一种新型的三相桥级联型PWM变换器

A novel three-phase-bridge cascaded PWM converter

传统的单相级联H桥变换器不易直接应用于三相高压场合,为此提出了三相桥级联型PWM变换器的拓扑结构,其子模块为电压源型三相桥式变换器。分析了该新型拓扑的构成思想,推导了二级和三级级联拓扑的电流和功率表达式,其可做整流器也可做逆变器,分别采用单周控制和载波相移控制对其进行仿真研究。仿真结果验证了该新型拓扑的可行性,表明其能够提升电压等级,与传统的单相级联H桥变换器构成的三相变换器相比,能够节省开关管和直流侧电容(独立电源)个数,且直流侧电压纹波较小,在三相高压场合具有较好的应用前景。

The traditional single-phase cascaded H-bridge converter （CHBC） can not be used for three-phase high-voltage applications directly, thus a novel topology of three-phase-bridge （3P-Bridge） cascaded PWM converter is proposed and its basic cell is a 3P-Bridge. Its construction idea is analyzed and the currents and power expressions are derived. The proposed topology in this paper can not only be operated as a rectifier but also an inverter. One-cycle control （OCC） and CPS-PWM are employed for their simulation research separately. Simulation results verify the feasibility of the proposed 3P-Bridge cascaded converter and show that the proposed topology can improve the voltage level, and comparing with the traditional single-phase CHBC, it can reduce the number of switches and DC capacitors （or separated DC sources）, and the voltage ripple at DC side is smaller. So the proposed 3P-Bridge cascaded converter has better prospect in three-phase high-voltage applications.