単一デルタブリッジセル変換器を用いた直流/三相変換器の低励磁インダクタンス動作

抄録

A single-delta bridge-cell converter (hereinafter referred to as an SDBC converter) is a prospective power converter for a static synchronous compensator (STATCOM). The authors have proposed a dc/3ϕ power converter using the SDBC converter and a medium-frequency single-phase transformer with an operating frequency of 150Hz; this converter can exchange a maximum active power of 37% of the rated reactive power with three-phase ac mains supply without increasing the voltage and current ratings of the SDBC converter. In particular, the negative-sequence reactive power control is a challenging task because of the high magnetizing inductance of the transformer. To achieve the negative-sequence reactive power control, a single-phase transformer with low magnetizing inductance is applied to the converter at the expense of the exchangable active and reactive power. The relationship of the magnetizing inductance, active power, and reactive power is revealed in this paper, and the operation of the converter under low magnetizing inductance is experimentally verified by employing a downscaled 110-V, 7-kVA model.