Title: Space vector modulation of multilevel inverters with online vector identification and reduced switching losses for HEV/EV applications
Authors: Scott Cash; Quan Zhou; Oluremi Olatunbosun; Hongming Xu
Addresses: Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, UK ' Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, UK ' Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, UK ' Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, UK
Abstract: Multilevel inverters are used in a wide range of medium-high power applications including hybrid and electric vehicles (HEV/EV). This paper investigates an online reduced intermediate switching space vector pulse width modulation (RIS-SVPWM) scheme to minimise switching losses without the need for large lookup tables or severely diminishing output harmonic quality. While previous online methods only calculate the switching patterns of a single enclosing voltage vector, this RIS-SVPWM method calculates all the switching patterns surrounding the reference voltage by incorporating only two more additional mapping iterations into the online algorithm regardless of the inverter level. The RIS-SVPWM method can operate in the sinusoidal, overmodulation mode-I and overmodulation mode-II regions of various inverter voltage levels and topologies. The performance of the RIS-SVPWM algorithm is examined over the entire driving range of an HEV/EV by controlling a MATLAB/Simulink model of a three-phase five-level cascade H-bridge inverter powering an induction motor model. The results of the simulation study show that there is a reduction in intermediate switching by up to 90% and a total switching reduction by 30% over a previous online SVPWM algorithm while maintaining acceptable voltage and current waveform harmonic quality.
Keywords: space vector pulse width modulation; SVPWM; multilevel inverter; hybrid and electric vehicle; HEV/EV; reduced switching; neutral-point balance; cascade H-bridge.
International Journal of Power Electronics, 2021 Vol.14 No.3, pp.271 - 291
Received: 01 Jul 2018
Accepted: 07 Apr 2019
Published online: 13 Sep 2021 *