Improved voltage regulation for current-source inverters

Abstract

Voltage regulation schemes for current-source inverters (CSIs) commonly use a simple proportional-integral (PI) stationary frame controller, but this approach is known to suffer from significant steady-state error. In contrast, the more advanced schemes that are routinely used for current regulation of voltage-source inverters (VSIs) avoid these problems. This paper presents an approach to directly utilize VSI current regulation strategies to control the voltage for a CSI, without requiring significant modification or development. The approach uses a space-vector mapping technique to convert VSI modulation signals to CSI gate drive signals, which allows VSI closed-loop current control strategies to be directly applied to CSI voltage regulation. Three new voltage regulation CSI controllers based on hysteresis, synchronous frame PI, and stationary frame P+Resonant control principles are presented based on this concept.