基于混合调制的混合H桥级联APF研究

Study of Hybrid H-bridge Cascaded Active Power Filter Based on Hybrid Modulation

有源电力滤波器能够有效地、实时地跟踪补偿非线性负载产生的幅值、频率变化的谐波和无功电流。研究了一种星型结构的混合3单元H桥级联三相APF,在中高压领域有比较广阔的应用前景。首先对其进行了数学建模,详细地分析了混合调制方式;指令电流采用基于瞬时无功功率理论的方法进行提取,H桥模块直流侧电压采用分层控制来实现稳压。通过仿真验证了设计的APF能够有效地补偿负载电流中的畸变成分,系统表现出良好的稳态和动态性能。

Active power filter is capable of,effectively and real-timely,tracking and compensating harmonic and reactive current varying in the amplitude and frequency,which generated by nonlinear loads. Presented a hybrid H-bridge three-phase APF with 3 units cascaded,as its main circuit was with star configuration,which has a further application prospects in the field of middle and high voltage. At first,the mathematical model was built,and the hybrid modulation method was analyzed in details. Then,instantaneous reactive power theory was adopted to extract the harmonic and reactive current. DC side voltages of H-bridge units were stabilized with using hierarchical control.The simulation results show that the APF designed can effectively compensate the distortion of load current,and the system revealed good steady and dynamic performance.