This document presents research on using a genetic algorithm to optimize switching angles in multilevel inverters in order to reduce total harmonic distortion. Specifically:
1) A genetic algorithm is developed and used to determine optimal switching angles for 7-level and 9-level cascaded inverters to eliminate low order harmonics and minimize total harmonic distortion, without needing to solve nonlinear equations.
2) Simulation results show the genetic algorithm approach produces switching angles that generate voltage waveforms with very low 5th, 7th, and 11th harmonics for the 9-level inverter and low 5th and 7th harmonics for the 7-level inverter.
3) The 9-level inverter achieves
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.
THD Minimisation for Phase Voltage of Multilevel Inverters Using Genetic Algo...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Correlative Study on the Modeling and Control of Boost Converter using Advanc...IJSRD
DC-DC converters are switched power converters. The converters are most widely used in research and industrial applications. The DC-DC Boost Converters are used to step-up the supply voltage given to the plant model. The main advantage of using the Boost Converters is that it works in the low voltage according to the design specifications. In order to regulate the uncontrolled supply of voltage, a controller has to be designed and modeled to stabilize the output voltage. Since the convectional controllers cannot work under dynamic operating conditions, advanced controllers are to be designed to overcome the problems. In this article, the advanced controllers such as NARMA-L2, Fuzzy Logic (FLC) and Sliding Mode Controllers (SMC) are implemented and their responses are compared using MATLAB.
Fuzzybased Transformerless Single-Phase Universal Apf for Harmonic and Reacti...IRJET Journal
This document presents a fuzzy logic controller-based universal active power filter (UAPF) for single-phase systems that compensates for harmonics and reactive power without using a transformer. The proposed UAPF configuration combines parallel and series active filters. It reduces lower order harmonics and total harmonic distortion. A mathematical model of the system is derived and it is shown that circulating current must be controlled. Simulation results using MATLAB/Simulink show that the proposed transformerless topology achieves harmonic compensation performance comparable to the conventional transformer-based configuration.
Performing of the MPPSO Optimization Algorithm to Minimize Line Voltage THD o...IOSR Journals
This document presents a novel optimization algorithm called Multi Population Particle Swarm Optimization (MPPSO) to minimize the Total Harmonic Distortion (THD) of the output line voltage of a 3-level inverter. MPPSO is used to optimize a new precise formula for line voltage THD derived for a 3-level inverter. The MPPSO algorithm combines the advantages of fundamental frequency harmonic minimization and swarm intelligence to improve output voltage quality. Simulation results in MATLAB validate that the proposed MPPSO method can effectively minimize line voltage THD.
Comparison of PWM Techniques and Selective Harmonic Elimination for 3-Level I...IJERA Editor
In this paper comparison of Selective Harmonic Elimination (SHE) method with different Pulse Width
Modulation (PWM) technique which are used as gate pulse for firing the IGBT‟s. Higher order harmonics are
easily eliminated by selecting a proper tuned value filters but lower order harmonics such as 3rd, 5th, 7th, and
9th are not easily eliminated. This paper includes Newton- Rapson method with random initial guess is used for
SHE reduction and shows where the solution can exit by solving transcendental non linear equations. With the
use of this method lower order harmonics as well as Total Harmonic Distortion (THD) will get reduce. In this
paper a cascaded H-bridge Multilevel Inverter using MATLAB/Simulink blocks is presented.
OPTIMAL TORQUE RIPPLE CONTROL OF ASYNCHRONOUS DRIVE USING INTELLIGENT CONTROL...elelijjournal
This document summarizes a research paper on optimizing torque ripple in an asynchronous drive using intelligent controllers. It describes using a hybrid controller combining PI and fuzzy logic control with direct torque control and space vector modulation of a three-level cascaded inverter to power an induction motor drive. Simulation results showed the hybrid controller approach minimized torque ripple compared to using just PI or fuzzy logic control alone under no-load and loaded conditions. The optimized torque control method provides benefits for general purpose induction motor applications.
A novel optimization harmonic elimination technique for cascaded multilevel i...journalBEEI
This document presents a novel optimization harmonic elimination technique (OHET) for cascaded multilevel inverters. The technique aims to minimize total harmonic distortion (THD) in the output voltage waveform. It utilizes selective harmonic elimination (SHE) to calculate switching angles that eliminate specific low-order odd harmonics. Modulation index and duty cycle are varied to further optimize the solution. Simulation results for a seven-level cascaded inverter show that OHET can reduce THD from 11.49% to 10.43% by adjusting the duty cycle and delaying the switching angles. The technique provides a two-step approach to further mitigate harmonics beyond conventional SHE.
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.
THD Minimisation for Phase Voltage of Multilevel Inverters Using Genetic Algo...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Correlative Study on the Modeling and Control of Boost Converter using Advanc...IJSRD
DC-DC converters are switched power converters. The converters are most widely used in research and industrial applications. The DC-DC Boost Converters are used to step-up the supply voltage given to the plant model. The main advantage of using the Boost Converters is that it works in the low voltage according to the design specifications. In order to regulate the uncontrolled supply of voltage, a controller has to be designed and modeled to stabilize the output voltage. Since the convectional controllers cannot work under dynamic operating conditions, advanced controllers are to be designed to overcome the problems. In this article, the advanced controllers such as NARMA-L2, Fuzzy Logic (FLC) and Sliding Mode Controllers (SMC) are implemented and their responses are compared using MATLAB.
Fuzzybased Transformerless Single-Phase Universal Apf for Harmonic and Reacti...IRJET Journal
This document presents a fuzzy logic controller-based universal active power filter (UAPF) for single-phase systems that compensates for harmonics and reactive power without using a transformer. The proposed UAPF configuration combines parallel and series active filters. It reduces lower order harmonics and total harmonic distortion. A mathematical model of the system is derived and it is shown that circulating current must be controlled. Simulation results using MATLAB/Simulink show that the proposed transformerless topology achieves harmonic compensation performance comparable to the conventional transformer-based configuration.
Performing of the MPPSO Optimization Algorithm to Minimize Line Voltage THD o...IOSR Journals
This document presents a novel optimization algorithm called Multi Population Particle Swarm Optimization (MPPSO) to minimize the Total Harmonic Distortion (THD) of the output line voltage of a 3-level inverter. MPPSO is used to optimize a new precise formula for line voltage THD derived for a 3-level inverter. The MPPSO algorithm combines the advantages of fundamental frequency harmonic minimization and swarm intelligence to improve output voltage quality. Simulation results in MATLAB validate that the proposed MPPSO method can effectively minimize line voltage THD.
Comparison of PWM Techniques and Selective Harmonic Elimination for 3-Level I...IJERA Editor
In this paper comparison of Selective Harmonic Elimination (SHE) method with different Pulse Width
Modulation (PWM) technique which are used as gate pulse for firing the IGBT‟s. Higher order harmonics are
easily eliminated by selecting a proper tuned value filters but lower order harmonics such as 3rd, 5th, 7th, and
9th are not easily eliminated. This paper includes Newton- Rapson method with random initial guess is used for
SHE reduction and shows where the solution can exit by solving transcendental non linear equations. With the
use of this method lower order harmonics as well as Total Harmonic Distortion (THD) will get reduce. In this
paper a cascaded H-bridge Multilevel Inverter using MATLAB/Simulink blocks is presented.
OPTIMAL TORQUE RIPPLE CONTROL OF ASYNCHRONOUS DRIVE USING INTELLIGENT CONTROL...elelijjournal
This document summarizes a research paper on optimizing torque ripple in an asynchronous drive using intelligent controllers. It describes using a hybrid controller combining PI and fuzzy logic control with direct torque control and space vector modulation of a three-level cascaded inverter to power an induction motor drive. Simulation results showed the hybrid controller approach minimized torque ripple compared to using just PI or fuzzy logic control alone under no-load and loaded conditions. The optimized torque control method provides benefits for general purpose induction motor applications.
A novel optimization harmonic elimination technique for cascaded multilevel i...journalBEEI
This document presents a novel optimization harmonic elimination technique (OHET) for cascaded multilevel inverters. The technique aims to minimize total harmonic distortion (THD) in the output voltage waveform. It utilizes selective harmonic elimination (SHE) to calculate switching angles that eliminate specific low-order odd harmonics. Modulation index and duty cycle are varied to further optimize the solution. Simulation results for a seven-level cascaded inverter show that OHET can reduce THD from 11.49% to 10.43% by adjusting the duty cycle and delaying the switching angles. The technique provides a two-step approach to further mitigate harmonics beyond conventional SHE.
