提出了一种能在单相并联型有源电力滤波器(Active Power Filters,APF)中使用单闭环控制策略的实现方法.该实现方法通过构造与网侧电压、电流正交的虚拟电压、电流分量后,采用单相PQ理论推导出了单相并联型APF在理想情况下补偿电流指令的表达式.在此基础上,本文通过功率预测算法求取了用于稳定APF直流侧电压而必须从电网吸收的有功功率表达式,进而获得实际工作状态下补偿电流指令.功率预测算法的使用可使本文提出的实现方法能取消常规方法中必须具备的电压调节环节而仅采用单闭环控制策略来对APF进行控制,因而具有控制参数设定简单、系统的动态响应快和鲁棒性强等特性.文中还以实际中使用最为广泛的一种单相并联型APF的电路为例,研究了APF在启动、正常运行和负载突变状况下的动态响应过程.仿真和实验结果验证了本文提出的实现方法的有效性.
A new implementation method for single-phase shunt active power filter (APF) with single closed-loop control strategy is presented. The ideal compensation current instruction is deduced with single PQ theory, which applies with actual and virtual quartered single-phase current and voltage. Based on the ideal compensation current, the practical compensation current instruction is achieved with power pre- dictive algorithm. Because the power predictive algorithm is adopted, the single closed-loop control strategy can be used in APF application. There is no voltage control loop in the implementation method, so the method has many favorable characteristics, such as easy designing, fast responding, strong robustness, etc. The different conditions of APF, such as startup, normal operation and load change, are also researched in the paper. The validity of implementation method for APF is proved by simulation and ex- perimental results.