基于三相4桥臂的逆变器优化冗余控制策略研究

Research on Optimal Redundant Control Strategy of Inverter Based on Three-phase Four-leg

提出了一种基于三相4桥臂的逆变器优化冗余控制策略———第4桥臂模式切换法。通过分析逆变器故障后各桥臂的工作状态,确定故障后逆变器的电压空间矢量分布图,并根据SVPWM控制算法,制定逆变器优化冗余控制策略,维持逆变器持续运行,提高逆变器的工作可靠性。采用该控制方法,通过第4桥臂模式的切换,增加了逆变器输出线电压的电平数,使逆变器输出线电压波形质量大幅度提高。在Matlab/Simulink环境下对控制策略进行了仿真,并在实验室条件下搭建了逆变器的硬件电路,利用TMS320LF2407 DSP芯片实现了冗余控制算法。理论分析、仿真和实际实验都验证了控制策略的有效性。

An optimal redundant control strategy of inverter based on three-phase four-leg, the method of mode switching of the fourth leg, was proposed. The diagram of voltage space vector distribution is determined by analyzing the post-fauh state of each leg. The optimal redundant control strategy, which can maintain the continuous work of inverter so as to enhance the reliability of inverter, is laid down according to SVPWM. Using this strategy adds the levels of inverter and improves the quality of waveforms through mode switching of the fourth leg. The strategy was emulated in Matlab/Simulink and realized through the TMS320LF2407. Hardware circuit was established in laboratory. Theoretical analysis, emulation and experiments all verify the availability of the control strategy.