基于新型双电压空间矢量调制的准Z源六桥臂电压源逆变器

Quasi Z-source six-leg voltage-source inverter based on a new space vector modulation strategy

传统多相逆变器输出电压幅值普遍低于输入电压。当负载过大,需要的直流母线电压会更高,相对应的滤波电容体积会更大,成本更高。在多相逆变器的传统控制中,死区设置的复杂性影响着输出波形的质量。针对这些缺点,将准Z源网络引入六桥臂电压源逆变器(QZS-SL-VSI)中,在分析传统六桥臂逆变器空间矢量调制策略的基础上提出了一种新的带直通控制的双电压空间矢量调制策略。首先,分析准Z源六桥臂电压源逆变器(QZS-SL-VSI)升压工作原理;接着,分析准Z源六桥臂电压源逆变器的电压矢量分布。在此基础上,详细阐述了所提出的带直通控制的双电压空间矢量调制策略以及两种基于直通零矢量作用时间分配的开关模式。最后,基于Matlab/Simulink进行仿真验证并设计了一台小功率样机进行实验验证。通过分析仿真与实验波形,充分验证准Z源六相逆变器及控制策略的正确性和可行性。

The output voltage amplitude of traditional multiphase inverter is always lower than the input side.When in a heavy load,higher DC-link voltage is needed,which will enlarge the volume of the filter capacitor and increase the cost.In the traditional control of multiphase inverter,the complexity of setting dead zones affects the quality of the output waveforms.For these drawbacks,the quasi Z-source network is introduced to the six-leg voltage-source inverter(QZS-SL-VSI)and an improved modulation strategy with shoot-through control is presented on the basis of the SVPWM for the traditional six-leg inverter.First,the boost operating principles are analyzed in detail.Then,the distribution of the voltage vectors of quasi Z-source six-leg inverter is analyzed.On this basis,the dual voltage space vector modulation strategy with shoot-through control and two switch modes based on the distribution working time of the shoot-through zero vector is expounded.Finally,Matlab/Simulink simulation is conducted,and a prototype machine is designed to experimental verification.Through analyzing simulative and experimental waveform,the feasibility and validity of the QZS-SL-VSI and new strategy are well verified.