsymmetrical control techniques for creating pulse signals for switches of three phase inverter are shown. All the methods are studied and compared with each other. The Total harmonic distortion (THD) of output voltage of both the control methods has been analyzed using FFT analysis. The experiments done and the results shown for capacitor voltage, load current and load line voltage for simple boost and constant boost control techniques are presented using MATLAB/ Simulink.
PV Based Load Resonant for Boost Converter by Using Quasi Z-Source NetworkIJMTST Journal
In this paper a novel resonant dc-dc converter utilizing fell semi Z-source system is displayed. Diverse routine converters like arrangement thunderous converter and LLC resonant converters experiences extensive variety of info voltage and load varieties since exchanging recurrence was shifted. The proposed Z-source dc-dc converter can limit changing recurrence range to lead high converter productivity. The fell QZS system is gotten from conventional semi Z source inverter by including one diode, one inductor, and two capacitor to it. The fell QZSI works as venture up converter in typical mode i.e. yield voltage is expanded three circumstances than information voltage and for lift mode yield voltage is expanded ten circumstances input voltage. At the point when contrasted and customary QZSI proposed arrangement lessens shoot through obligation cycle by more than 30% at same voltage support figure. Two phase QZSI in shoot through and non-shoot through modes are portrayed hypothetically. This proposed framework is dependability is incredibly made strides. Its exhibitions are confirmed utilizing MATLAB\SIMULINK instrument to check hypothetical presumptions and equipment is actualized by utilizing sunlight based vitality as info.
Space Vector and Sinusoidal Pulse Width Modulation of Quasi Z-Source Inverter...IJPEDS-IAES
This paper compares the execution of Sinusoidal Pulse width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVM) methods for a Quasi Z-source inverter (QZSI) is an another topology got from the standard Z-source inverter (ZSI). The QZSI gets each one of the upsides of the ZSI, which can comprehend buck/boost, inversion and power forming in a singular stage with upgraded trustworthiness. In like manner, the proposed QZSI has the novel purposes of enthusiasm of lower part evaluations and unfaltering dc current from the source. The QZSI highlights a broad assortment of voltage expansion which is reasonable for applications in photovoltaic (PV), as a result of the way that the PV cells yield contrasts comprehensively with temperature and daylight based enlightenment. The working qualities of the proposed course of action is analyzed in inconspicuous component and appeared differently in relation to that of the SPWM and SVM. Speculative examination of voltage help and direction methods for the QZSI in PV is explored in this paper. Amusement of the circuit setup for the previously stated equalization procedures have been taken a gander at in MATLAB/Simulation. Besides, the THD examination of both SPVM and SVM is compared.
This paper proposes maximum boost control for 7-level z-source cascaded h-bridge inverter and their affiliation between voltage boost gain and modulation index. Z-source network avoids the usage of external dc-dc boost converter and improves output voltage with minimised harmonic content. Z-source network utilises distinctive LC impedance combination with 7-level cascaded inverter and it conquers the conventional voltage source inverter. The maximum boost controller furnishes voltage boost and maintain constant voltage stress across power switches, which provides better output voltage with variation of duty cycles. Single phase 7-level z-source cascaded inverter simulated using matlab/simulink.
New Hybrid Structure Based on Improved Switched Inductor Z-Source and Paralle...IJPEDS-IAES
Nowadays, more and more distributed generations and renewable energy
sources, such as wind, solar and tidal power, are connected to the public grid
by the means of power inverters. They often form microgrids before being
connected to the public grid. Due to the availability of high current power
electronic devices, it is inevitable to use several inverters in parallel for highpower
and/or low-cost applications. So, inverters should beconnected in
parallel to provide system redundancy and high reliability, which are
important for critical customers. In this paper, the modeling, designing and
stability analysis of parallel-connected three-phaseinverters are derived for
application in renewable energy systems. To enlarge voltage adjustability,
the proposed inverter employs an improved switched inductor Z-source
impedance network to couple the main circuit and the power source.
Compared with the classical Z-source inverter (ZSI) and switched inductor
Z-source inverter (SL-ZSI), the proposed inverter significantly increases the
voltage boost inversion ability and also can increase the power capacity and
the reliability of inverter systems. The proposed topology and its
performances are validated using simulation results which are obtained in
Matlab/Simulink.
IMPEDANCE SOURCE INVERTER TOPOLOGIES FOR PHOTOVOLTAIC APPLICATIONS – A REVIEWIAEME Publication
The impedance source inverters can step up the voltage and hence, they are greatly preferred for photovoltaic applications. There are many impedance and quasi impedance network topologies available. The key factor in selection of topology is the amount of voltage gain obtained along with the reduced number components. This paper compares some of the impedance and quasi - impedance source inverter (qZSI) topologies for photovoltaic applications namely, switched coupled inductor qZSI, switched ZSI, enhanced-boost quasi ZSI with continuous and discontinuous source current topologies, enhanced -boost active qZSI, switched-boost ZSI and high gain switched boost inverter. The parameters taken for comparison are voltage gain, boost factor, voltage, and current stresses on the components etc. Based on the comparison, the high gain switched boost ZSI is found to have high voltage gain along with reduced voltage and current stress. The review will be useful for researchers working in impedance source inverter network.
