Level Diode Clamped Inverter Research Articles

Dual Control of Asynchronous Motor for EV Fed by 5-level Diode Clamped Multilevel Inverter using SPWM Technique

This paper presents the discussion about the working principle and simulation of three phases Induction Motor (IM) for electric vehicle fed by five level diode clamped multilevel inverter. Multilevel inverter technology has emerged recently as a very important alternative in the area of EV system. The main objective of this paper is to control the speed of an IM by using 5-level diode clamped multilevel inverter. To obtain high quality sinusoidal output voltage with reduced harmonics, multicarrier PWM control scheme is proposed for diode clamped multilevel inverter. A speed control and torque control can be achieved by using sinusoidal output voltage which has high quality by multicarrier Sinusoidal Pulse Width Modulation (SPWM) technique. The planned system is best progress in production of towering switching losses results compared with other conventional method. The proposed system is an effective replacement for the conventional method which produces high switching losses and results in poor drive performance. The simulation results reveal that the proposed circuit effectively controls the motor speed and enhances the drive performance through reduction in total harmonic distortion. Also this shows that the planned method controls the speed and torque of motor in efficient manner. Hence, the system usefulness is established through simulation.

Optimal HSE-PWM based on genetic algorithm for seven levels diode clamped multilevel inverter

In this paper, the control of seven level diode clamped inverter with selective harmonic elimination (SHE) pulse width modulation (PWM) technique based on genetic algorithm (GA) has been developed. In standard SHE-PWM, the seven level inverters allow the elimination of only two low order harmonics. To improve the total harmonic distortion (THD), and without any modification to the inverter structure, five low order harmonics can be eliminated by suitably adding holes in the stairecase voltage leg. Furtheremore, a hole distribution in agreement with the sin function shape is proposed. For this, a real-coded genetic algorithm is applied under the standard constraints with a proposed cost function minimization that allow a better near sin function reshape of the output voltage leg. This GA computation allow to determine the switching angles for a seven-level diode clamped inverter to produce the required fundamental voltage and to eliminate undesirable harmonics. This developed procedure can eliminate a desired number of low harmonics and is only restricted by the maximal switching frequency of the power switches. The results of the suggested method are compared to the conventional SHE-PWM involved with a seven level staircase wave. They reveal that the developed method is a very effective one for optimal harmonic elimination technique.

Three-phase five level diode clamped inverter for AC load interfacing in DC Microgrid

In this paper, diode clamped type three-phase five-level inverter is used for AC load interfacing in DC microgrid. Multilevel inverters generate staircase voltage waveform with a series of power semiconductor switches from several layer voltage DC sources. Therefore, the output voltage waveforms in multilevel inverters can be generated at low switching frequency with high efficiency and low distortion. In two-level inverter, various pulse width modulation (PWM) strategies with high switching frequency is required to obtain a output voltage or a current waveform with a small amount of harmonic content. In existing DC microgrid, three-phase conventional two-level Sine-PWM inverter is used and so, total harmonic distortion (THD) is high. To reduce the THD and the size of AC filter and to get the quality output, diode clamped type three-phase five-level inverter is applied in this research. Level shift multi carrier Sine-PWM method is used for the diode clamped circuit topology. The output waveforms of conventional two-level inverter and diode clamped five-level inverter are measured and compared the each output waveform qualities such as voltage THD, current THD and AC filter size. The performance of five level diode clamped inverter is illustrated by PSIM software and experimental results are carried out with prototype.

THD minimisation using genetic algorithm on the nine-level multilevel inverters

Determination of optimal switching angles in inverters is a significant research area and involves maximum and quality power is achievement by reducing the total harmonic distortion (THD) present in the output waveform. Hence, by computing the appropriate switching angles of the inverters, these harmonics appearing in the output voltage could be reduced. The problem formulation in the proposed research paper lies in formulating an appropriate switching strategy to maintain optimality in power quality. A genetic algorithm (GA) optimisation technique to compute the optimum switching angles of a nine-level multilevel inverter is investigated, algorithm formulated and experimental analysis carried out. In three-phase applications, the line-voltage harmonics are of the main concern from the load point of view. In this paper, using the genetic algorithm and sinusoidal PWM technique, a THD minimisation process is applied to the line-to- line voltage of the inverter. This paper is based on a comparison between seven level cascaded and nine level diode clamped multilevel inverter.

