三相电压型准Z源逆变器电路拓扑和调制策略

准Z源逆变器具有宽范围升压能力,适用于光伏风力等可再生能源发电。从拓扑和调制策略两方面详述了三相电压型准Z源逆变器的发展与现状,并获得了重要结论。其电路拓扑包括基本型、强升压能力改进型、低电压应力改进型和能量存储型4类,其中强升压能力改进型又分为单阻抗网络和级联阻抗网络2类,给出了电压应力、升压能力等特性比较;低电压应力改进型包括三相三电平中点钳位、级联多电平和级联Trans等。调制策略有正弦脉宽调制SPWM(sinusoidal pulse width modulation)、改进空间矢量脉宽调制SVPWM(space vector pulse width modulation)和消除共模漏电流改进脉宽调制PWM(pulse width modulation)3类,给出了调制系数、电压应力特性比较。

Circuit Topologies and Modulation Strategies for Three-phase Voltage-fed Quasi-Z-source Inverter

Owing to its wide range of voltage boost capability, quasi-Z-source inverter(qZSI) is suitable for the ren-ewable energy power generation, such as photovoltaic and wind. In this paper, the development and current situation of three-phase voltage-fed qZSI are presented from the aspects of circuit topology and modulation strategy, and some conclusions are obtained. The circuit topologies include basic type, strong boost capability improved type, low voltage stress improved type, and energy storage type; the second type can also be categorized into single and cascaded impedance-source networks, and their characteristics including voltage stress and boost capability are compared; the third type consists of three-phase three-level neutral-point-clamped, cascaded multilevel, and cascaded Trans, etc. The modulation strategies have three types, i.e., sinusoidal pulse width modulation(SPWM), modified space vector pulse width modulati-on(SVPWM), and modified pulse width modulation(PWM) with common mode leakage current decreasing, and their ch-aracteristics including modulation coefficient and voltage stress are compared.