Analysis and simulation of even-level quasi-Z-source inverterIJECEIAES
This research proposes a seven-level inverter with quasi-Z-source boost converters. The proposed topology employs a packed U-cell asymmetrical type multilevel inverter along with front-end quasi-Z-source networks. The quasi networks provide high gain compared to a conventional boost converter. This topology is the most suitable for photovoltaic multi-string applications. The proposed topology has the potential to supply both the alternating current (AC) and direct current (DC) type load. The inverter structure has a lower number of active switches which helps in the reduction of losses and improvement in efficiency. In this paper, the operation principle of a quasi-network and inverter circuit are explained in detail. In addition, the simulation results for various modulation indices are presented. In the MATLAB/Simulink environment, the architecture is proposed by using gated sinusoidal “Pulse width modulation”.
Hybrid Two Quasi Z-Source Converter for Photovoltaic ApplicationPremier Publishers
This paper presents a Hybrid Two Quasi Z-source (HTQZS) DC-DC converter for photovoltaic applications. These are mainly employed to full fill the demand of the voltage boost in photovoltaic applications from the lower value voltage. The traditional z source networks have some limitations in voltage boosting, so the modified z source means the different combination of the LC components is combined to form the hybrid quasi z source networks. This hybrid two quasi z source dc-dc converters can be applied for the dc-ac, ac-ac, and ac-dc conversions. The structure of the proposed converter is simpler. This converter adds the benefits to the traditional z source converter. This converter draws the continuous input current. The converter simulated is the combination of two different quasi z source networks. This converter uses the duty cycle less than the traditional z source network and gives the more gain than that. PV panel used as source to converter and then the output is inverted and step up.
Similar to Comparison of Sine and Space Vector Modulated Embedded Z-Source Inverter fed Three Phase Induction Motor Drive System (20)
42 30 nA Comparative Study of Power Semiconductor Devices for Industrial PWM ...IAES-IJPEDS
The growing demand of energy translates into efficiency requirements of
energy conversion systems and electric drives. Both these systems are based
on Pulse Width Modulation (PWM) Inverter. In this paper we firstly present
the state of art of the main types of semiconductors devices for Industrial
PWM Inverter. In particular we examine the last generations of Silicon
Carbide (SiC) MOSFETs and Insulated Gate Bipolar Transistors (IGBTs)
and we present a comparison between these devices, obtained by SPICE
simulations, both for static characteristics at different temperatures and for
dynamic ones at different gate resistance, in order to identify the one which
makes the PWM inverter more efficient.
Modeling and State Feedback Controller Design of Tubular Linear Permanent Mag...IAES-IJPEDS
In this paper a state feedback controller for tubular linear permanent magnet
synchronous motor (TLPMSM) containing two gas springs, is presented.
The proposed TLPMSM controller is used to control reciprocating motions
of TLPMSM. The analytical plant model of TLPMSM is a multi-input
multi-output (MIMO) system which is decoupled to some sub single-input
single-output (SISO) systems, then, the sub SISO systems are converted to
sub-state space models. Indeed, the TLPMSM state space model is decoupled
to some sub-state spaces, and then, the gains of state feedback are calculated
by linear quadratic regulation (LQR) method for each sub-state space
separately. The controller decreases the distortions of the waveforms.
The simulation results indicate the validity of the controller.
Analysis of Harmonics and Ripple Current in Multi-Module Converters with Incr...IAES-IJPEDS
Controlled rectifiers are considered as the most important hardware part in
the field of HVDC systems in transmission lines and can be used for a
number of power electronics based system operation, control and utility
applications. In this paper, a brief design of a 12-pulse, 24-pulse, 36-pulse
and a 48-pulse converter connected to the grid is presented along with the
harmonic and ripple current analysis with its comparison statistics and thus
providing a justification for the suitable ones. The performance of the
12, 24, 36 and 48-pulse converters are compared for their effectiveness in
both quantitatively as well as qualitatively. Further, comparison of the
48-pulse converter on its THD and current ripple which is connected towards
the grid with simple pulse width modulation technique is also proposed. It
combines all features of the low switching concepts and DC current reinjection
techniques. Some basic topological explanation of the controlled
rectifiers and simulation results using MATLAB are also presented in this
paper in order to justify the harmonic analysis. The simulation results along
with the quantitative results shows the effectiveness of the proposed scheme
for the cancelation or the elimination of the harmonics result in maximum
harmonic mitigation, for high power utility applications, the 48-pulse
converter is most fitting to improve the conversion efficiency, low di/dt
and dv/dt and active and reactive power controllability.
Comparative Study of Various Adjustable Speed Drives during Voltage SagIAES-IJPEDS
This Paper compares the sensitivity of various adjustable speed drives to
voltage sag for the process control applications. Three phase voltage sag of
type B caused due to SLG fault is considered and four topologies of ASD’s
are compared in this paper. The comparison is done especially in speed,
voltage, current and torque of the ASDs. Diode rectifier without z source
inverter, diode rectifier with z source inverter, single phase two leg Vienna
rectifier and single phase neutral linked Vienna with z source inverter are
compared and the best one is highlighted. The circuits of various ASD’s are
simulated using Matlab /Simulink.
Modified Distribution Transformer for Enhancing Power Quality in Distribution...IAES-IJPEDS
The percentage of non-linear loads in the power distribution sector is increasing
day by day. Harmonics injected by these non-linear loads circulate in the delta
windings of the conventional distribution transformer thereby increasing the
temperature and losses. This reduces the efficiency and life of the transformers.
