四桥臂三相逆变器的解耦控制

四桥臂三相逆变器是针对三相不平衡或非线性负载供电提出来的。由于第四桥臂的滤波电感引起的耦合效应，使三相电压的控制变得十分复杂。该文针对这一问题，提出了一种解耦控制策略，将滤波电感看成电源内部阻抗，并从改变电源内部阻抗思想出发，推导出变换关系，使三相电压控制实现解耦，将复杂的三相电压的控制，转化为单相电压控制问题，同时，解决了第四桥臂电感值的选择问题。该变换需要的参数和变量较少，简化了四桥臂三相逆变器的控制算法。以该解耦变换思想为基础，构造了四桥臂三相逆变器控制系统。仿真结果显示，该逆变器可带任意负载，且具有良好的动态特性和静态特性.

Decoupling Control of Three-phase Four-legged Inverter

The three-phase Four-legged inverter was proposed for unsymmetrical and nonlinear three-phase load. because of the existence of the fourth leg and the coupling effect of the filter inductance,the control of the three-phase voltage became very complicated.This paper proposed a new decoupling control strategy for the above problem.In this paper the filter inductance is regarded as an inner resistance of the power source.A transformation relationship is proposed based on the idea of changing the inner resistance of the power source Therefore the three-phase voltage can be decoupled entirely and the complex control problem can be changed a into simple single-phase voltage control.At the same time,this method gives how to choose the value of the fourth leg's inductance. The method needs fewer parameters and variables and simplifies the control algorithm of Three-phase Four-legged Inverter.Based on the decoupling transform idea,the Three-phase Four-legged Inverter control system is constructed. The simulation result shows that this inverter fits any load and has excellent dynamic and static characteristics.