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.
Control of inverters to support bidirectional power flow in grid connected sy...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Hysteresis Current Control Based Shunt Active Power Filter for Six Pulse Ac/D...IJERA Editor
This document summarizes a research paper on a hysteresis current control based shunt active power filter for a six pulse AC/DC converter. It describes using p-q theory and a PI controller to calculate reference currents for the shunt active power filter to compensate harmonic currents drawn by a three phase six pulse AC/DC converter. Simulation results show the filter is effective at reducing total harmonic distortion at the source from over 23% to under 2.4% transiently and 1.1% steadily, meeting IEEE standards. The shunt active power filter configuration, hysteresis current control approach, and simulation results validating the compensation of harmonics are summarized.
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.
Implementation of Fan6982 Single Phase Apfc with Analog ControllerIJRESJOURNAL
This document summarizes the implementation of a single-phase active power factor correction (APFC) circuit using the FAN6982 analog controller chip. It describes the basic principle of the single-stage boost APFC circuit and double closed-loop voltage and current control. It proposes a new duty cycle compensation method based on voltage loop dynamic compensation. Simulation results show the input current tracks the voltage waveform well with power factor of 0.99 and total harmonic distortion of 5.42%. Experimental results for a 500W circuit show an efficiency of 96.25%, power factor of 0.99, and total harmonic distortion of 10.74%, demonstrating effective power factor correction.
The document summarizes a study on using Clarke's transform and fuzzy logic for power transformer differential protection. It proposes a new algorithm to improve on traditional percentage differential protection. The methodology section describes using Clarke's transform to calculate differential currents as inputs to a fuzzy system. The fuzzy system classifies conditions as internal fault, external fault, or normal. Simulation results on 690 cases showed the proposed algorithm had faster operation and fewer misoperations than a commercial relay. It was able to correctly discriminate all fault and operating conditions. The conclusions state the new algorithm improves protection coverage and performance while maintaining simplicity for commercial applications.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
A Novel Optimal PI Parameter Tuning Strategy to Improve Constant Switching Pe...IJPEDS-IAES
This paper presents a novel method of optimal Propotional-Intergral (PI)
controller’s parameter tuning strategy in-order to improve the constant
switching performance of 3-phase direct torque control (DTC) shceme. The
DTC sheme is acknowledged to provide fast decoupled control over the
torque output and stator flux via a simple control structure. However, DTC
sheme has two major downsides, which are the inconsistent inverter
switching frequency and high torque output ripple. The main reason that
contributes to these tribulations is the usage of hysteresis comparators in
order to control the output torque. The realization of PI based controller
method as replacement of hyterisis controller in DTC system able to provide
significant solutions to over come the fall back while retaining the simple
control structure of conventional DTC. The combination usage of higher
sampling controller DS1004 and also 3-level cascaded H-bridge multilevel
inverters (CHMI) in this system can further minimize the output torque ripple
by providing higher resolution with lower digital error and greater number of
vectors. This paper presents detail explanation and calculation of optimal PI
parameter tuning strategy consecutively to enhance the performance of 3-
level DTC system. In order to verify the feasibility of the proposed method
experimentation, the proposed method is compared with convention DTC
system via simulation and experiment results.
Power System Modeling and Simulation lab manualDHEERAJ DHAKAR
This document summarizes an experiment simulating a swing equation in Simulink. It involves:
1) Simulating the swing equation for a generator connected to an infinite bus through parallel lines, with a fault on one line.
2) Plotting the swing curve for a sustained fault and when the fault is cleared after 0.1 seconds.
3) Calculating the critical clearing angle as 57 degrees.
This document compares three switching methods for an asymmetric cascaded H-bridge multilevel inverter: selective harmonic elimination (SHE), nearest level control (NLC), and multi-carrier pulse width modulation (PWM). SHE and NLC aim to minimize total harmonic distortion but are offline methods not suitable for closed-loop systems. Multi-carrier PWM provides appropriate harmonic performance while being an online method. Equations are presented for generating PWM signals to control the switches in each cell based on multiple carrier waves to synthesize a high number of voltage levels from asymmetric DC input voltages. Simulation results show multi-carrier PWM has advantages over SHE and NLC for use in an asymmetric multilevel inverter system.
This document compares symmetrical and asymmetrical cascaded current source multilevel inverters. It discusses their structures, operational characteristics, advantages, and simulation results. Symmetrical multilevel inverters have equal current sources, while asymmetrical have unequal sources in a geometric progression. For the same number of components, asymmetrical inverters can produce more output levels and higher voltages with lower total harmonic distortion. Simulation results show the output waveform and THD for different configurations, confirming asymmetrical inverters have better performance.
Comparison of symmetrical and asymmetrical cascaded current source multilevel...eSAT Journals
Abstract This paper presents symmetrical and asymmetrical cascaded multilevel inverter approach for high power output applications. It is based on the cascade connection of the H-bridge inverter cells. Comparison of symmetrical and asymmetrical current source multi level inverter is shown using 2 H-bridge inverter cells with cascade connection. Now ever by the supplies which are in GP with different ratios like 2,3,etc. Structural and operational characteristics are discussed and their inherent advantages are shown. Simulation using Matlab Simulink is done to verify the performance. Simulation and results for this proposed scheme are presented in this paper. Index Terms: Asymmetrical cascaded multilevel inverter, Current source multi level inverter, MATLAB Simulink, Optimization angle control, Symmetrical multi level inverter, Total harmonic distortion (THD).
This document presents research on a cascaded nine-level inverter using pulse width modulation (PWM) and hybrid PWM techniques. It describes the topology and operation of a cascaded multilevel inverter using H-bridge cells. Phase shifted PWM and a hybrid modulation strategy are analyzed for controlling the inverter. Simulation results show the line voltage, phase voltage, and load current waveforms for both modulation methods. Total harmonic distortion is calculated, showing 17.44% for phase shifted PWM and 9.92% for hybrid PWM modulation. The hybrid method achieves lower distortion by operating higher voltage cells at lower switching frequencies.
In the proposed approach,instead of a conventional 3- Phase inverter a component minimized single pha se inverter is utilized which reduces the cost of the inverter,th e switching losses,and the complexity of interface circuits to generate logic signals. A performance comparison of the prop osed inverter fed drive with a conventional 3Phase inverter fed drive is also mode in terms of speed response and t otal harmonic distortion (THD) of the stator curren t. The proposed inverter fed IM drive is found acceptable consideri ng its cost reduction and other advantageous featur es. A general pulse width modulation (PWM) method for c ontrol of 1-phase inverters is presented. The vecto r PWM offers a simple method to select three or four vectors tha t effectively synthesize the desired output voltage,even in presence of voltage oscillations across the two dc-link capacit ors. The influence of different switching patterns on output voltage symmetry,current waveform,switching frequency and common mode voltage can be examined. The paper als o discusses how the use of the wye and delta connecti ons of the motor windings affects the implementatio n of the pulse width modulator.
Design and Experimental Verification of Linear Switched Reluctance Motor with...IAES-IJPEDS
This paper presents the realization and design of a linear switched reluctance motor (LSRM) with a new stator structure. One of the setbacks in the LSRM family is the presence of high force ripple leads to vibration and acoustic noise. The proposed structure provides a smooth force profile with reduced force ripple. Finite element analysis (FEA) is used to predict the force and other relevant parameters.A frequency spectrum analysis of the force profile using the fast Fourier transform (FFT) is presented.The FEA and experimental results of this paper prove that LSRMs are one of the strong candidates for linear propulsion drives.
This paper presents simplified control strategy of Space Vector Pulse Width Modulation method including over modulation region with linear transfer characteristic for cascaded H-bridge inverters. Because of large number of switching states of the cascaded H- Bridge inverter, the over modulation operation is very complex. And also requires incorporation of both under modulation and over modulation algorithms. The proposed control method is effective in terms of selecting the optimal switching states with reduced computational complexity using simplified linear calculations which makes it easier for digital implementation. The performance of the proposed method is simulated and tested experimentally through Spartan 3A FPGA processor for five level Cascaded H-bridge Inverter. The simulation results and harmonic analysis of voltage and current at various modulation indexes as are presented which are in well agreement.
