三相四线APF直流侧的T-S模糊均压控制

电容分裂中点式三相四线有源电力滤波器（APF）是解决三相四线电力系统谐波治理的有效方法，由于直流侧两组电容电压需要单独控制，增加了均压控制难度并直接影响补偿的效果。分析了该APF的电路拓扑，采用T-S模糊控制的方法对电容分裂中点式三相四线APF的直流侧均压控制进行建模，将直流侧两组电容电压分别作为输入前件变量，对电源电流实施反馈控制。设计的T-S模糊反馈控制器使APF直流侧两组电容电压实现自动均压，满足了APF对负载谐波的补偿控制要求。仿真及实验结果验证了所建立T-S模糊均压控制模型的有效性，APF直流侧两组电容的电压保持均衡，具有较高的稳态精度和良好的动态性能。

T-S fuzzy control for three-phase-four-wire active power filter DC-side volt-age equilibrium

Capacitor splitted midpoint three-phase-four-wire Active Power Filter（APF）is an effective tool for harmonics abatement and three-phase-four-wire power quality improvement, but the difficulty of individual voltage control to the splitted capacitor impresses that it reduces the efficiency of compensation. To tackle this problem, by analysis of the main circuit, it employs Takagi-Sugeno（T-S）fuzzy control method to build the model of voltage equilibrium of the three-phase-four-wire APF in which the two voltages in DC side considered as input variables, and the source currents are feedback controlled. Satisfying the T-S fuzzy control model, the designed T-S fuzzy controller makes a balanced midpoint voltage, meeting the requirement of harmonics compensation. Computer simulations and examination results show the validity of the T-S fuzzy controller and the efficacy of equilibration of the midpoint voltage. The controller is able to carry out the operation in good steady-state accuracy and high quality dynamic characteristics.