三相并网逆变器改进型重复控制策略

Three-phase Inverter With Modified Repetitive Control Strategy

为抑制并网逆变器注入电网的谐波,一般采用重复控制的方法以保证并网电流的稳态精度。单一的重复控制难以保证控制系统的响应速度,比例积分(PI)+重复控制的方法可有效解决控制响应速度与控制稳态精度间的矛盾。然而PI与重复控制算法间存在控制上的耦合性,在电流指令瞬态变化的过程中会造成电流波形的畸变。此处一方面使用了动态延时处理的改进型重复控制策略,另一方面就该改进重复控制算法因参数漂移而导致系统镇定补偿器设计难的问题重新设计了控制结构。通过仿真和实验对比验证了所提算法的正确性。

To suppress harmonic injection of grid-connected inverter, the general process is adopt to ensure steady ac- curacy of grid-connected current with the method of repetitive control.Single repetitive control is difficult to guarantee the response speed of the control system, proportional integral （PI）＋repeat control method can effectively solve the con- tradiction between the corresponding speed and the precision of steady state.However,PI and repetitive control exist coupling between the control agorithm,transient changes in the current command procedure will cause distortion of current waveform.The improved dynamic time delay process of repetitive control strategy is used, the control structure is designed as a result of the existence of parameters drift cause by the system stabilization compensator design diffi- cult problem.The correctness of the proposed algorithm is verified by simulation and experimental.