International Refereed Journal of Engineering and Science (IRJES)irjes
a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications.
Comparative Analysis of PWM Techniques for Three Level Diode Clamped Voltage ...IAES-IJPEDS
Multilevel inverters are increasingly being used in high-power medium voltage industrial drive applications due to their superior performance compared to conventional two-level inverters. Thre are a number of Pulse width modulation (PWM) techniques applied in recent years. The most widely applied PWM techniques are Sine Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM). SPWM is the most simple modulation technique that can realize easily in analog circuit. However, it has some drawbacks such as higher total harmonic distortion (THD), lower effective DC utilization and lower switching frequency. Space vector pulse width modulation (SVPWM) is widely used because of their easier digital realization and better DC bus utilization and lower THD. The complexity is due to the difficulty in determining the reference vector location, on times calculation, and switching states selection. This paper presents a simple SVPWM algorithm for diode clamped three level inverters based on standard two-level SVPWM which can easily determine the location of reference vector, calculate the on-times, the selection of switching states. Three level diode clamped inverter (3LDCI) using space vector modulation technique has been modeled and simulated using MATLAB/SIMULINK and Origin 6.1 with a passive R-L load that can be extended to any level. Simulation results are presented to verify the proposed SVPWM control in terms of THD. The results arecompared with conventional sinusoidal pulse width modulation (SPWM) where SVPWM shows better performance than SPWM in terms of THD.
This document describes simulations carried out on Distributed Power-Flow Controller (DPFC) technology. Key points:
- DPFC is derived from Unified Power Flow Controller (UPFC) but eliminates the common DC link between shunt and series converters. Active power is exchanged through the transmission line using third-harmonic frequency components.
- DPFC has advantages over UPFC of lower cost due to lower component ratings/isolation for series converter, and higher reliability due to redundancy of series converters.
- Detailed simulations were performed on a two-machine system to illustrate DPFC's control features and ability to increase power transfer capability and improve system reliability compared to conventional systems. Laboratory tests validated the DPFC operating principle and
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.
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.
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.
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.
Control of inverters to support bidirectional power flow in grid connected sy...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Hysteresis Current Control Based Shunt Active Power Filter for Six Pulse Ac/D...IJERA Editor
This document summarizes a research paper on a hysteresis current control based shunt active power filter for a six pulse AC/DC converter. It describes using p-q theory and a PI controller to calculate reference currents for the shunt active power filter to compensate harmonic currents drawn by a three phase six pulse AC/DC converter. Simulation results show the filter is effective at reducing total harmonic distortion at the source from over 23% to under 2.4% transiently and 1.1% steadily, meeting IEEE standards. The shunt active power filter configuration, hysteresis current control approach, and simulation results validating the compensation of harmonics are summarized.
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.
Implementation of Fan6982 Single Phase Apfc with Analog ControllerIJRESJOURNAL
This document summarizes the implementation of a single-phase active power factor correction (APFC) circuit using the FAN6982 analog controller chip. It describes the basic principle of the single-stage boost APFC circuit and double closed-loop voltage and current control. It proposes a new duty cycle compensation method based on voltage loop dynamic compensation. Simulation results show the input current tracks the voltage waveform well with power factor of 0.99 and total harmonic distortion of 5.42%. Experimental results for a 500W circuit show an efficiency of 96.25%, power factor of 0.99, and total harmonic distortion of 10.74%, demonstrating effective power factor correction.
The document summarizes a study on using Clarke's transform and fuzzy logic for power transformer differential protection. It proposes a new algorithm to improve on traditional percentage differential protection. The methodology section describes using Clarke's transform to calculate differential currents as inputs to a fuzzy system. The fuzzy system classifies conditions as internal fault, external fault, or normal. Simulation results on 690 cases showed the proposed algorithm had faster operation and fewer misoperations than a commercial relay. It was able to correctly discriminate all fault and operating conditions. The conclusions state the new algorithm improves protection coverage and performance while maintaining simplicity for commercial applications.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
A Novel Optimal PI Parameter Tuning Strategy to Improve Constant Switching Pe...IJPEDS-IAES
This paper presents a novel method of optimal Propotional-Intergral (PI)
controller’s parameter tuning strategy in-order to improve the constant
switching performance of 3-phase direct torque control (DTC) shceme. The
DTC sheme is acknowledged to provide fast decoupled control over the
torque output and stator flux via a simple control structure. However, DTC
sheme has two major downsides, which are the inconsistent inverter
switching frequency and high torque output ripple. The main reason that
contributes to these tribulations is the usage of hysteresis comparators in
order to control the output torque. The realization of PI based controller
method as replacement of hyterisis controller in DTC system able to provide
significant solutions to over come the fall back while retaining the simple
control structure of conventional DTC. The combination usage of higher
sampling controller DS1004 and also 3-level cascaded H-bridge multilevel
inverters (CHMI) in this system can further minimize the output torque ripple
by providing higher resolution with lower digital error and greater number of
vectors. This paper presents detail explanation and calculation of optimal PI
parameter tuning strategy consecutively to enhance the performance of 3-
level DTC system. In order to verify the feasibility of the proposed method
experimentation, the proposed method is compared with convention DTC
system via simulation and experiment results.
Power System Modeling and Simulation lab manualDHEERAJ DHAKAR
This document summarizes an experiment simulating a swing equation in Simulink. It involves:
1) Simulating the swing equation for a generator connected to an infinite bus through parallel lines, with a fault on one line.
2) Plotting the swing curve for a sustained fault and when the fault is cleared after 0.1 seconds.
3) Calculating the critical clearing angle as 57 degrees.
This document compares three switching methods for an asymmetric cascaded H-bridge multilevel inverter: selective harmonic elimination (SHE), nearest level control (NLC), and multi-carrier pulse width modulation (PWM). SHE and NLC aim to minimize total harmonic distortion but are offline methods not suitable for closed-loop systems. Multi-carrier PWM provides appropriate harmonic performance while being an online method. Equations are presented for generating PWM signals to control the switches in each cell based on multiple carrier waves to synthesize a high number of voltage levels from asymmetric DC input voltages. Simulation results show multi-carrier PWM has advantages over SHE and NLC for use in an asymmetric multilevel inverter system.
This document compares symmetrical and asymmetrical cascaded current source multilevel inverters. It discusses their structures, operational characteristics, advantages, and simulation results. Symmetrical multilevel inverters have equal current sources, while asymmetrical have unequal sources in a geometric progression. For the same number of components, asymmetrical inverters can produce more output levels and higher voltages with lower total harmonic distortion. Simulation results show the output waveform and THD for different configurations, confirming asymmetrical inverters have better performance.
Comparison of symmetrical and asymmetrical cascaded current source multilevel...eSAT Journals
Abstract This paper presents symmetrical and asymmetrical cascaded multilevel inverter approach for high power output applications. It is based on the cascade connection of the H-bridge inverter cells. Comparison of symmetrical and asymmetrical current source multi level inverter is shown using 2 H-bridge inverter cells with cascade connection. Now ever by the supplies which are in GP with different ratios like 2,3,etc. Structural and operational characteristics are discussed and their inherent advantages are shown. Simulation using Matlab Simulink is done to verify the performance. Simulation and results for this proposed scheme are presented in this paper. Index Terms: Asymmetrical cascaded multilevel inverter, Current source multi level inverter, MATLAB Simulink, Optimization angle control, Symmetrical multi level inverter, Total harmonic distortion (THD).
This document presents research on a cascaded nine-level inverter using pulse width modulation (PWM) and hybrid PWM techniques. It describes the topology and operation of a cascaded multilevel inverter using H-bridge cells. Phase shifted PWM and a hybrid modulation strategy are analyzed for controlling the inverter. Simulation results show the line voltage, phase voltage, and load current waveforms for both modulation methods. Total harmonic distortion is calculated, showing 17.44% for phase shifted PWM and 9.92% for hybrid PWM modulation. The hybrid method achieves lower distortion by operating higher voltage cells at lower switching frequencies.
