有源电力滤波器的PR+滞环电流控制策略研究

Research on PR + Hysteresis Current Control Strategy for Active Power Filter

为有效解决传统滞环控制存在较大纹波和比例谐振(PR)控制器设计复杂的问题,对PR控制和滞环控制原理进行分析,提出了一种PR与滞环复合(PR+滞环)的电流环控制策略。该策略首先利用基于瞬时无功功率的ip-iq谐波检测法分离出谐波电流,然后通过电流环控制实现对谐波电流的补偿计算,最后控制双极型晶体管的通断对电网谐波电流进行补偿。在Matlab/Simulink下搭建有源电力滤波器仿真模型,将对比PR+滞环控制与传统的滞环控制的电网电流波形并进行频谱分析,发现电网电流波形毛刺明显减少,畸变率下降8. 79%。对比结果表明,在PR+滞环控制下的系统具有较高的动态性能和稳态性能,能快速跟踪补偿谐波电流,有效抑制电网电流畸变。

In order to effectively solve the problems of large ripple exists in traditional hysteresis loop control and complex structure design of proportional resonant(PR)controller,the principles of PR control and hysteresis control are analyzed,and a combined current loop control strategy based on proportional resonance with hysteresis loop(PR+Hysteresis-loop)is proposed.The strategy uses the instantaneous reactive power based i p-i q harmonic detection method to separate harmonic currents,then the compensation calculation of harmonic current is realized through current loop control;finally,the on/off of the bipolar transistor is controlled to compensate the harmonic current of the grid.The simulation model of active power filter is built under Matlab/Simulink;the grid current waveforms under two control methods are compared and analyzed by spectrum,the burr of the current waveform of the power grid significantly reduces and the distortion rate decreases by 8.79%.The result indicates that the system under PR+Hysteres loop control has high dynamic and steady-state performances,and can quickly track the compensation harmonic signal and effectively suppress the distortion of the grid current.