统一电能质量调节器控制策略及仿真

Control scheme of unified power quality controller and simulation

通过对统一电能质量调节器(UPQC)电路拓扑的稳态功率进行详细分析,并与基于传统控制策略下UPQC所需容量进行一系列比较,提出一种基于串联侧无有功注入的新型控制策略。该控制策略根据相应的负载功率因数角、电压跌落程度决定串联侧补偿电压的幅值,在特定补偿电压注入角情况下,使得串联侧不消耗任何有功,同时能够减小并联侧无功补偿容量。该控制策略不仅能完成电网电压跌落补偿、谐波治理、负载无功补偿和输入功率因数校正,且在串联侧不消耗任何有功的情况下降低整个UPQC的补偿容量。为了克服滞环控制的不足,串联侧采用恒频滞环来保持开关频率的稳定。仿真结果验证了理论分析的正确性与可行性。

The steady-state power of UPQC（Unified Power Quality Controller） circuit topology is analyzed and a control scheme without active power injection at the serial side is presented based on the comparison of its required capacity with traditional control scheme. It decides the amplitude of serial side compensation voltage by the load power factor angle and the voltage drop,and,with a particular compensation voltage injection angle,makes the active power consumption at serial side zero and the reactive power compensation capacity at parallel side reduced. It not only compensates voltage sag, suppresses harmonics,compensates load reactive power and corrects input power factor,but also reduces the total compensation capacity of UPQC without active power consumption at the serial side. The constant frequency hysteresis is adopted to keep switching frequency stable and improve the hysteretic control. The accuracy and reliability of the theoretical analysis are verified by simulative results.