In the proposed approach,instead of a conventional 3- Phase inverter a component minimized single pha se inverter is utilized which reduces the cost of the inverter,th e switching losses,and the complexity of interface circuits to generate logic signals. A performance comparison of the prop osed inverter fed drive with a conventional 3Phase inverter fed drive is also mode in terms of speed response and t otal harmonic distortion (THD) of the stator curren t. The proposed inverter fed IM drive is found acceptable consideri ng its cost reduction and other advantageous featur es. A general pulse width modulation (PWM) method for c ontrol of 1-phase inverters is presented. The vecto r PWM offers a simple method to select three or four vectors tha t effectively synthesize the desired output voltage,even in presence of voltage oscillations across the two dc-link capacit ors. The influence of different switching patterns on output voltage symmetry,current waveform,switching frequency and common mode voltage can be examined. The paper als o discusses how the use of the wye and delta connecti ons of the motor windings affects the implementatio n of the pulse width modulator.
Design and Experimental Verification of Linear Switched Reluctance Motor with...IAES-IJPEDS
This paper presents the realization and design of a linear switched reluctance motor (LSRM) with a new stator structure. One of the setbacks in the LSRM family is the presence of high force ripple leads to vibration and acoustic noise. The proposed structure provides a smooth force profile with reduced force ripple. Finite element analysis (FEA) is used to predict the force and other relevant parameters.A frequency spectrum analysis of the force profile using the fast Fourier transform (FFT) is presented.The FEA and experimental results of this paper prove that LSRMs are one of the strong candidates for linear propulsion drives.
This paper presents simplified control strategy of Space Vector Pulse Width Modulation method including over modulation region with linear transfer characteristic for cascaded H-bridge inverters. Because of large number of switching states of the cascaded H- Bridge inverter, the over modulation operation is very complex. And also requires incorporation of both under modulation and over modulation algorithms. The proposed control method is effective in terms of selecting the optimal switching states with reduced computational complexity using simplified linear calculations which makes it easier for digital implementation. The performance of the proposed method is simulated and tested experimentally through Spartan 3A FPGA processor for five level Cascaded H-bridge Inverter. The simulation results and harmonic analysis of voltage and current at various modulation indexes as are presented which are in well agreement.
International Refereed Journal of Engineering and Science (IRJES)irjes
a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications.
Comparative Analysis of PWM Techniques for Three Level Diode Clamped Voltage ...IAES-IJPEDS
Multilevel inverters are increasingly being used in high-power medium voltage industrial drive applications due to their superior performance compared to conventional two-level inverters. Thre are a number of Pulse width modulation (PWM) techniques applied in recent years. The most widely applied PWM techniques are Sine Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM). SPWM is the most simple modulation technique that can realize easily in analog circuit. However, it has some drawbacks such as higher total harmonic distortion (THD), lower effective DC utilization and lower switching frequency. Space vector pulse width modulation (SVPWM) is widely used because of their easier digital realization and better DC bus utilization and lower THD. The complexity is due to the difficulty in determining the reference vector location, on times calculation, and switching states selection. This paper presents a simple SVPWM algorithm for diode clamped three level inverters based on standard two-level SVPWM which can easily determine the location of reference vector, calculate the on-times, the selection of switching states. Three level diode clamped inverter (3LDCI) using space vector modulation technique has been modeled and simulated using MATLAB/SIMULINK and Origin 6.1 with a passive R-L load that can be extended to any level. Simulation results are presented to verify the proposed SVPWM control in terms of THD. The results arecompared with conventional sinusoidal pulse width modulation (SPWM) where SVPWM shows better performance than SPWM in terms of THD.
This document describes simulations carried out on Distributed Power-Flow Controller (DPFC) technology. Key points:
- DPFC is derived from Unified Power Flow Controller (UPFC) but eliminates the common DC link between shunt and series converters. Active power is exchanged through the transmission line using third-harmonic frequency components.
- DPFC has advantages over UPFC of lower cost due to lower component ratings/isolation for series converter, and higher reliability due to redundancy of series converters.
- Detailed simulations were performed on a two-machine system to illustrate DPFC's control features and ability to increase power transfer capability and improve system reliability compared to conventional systems. Laboratory tests validated the DPFC operating principle and
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.
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.
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.
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.
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.
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.
This document contains identifying information for an individual named Trent Layell including a student ID number, date, and what appears to be an authentication code or password. In a few words, it seems to be documentation related to an individual's academic or account information.
This document contains personal information including a name, student ID number, and date for an individual. It also includes a string of random characters that is likely an identification code or password. In summary, the document appears to be records containing private identification information for an individual.
El documento proporciona información sobre la secadora de granos SUNCUE PHS-320, incluyendo sus especificaciones, capacidad, potencia requerida, seguridad y dimensiones. La PHS-320 ofrece secado rápido y uniforme de baja temperatura para arroz u otros granos utilizando combustibles de biomasa a bajo costo.
Este hoja de vida presenta la información personal, académica y laboral de Jarinso Viloria Andrades. Incluye sus datos personales, estudios primarios, secundarios y universitarios, idiomas, cursos y seminarios, experiencia laboral y referencias personales y familiares. El documento provee los detalles clave para evaluar el perfil profesional y antecedentes de Jarinso Viloria Andrades.
El documento discute los beneficios del aprendizaje colaborativo, incluyendo la creación de debates, el intercambio de información, y la construcción social del conocimiento. Señala que trabajar en equipo tiene más sentido que trabajar solo, y que el diseño de actividades colaborativas bien estructuradas es clave para un aprendizaje significativo. También destaca que la tecnología puede mejorar los procesos interactivos de aprendizaje.
This document summarizes a research paper on minimizing total harmonic distortion (THD) in a three-phase, five-level cascaded H-bridge inverter. It first describes the configuration and operation of a cascaded H-bridge multilevel inverter. It then reviews the generalized formulation of selective harmonic elimination (SHE) for multilevel inverters. The document presents a MATLAB/Simulink model of a three-phase, five-level inverter that compares sinusoidal pulse width modulation to SHE for harmonic reduction. Simulation results show that SHE reduces THD from 71.2% to 4.66% by eliminating specific lower-order harmonics through optimization of the switching angles.
This document discusses selective harmonic elimination pulse width modulation (SHEPWM) for multilevel inverters using a generalized Hopfield neural network. It begins with an abstract that introduces multilevel inverters, SHEPWM, and the use of a generalized Hopfield neural network for SHEPWM. It then provides more details on the background and concepts of multilevel inverters, SHEPWM, and the Fourier expansion of the staircase output voltage waveform generated by multilevel inverters. The document focuses on applying SHEPWM to eliminate lower order harmonics from the output waveform using a generalized Hopfield neural network approach.
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.
Fuzzy Logic Controlled Harmonic Suppressor in Cascaded Multilevel InverterIJPEDS-IAES
This paper presents an investigation of seven level cascaded H-bridge (CHB)
inverter in power system for compensation of harmonics. For power quality
control a Fuzzy Logic Control (FLC) giving comparatively better harmonic
reduction than the conventional controllers. Harmonic distortion is the most
important power quality problem stirring in multilevel inverter; the
harmonics can be eliminated by an optimal selection of switching angles. A
hybrid evaluation technique evaluates the obtained optimal switching angles
that are attained from the fuzzy inference system as well as neural network.
The proposed method will be implemented in MATLAB working platform
and the harmonic elimination performance will be evaluated.
THD Optimization in 13 level photovoltaic inverter using Genetic AlgorithmSuman Debnath
Minimum Total Harmonic Distortion (THD) is one of the most important requirements from multilevel inverter concerning good Power Quality. This paper presents the optimization of THD in 13 level Cascaded Multilevel Inverter with unequal dc source using Genetic Algorithm (GA). THD minimization is taken as an optimization problem derived from Selective Harmonic Elimination Pulse width Modulation (SHE-PWM). Results give all possible solutions at each modulation index. Switching strategy, FFT analysis and computational time has been analyzed using MATLAB simulation environment.
This document discusses performance enhancement of a multilevel inverter using genetic algorithms. It presents an optimal solution for eliminating pre-specified harmonics from a stepped waveform generated by a multilevel inverter topology with equal DC sources. A genetic algorithm is proposed that reduces computational burden and allows for fast convergence in solving the non-linear equations involved. Simulation results show the genetic algorithm approach achieves significant improvement in harmonic profile compared to the conventional Newton-Raphson method.
