High quality voltage regulation of a five-level current source inverter

This paper presents a high performance voltage regulation algorithm for a five-level current source inverter. The work combines linear voltage regulation concepts for a two level CSI, with an advanced modulation strategy that directly controls the intermediate link inductor currents of the 5-level converter. The voltage control loop is based around PI and PR stationary frame regulators, which achieve an excellent performance when their gains are maximized while still taking into account practical factors such as transport delay. The theoretical analysis is verified with simulated and matching experimental results.