In a modified distribution transformer configuration proposed recently, called
star-star-delta_utilized configuration (YYD_utilized), the harmonics circulating
in the delta winding was utilized and the drainage power thus recovered was
used to power auxiliary loads. This paper presents the experimental studies
conducted on YYD_utilized distribution transformer. When compared to
conventional star-star, delta-star and star-star-delta transformers, the new
configuration of YYD_utilized transformer has shown considerable
improvement in transformer efficiency. The results obtained show that when
the power from the circulating harmonics is recovered and utilized, it not only
improves transformer efficiency but also improves the power factor
and reduces the harmonic distortions at the primary side of the transformer.
The results obtained also suggest the existence of maximum power point or an
optimum loading for the recovered harmonic power.
Modelling of Virtual Synchronous Converter for Grid-Inverter Synchronization ...IAES-IJPEDS
In this paper, virtual synchronous converter (VSCon) is been developed
which mimic the behavior of synchronous generator as in order to have fast
synchronization between the inverter with the grid. This synchronization is
important before can sent the power among inverter-grid connection. This
technique can also been applied at the distributed generated sources when are
connected to the local microgrids. Here, the frequency and voltage
synchronization also can be controlled at the same time some improvement
on synchronous generator mathematical model that is suitable to be
implemented into the inverter control. The whole unit of VSCon is operated
and simulated in Matlab/Simulink in order to observe all consequences
during synchronizing the voltage, frequency and phase-angle. It has been
verified by the simulation circuit where, the power converter can be
synchronized with the microrids without using a PLL unit for self
synchronization. This VSCon technique has proven that, by applying the
concept of the synchronous generator model in inverter control, it can cause
the inverter to behave as generator system, which does not required any
phase information from the grid in order to be synchronized.
Enhanced Crowbar Protection for Fault Ride through Capability of Wind Generat...IAES-IJPEDS
Due to increasing demand in power, the integration of renewable sources like
wind generation into power system is gaining much importance nowadays.
The heavy penetration of wind power into the power system leads to many
integration issues mainly due to the intermittent nature of the wind and the
desirability for variable speed operation of the generators. As the wind power
generation depends on the wind speed, its integration into the grid has
noticeable influence on the system stability and becomes an important issue
especially when a fault occurs on the grid. The protective disconnection of a
large amount of wind power during a fault will be an unacceptable
consequence and threatens the power system stability. With the increasing
use of wind turbines employing Doubly Fed Induction Generator (DFIG)
technology, it becomes a necessity to investigate their behavior during grid
faults and support them with fault ride through capability. This paper
presents the modeling and simulation of a doubly fed induction generator
according to grid code compatibility driven by a wind turbine connected to
the grid. This paper analyses the voltage sag due to a three-phase fault in the
wind connected grid. A control strategy including a crowbar circuit has been
developed in MATLAB/SIMULINK to bypass the rotor over currents during
grid fault to enhance the fault ride through capability and to maintain system
stability. Simulation results show the effectiveness of the proposed control
strategies in DFIG based grid connected wind turbine system.
An Improved of Multiple Harmonic Sources Identification in Distribution Syste...IAES-IJPEDS
This paper introduces an improved of multiple harmonic sources
identification that been produced by inverter loads in power system using
time-frequency distribution (TFD) analysis which is spectrogram.
The spectrogram is a very applicable method to represent signals in
time-frequency representation (TFR) and the main advantages
of spectrogram are the accuracy, speed of the algorithm and use low memory
size such that it can be computed rapidly. The identification of multiple
harmonic sources is based on the significant relationship of spectral
impedances which are the fundamental impedance (Z1) and harmonic
impedance (Zh) that extracted from TFR. To verify the accuracy of the
proposed method, MATLAB simulations carried out several unique cases
with different harmonic producing loads on IEEE 4-bus test feeder cases. It is
proven that the proposed method is superior with 100% correct identification
of multiple harmonic sources. It is envisioned that the method is very
accurate, fast and cost efficient to localize harmonic sources in distribution
system.
Performance and Energy Saving Analysis of Grid Connected Photovoltaic in West...IAES-IJPEDS
The paper presents performance and energy saving analysis of 1.25 kWp grid
connected photovoltaic system under difference weather condition in West
Sumatera. The measured data were performed during weather data that often
occur in West Sumatra i.e. sunny, overcast, raining and cloudy.
The synchronizing process successfully done even bad weather conditions
when sunlight was low automatically. Photovoltaic in average start
producing power from 7:00 AM to 6:00 PM for normal or clear sky, however
under overcast, raining and cloudy weather, the PV power decreased and
disconnected earlier before sunset. During intermittent raining, overcast and
cloud covered the PV power output show an irregular profile. The PV energy
saving performed for three residential connection cases: 1300 VA, 900 VA
with subsidized and 900 VA without subsidized. The solar PV installation
have more benefits and energy saving for 1300 VA, 900 VA without
subsidized with payback period around 8.5 years. However, the 900 VA with
subsidized take longer 20.8 years, but still in PV lifespan 25 years. In the
future, household subsidies may be reduced or eliminated, the solar energy
will be viable alternative of energy resources when it can produce electricity
at a cost equivalent to utility grid PLN rate.
