GH-reference frame based SVPWM controlled T-type NPC Inverter fed PMSM drive for Electric Vehicle applications

Abstract

The performance of a multilevel inverter is dependent on the appropriate selection of modulation strategy. Among all other available methods, space vector pulse width modulation (SVPWM) is widely used due to advantages like reduction in switching losses, more utilization of inverter DC-link voltage, and simpler digital implementation. However, the implementation of SVPWM is very complex because of a greater number of space vectors, time consumption towards calculating dwell time, and the determination of switching states. The complexity of the conventional SVPWM strategy can be reduced to a great extent using the gh-reference frame based on the 60° coordinate system. This paper proposes a gh-reference framed SVPWM-based field-oriented-control (FOC) algorithm in a three-level T-type NPC inverter fed permanent magnet synchronous motor (PMSM) drive for electric vehicle (EV) applications. In this proposed technique, the value of the reference voltage vector is obtained directly after the proportional-integral (PI) type current controller. Then the PI controller associated with the SVPWM technique is used to realize the speed control of the PMSM in the 60° coordinate system. Experimental and simulation results are presented here to justify the viability of the FOC strategy in the gh-reference frame.