Recent developments of modulation and control for high-power current-source-converters fed electric machine systems

The pulse-width-modulated (PWM) current-source converters (CSCs) fed electric machine systems can be considered as a type of high reliability energy conversion systems, since they work with the long-life DC-link inductor and offer high fault-tolerant capability for short-circuit faults. Besides, they provide motor friendly waveforms and four-quadrant operation ability. Therefore, they are suitable for high-power applications of fans, pumps, compressors and wind power generation. The purpose of this paper is to comprehensively review recent developments of key technologies on modulation and control of high-power (HP) PWM-CSC fed electric machines systems, including reduction of low-order current harmonics, suppression of inductor-capacitor (LC) resonance, mitigation of common-mode voltage (CMV) and control of modular PWM-CSC fed systems. In particular, recent work on the overlapping effects during commutation, LC resonance suppression under fault-tolerant operation and collaboration of modular PMW-CSCs are described. Both theoretical analysis and some results in simulations and experiments are presented. Finally, a brief discussion regarding the future trend of the HP CSC fed electric machines systems is presented.