An Improved Constant Voltage Based MPPT Technique for PMDC MotorIAES-IJPEDS
Stand-alone photovoltaic (SAPV) systems are being used in remote areas
and are being seen as one of the promising solution in this regard. The SAPV
system as presented in the paper consists of solar PV panel, a DC-DC
converter, a controller and a PMDC motor. The current-voltage and powervoltage
characteristics being nonlinear, the SAPV system require maximum
power point techniques (MPPT) control techniques to extract maximum
power available from the PV cell. A voltage based MPPT technique which is
capable of tracking MPP has been selected because of numerous advantages
it offers such as: simple and low cost of implementation. The limitation of
constant voltage method is that its efficiency is low as the PV panel has to be
disconnected from the load for measurement of the open circuit voltage
(Voc). In the presented paper, the authors have removed this limitation by
using a pilot PV panel for measurement of Voc. A proportional-integrator (PI)
based controller is used in implementation of constant voltage MPP
technique and the modeling is done in MATLAB®/SIMULINK simulation
environment. The simulation results are presented and discussed in the paper,
the results shows that the efficiency of the system has increased.
A Discrete PLL Based Load Frequency Control of FLC-Based PV-Wind Hybrid Power...IAES-IJPEDS
The sun and wind-based generation are considered to besource of green
power generation which can mitigate the power demand issues. As solar and
wind power advancements are entrenched and the infiltration of these
Renewable Energy Sources (RES) into to network is expanding dynamically.
So, as to outline a legitimate control and to harness power from RES the
learning of natural conditions for a specific area is fundamental. Fuzzy Logic
Controller (FLC) based Maximum Power Point Tracking (MPPT) controlled
boost converter are utilized for viable operation and to keep DC voltage
steady at desired level. The control scheme of the inverter is intended to keep
the load voltage and frequency of the AC supply at aconstant level regardless
of progress in natural conditions and burden. A Simulink model of the
proposed Hybrid system with the MPPT controlled Boost converters
and Voltage regulated Inverter for stand-alone application is developed in
MATLAB R2015a, Version 8.5.0. The ongoing information of Wind Speed
and Solar Irradiation levels are recorded at BITS-Pilani, Hyderabad Campus
the performance of the voltage regulated inverter under constant and varying
linearAC load is analyzed. The investigation shows that the magnitude of
load voltage and frequency of the load voltage is maintained at desired level
by the proposed inverter control logic.
An Adaptive Virtual Impedance Based Droop Control Scheme for Parallel Inverte...IAES-IJPEDS
This paper presents an adaptive virtual impedance based droop control
scheme for parallel inverter operation in low voltage microgrid. Because it is
essential to achieve power sharing between inverters in microgrid, various
droop control schemes have been proposed. In practice, the line impedance
between inverters and the point of common coupling (PCC) in microgrid are
not always equal. This imbalance in line impedance often results in a reactive
power mismatch among inverters. This problem has been solved by
introducing a virtual impedance loop in the conventional droop control
scheme. However, the reactive power sharing performance of this method is
still deteriorated when the line impedances change during operation. To
overcome such a problem, a new control scheme that is based on a virtual
impedance loop and an impedance estimation scheme is proposed.
To monitor the changes in line impedances, the impedance estimator is
implemented by using the output voltages and currents of inverters as well as
the voltages at the PCC. To compensate for the reactive power mismatch due
to the line impedance changes, the estimated line impedance is fed to the
virtual impedance loop in which it adjusts the virtual impedance value.
Comparative simulation results with the conventional ones verify the
effectiveness of the proposed adaptive virtual impedance based droop control
scheme.
Open-Switch Fault-Tolerant Control of Power Converters in a Grid-Connected Ph...IAES-IJPEDS
This paper presents the study of an open switch fault tolerant control of a
grid-connected photovoltaic system. The studied system is based on the
classical DC-DC boost converter and a bidirectional 6-pulse DC-AC
converter. The objective is to provide an open-switch fault detection method
and fault-tolerant control for both of boost converter and grid-side converter
(GSC) in a grid-connected photovoltaic system. A fast fault detection method
and a reliable fault-tolerant topology are required to ensure continuity of
service, and achieve a faster corrective maintenance. In this work, the mean
value of the error voltages is used as fault indicator for the GSC, while, for
the boost converter the inductor current form is used as fault indicator. The
fault-tolerant topology was achieved by adding one redundant switch to the
boost converter, and by adding one redundant leg to the GSC. The results of
the fault tolerant control are presented and discussed to validate the proposed
approach under different scenarios and different solar irradiances.
Photovoltaic System with SEPIC Converter Controlled by the Fuzzy LogicIAES-IJPEDS
In this work, a fuzzy logic controller is used to control the output voltage of a
photovoltaic system with a DC-DC converter; type Single Ended Primary
Inductor Converter (SEPIC). The system is designed for 210 W solar
photovoltaic (SCHOTT 210) panel and to feed an average demand of 78 W.
This system includes solar panels, SEPIC converter and fuzzy logic
controller. The SEPIC converter provides a constant DC bus voltage and its
duty cycle controlled by the fuzzy logic controller which is needed to
improve PV panel’s utilization efficiency. A fuzzy logic controller (FLC) is
also used to generate the PWM signal for the SEPIC converter.
An Approach to Voltage Quality Enhancement by Introduction of CWVM for Distri...IAES-IJPEDS
This paper presented with problems related with voltage flicker in power
system networks. Several international standard issued to control the voltage
flicker are briefly described and some important methods to analyse
electrical circuits with sinusoidal and non-sinusoidal waveforms are
introduced and evaluated. One of these methods-Cockcroft Walton Voltage
Multiplier (CWVM) has been used to increase the voltage of a filter, which is
also described in this paper as a practical application. The filter can
compensate for harmonic currents, power factor, and unbalance voltage.The
simulation results using Multisimare presented, showing that good dynamic
and steady-state response can be achieved with this approach.
