抑制三相四桥臂逆变器共模电压的三维SVPWM控制策略

Three-dimensional SVPWM Control Strategy for Suppressing Common-mode Voltage of Three-phase Four-bridge Inverter

研究基于三相四桥臂逆变器的三维空间矢量脉宽调制(3D-SVPWM)控制策略。针对大功率变流系统存在较大共模电压,易对电机等负载造成伤害,影响电网电能质量等问题,提出一种改进的3D-SVPWM控制策略。首先,对三相四桥臂逆变器的拓扑结构进行分析,说明了产生共模电压的原因。然后,在传统3D-SVPWM控制策略的基础上,提出选取参考电压矢量附近两个相反的非零矢量来代替零矢量的方法。最后,通过MATLAB/Simulink建模仿真证明,改进后的控制策略不受负载平衡状态改变等方面的影响,在不改变直流电压利用率的前提下,可以有效降低共模电压,达到主动抑制的目的。

The three-dimensional space vector pulse width modulation（3 D-SVPWM）control strategy for suppressing commonmode voltage of three-phase four-bridge inverter is analyzed.Because the common mode voltage generated from the high power convertor system is easy to damage the load such as motor,and affect the power quality of the power supply,an optimized 3 DSVPWM control strategy is proposed.Firstly,the topology of three-phase four-bridge inverter is described,and the reason of generating the common mode voltage is given.Then,according to the traditional 3 D-SVPWM control strategy,two converse non-zero vectors near the reference vector are selected to replace the zero vectors.Finally,the modeling and simulation are carried out through MATLAB/Simulink and the results show that the improved control strategy is not affected by the changes of load balance status.Moreover,without changing the DC voltage utilization,the common-mode voltage can be effectively decreased to realize active suppression.