具有不对称负载补偿功能的三相串并联补偿式UPS（下）

Three-Phase Series-Parallel Compensated UPS with Unsymmetrical Load Compensation （II）

文中叙述了具有不对称负载补偿功能的三相串并联补偿式UPS的工作原理与控制方式，提出的控制方式可以实现串并联补偿式UPS全部控制功能，在电源电压不是额定值且含有谐波电压、负载有谐波电流和无功电流的情况下，电源输入电流被控制成正弦波，COSФ=1，负载电压被控制成额定值正弦波，并具有不对称负载补偿功能。

This essay describes the operating principle and the control method of the three-phase series- parallel compensated UPS. The proposed control strategy achieves all the control goals as follows. When the power supply voltage containing harmonics deviates from the rated value and the load current contains harmonics and reactive current, the source input current can be controlled to be sinusoidal while the power factor approximately equals to 1, and the load voltage can be regulated to a sine wave of the rating voltage. The UPS can also compensate unsymmetrical loads.