Electric Power Converter with a Wide Input Voltage RangeIAES-IJPEDS
The electric power converter for downhole telemetry systems of oil-well
pumps include a downhole block connected to the pump that contains
electronic circuits required for the operation of the motor pump sensors
and transmission of data about their condition to the surface are described.
A few methods of electric power conversion for this purpose are considered.
The circuit contained two steps of voltage converting are proposed.
The electrical scheme of this method is considered in the article. Proposed
decisions are simulated and verified experimentally. The input high supply
voltage range (200-4200 V) without loss of efficiency (even temporary) was
obtained. The results of simulation and experimental studies have shown
very close results.
Design and Implementation of Real Time Charging Optimization for Hybrid Elect...IAES-IJPEDS
Electric vehicle (EV) has gained incredible interest from the past two decade
as one of the hopeful greenhouse gasses solution. The number of Electric
Vehicle (EV) is increasing around the world; hence that making EVs user
friendly becomes more important. The main challenge in usage of EV is the
charging time required for the batteries used in EV. As a consequence, this
subject matter has been researched in many credentials where a wide range
of solutions have been proposed. However those solutions are in nature due
to the complex hardware structure. To provide an unswerving journey
an Android application based charging optimization is proposed.
This application is aimed at giving relevant information about the EV’s
battery state of charge (SOC), accurate location of the EV, booking of the
charging slots using token system and route planner. At emergency
situations, an alternative service is provided by mobile charging stations.
Route planner indicates the temperature by which prediction of reaching the
destination can be done. In addition to that nearest places such as parks,
motels are indicated. The estimated time and distance between the electric
vehicle and the charging station is calculated by the charging station server
according to which the parking lot is allocated. Vehicle to charging station
communication is established for the time estimation of charging. This will
help the EV users to know about charge status and charging station, which
support fast charging method and availability of the station on the go
and also when to charge their EV. The Arduino UNO board has been used
for the hardware part. The hardware results are confirming the conceptual of
the proposed work.
Performance Analysis of Photovoltaic Induction Motor Drive for Agriculture Pu...IAES-IJPEDS
This paper presents water pumping system using renewable source (solar)
without the use of chemical storage batteries. In this converter-inverter
circuit is used to drive Induction motor. The Converter used here is Two
Inductor boost converter (TIBC), which consists of a resonant tank, voltage
doubler rectifier and a snubber circuit. TIBC is designed to drive the three
phase induction motor from PV energy. TIBC converter is also known as
current fed multi resonant converter having high voltage gain and low input
current ripple. Converter switches are controlled through hysteresis controller
and ZCS resonant topologies. Solar PV power fluctuates according to
irradiation level of sunlight and hence tracking of maximum power at all
time is mandatory. SPWM control with third harmonic injection is used to
trigger the IGBT’s in the inverter. The development is oriented to achieve a
more efficient, reliable, maintenance free and cheaper solution than the
standard ones, that uses DC motors or low voltage synchronous motors.
The proposed method is verified with MATLAB/SIMULINK and the system
simulation confirms the performance of the proposed system.
Single-Phase Multilevel Inverter with Simpler Basic Unit Cells for Photovolta...IAES-IJPEDS
This paper presents a single-phase multilevel inverter (MLI) with simpler
basic unit cells. The proposed MLI is able to operate in two modes, i.e.
charge mode to charge the batteries, and inverter mode to supply AC power
to load, and therefore, it is inherently suitable for photovoltaic (PV) power
generation applications. The proposed MLI requires lower number of power
MOSFETs and gate driver units, which will translate into higher cost saving
and better system reliability. The power MOSFETs in the basic unit cells
and H-bridge module are switched at near fundamental frequency, i.e. 100
Hz and 50 Hz, respectively, resulting in lower switching losses. For low total
harmonic distortion (THD) operation, a deep scanning method is employed
to calculate the switching angles of the MLI. The lowest THD obtained is
8.91% at modulation index of 0.82. The performance of the proposed MLI
(9-level) has been simulated and evaluated experimentally. The simulation
and experimental results are in good agreement and this confirms that the
proposed MLI is able to produce an AC output voltage with low THD.
Electric Power Converter with a Wide Input Voltage RangeIAES-IJPEDS
The electric power converter for downhole telemetry systems of oil-well
pumps include a downhole block connected to the pump that contains
electronic circuits required for the operation of the motor pump sensors
and transmission of data about their condition to the surface are described.
A few methods of electric power conversion for this purpose are considered.
The circuit contained two steps of voltage converting are proposed.
The electrical scheme of this method is considered in the article. Proposed
decisions are simulated and verified experimentally. The input high supply
voltage range (200-4200 V) without loss of efficiency (even temporary) was
obtained.The results of simulation and experimental studies have shown very
close results.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
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/
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.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
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.
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conversion. Various modulation strategies have been developed and applied to the Z-Source Inverter to
improve the voltage gain and reduce the harmonics [7]-[10]. Different topological developments of Z-Source
Inverter for various applications are discussed in [11]-[17]. Modeling, analysis and controlling of Z-Source
Inverter has been discussed in [18]-[20]. But the impedance network draws chopping current from the source.
