单周控制双Buck型电压源换流器

为了改善轻型直流输电网络的波形质量,目前电压源换流器使用较多的高频开关器件,导致损耗加大,成本增高,限制了其实际应用.该文提出了一种双Buck型电压源换流器（BVSC）,该BVSC由一组双Buck变换器和一个工频逆变桥组成,仅用两个高频开关,即可取得较好的输出波形,大大降低了系统成本.同时文中提出了基于单周控制的控制策略实现换流器输出电流与电网电压同相,应用简单的控制电路可以实现单位功率因数.实验结果证明了单周控制双Buck换流器的正确性和实用价值.

A NOVEL DUAL-BUCK VOLTAGE SOURCE CONVERTER WITH ONE CYCLE CONTROL

In this paper a new Buck type voltage source converter (BVSC) is proposed in order to reduce the cost of voltage source converter. The new BVSC comprises a dual-buck converter and a three-phase inverter operating in grid frequency. Only two high frequency switches are used, which results good output waveform performance. The BVSC can be decoupled into a series-connected dual-buck topology during each 60 degree of grid cycle. A new extension of the constant-frequency one cycle control strategy is proposed to provide the PFC function for the new BVSC. No multiplier is necessary to scale the current reference as required by many other approaches. The new BVSC and control method are verified by experiment.