Improved hybrid algorithm based on GA and local search method for asymmetric...nooriasukmaningtyas
This document summarizes a research paper that proposes an improved hybrid genetic algorithm and local search method for selective harmonic elimination in a 9-level uniform step asymmetrical multilevel inverter (USAMI). The paper begins with background on multilevel inverters and selective harmonic elimination techniques. It then describes the design of the USAMI and modulation control approach. The main contribution is a hybrid genetic algorithm combined with local search (GA-LS) to optimize switching angles and minimize harmonics. Simulation results applying the GA-LS method show optimal angles can be found to eliminate the 5th, 7th, and 11th harmonics for most modulation indices between 0.629 and 0.921, with two possible solutions between 0.7
Harmonic Minimization In Multilevel Inverters By Using PSOIDES Editor
Harmonic Elimination in a multilevel inverters is
an optimization problem which is solved by applying particle
swarm optimization (PSO) technique. The derived equation
for the computation of total harmonic distortion (THD) of the
output voltage of the multilevel inverter is used as the objective
function in PSO algorithm. The objective function used is to
reduce the THD of the multilevel inverter and obtain the
corresponding switching angles with the elimination of
possible lower order harmonics. In this paper a pseudo code
based algorithm is proposed to deal with inequality constraints
which will helps in accelerating the optimization process. The
proposed method is applied for seven level cascade inverter to
eliminate the 5th and 7th order harmonics to reduce the total
harmonic distortion .This proposed PSO algorithm is effective
in reducing the total harmonic distortion corresponding the
range of modulation index. The simulation results shows that
the proposed PSO method is indeed capable of obtaining
higher quality of solutions to eliminate 5th and 7th order
harmonics and to reduce the total harmonic distortion of 7-
level cascade inverter
A Novel Hybrid Negative Half Cycle Biased Modulation Scheme for Cascaded Mult...IJPEDS-IAES
This paper proposes a new Modified hybrid modulation scheme for cascaded multilevel inverter. The proposed method employs novel single carrier sinusoidal pulse width modulation with its negative cycle biased (HNHCBM) for reducing switching losses when compared to other sinusoidal modulation methods using a hybrid scheme. This scheme is a derivative of various single carrier sinusoidal pulse width modulation scheme and main advantages are reduced harmonics, enhanced output voltage, reduced power loss in the series cells and ease of implementation. The simulation results are analysed with matlab/simulink and compared with experimental results obtained using 5-level inverter and the results are summarized.
Closed Loop Analysis of Multilevel Inverter Fed Drives IJPEDS-IAES
This paper deals with the simulation and implementation of multilevel inverter for drives application. Here the focuses will be onimproving the efficiency of the multilevel inverter and quality of output voltage waveform. The circuit is developed towards high efficiency, high performance, and low cost, simple control scheme. Harmonics Elimination was implemented to reduce the Total Harmonics Distortion (THD) value which is achieved by selecting appropriate switching angles. In this paper to determine the performance of rectifier, steady state analysis is done. Furthermore, the merits of multilevel inverter topology are inherited.Closed loop control is done to analysis the stability of the system.
The document discusses multilevel inverters and their advantages over traditional inverters. It describes that multilevel inverters produce stepped AC signals that reduce harmonics. There are three main topologies discussed - diode clamped, flying capacitor, and cascaded H-bridge inverters. Diode clamped inverters use capacitors between DC links to create voltage levels, while flying capacitor uses capacitors instead of diodes. Cascaded H-bridge uses separate DC sources and single-phase H-bridge inverters to synthesize voltage waves. Total harmonic distortion is a key metric for inverter output quality, with multilevel inverters producing less distortion than traditional designs.
Multi Carrier based Multilevel Inverter with Minimal Harmonic DistortionIJPEDS-IAES
This paper presents performance features of Asymmetric Cascaded
Multilevel inverter. Multilevel inverters are commonly modulated by using
multicarrier pulse width modulation (MCPWM) techniques such as phaseshifted
multicarrier modulation and level-shifted multicarrier modulation.
Amongst these, level-shifted multicarrier modulation technique produces the
best harmonic performance. This work studies about multilevel inverter with
unequal DC sources using level shifting MCPWM technique. The
Performances indices like Total Harmonic Distortion (THD), number of
switches and DC Sources are considered. A procedure to achieve an
appropriate level shifting is also presented is this paper.
Harmonic elimination at the fundamental frequency is very much appropriate for high and medium range of power generation and applications. This paper considers a new technique for selective harmonic elimination (SHE), in which the total harmonic distortion (THD) is minimized when compared with that of the conventional one. With this technique, the harmonics at lower order are eliminated, which are more predominant than the higher ones.Cascaded H-Bridge inverter fed by a single DC is considered which is simulated with the switching angles generated by both the conventional method of SHE and the new method of SHE. The simulated results of the load voltage and the waveforms of the harmonic analysis are shown. The THD values are compared for the two techniques. The experimental results are also shown for the new technique. The switching angles are generated with the help of field programmable gated array (FPGA) in the hardware. The value of experimental THD of voltage is compared with that of simulated THD and the comparison prove that the results are satisfactory.
This paper compares the reduction of harmonics in various level cascaded H-bridge inverters. The switching angles for the cascaded H-bridge inverter were calculated by evolutionary optimization technique. Fourier analysis is used to determine the switching angles for the desired electrical parameters.
Lower order harmonics such as third, fifth, seventh, ninth and eleventh order harmonics were taken into consideration to reduce the total harmonic distortion. Simulation was done for thirteen, fifteen and seventeen level cascaded H-bridge inverters using Matlab. Total harmonic distortion of voltage and current for R, RL and Motor load were analyzed.
A Novel Approach to GSA, GA and Wavelet Transform to Design Fuzzy Logic Contr...IAES-IJPEDS
This paper proposes a novel approach for obtaining a closed loop control
scheme based on Fuzzy Logic Controller to regulate the output voltage
waveform of multilevel inverter. Fuzzy Logic Controller is used to guide and
control the inverter to synthesize a stepped output voltage waveform with
reduced harmonics. In this paper, three different intelligent soft-computing
methods are used to design a fuzzy system to be used as a closed loop control
system for regulating the inverter output. Gravitational Search Algorithm
and Genetic Algorithm are used as optimization methods to evaluate
switching angles for different combination of input voltages applied to MLI.
Wavelet Transform is used as synthesizing technique to shape stepped output
waveform of inverter using orthogonal wavelet sets. The proposed FLC
controlled method is carried out for a wider range of input dc voltages by
considering ±10% variations in nominal voltage value. A 7-level inverter is
used to validate the results of proposed control methods. The three proposed
methods are then compared in terms of various parameters like
computational time, switching angles and THD to justify the performance
and system flexibility. Finally, hardware based results are also obtained to
verify the viability of the proposed method.
A Tactical Chaos based PWM Technique for Distortion Restraint and Power Spect...IJPEDS-IAES
The pulse width modulated voltage source inverters (PWM-VSI) dominate in the modern industrial environment. The conventional PWM methods are designed to have higher fundamental voltage, easy filtering and reduced total harmonic distortion (THD). There are number of clustered harmonics around the multiples of switching frequency in the output of conventional sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) inverters. This is due to their fixed switching frequency while the variable switching frequency makes the filtering very complex. Random carrier PWM (RCPWM) methods are the host of PWM methods, which use randomized carrier frequency and result in a harmonic profile with well distributed harmonic power (no harmonic possesses significant magnitude and hence no filtering is required). This paper proposes a chaos-based PWM (CPWM) strategy, which utilizes a chaotically changing switching frequency to spread the harmonics continuously to a wideband and to reduce the peak harmonics to a great extent. This can be an effective way to suppress the current harmonics and torque ripple in induction motor drives. The proposed CPWM scheme is simulated using MATLAB / SIMULINK software and implemented in three phase voltage source inverter (VSI) using field programmable gate array (FPGA).