This chopping current raises the semiconductor current rating and also complicates the maximum power
point tracking(MPPT).Second order LC filter can be placed before the diode D, to reduce high frequency
current ripple, but this increases the overall cost as well as resulting in dynamic and resonant problems. To
maintain smooth voltage/current across the DC source without adding the external LC filter, the new
topology of Z-source network named as Embedded Z-Source Inverter (EZSI) was proposed and analyzed in
[21]-[23]. The above literature does not deal with the comparison of sinusoidal PWM controlled EZSI fed
induction motor and space vector modulated EZSI fed induction motor.
2. OPERATING PRINCIPLE OF EMBEDDED EZ-SOURCE INVERTER
The two level voltage type EZ-source is shown in Figure 1 has its two dc sources each of Vdc/2 are
embedded within the X shaped LC impedance network. The impedance network is a symmetrical network it
is assumed that the value of inductances L1=L2=L and the value of capacitances C1=C2=C. The inductive
elements present in the network are used for filtering the current drawn from the two DC sources; this
eliminates the requirement of external LC filter and the size of the capacitor is also reduced [21]. As the
impedance network is added with the three phase inverter bridge circuit any two switches can be turned on
safely inorder to introduce the shoot-through or short circuit state.Since the current paths in DC frontend are
effectively limited by inductive element L1, L2 or by both.The inserted shoot-through exhibit the voltage
boosting capability, just like Z-Source inverter and can be proven with the gain expression derived from the
inverter-state equations during shoot-through and non-shoot-through states expressed by (1)-(4). The
non-shoot throuh state can represent any of its six traditional active states (i1 0) along with two null states
(i1=0) are solely determined by the modulation process.
Figure 1. Two level voltage type Three-phase Embedded Z-Source Inverter
EZSI has shoot-through zero state as in ZSI. The equivalent circuit of EZSI during shoot-through
state is shown in Figure 2 (a). The front-end diode D is reverse biased when the circuit is in its shoot-through
state. The equivalent circuit of EZSI for non shoot through state is shown in Figure 2 (b).
2.1. Active state
The inverter is operated in one of its six active states. The diode D is forward biased. The load and
the Inverter bridge is replaced by the current source as shown in Figure 2(b). (The switches Sx ≠ Sx‟, x = A,
B, or C; D = ON. For time interval T1)
⁄ (1)
(2)
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2.2. Nonshoot-Through zero state
Inverter bridge is operating in any one of its two nonshoot-through zero states. Inverter short circuits
the load through either upper or lower three switches. The bridge can be viewed as a open circuit. The input
DC voltage appears across the inductor and capacitor. But no inverter output current flows to the load.
During nonshoot-through zero state the switches Sx ≠ Sx‟, x = A, B, or C; D = ON.
⁄ (3)
(4)
2.3. Shoot-through zero state
Shoot through zero state is possible by seven different ways. Without disturbing the active states,
shoot-through state is allocated into each phase within total zero time. The front-end diode D is reverse
biased. The inverter is viewed as a short circuit from its DC link. There is no voltage across the load but the
capacitor voltage is boosted based on the shoot through duty ratio. (The switches Sx = Sx‟ = ON, x = A, B,
or C; D = OFF. For time interval (T0)
⁄ (5)
(6)
Averaging of voltage across the inductor over a switching period results in the following set of
equations for is the capacitive voltage, is the DC- link voltage, = = voltage across the front-end
diode, ̂ the peak DC- link voltage, ̂ peak ac output voltage are obtained.
⁄
⁄
(7)
̂
⁄
⁄
(8)
̂
̂
⁄
( ) (9)
In the above equations T0/T refers the shoot-through duty ratio (T0/T ˂ 0.5) per switching period. M
represents the modulation index and B is the boost factor, B=1/(1−2 T0/T). The boost factor B in the above
expression is due to the existence of shoot-through states in the switching sequence of the three phase
inverter switches.
Figure 2(a). Equivalent circuit of two-level EZ-
source inverter when in shoot-through state
Figure 2(b). Equivalent circuit of two-level EZ-
source inverter when in nonshoot-through state
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3. SINUSOIDAL PULSE WIDTH MODULATION
Many modulation techniques have been developed and applied to ZSI and the same can be applied
to EZSI also. In traditional sine PWM, three phase sinusoidal reference signal with 120 degree phase shift is
compared with the triangular carrier signal to generate the gating signals. When the magnitude of the
reference signal is greater than the carrier signal, the upper power switch in the respective phase is ON, the
reference signal is lesser than the carrier signal, and the power switch is OFF. The complement signals are
given to the lower switch of the same phase [9]. This is the maximum boost control method of sine PWM
controlled EZSI. In this method all the traditional non-shoot through zero states turned into shoot-through
zero states with six active states remains unchanged. The switching sequence for VSI is derived first, then the
shoot through states are allocated within the non-shoot through zero states without disturbing the active
states. Figure 3, shows the switching pulses along with shoot-through zero states. As all the non-shoot
through zero states are turned into shoot-through zero states maximum shoot-through time T0 and boost
factor B are obtained for any given modulation index M. The maximum boost control method introduces a
low frequency current ripple in inductor current and capacitor voltage [8]. In this method shoot-through zero
state repeats periodically in every n/3 degrees , with the assumptions that switching frequency is much higher
than the modulation frequency, the average duty ratio over one switching cycle can be expressed in [8] as
follows,
√
(10)
The Boost factor is given by
(11)
The relationship of modulation index and gain,
√
(12)
Then,
√
(13)
The voltage stress on the switch is,
√
√
(14)
4. SPACE VECTOR MODULATION (SVM)
SVPWM is an advance computation intensive PWM method most suitable modulation technique for
variable-frequency drive system. SVPWM technique provides higher inverter output voltage to the motor
with lower harmonic distortion. SVPWM is a different approach from PWM modulation based on space
vector representation of the voltage in the α-β plane. Space vector concept derived from the rotating magnetic
field of the induction motor is used to modulate the inverter output voltage. In SVPWM technique the three
phase quantities can be transformed into their equivalent two-phase quantity either in synchronously rotating
frames or stationary frame. The voltage vector is used as the reference vector; this gives the advantage of a
better overview of the system [10]. In this proposed SVPWM technique, switching sequence for VSI using
SVPWM have been generated and then shoot through states can be allocated within the non-shoot through
zero states without altering the active state of the switching sequence.
