一种高频链矩阵整流器的闭环控制方法

A Closed-loop Control Method for High-frequency Matrix-type Rectifier

为解决三相高频链矩阵整流器稳态情况下LC滤波器谐振导致电网电流低频振荡,动态过程中系统强耦合造成输出响应差的问题,提出了一种基于输入滤波电容电压和滤波电感电流反馈的闭环控制方法。首先建立三相高频链矩阵整流器的数学模型,根据整流器的小信号数学模型,建立电容电压控制内环、电感电流控制外环的双闭环控制策略;利用波特图和零极点对消,设计双闭环控制策略中比例积分(PI)控制器的系数。在闭环控制策略中,前馈解耦的控制方法消除了坐标变换导致的d,q轴电流互相影响,并且动态电容电压的闭环控制抑制了电网输入侧LC谐振导致的电网电流低频振荡。最后,通过实验验证了所提矩阵整流器闭环控制方法的可行性与有效性。

In order to solve the problems including steady-state grid current low-frequency oscillation and poor output response of three-phase high-frequency matrix-type rectifier,which are caused by LC resonance of filters and strong system coupling during dynamic process,a closed-loop control scheme based on input filter capacitor voltages and filter inductor current feedback is proposed.Firstly,the mathematic model of three-phase high-frequency matrix-type rectifier is established and the double closed-loop control scheme including the capacitor voltage control in the inner loop and the inductor current control in the outer loop is designed according to the small signal mathematic model of the rectifier.The coefficients of the proportional integral(PI)controllers used in the double closed-loop scheme are designed with Bode diagrams and zero-pole cancellation.The feedforward decoupling control method is employed to eliminate the coupling effects of d,q axis currents caused by coordinate transform in the closed-loop control scheme.Moreover,the grid current low-frequency oscillation caused by the grid input side LC resonance is suppressed with the dynamic capacitor voltage closed-loop control.Finally,the feasibility and effectiveness of the proposed matrix-type rectifier closed-loop control scheme are validated by experiments.