Total Harmonic Distortion of Dodecagonal Space Vector ModulationIJPEDS-IAES
Space vector modulation technique is one of the best PWM techniques which have been implemented to the Multilevel inverter circuit to get the purely sinusoidal cuurent. This is a important algorithm which is implemented in open wind induction motor. This type of I.M has great impact on Electric Drive system. SVM is nothing but the technique of switching algorithm. The Hexagonal space vector modulation has been implemented before, but elimination of higher order harmonics is not possible. Torque pulsation arises. Speed control of Induction motor was not smooth. So Dodecagonal (12) structure developed. A 12 side polygonal space vector structure is meant for eliminating (6n±1) harmonics in the phase current waveform throughout the modulating range. A high resolution of PWM technique is proposed involving multiple 12 sided polygonal (Dodecagonal) structure that can generate highly sinusoidal voltage at a reduced switching frequency. In this paper different values of frequencies have been taken for harmonic analysis. SVM method features a higher level of dc-bus voltage utilization compared to the conventional PWM.
This paper recommends the use of grasshopper optimization algorithm (GOA), a nature-inspired optimization algorithm, for optimizing switching-angle applied to cascaded H-bridge multilevel inverter (CHBMLI). Switching angles are selected based on the minimum value of the objective function formulated using the concept of selective harmonic minimization pulse width modulation (SHMPWM) technique. MATLAB/Simulink-PSIM dynamic co-simulation conducted on a 3-phase 9-level CHBMLI shows that the CHBMLI controlled using GOA derived switching-angle is able to respond to varying modulation index demand and synthesize an AC staircase output voltage waveform with the desired fundamental harmonic and minimized selected low-order harmonics. Compared to Newton Raphson (NR) technique, GOA is able to find optimum switching-angle solutions over a wider modulation index range. Compared to Genetic Algorithm (GA), GOA is able to find global minima with higher probability. The simulation results validate the performance of GOA for switching-angle calculation based on the concept of SHMPWM.
Harmonic Minimization using PSO of meld μgird-MLCIIJERA Editor
Microgrids are new approach of electrical systems consisting of distributed generators, renewable energy sources and sensitive loads. The objective of microgrid operation is to serve reliable and high-quality electric power regardless of faults or abnormal operating conditions. A transformation is being observed to advance the part of distributed generations from alternate the constitutional source in the network of microgrid. In this paper Microgrid with three important distributed generators & an effective solution for protection of sensitive loads against voltage disturbances in power distribution system are considered. The main objective is to lower the total harmonic distortion (THD) of the cascaded multilevel inverter, which is an optimization problem and can be clear up by applying particle swarm optimization (PSO) approach are considered in the paper. The simulation outcome fair that the prospective PSO method is truly adept of concluding outstanding attributes of the decision to eliminate the 3rd, 5th and 7th order harmonics and within the range of modulation index the total harmonic distortion must be reduced for meld μgrid-MLCI.
Full-RAG: A modern architecture for hyper-personalizationZilliz
Mike Del Balso, CEO & Co-Founder at Tecton, presents "Full RAG," a novel approach to AI recommendation systems, aiming to push beyond the limitations of traditional models through a deep integration of contextual insights and real-time data, leveraging the Retrieval-Augmented Generation architecture. This talk will outline Full RAG's potential to significantly enhance personalization, address engineering challenges such as data management and model training, and introduce data enrichment with reranking as a key solution. Attendees will gain crucial insights into the importance of hyperpersonalization in AI, the capabilities of Full RAG for advanced personalization, and strategies for managing complex data integrations for deploying cutting-edge AI solutions.
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
Infrastructure Challenges in Scaling RAG with Custom AI modelsZilliz
Building Retrieval-Augmented Generation (RAG) systems with open-source and custom AI models is a complex task. This talk explores the challenges in productionizing RAG systems, including retrieval performance, response synthesis, and evaluation. We’ll discuss how to leverage open-source models like text embeddings, language models, and custom fine-tuned models to enhance RAG performance. Additionally, we’ll cover how BentoML can help orchestrate and scale these AI components efficiently, ensuring seamless deployment and management of RAG systems in the cloud.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
Ocean lotus Threat actors project by John Sitima 2024 (1).pptxSitimaJohn
Ocean Lotus cyber threat actors represent a sophisticated, persistent, and politically motivated group that poses a significant risk to organizations and individuals in the Southeast Asian region. Their continuous evolution and adaptability underscore the need for robust cybersecurity measures and international cooperation to identify and mitigate the threats posed by such advanced persistent threat groups.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
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Ei35761766
1. Jitendra Jain et al. Int. Journal of Engineering Research and Application
ISSN : 2248-9622, Vol. 3, Issue 5, Sep-Oct 2013, pp.761-766
RESEARCH ARTICLE
www.ijera.com
OPEN ACCESS
Reduction of Total Harmonic Distortion in Power Invertors Using
Genetic Algorithm
Mrs. Geetika Gera, Mr. Ashish Malik, Mr. Darshan Kumar
(Assistant Professor Department of Computer Science Engineering, Dr. Radhakrishnan Institute of Technology,
Jaipur)
(M.D of Softhunter company, jaipur)
(Assistant professor, Department of Electronics and Communication Engineering, JECRC UDML college of
Engineering, Jaipur)
ABSTRACT
In this paper, Genetic Algorithm is developed as the favored solution algorithm of specific harmonic elimination
(PWM-SHE) switching pattern. Genetic algorithms are a class of parallel processing learning techniques. In this
paper first, the 7-level and 9-level cascaded inverter's structures are briefly described, and optimum switching
angles are determined to eliminate low order harmonics and to reduce THD. Comparison has been done between
the 7-level and 9-level with respect to the consideration of THD. Simulation results validate purpose method.
Keywords - Genetic algorithm, multilevel inverter, Selective harmonic elimination pulse width modulation
(SHEPWM), Total harmonic distortion
I.
INTRODUCTION
In recent years, Multilevel inverters have
attracted a great deal of attention in medium –voltage
and high power applications due to their lower
switching losses , higher efficiency and more
electromagnetic compatibility than those of
conventional two-level inverters. Use of multilevel
inverters is becoming popular for high power
applications [1]-[5], especially in the distributed
generation where a number of batteries, fuel cells,
solar cell, and micro-turbines can be connected
through a multilevel inverter to feed a load or the ac
grid without voltage balancing problems. Another
major advantage of multilevel inverters is that their
switching frequency is lower than a traditional twolevel inverter, which leads to reduced switching losses
[1], [3], [6]. The cascaded inverter has the advantages
that the DC-link voltage is balanced, circuit layout
flexibility, and it has the least components per phase
but require many separated dc sources in motor drive
applications. The cascaded inverter has been largely
studied and used in fields of SVCs (static VAR
compensators), stabilizers, HVDC transmissions and
so on [12]-[16]. Many switching strategies are applied
to multilevel inverter to reduce harmonics, but
SHEPWM is most well-known strategy. SHE-based
methods have been proposed for both two-level [17]–
[19] and multilevel inverters. The desired output of a
multi level converter is synthesized with several
methods including staircase modulation, sinusoidal
pulse width modulation (PWM) with multiple
triangular carriers, and multilevel space vector
modulation. The elimination of specific low-order
harmonics from a given voltage /current waveform
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generated by a voltage/current source inverter using
what is widely known as optimal , “Programmed” or
selective harmonic elimination PWM (SHE-PWM)
techniques has been deal with in numerous papers and
for various converter topologies, systems, and
applications [6]-[11].The general function of this
multilevel inverter is to synthesize a staircase
waveform from several separate dc sources (SDCSs),
which may be obtained from solar cells, fuel cells,
batteries, ultra capacitors, etc. For output staircase
waveform, it is necessary to obtain the switching
timing angles or the conducting angles of switching
devices. The conventional method has the merit that
the predominant low-order harmonics can be
eliminated. However, it has to solve simultaneous
equations, which are the set of nonlinear
transcendental equations for the fundamental
component and the harmonic ones. It is difficult to
obtain the conducting angles because the conventional
method needs an iterative method such as the Newton–
Raphson one. Additionally, the switching angles are
obtained by means of an off-line calculation to
minimize the harmonics for each modulation index,
which leads to increased use of look-up tables.