The three phase PWM VSI is shown in Figure 4, In traditional VSI the switching variables
a, a‟, b, b‟, c and c‟ controls the switching of the power switches S1 to S6. When the upper switch is ON i.e a,
b or c is 1, the corresponding lower switch is switched OFF i.e a‟, b‟, c‟ is zero. Therefore ON and OFF
states of the upper switches S1, S3 and S5 determines the output voltage. The eight possible switching states
are represented as vectors in SVPWM, (V1 to V6) are active vectors, V0 and V7 are two zero vectors applying
zero voltage across the load. The eight possible switching states for the PWM VSI, with six active states and
two zero states are given in Table 1.
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The relationship between the switching variable vector [a,b,c]t
,line-to-line output voltage
[Vab Vbc Vca]t
and the phase voltage vector [Va Vb Vc]t
are expressed.
[ ] =Vdc [ ] [ ] (15)
[ ] = 1/3 Vdc [ ] [ ] (16)
Figure 3. Sin PWM with shoot-through states Figure 4. Three phase Voltage Source Inverter
Table 1. Switching vectors, phase voltages and output line to line voltage
Voltage
Vectors
Switching
vectors
Line to Neutral Voltage Line to Line Voltage
A b c Va Vb Vc Vab Vbc Vca
V0 0 0 0 0 0 0 0 0 0
V1 1 0 0 2/3 -1/3 -1/3 1 0 -1
V2 1 1 0 1/3 1/3 -2/3 0 1 -1
V3 0 1 0 -1/3 2/3 -1/3 -1 1 0
V4 0 1 1 -2/3 1/3 1/3 -1 0 1
V5 0 0 1 -1/3 -1/3 2/3 0 -1 1
V6 1 0 1 1/3 -2/3 1/3 1 -1 0
V7 1 1 1 0 0 0 0 0 0
4.1. Device On/Off States and Corresponding Outputs of a Three Phase VSI
The vector representation of the phase voltages corresponding to the eight combinations can be
obtained by applying α-β transformation to the phase voltage. This transformation is equivalent to an
orthogonal projection of [a b c]t
onto the two dimensional plane perpendicular to the vector [1 1 1]t
in a three
dimensional co-ordinate system which results in six non-zero vectors (V1-V7) and two zero vectors
(V0 and V7). The non-zero vectors forms the axes of a hexagonal. The angle between any two adjacent non-
zero vector is 60 degrees. The zero vectors are at the origin and apply zero voltage to a three phase load. The
eight vectors are called basic space vectors and are shown in Figure 5. The reference voltage vector in αβ-
plane is shown in Figure 6. This is a two-dimensional plane transformed into a three-dimensional plane,
containing vectors of three phase voltages.
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Figure 5. Space Voltage Vectors in Different Sectors Figure 6. Reference Vector in the Two and Three
Dimensional Plane
The ON and OFF state of the switches are determined by the location of the reference vector on the
αβ-plane. The relationship between these two frames is given,
fαβ0 = ksfabc (17)
where ks is,
[ √ √ ] (18)
Here f denotes either a voltage variable or a current variable. The objective of the SVPWM technique is to
approximate the reference voltage Vref instantaneously by combination of the switching states corresponding
to the basic space vectors. The magnitude and angle of the reference voltage vector can be calculated using
clerk‟s transformation.
Vref = Vα+jVβ = (19)
Where „a‟ is given by ⁄
The magnitude of |Vref| =√
Angle θ = ( ⁄ )
Vα = ( ) (20)
Vβ = (
√ √
) (21)
The next step is to calculate the duration time for each vector V1–V6. The switching time duration at any
sector can be obtained as follows,
jβ
α
010
(V3)
110
(V2)
011 (V4) 111 (V7) 000(V0) 100(V1)
001 (V5) 101 (V6)
Vref
jβ
α
Vβ Vref
Vα
a
c
b
Ɵ
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√
(22)
√
(23)
T0 = – T1 – T2 (0 ≤ 0≤ 600
) (24)
Where, n=1 through 6 (i.e., sector 1 to 6) and D0= T0 / Ts Shoot through duty ratio
D0 =
√
Boost factor (B), can be found as,
√
(25)
Similarly, the voltage gain can be found as;
̂
√
(26)
The voltage stress across the devices can be;
VS =
√
(27)
The switching pattern is obtained with SVM technique then shoot-through states (ST) are allocated into each
phase. This is shown in Figure 7.
