* Corresponding author: Suresh L., Department of Electrical and Electronics Engineering, Vignan’s Lara Institute of Technology and Science, Vadlamudi, India, E-mail:suresh.201@gmail.com 1, 2 & 3 Faculty of Electrical and Electronics Engineering, Vignan’s Lara Institute of Technology and Science, Vadlamudi, India. Copyright © JES 2013 on-line : journal/esrgroups.org/jes Suresh L. * , G. R. S. Naga Kumar 1 , M.V. Sudarsan 2 , K. Rajesh 3 J. Electrical Systems 9-4 (2013): 453-467 Regular paper A Comparative Analysis of PWM Techniques for ZSI in Application of Electric Vehicles JES Journal of Electrical Systems This paper focus on, three pulse width modulation (PWM) techniques such as simple boost control (SBC), maximum boost control (MBC) and constant boost control (CBC) are analyzed for impedance source inverter (ZSI) topology, because of its boosting capability of applied input voltage, compared with traditional voltage or current source inverters. For the purpose of comparison, the ZSI topology is simulated by using different PWM techniques for the same input voltage, switching frequency, peak voltage of inverter and duty ratio. These simulations have been developed for ZSI for electric vehicle applications. The comparison results show that constant boost control technique is a suitable PWM method for ZSI topology. Keywords: Zsi; sbc; mbc; cbc; Electric Vehicle (EV). 1. Introduction Electric Vehicle (EV) is achieving alternative applications for conventional internal combustion engine vehicle [1].These vehicles are being developed by auto manufacturers [2], [3], [4], and have generated interest between industry and consumers. An EV promises the air quality benefits of a battery-powered electric vehicle, with the driving range and convenience of a conventional internal combustion engine vehicle. If conventional PWM inverter is used for EV applications, an additional DC – DC boost converter will be required, which causes reduced efficiency and high cost of overall system. Recently proposed Z – source inverter [6] shown in fig. 1, is suited for many applications. The main advantages are 1) It either boosts or buck input voltage based on the modulation index, does not require an additional converter 2) It provides ride through capability against sags & swells 3) It improves the overall system efficiency and power factor. Many PWM control methods are proposed for traditional voltage source inverter (VSI). The proposed control methods include six active states and two zero states. During six active states DC voltage is impressed across the load, in zero states any upper or lower leg switches are short circuited. Here ZSI another state is introduced as shoot through state. How to introduce this shoot through state is important in ZSI topology. There are mainly three PWM control methods for ZSI. The main aim of this paper is to present a detailed analysis of these control methods and to make a comparison between them.