Therefore, Genetic Algorithm (GA) [20]-[23] is
adopted here to replace numerical algorithms to
overcome this difficulty, because of its intrinsic ability
to begin searching randomly, handle large amount data
simultaneously and "jump" out of local optimum
automatically. GA is kind of artificial intelligence
approaches, and origins from optimizing problems. It
has entirely different operation mechanism, comparing
with numerical methods based on mathematical
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2. Jitendra Jain et al. Int. Journal of Engineering Research and Application
ISSN : 2248-9622, Vol. 3, Issue 5, Sep-Oct 2013, pp.761-766
www.ijera.com
differential operation, which needs on some extent
restrict requirements on objectives.
1.1 Structure of cascaded multi level inverter
The cascaded multilevel inverter is one of
several multilevel configurations. It is shaped by
connecting several single-phase H-bridge inverters in
series as shown in Fig. 1 for 9-level inverter Each Hbridge has its own isolated DC source. Each separated
DC sources is connected to H-bridge inverter and can
produce voltages of 0, +Vdc and –Vdc, by different
combination of the four switches, S1, S2, S3 and
S4,where Vdc is the voltage of its DC bus.
Fig. 2 Structure of cascaded multilevel Inverter
In this paper, a multilevel inverter based on
the cascaded converter topology with 5 equal dc
sources is studied. The key purpose of this paper is to
commence a minimization technique assisted with
Genetic Algorithm (GA) in order to decrease the
computational burden associated with the solution of
the nonlinear transcendental equations of the selective
harmonic elimination method to reduce low order
harmonics and to reduce THD.
1.2 Selective harmonic elimination method
The Selective Harmonic Eliminated PWM
(SHE PWM) technique is used to find appropriate
switching angles namely ,
,…,
so that the
(N-1) odd harmonics can be eliminated and control of
the fundamental voltage is also achieved. The Fourier
series expansion for the quarter-wave symmetric
staircase waveform as shown in Figure .1 is written as
follows:
Vout(ωt) =
(1)
Where,
is the switching angles, which must satisfy
the following condition: , , ,………, < π/2
and s is the number of H-bridge cells.
Fig. 1 Structure of cascaded multilevel Inverter
Each inverter generates quasi-square wave
voltage waveform with different duty cycle ratios,
which together form the staircase output voltage
waveform as shown in Fig. 2 The synthesized voltage
waveform is, therefore, the sum of the inverter
outputs. The number of output phase voltage levels in
a cascade multilevel inverter is then 2s+1, where s is
the number of isolated dc sources.
n is odd harmonic order And, V is the amplitude of dc
voltage The harmonic components in the waveform
can be describes as follows:
the amplitude of dc component equals zero
the amplitude of the fundamental component, n =
1, and odd harmonic component are given by:
, and
π
(2)
The amplitude of all even harmonics equals zero
Thus, only the odd harmonics in the quarter-wave
symmetric multilevel waveform need to be eliminated.
The switching angles of the waveform will be adjusted
to get the lowest output voltage THD. The total
harmonics distortion (THD) is mathematically given
by:
THD = √Σhn²∕ h1
(3)
In order control the fundamental amplitude
and to eliminate the 5th, 7th, 11th, & 13th lower order
harmonics, the nonlinear transcendental equations set
(4) must be solved and the five switching angles 1, 2,
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762 | P a g e
3. Jitendra Jain et al. Int. Journal of Engineering Research and Application
ISSN : 2248-9622, Vol. 3, Issue 5, Sep-Oct 2013, pp.761-766
3,
START
and 5 are calculated offline to minimize the
harmonics for each modulation index in order to have
a total output voltage with a harmonic minimal
distortion rate.
+
+
+
+
= 3πM/4
3
+
+
+
+
FIND NUMBER OF
VARIABLES
SET POPULATION SIZE
=
0
+
+
+
+
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EVALUTAE FITNESS
FUNCTION
=
0
+
+
+
+
IF NO. OF
ITERATION
LESS THAN
100
Yes
=0
+
=0
+
+
+
(4) the modulation index for the multilevel waveform
is given as:
M=
(5)
Where, h1 is the amplitude of the fundamental
component. From equation, varying the modulation
index value can control the amplitude of the
fundamental component and the other s-1 nonlinear
equations, which are the undesirable harmonic
components, can be eliminated. These equations are
solved by Newton-Raphson method [11]. In the
natural sinusoidal PWM strategy, a large number of
switching is required, with the consequent increase of
switching losses. With the method of Selective
Harmonic Elimination, only selected harmonics are
eliminated with the smallest number of switching.
This technique is very suitable for inverters control.
By employing this technique, the low THD output
waveform without any filter circuit is possible.
Another approach uses genetic algorithm to optimize
switching angle to reduce THD.
II.
Genetic Algorithm
Genetic algorithm is a computational model
that solves optimization problems by imitating genetic
processes and the theory of evolution by using genetic
operators like reproduction, crossover, mutation etc.
Amounts of applications have benefited from the
utilization of genetic algorithm. Genetic algorithm is
still a novel technique for PWM-SHE technique.
No
GA OPERATIONS
No
IF COST
FUNCTION
LESS THAN 1
STOP
Yes
Fig. 3 Flowchart of Genetic Algorithm
This algorithm is usually used to accomplish
a near global optimum solution. Each iteration of the
GA is a new set of strings, which are called
chromosomes, with improved fitness, is produced
using genetic operators.
2.1 Chromosome representation
In GA, each chromosome is used as a feasible
solution for the problem, where each chromosome is
developed based on single dimensional arrays with a
length of S, where S is the number of angles.
2.2 Initialize population
Set a population size, N, i.e. the number of
chromosomes in a population. Then initialize the
chromosome values randomly. If known, the range of
the genes should be considered for initialization.
Population size depends only on the nature of the
problem and it must achieve a balance between the
time complexity and the search space measure. The
narrower the range, the faster GA converges. In this
paper, population size is considered as 100.
2.3 Reproduction
The reproduction operator determines how
the parents are chosen to create the offspring. This
operator is a process in which chromosomes are
copied according to their objective function values i.e.
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763 | P a g e
4. Jitendra Jain et al. Int. Journal of Engineering Research and Application
ISSN : 2248-9622, Vol. 3, Issue 5, Sep-Oct 2013, pp.761-766
the degree of conformity of each object is calculated
and an individual is reformed under a flat rule
depending on the degree of conformity.
2.4 Crossover
Crossover is the most significant operation in
GA. It creates a group of children from the parents by
exchanging genes among them. The new offspring
contain mixed genes from both parents. By doing this,
the crossover operator not only provides new points
for further testing within the chromosomes, which are
already represented in the population, but also
introduces representation of new chromosomes into
the population to allow further evaluation on
parameter optimization.
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simulation results for the output voltage waveform of
9-level inverter for M = 0.8, Fig.6, Fig. 8 shows the
FFT spectrum of THD of an 9- level multilevel
inverter, Optimal switching angles for various values
of M and THD of 9-level multilevel inverter. Fig.7
shows the simulation results for the output voltage
waveform of 7-level inverter for M = 0.8, Table. 3
shows THD for 9-level and 7- level inverter.
Table.1 Switching angles generated by GA for 7-level
Switching Angles
Modulation
Index (M)
θ1 (rad.)
θ2 (rad.)
θ3 (rad.)
2.6 Evaluation of fitness function
The most vital item for the GA to evaluate
the fitness of each chromosome is the cost function.
The purpose of this study is to minimize specified
harmonics; therefore the fitness function has to be
associated to THD. In this work the fifth, seventh,
eleventh, and thirteenth harmonics at the output of an
eleven-level inverter are to be minimized.
FV =
(6)
For each chromosome a multilevel output voltage
waveform
is produced using the switching angles in the
chromosome and the required harmonic magnitudes
are calculated using FFT techniques.
GA is typically set to run for a certain number of
iterations (100 in this case) to get an answer. After the
first iteration, FV’s are used to determine new
offspring. These go through crossover and mutation
operations and a new population is created which goes
through the same cycle starting from FV evaluation.
Sometimes, GA can converge to a solution much
before 100 iterations are completed. To save time, in
this paper, the iterations have been stopped when the
cost function goes below 1.
III.
