V. Kamaraj

A novel space vector PWM for Z-source inverter

This paper presents a novel space vector pulse width modulation (SVPWM) technique for three phase Z-source inverter. The proposed modified SVPWM has an additional shoot-through state for boosting the dc link voltage of the inverter beside active and zero states. The shoot-through states are evenly assigned to each phase within zero state. So zero voltage period is diminished for generating a shoot-through time, and active states are unchanged. Simulation and experimental results are presented to demonstrate the new features.

GA based optimization and critical evaluation SHE methods for three-level inverter

The Selective Harmonic Elimination Pulse-Width Modulation (SHE-PWM) has been an inclusive research area in the field of Power Converters. This technique offers a tight control of the harmonic spectrum of a given voltage waveform generated by a power electronic converter along with a low number of switching transitions. It involves the solution of non-linear transcendental equation sets representing the relation between the amplitude of the fundamental wave, harmonic components and the switching angles. This paper reports solutions to the Selective Harmonic Elimination (SHE) method based on novel usage of Artificial Intelligence (AI) technique such as Genetic algorithm (GA) for single-phase unipolar waveform. This paper uses Matlab GA Toolbox to generate the gate pulse pattern to eliminate the required order of harmonics at any demanded fundamental output voltage.

Switched reluctance machine in automotive applications — A technology status review

Switched reluctance machines have emerged as an important technology to be deployed in automotive electric drives; they represent a real alternative to conventional electrical machines in automotives. This paper reviews the technology status and trends in switched reluctance machines. It covers the various aspects of modeling, design, simulation, analysis, and control. Finally, it discusses the impact of switched reluctance machines technology on intelligent motion control.

Design optimization of Switched Reluctance Machine using Particle Swarm Optimization

This paper presents Particle Swarm Optimization (PSO) based design optimization of Switched Reluctance Machine (SRM). The SRM design is formulated as multiobjective constrained optimization problem. The objective functions for obtaining desired design are maximization of average torque and minimization of torque ripple with stator and rotor pole arc as design variables. The optimization procedure is tested on 8/6, four-phase, 5 HP, 1500 rpm SRM. The results are compared and investigated with those obtained from Genetic Algorithm (GA) technique and FEA simulation. The results demonstrate that the proposed method is effective and outperforms GA in terms of solution quality, accuracy, constraint handling and computational time.

Integer lifting wavelet transform based hybrid active filter for power quality improvement

This paper advances a novel method for power quality monitoring by using integer lifting wavelet transform (ILWT). ILWT based wavelet uses time domain for its integer calculation and could lessen calculation complexity due to its structure, compared with modified wavelet transform (MWT) and wavelet transform (WT) which depends on floating point coefficients. The whole method is tested over sample disturbances like voltage sag, voltage swell and harmonics. As shown by the simulation experiment results, the proposed approach displays a good decomposition of various power quality waveforms. The hybrid active filter is modeled using P-Q theory and simulation studies are performed using MATLB software. The simulation results, the proposed approach displays a good reduction in harmonics in comparison with passive filter, active filter and hybrid active filter.

Soft switched high step-up DC-DC converter for automotive application

In this paper, a hybrid topology that combines clamp-mode coupled inductor and voltage multiplier cell is proposed to provide high voltage gain, reduced switching losses and higher power density. The duty ratio of the converter is also maintained at safe limits while obtaining the required voltage gain. The topology has been designed for a 220V, lkW application operating from 12V input. The reactive elements are designed for a switching frequency of 50 kHz. Various operating modes, design equations, simulation and hardware results are presented. Hardware results prove that the converter performs satisfactorily.

Grid integration of 10kW solar panel

Renewable energy resources such as wind and solar are more widely used for power generation. Photovoltaic panels are used to convert solar energy into electrical energy. Solar energy can be used for both stand alone and grid side applications. Grid tied systems are connected to electrical grid and allow residents of building to use solar energy. The photovoltaic system consists of PV panels connected through DC-DC converter and DC-AC inverter to the grid. The IV and PV characteristics of PV panels are used to determine the MPP. The MPPT algorithm used for tracking maximum power is incremental conductance algorithm. In addition to operate at the international standards, three phase PWM inverter with PI controller is used. This paper deals with the grid interaction of 10kW panel and the study of real power flow from the source to the utility grid.

Sensitivity Analysis of Geometrical Parameters of a Switched Reluctance Motor with Modified Pole Shapes

A major problem in Switched Reluctance Motor (SRM) is torque ripple, which causes undesirable acoustic noise and vibration. This work focuses on reducing the undesirable torque ripple in SRM by modifying stator and rotor geometry. This paper presents a comparative study on torque ripple minimization in SRM with modified pole shapes such as stator pole taper, stator pole face with non-uniform air gap and pole shoe attached to rotor pole. Further this paper presents a detailed sensitivity analysis of the effect of different geometrical parameters that alter the pole face shapes on the performance of SRM. The analysis is performed using finite-element method considering average torque and torque ripple as performance parameters. Based on the analysis, a design combining stator pole taper with non-uniform air gap is proposed to improve the torque characteristics of SRM. The dynamic characteristics of the proposed design are simulated and the results show satisfactory reduction in torque ripple.

Z-source inverter with improved performance for photovoltaic applications

A Z-source inverter with a modified carrier based pulse width modulation technique is proposed for photovoltaic systems. In this new technique, two carrier waves and three reference waves are used to produce the switching pulses. This paper demonstrates that the Z-source inverter can boost DC voltage when needed, perform maximum tracking and minimum output distortion, and interface with photovoltaic system. The control method is analyzed to exhibit the novelty of features. The control algorithm is corroborated by simulation and experimental results. A comparison in harmonic distortion between the new and traditional pulse width modulation techniques is performed.

Bipolar multicarrier PWM techniques for cascaded quasi-Z-source multilevel inverter

Quasi-Z-source inverters are educed with additional advantages of continuous current from source, lower switch stress and smaller component ratings in addition to buck/boost capability, inversion and single stage conversion of the basic topology of Z-source inverters. This work proposes a novel topology of cascaded quasi-Z-source multilevel inverter. The working and switching states of the proposed topology are explained. Modified multi-carrier bipolar PWM techniques are explicated for the proposed inverter. A five level quasi-Z-source inverter is designed, modeled and the simulation results are obtained. The total harmonic distortion and individual harmonic contribution in each pulse width modulation techniques are performed.