Fuzzy logic-based multi-level shunt active power filter for harmonic reduction

In this paper, using a three level diode clamped multilevel inverter and DC capacitor, a shunt active power filter (SAPF) is implemented to mitigate the supply current harmonics and compensate reactive power drawn from nonlinear load. The advantage of using three-level inverter paves way to reduced harmonic distortion and switching losses. Fuzzy logic control and unit sine vector control are proposed in this paper for generating reference current for the SAPF. The advantage of fuzzy control is that it is based on a linguistic description and does not require a mathematical model of the system. The implementation of fuzzy logic control (FLC) algorithm is executed using MATLAB fuzzy logic tool box. The proposed pulse width modulation (PWM) method produces the switching signals to the inverter from the sampled reference phase voltage magnitudes as in the case of conventional space vector PWM (SVPWM). The simulation results illustrate that the proposed three-level SAPF with low harmonic content in supply current and in phase with the line voltage. The simulation results are validated with prototype model for demonstrating the effectiveness of the system.

Fuzzy logic-based multi-level shunt active power filter for harmonic reduction

In this paper, using a three level diode clamped multilevel inverter and DC capacitor, a shunt active power filter (SAPF) is implemented to mitigate the supply current harmonics and compensate reactive power drawn from nonlinear load. The advantage of using three-level inverter paves way to reduced harmonic distortion and switching losses. Fuzzy logic control and unit sine vector control are proposed in this paper for generating reference current for the SAPF. The advantage of fuzzy control is that it is based on a linguistic description and does not require a mathematical model of the system. The implementation of fuzzy logic control (FLC) algorithm is executed using MATLAB fuzzy logic tool box. The proposed pulse width modulation (PWM) method produces the switching signals to the inverter from the sampled reference phase voltage magnitudes as in the case of conventional space vector PWM (SVPWM). The simulation results illustrate that the proposed three-level SAPF with low harmonic content in supply current and in phase with the line voltage. The simulation results are validated with prototype model for demonstrating the effectiveness of the system.

THD minimisation using genetic algorithm on the nine-level multilevel inverters

Determination of optimal switching angles in inverters is a significant research area and involves maximum and quality power is achievement by reducing the total harmonic distortion (THD) present in the output waveform. Hence, by computing the appropriate switching angles of the inverters, these harmonics appearing in the output voltage could be reduced. The problem formulation in the proposed research paper lies in formulating an appropriate switching strategy to maintain optimality in power quality. A genetic algorithm (GA) optimisation technique to compute the optimum switching angles of a nine-level multilevel inverter is investigated, algorithm formulated and experimental analysis carried out. In three-phase applications, the line-voltage harmonics are of the main concern from the load point of view. In this paper, using the genetic algorithm and sinusoidal PWM technique, a THD minimisation process is applied to the line-to- line voltage of the inverter. This paper is based on a comparison between seven level cascaded and nine level diode clamped multilevel inverter.

A Sliding Mode Controller Approach for Three Phase Single Stage Seven Level Multilevel Inverter for Grid Connected Photovoltaic System

This paper brought out the interest of eliminating a dc-dc converter stage in a two stage power conversion system to reduce the complxity, size and cost. The problem of the paper is formulated from the observations made by the existing literature, which have very less scope about the elimination of dc-dc converter stage in power conversion system.It is proposed and evaluated by implementing the combinations of the proportional Integral and sliding mode controllers to evaluate the grid side parameters such as grid voltage and current, real power,reactive power, power factor and dc link voltage settling time for standard atmospheric condition and changing atmospheric condition. Existing inverter topologies have the drawbacks in the terms of number of levels to rediuce the harmonics and dc link voltage maintenace for the disturbances caused at grid side and source side. The proposed system is analysed by implementing a three phase seven level diode clamped multilevel inverter. A multiloop controller is designed as the inner loop controls the power factor and the outerloop track the maximum power from photovoltaic syatem. This paper finally arrives at a conclusion about the stastical and simulated results of the proposed system by using MATLAB/SIMULINK.