Simulation results
From the simulation results using genetic
algorithm, it is clear that for 9-Level cascaded
multilevel inverter the 5th, 7th, and 11th harmonics and
for 7-Level inverter 5th and 7th, harmonics and their
magnitudes are negligible relatively to the
fundamental component. The obtained switching
angles for various values of modulation index using
GA for 7-level inverter and 9-Level inverter is shown
in Table1 and Table 2 respectively. Fig.4 shows the
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0.215
0.373
0.621
0.2
0.212
0.356
0.602
0.3
0.225
0.358
0.61
0.4
0.19
0.524
0.723
0.5
0.348
0.633
0.907
0.6
0.475
0.777
0.896
0.7
2.5 Mutation
Mutation is another vital operation. It works
after crossover operation. In this operation, there is a
probability that each gene may become mutated when
the genes are being copied from the parents to the
offspring. This process is repeated, until the preferred
optimum of the objective function is reached.
0.1
0.041
0.236
0.592
0.8
0.098
0.299
0.514
0.9
0.154
0.419
0.721
1.0
0.324
0.655
0.968
Table.2 Switching angles generated by GA for 9-level
Modulation
Index (M)
0.1
θ1 (rad.)
0.525
Switching Angles
θ2 (rad.) θ3 (rad.)
0.859
0.997
θ4 (rad.)
1.274
0.2
0.20
0.5
0.99
1.568
0.3
0.194
0.46
0.793
1.117
0.4
0.094
0.609
0.774
1.367
0.5
0.091
0.605
0.774
1.374
0.6
0.312
0.666
0.954
1.169
0.7
0.082
0.354
0.49
0.95
0.8
0.628
0.89
1.133
1.48
0.9
0.09
0.589
0.781
1.382
1.0
0.292
0.64
1.107
1.563
Table.3 THD for 9-level and 7-level inverter
Level
THD(%)
nine
15.13
Seven
17.29
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5. Jitendra Jain et al. Int. Journal of Engineering Research and Application
ISSN : 2248-9622, Vol. 3, Issue 5, Sep-Oct 2013, pp.761-766
50
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5
theta-4
3
Theta-3
2
0
Theta-2
1
Theta -1
0
1 2 3 4 5 6 7 8 9 10
Fig.8 Optimal switching angles Vs M.
-50
0
1000
2000
3000
4000
5000 6000
time(sec)
7000
8000
9000
10000
Fig. 4 Output Voltage of 9-Level Inverter
10
9
8
Total Harmonic Distortion
output votlages(v)
4
7
6
5
4
3
2
1
0
0
500
1000
1500
2000
2500
Time
3000
3500
4000
4500
5000
Fig.5 THD of a 9- level multilevel inverter
Fig. 6 FFT analysis of 9-Level Multilevel inverter
Fig. 7 Output Voltage of 7-Level Inverter
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IV.
CONCLUSION
In this work, genetic algorithm optimization
technique is applied to find the switching angles of the
cascaded inverter for the reduction of harmonics. The
use of the GA is proposed to solve the selective
harmonics elimination problem in PWM inverters. The
paper successfully demonstrates the validity of genetic
algorithm for the estimation of optimum switching
angles of staircase waveform generated by multilevel
inverters, and Comparison has been done between the
7-level and 9-level with respect to the consideration of
THD. As number of level increases THD decreases;
therefore THD of 7-level inverter is greater than THD
of 9-level.As in this approach, GA can be applied to
any problem where optimization is required; therefore,
it can be used in many applications in power
electronics.
REFERENCES
[l]
P.M. Bhagwat and V.R. Stefanovic,
"Generalized structure of a multilevel PWM
inverter", IEEE Trans. On I.A., Vol. IA-19, n.
6. 1983, pp. 1057-1069.
[2]
J. Lai and F.Z. Peng, "Multilevel converters A new breed of power converters", IEEE IAS
Annual Conference Records, 1995, pp. 23482356.
[3]
F.Z. Peng, J. Lai, J. McKeever and J.
VanCOevering, "A multilevel voltage-source
inverter with separate dc sources for static var
generation", IEEE IAS Annual Conference
Records, 1995, pp. 2541-2548.
[4]
H. L. Liu and G.H. Cho, "Three-level space
PWM in low index modulation region
avoiding narrow pulse problem", IEEE IAS
Annual Conference Records, 1993, pp. 257262.
[5]
Rodriguez J, Bernet S, Wu B, Pontt J.O,
Kouro S. "Multilevel voltage-sourceconverter topologies for industrial mediumvoltage drives". IEEE Trans. Ind. Electron.
Vol. 54, Dec. 2007, 2930 – 2945
[6]
A. Nabae, I. Takahashi, H. Agaki “A New
Neutral-Point-Clamped PWM, Inverter,”
IEEE Transactions on Industry Applicaitions.
Vol.IA-17, No.5, Sep./Oct 1981, pp.518-523.
765 | P a g e
6. Jitendra Jain et al. Int. Journal of Engineering Research and Application
ISSN : 2248-9622, Vol. 3, Issue 5, Sep-Oct 2013, pp.761-766
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
B. Wu, P. G Song, "Comprehensive Analysis
of Multi-Megawatt Variable Frequency
Drives",
Transaction
of
China
Electrotechnical Society, Vol.19, No.8, pp.
40-52, 2004
L. M. Tolbert, F. Z. Peng, and T. G. Habetler,
"Multilevel converters for large electric
drives," IEEE Trans. Ind Applicat., Vol. 35,
pp. 36-44, Jan./Feb.1999.
P.W. Hammond, "A New Approach to
Enhance Power Quality for Medium Voltage
AC Drives,' IEEE Trans. on Industry
Applications,"
Vol.33,
No.1,
pp202208,1997.
W A Hill, and C D Harbourt, Performance of
Medium Voltage Multi-level Inverter, IEEE
Industry Application Society Annual Meeting
(IAS), pp.1186-1192, 1999.
Sirisukprasert, Siriroj. (1999) “Optimized
Harmonic Stepped-Waveform for Multilevel
Inverter”,
Msc
thesis,
available
at
http://www.worldcatlibraries.org
F. Z. Peng, J. S. Lai, J. McKeever and
J.VanCoevering, “A Multilevel VoltageSource Inverter with Separate DC Sources for
Static Var Generation,” IEEE-IAS Con$
Rec., pp2541 -2548.
G. Joos, X. Huang and B. T. Ooi, “Directcoupled Multilevel Cascaded Series VAR
Compensators,” IEEE-IAS Con$. Rec., pp.
1608-1615, 1997.
F. Huang, P. I. Lim and E. K. Goh, “Design
and Implementation of a 3- Phase Voltage
Stabilizer Using 1 1-Level Voltage Source
Inverter,” IEEEIECON Con$ Rec., pp. 722725, 1997.
Lai Y S, Shyu F S. (2002) “Topology for
hybrid multilevel inverter,” IEE ProceedingsElectric Power Applications, , vol.149,
pp.449-458.
P.P. Bhagwat, and V. R. (1983) “Generalized
structure of a multilevel PWM inverter,”
IEEE Transactions in Industry Applications,
vol.19, pp.1057-1069.
J. Sun, S. Beineke, and H. Grotstollen,
“Optimal PWM based on realtime solution of
harmonic elimination equations,” IEEE
Trans. Power Electron., vol. 11, no. 4, pp.
612–621, Jul. 1996.
J. R. Wells, X. Geng, P. L. Chapman, P. T.
Krein, and B. M. Nee, “Modulation-based
harmonic elimination,” IEEE Trans. Power
Electron., vol. 22, no. 1, pp. 336–340, Jan.
2007.
J. Wang, Y. Huang, and F. Z. Peng, “A
practical harmonics elimination method for
multilevel inverters,” in Conf. Rec. IEEE IAS
Annu. Meeting, Oct. 2005, vol. 3, pp. 1665–
1670.
www.ijera.com
[20]
[21]
[22]
[23]
www.ijera.com
L. Chambers.( 1995) “Practical handbook of
genetic algorithms” Boca Raton, CRC Press.
S.N.Sivanandam, & S.N.Deepa (2011).
Principles of Soft Computing, Second edition
page(s):385-401
Goldberg D.E. (1989). Genetic Algorithm in
Search, Optimization and Machine Learning,
MA: Addison Wesley
Davis.L. (1991). Handbook of Genetic
Algorithm, New York: Van Nostran
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