孤岛微网不平衡负荷下控制策略  

Islanded microgrid control strategy under unbalanced loads

作　　者：屈克庆[1] 李文旗[1] 赵晋斌[1] 李芬[1] 

机构地区：[1]上海电力学院,上海200090

出　　处：《电力系统保护与控制》2017年第11期8-14,共7页Power System Protection and Control

基　　金：上海市自然科学基金项目(16ZR1413000)~~

摘　　要：在三相孤岛微网系统中,负载的不平衡将会导致负序电流和电压的产生。线路参数的差异会造成各微源之间负序电流的无序分配,低压电网中较大的线路阻抗将会进一步增大微网的不平衡性,进而影响负荷的正常工作。针对这些问题提出了一种基于PR控制器的孤岛微网不平衡负荷下控制策略。该策略通过两相静止坐标系下的正负序独立控制,实现了负序虚拟负阻抗的设计,减小了微源传输阻抗,实现了微源之间负序环流的抑制,并减小了PCC点的电压不平衡度,保证了微源以及微网的正常工作。通过Matlab/Simulink的仿真验证了所提出的控制策略的正确性和有效性。In three-phase islanded mierogrid systems, unbalanced loads will cause negative-sequence current and negative-sequence voltage. The difference between line parameters will seriously affect the distribution of negative sequence current between micro sources and reduce the reliability of the microgrid systems. Besides, the bigger line impedance in low voltage microgrid systems will increase the unbalance of the microgrid systems. To solve these problems, this paper proposes a new islanded microgrid control strategy based on PR controllers under unbalanced loads. By controlling positive-sequence and negative-sequence independently, the strategy can realize the design of negative-sequence virtual impedance to reduce transfer impedance of the micro sources, suppress the negative-sequence circulating current and reduce unbalanced degree of the microgird systems. Simulation by Matlab/Simulink results demonstrate that the control strategy is correct and effective. This work is supported by Natural Science Foundation of Shanghai （No. 16ZR1413000）.

关 键 词：微网 不平衡 独立控制 虚拟负阻抗 

分 类 号：TM727[电气工程—电力系统及自动化]