改善微网电能质量的有源电能质量调节器研究

提出在微网交流母线和低压配网公共连接点之间并入有源电能质量调节器,可改善微网电能质量,减小微网接入对低压配网电能质量的影响.提出了基于瞬时无功理论的同步锁相方法,准确分解出公共连接点电压基波正序分量,进而求得其相位.由补偿电流控制策略计算得到参考电流,控制有源电能质量调节器实时向微网补偿谐波电流和无功电流,即使在三相负载不平衡时,使公共连接点三相电流平衡且为正弦波,从而平衡公共耦合点的三相电压.Matlab/Simulink 仿真结果证明了所提同步锁相方法和补偿电流控制策略的有效性

Research on Active Power Quality Conditioner for Improving Power Quality of Microgrid

To improve power quality of microgrid and reduce the influence of connecting with microgrid on power quality of low voltage distribution network,it is proposed to connect a shunt active power quality conditioner(APQC) between the AC bus of microgrid and the point of common coupling(PCC) of low voltage distribution network.A synchronous phase-locking method based on instant reactive power theory is put forward to accurately detect the positive-sequence fundamental frequency voltage component at PCC and then obtain the phase of the component.The reference current is calculated by the control strategy of compensation current to control APQC that compensates both harmonic currents and reactive current in real-time mode.Although the three-phase loads are unbalanced,the proposed method can make the three-phase line currents at PCC sinusoidal and balanced,thus the three-phase voltages at PCC can be balanced.Results of simulation based on Matlab/Simulink show that the proposed synchronous phase-locking method and control strategy for compensation current are effective.