Loss and stress reduction in VSI devices for EVs using general discontinuous PWM

Abstract

In this paper, a new carrier based discontinuous pulse width modulation (DPWM) strategy for voltage source inverter (VSI) is presented in order to use in electric vehicles (EV). The basic idea of DPWM techniques, is clampimg to upper or lower terminal of DC-link to avoid commutations. Clamping interval of this algorithm is controlled on-line by output current values, to avoid switching with highest current values. The triangular carrier signals are generated as well, depending on output currents to ensure minimum input current ripple. This reduces DC-link capacitor current, and so, reduce stress in capacitor. Switching losses and capacitor current are optimized for whole load angles.