针对有源滤波器电流谐波分量检测复杂且在非线性负载变化时出现电源电流畸变的现象.基于非线性控制理论.从能量平衡关系出发,提出了新型的有源滤波器控制方法。利用本质上是非线性反馈的无源性控制(PBC)策略,实现直流侧电容电压的补偿控制,在非线性负载时变未知情形下.确保系统稳定的同时.实现谐波电流的精确计算与跟踪。基于此,将PBC方法与滑模、自适应控制相结合.现线路参数与负载变化时参考谐波电流的准确跟踪.并有效抑制由电阻、电感变化引起的跟踪误差。该方法从能量角度分析并联型有源滤波器的控制系统,确定不必抵消的“无功力”.设计全局定义的控制律。具有形式简单、无奇异点、鲁棒性好等的特点。基于dSPACE的实验结果证明了该控制策略的有效性。
A control algorithm based on the nonlinear control theory and energy balance is proposed for active filters. It applies the PBC(Passivity-Based Control) with nonlinear feedback in DC voltage compensation control to calculate the harmonic current and ensure the stability of system with time-varying nonlinear load. A passivity-based adaptive sliding mode control is developed to accurately track the reference harmonic current during the line parameter change and load change. It analyzes the control system of shunt active filters from the viewpoint of energy,identifies the "workless forces" and designs the control laws with global definition. It is robust,simple in format,and without singular points. Its effectiveness is testified by the experiments based on dSPACE.