A Novel Current Injection Circuit For Adjustable Speed Drives

An adjustable speed drive creates the harmonics. The novel current injection circuit does not need any additional active devices. With the significant reduction in current harmonics, the AC input line current is sinusoidal. The ZVS technique is used for all the switches operation. The rectifier diodes are by soft switching. The output voltage regulated by fixed duty ratio with varying switching frequency. The advantages of proposed AC-DC-AC systems are low price, compact, high efficiency, and simplicity. Nine level diode clamped inverter produces the voltage harmonics of 8.75%. The Total Harmonic Distortion (THD) of input current is as low as 7.72 % and power factor as high as 0.99. Theoretical results are verified initially through PSIM simulation and validated with an experimental prototype of 2.5Kw.

Effective harmonic reduction technique for an ESTLDC inverter in hybrid energy based application

ABSTRACT The increasing concern about the deficiency of energy resources and the risky outcome of fossil fuel emission has started a new necessity of trustworthy and cleaner green power sources such as solar and wind system. The output of these sources is connected to the grid via the use of five-level inverter in recent times which has started attracting extra attention, due to many benefits that they provide in comparison to the three-level inverter. This paper analyses the eight switch three level diode clamped (ESTLDC) inverter supplied to grid and investigates the three space vector pulse width modulation (SVPWM) strategies namely α-β frame, g-h frame, and m-n-o-p frame for the suitable working of the system. The assessment of these methods is specified in terms of the voltage waveforms, total harmonic distortion (THD) in an entire linear modulation index choice. In this work, the ESTLDC inverter is employed as a harmonic mitigation device, this enables the grid to always absorb or supply a high-quality power. Besides, the comparison outcomes authenticates that SVPWM based on m-n-o-p frame is found easier to recognise and offers improved control of the grid-connected inverter. Further, the proposed inverter uses eight switches consequently losses are minimised. Experimental outcomes have revealed the strength and viability of the proposed technique.

A Six Level Diode Clamped Multi Level Inverter with APOD PWM

In this paper a six level diode clamped multi level inverter (DCMLI) with alternate phase opposition disposition (APOD) PWM technique is discussed and simulated using Matlab/Simulink. This DCMLI is capable of giving an output of six levels without a zero level. The six level consist of equal positive and negative level. The inverter uses five carrier waves, and one trapezoidal wave as the reference signal for pulse generation. The THD analysis for the same is carried out.

A simplified and generalised SVPWM method including over modulation zone for seven level diode clamped inverter - FPGA implementation

This paper presents simplified and generalised SVPWM technique for a neutral point clamped multilevel inverter of any level. This modulation technique provides a simplistic strategy for transition between various modulation indexes with linear transfer characteristic which provides a general solution for over modulation zone. The proposed technique is based on 60° coordinate system with all the computational work is carried out online, generating the desired switching states and their sequences through simplified expressions without any additional storage requirement. This modulation technique combines the concept of reference vector modification and on duration modification during over modulation zones. The performance of the proposed technique is tested through FPGA spartan3A processor experimentally for seven level diode clamped inverter. The simulation and experimental results are validated at various modulation indexes and are in well agreement with each other.

A simplified and generalised SVPWM method including over modulation zone for seven level diode clamped inverter - FPGA implementation

A simplified and generalised SVPWM method including over modulation zone for seven level diode clamped inverter - FPGA implementation

Multicarrier SPWM Control Techniques for Three Phase Eleven Level Diode Clamped Multilevel Inverter and Hybrid Inverter with Reduced Number of Components

<p class="Els-Abstract-text">A comparative analysis of three phase eleven level diode clamped multilevel inverter (DCMLI) and hybrid inverter is performed in this paper in which the later requires fewer carrier signals, less number of devices and gate drive circuits. The performance is evaluated using phase disposition (PD), alternate phase opposition disposition (APOD) and carrier overlapping (CO) sinusoidal pulse width modulation (SPWM) methods. The hybrid multilevel inverter has superior features over diode clamped multilevel inverters and is more efficient since the positive levels of the inverter that are generated by high frequency switches (level generation part), are reversed by low frequency switches (polarity generation part) when the voltage polarity is required to be changed for negative polarity. Therefore, the overall cost and complexity of the hybrid inverter are greatly reduced particularly for higher inverter output voltage levels. Simulation is performed for three phase eleven level diode clamped multilevel inverter and hybrid multilevel inverter using MATLAB/Simulink for induction motor load and the total harmonic distortion is evaluated at different load torques.</p>

