Event date:
Jul 5 2022 2:00 pm

An Advanced Pulse Width Modulation Method to Achieve Superior Performance in Electric Vehicle Powertrains and Grid-Connected Photovoltaic Converters

Dr. Hafsa Qamar
Reading Room (Tesla Wing), Electrical Engineering Department, SBASSE
The performance of voltage source inverter (VSI) in terms of output waveform quality, conversion efficiency and common mode noise depends greatly on the pulse width modulation (PWM) method. In this talk, I will discuss an advanced PWM method i.e., 240° clamped space vector PWM (240CPWM) to improve the performance of VSIs in electric vehicle/hybrid electric vehicle (EV/HEV) powertrains and grid-connected photovoltaic (PV) converters. The salient features of 240CPWM include 240 degrees clamping of each phase pole to positive or negative DC bus in a fundamental cycle ensuring that switching losses are reduced by a factor of seven as compared to conventional space vector PWM (CSVPWM) at unity power factor. Zero states are completely eliminated and only two nearest active states are used ensuring that there is no penalty in terms of total harmonic distortion in line current. The elimination of zero states in 240CPWM also reduces the peak common mode voltage to one sixth of the DC link voltage whereas it is one half of the DC link voltage for CSVPWM. The performance benefits of 240CPWM are verified using a 10 kW experimental prototype where the inverter efficiency exceeds 99% with 240CPWM. The achieved superior performance translates to highly efficient, power dense, reliable, and low cost inverters used in EV/HEV drive trains and PV converters.

Dr. Hafsa Qamar received her BS degree in electrical engineering from University of Engineering and Technology, Lahore, Pakistan, in 2015, followed by the M.S. degree in energy systems engineering from Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Swabi, Pakistan, in 2017. She carried out her M.S. research from University of Sannio, Italy on Erasmus Mundus scholarship. Dr. Hafsa received her Ph.D. degree in Electrical Engineering from Arizona State University, USA on Fulbright scholarship in May 2022. She published her work in high impact factor journals and reputed conferences in the USA. Dr. Hafsa was awarded with outstanding engineering graduate scholarship by Ira A. Fulton School of Engineering in Arizona State University. Her research interests include advanced pulse width modulation methods for improving the performance in EV/HEV drive trains and grid connected PV converters.