并联型有源电力滤波器直流侧电压优化控制

Optimization Control of DC Link Voltage for Shunt Active Power Filter

直流侧电压的控制是并联型有源电力滤波器(active power filter,APF)的关键技术之一。直流侧电压的大小将影响到APF的功率损耗和补偿性能。而在复杂的工业应用场合,各种负载的波动将会造成APF公共耦合点的电网电压的波动,进而影响到APF的补偿性能。以三相三线并联型有源电力滤波器为例,分析APF的功率损耗和直流侧电压之间的关系以及补偿性能和直流侧电压、电网电压之间的关系,并提出一种采用下垂调节器来控制直流侧电压指令值的控制策略。当电网电压升高时,提高直流侧电压,从而提高APF的补偿性能;当电网电压降低时,降低直流侧电压,在保证APF的补偿性能的基础上降低功率损耗。仿真和实验结果验证了理论分析,采用下垂调节器能够实现APF功率损耗和补偿性能的综合优化。

Control of DC link voltage is a key technique of shunt active power filters（APF）.The magnitude of the DC link voltage has an effect on power losses and the compensative ability of APF.In the complex industrial environment,the fluctuant load brings about the grid voltages fluctuation at in the point of common coupling（PCC）,then exerts an effect on the compensative ability of APF.This paper analyzed the relation between the DC link voltage and power losses of APF.Then the influences of the DC link voltage and the grid voltage on compensative ability were shown.Finally,this paper introduced a control strategy that uses a drop regulator to regulate the reference value of the DC link voltage.When the grid voltage increases,the DC link voltage will increase adjusted by the drop regulator,so as to improve compensative ability of APF.When the grid voltage decreases,the DC link voltage will decrease adjusted by the drop regulator,so as to reduce power losses of APF.Based on the simulation analyses and experiment,it has been proved that the drop regulator can realize a comprehensive optimization between power losses and the compensative ability of APF.