A NEW STRUCTURE OF FIVE-LEVEL DIODE CLAMPED INVERTER WITH REDUCING ITS ELEMENTS

At the high power switching circuit's applications, when the harmonic distortion is harmful, a multi-level diode clamped inverter is useful, especially when reduced total harmonic distortion and high power are desired. But when the levels get a rise, number of semiconductors are also rising, which leads to many problems such as increasing cost, losses, installation area, and total harmonic distortion. Many researchers have tried to find solutions to these problems. In this sense, this paper focuses on: a) build a new structure of five level diode clamped inverter. b) Increase the efficiency of the inverter by reducing the number of switches. c) Reduce the total harmonic distortion. The theoretical calculation and simulation results are performed for five level diode clamped inverter by MATLAB/ SIMULINK.

Operation of Direct Power Control Scheme in Grid-Connected Mode Using Improved Sliding Mode Observer and Controller

Abstract This paper introduces the direct power control (DPC) scheme controlled by a new version of the 1st order sliding mode control to operate a distributed generator. This distributed generator is a core of the distributed generation system (DGS), which injects active and reactive power to the distribution system in a grid-connected mode. The presented 1st order sliding mode control based direct power scheme is very efficient in terms of chattering at steady-state and its dynamic performance. The superior performance of the presented control scheme results from a novel combination of an integral form for the sliding surface along with an innovative power-rate reaching law. The feedback power of the direct power scheme is estimated using an accurate developed formulation of the sliding mode observer. The distributed generator is based on the 5-level diode clamped inverter to minimize the injected harmonics. To prove the accurate performance of this new combination of the sliding mode control with sliding mode observer, the developed sliding mode observer is compared to Luenberger observer and the traditional virtual-flux based power estimation. Also, the whole control scheme is compared to other schemes for the same application such as conventional direct power control and conventional sliding mode control based direct power control.

Direct Power Control Applied on 5-Level Diode Clamped Inverter Powered by a Renewable Energy Source

Direct Power Control Applied on 5-Level Diode Clamped Inverter Powered by a Renewable Energy Source

Performance Analysis of FPGA based Diode Clamped Multilevel Inverter Fed Induction Motor Drive using Phase Opposition Disposition Multicarrier Based Modulation Strategy

<p>Multilevel inverters (MLI) are becoming more popular over the years for medium and high power applications because of its significant merits over two level inverters. This paper presents an implementation of multicarrier based sinusoidal pulse width modulation technique for three phase seven level diode clamped multilevel inverter. This topology is operated under phase opposition disposition pulse width modulation technique. The performance of three phase seven level diode clamped inverter is analyzed for induction motor (IM) load. Simulation is performed using MATLAB/SIMULINK. Experimental results are presented to validate the effectiveness of the operation of the diode clamped multilevel inverter using field programmable gate array.</p>

A Simplified Spam Algorithm for Three Level Diode Clamped Inverter

A Simplified Spam Algorithm for Three Level Diode Clamped Inverter

Fuzzy Logic Control of Wind Turbine Storage System Connected to the Grid Using Multilevel Inverter

This paper aimed to evaluate the use of wind turbine storage systems to provide electricity in the electrical grid through a five-level inverter. The proposed system is composed of four wind turbine generators based on permanent magnet synchronous generator (PMSG), four battery storage systems connected to each capacitor of the DC link and a five level diode clamped inverter connected to the grid by three phase transformer. The control algorithm proposed is based on fuzzy logic to tracks and extract the maximum wind power by controlling the rotational speed of wind turbine, which is most appropriate when there is a lack of information on the characteristic Cp (λ,β) of the turbine. The system operator controls the power production of the four wind turbine generators by sending out reference power signals to each input side regulation unit, the input side regulation units regulate the voltage of each capacitor of the DC link, regulate the voltage and the state of charge of each battery storage system. The inverter is controlled by simplified space vector modulation which allows us to reduce the computational time and reduce the algorithm complexity compared to the conventional five levels space vector modulation, the grid side control level regulate the power and the current injected to the grid.