5. SIMULATION RESULTS
The simulation circuit of sine PWM controlled two level voltage type Embedded Z-Source Inverter
fed three phase Induction Motor drive is shown in Figure 8, two similar PV-source each of delivering
Vdc/2= 24 volts are used as a DC source of EZ-network. Simulation circuit for EZSI fed three phase induction
motor is modeled and simulated using MATLAB/SIMULINK. The simulation is carried out with
L1=L2=20mH, C1=C2=2200 . The solar output voltage of Vdc/2=24 volts is applied to EZS network.
The boosted output voltage of Embedded Z-Source network with the duty ratio T0/T = 0.25 is 96 volts shown
in Figure 9. The shoot-through states are allocated in the switching sequence and the switching pulses
generated for the switches. The three phase output voltages are shown in Figure 10. The speed of the motor
increase with an increase in voltage and settles at 1000 RPM, is shown in Figure 11. The FFT analysis of the
inverter output voltage is done with MATLAB and the Total Harmonic Distortion (THD) 6.01% is measured.
The Harmonic Spectra is shown in Figure 12. From the above analysis, the boost factor is given by,
,
The DC link voltage is given by,
The DC ̂
⁄
⁄
The output peak phase voltage from the inverter can be expressed as
̂
̂
⁄
( ) ,
With the modulation index M=0.8, ̂
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Figure 7. Space Vector modulated switching pulses with shoot-through state
Figure 8. Simulation circuit of Sinusoidal pulse width modulated three phase induction motor drive
Figure 9. Output voltage of Embedded Z-Source Figure 10.Output phase voltages of three phase
EZSI
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Figure 11. Motor Speed Figure 12. Harmonic Spectrum
5.1. SVM Controlled Induction Motor Drive
The simulation circuit for space vector modulated EZSI fed three phase induction drive is shown in
Figure 13. The sine PWM generation block is replaced by SVM block. The solar output voltage of Vdc/2= 24
volts is shown in Figure 14. The boosted output voltage of EZ-NETWORK with the duty ratio T0/T= 0.3
shown in Figure 15, and its value is 120 volts. The three phase voltages are shown in Figure 16. The speed of
the three phase induction motor is shown in Figure 17 the speed gradually increases with an increase in
voltage at the time of starting and settles at 1200rpm. FFT analysis is done for the inverter output voltage
using MATLAB and the measured THD for space vector modulated voltage is 3.87%, Harmonic spectrum is
shown in Figure 18.
Figure 13. Simulation circuit for SVM EZSI fed three phase induction motor drive
The boost factor is given by,
,
The DC link voltage is given by
̂
⁄
⁄
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The output peak phase voltage from the inverter can be expressed as
̂
̂
⁄
( ) ,
With the modulation index M=0.8, ̂
Figure 14. Solar output voltage Figure 15. Output voltage of EZS network
Figure 16. Output phase voltages of three phase EZSI Figure 17. Motor Speed
Figure 18. Harmonic Spectrum
Table 2. Comparison of Sine PWM EZSI and SVW EZSI fed induction motor drive
PARAMETERS Sine PWM SVM
Input Voltage(V) 24 24
EZ-Output Voltage(V) 96 120
Speed(RPM) 1000 1200
THD% 6.01 3.87
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6. CONCLUSION
PV powered Embedded Z-Source Inverter fed three phase Induction motor drive is modeled
and simulated successfully with Sine PWM and SVM methods. FFT analysis was done and the details of
THD are presented. The simulation results indicate that the harmonic content with SVM is less than that of
Sine PWM controlled inverter fed Induction Motor Drive. For the same input voltage of 48 volts SVM
provides increased output voltage with increase in speed. The comparison results are presented in Table 2.
The drawbacks of this drive system are that it requires two similar PV-sources which increases the initial cost
of total drive system.The closed loop controlled induction motor system will be investigated in future.
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12. ISSN: 2088-8694
IJPEDS Vol. 7, No. 4, December 2016 : 1240 – 1251
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BIOGRAPHIES OF AUTHORS
Mrs. R. Malathi, born in Cuddalore, Tamilnadu, India, on July 10, 1974. She graduated from
Annamalai University under Electrical and Electronics Engineering in the year 1995. She
obtained her post graduation in Power Electronics & Industrial Drives from the Sathyabama
University in the year 2005. She has put around 18 years of experience in teaching Electrical
Engineering. Her areas of interest are Power Electronics, Electric Drives and Renewable energy
System. Presently she is working as Associate Professor in the Department of Electrical and
Electronics Engineering SCSVMV University, Enathur, Kanchipuram, Tamilnadu, India.
Dr. M. Rathinakumar, born in Madurai, Tamilnadu, India, on July 19, 1969. He graduated from
Thiyagarajar College of Engineering, affiliated to Madurai Kamaraj University under Electrical
and Electronics Engineering in the year 1993. He obtained his post graduation in Power Systems
from the same University in the year 1995.
He obtained his Ph.D from SCSVMV University, Enathur, Kanchipuram, Tamilnadu, India in
the year 2010. He has put around 20 years of experience in teaching Electrical Engineering. His
areas of interest are Power systems, Power Quality, Power System Operation and Control.
Presently he is working as Professor and Head in the Department of Electrical and Electronics
Engineering SCSVMV University, Enathur, Kanchipuram, Tamilnadu, India.