SiC-MOSFET three phase unbalance compensation device with interleaved parallel structure

In this paper, a three-phase unbalance compensation device with two-module interleaved parallel structure is proposed, which can reduce the harmonic of output voltage and output ripple current. Meanwhile, by using SiC-MOSFET as the switching device, the switching frequency of the device has been increased to 50 kHz to increase the harmonic frequency of the output voltage. With the above two designs, only a single L filter can be used to effectively filter the output voltage harmonics of the inverters, and the detection and compensation accuracy is also optimized. A 50 kVA prototype has been fabricated based on the theories above, which is at least half smaller than a conventional device of the same capacity. The PI + repeat controller (RC) is used to achieve the none-static-error tracking of sinusoidal signals, so as to achieve a good compensation effect.