Power Losses and THD Analysis of Current Source Inverters in Motor Drive Applications: A Comparative Study of Control Schemes

Current Source Inverters (CSIs) for motor drive application historically suffered the need of a pre-stage to control DC-link current and the problem of CL resonance of output currents. The advent of innovative control schemes and architectures solved the need for a pre-stage, but the efficiency gain given by eliminating pre-stage has never been explored, as does the investigation of the CL resonance problem. While prior research has addressed resonance issues using various control strategies, few studies have delved into the efficiency implications of these solutions. This paper undertakes a comparative analysis of traditional CSI control schemes against innovative alternatives, evaluating power losses and Total Harmonic Distortion (THD) of the output currents. Specifically, two distinct control schemes are analyzed over the classical field oriented control: the first in- corporates an inner closed-loop on voltage to mitigate resonance, while the second obviates the need for a pre-stage in high-speed operations, demonstrating improved power loss performance.