Modulation Schemes for a 36MVA Press-Pack IGBT Converter under Interleaved Operation

In this paper, modulation schemes for a press-pack insulated gate bipolar transistor (IGBT) converter under interleaved operation are investigated. This article focuses on how to maximize the output capacity of paralleled converters while ensuring the power quality. Therefore, there are several important targets should be considered in the design of modulation algorithms: 1) the total harmonic distortion (THD) of the output current, 2) neutral-point potential balancing, 3) suppression of the circulating current. Then, a novel five-level (5L) space vector modulation scheme with two-layer redundant state active control is proposed in this article. At each switching cycle, the 5L state is immediately distributed to two three-level (3L) states by the smart redundancy selection, which is integrated the predicted and the priority control. The proposed scheme is experimentally validated up to 36 MVA on a press-pack IGBT converter prototype.