并联型有源电力滤波器的起动策略研究

Research on Start Strategy of Shunt Active Power Filter

传统控制方式下并联型有源电力滤波器(SAPF)起动时会引起直流侧电压超调和交流侧补偿电流冲击。本文设计了软起动控制器。有源电力滤波器首先采用直流侧预充电的电路拓扑结构,减小了SAPF起动时的直流侧电压偏差,缓解了冲击电压和电流;然后针对传统变PI参数控制器在动态和稳态特性上的缺点,提出了模糊PI切换器。该控制器利用模糊控制的非线性优点,消除了电压超调,降低了电流冲击。再利用PI控制器响应速度快的优点,保证稳态补偿精度。为了进一步减小冲击,设计了参考电流线性递增控制方法。通过参考电流的线性控制,实现了软起动控制目的。仿真结果证明了所提出的软起动控制策略的有效性。

The launch of shunt active power filter（SAPF） under traditional control method has been proved to cause DC voltage overshoot and AC current shock. To solve this problem, a soft start controller was designed. Based on the circuit topologies structure of DC capacity preeharge, the voltage offset is decreased, which remits the shock voltage and current. Considering the disadvantage of PI controller whose parameters were changeable in dynamic response and steady response, a switching controller between fuzzy controller and PI controller was proposed. The fuzzy controller is utilized to eliminate voltage overshoot and reduce current shock because of the nonlinear advantage of fuzzy control, while the PI controller is adopted to guarantee the steady state accuracy with a fast response speed. A new linear increase control method of referenced current was used to solve the current shock. With linear control of referenced current, the soft start of SAPF is accomplished. The control strategy of soft start is oroved to be effective by the simulation.