When the microgrid is operating in the island mode,each distributed generation unit needs to achieve a good load sharing. Aiming at this problem,a method using communication and adaptive virtual impedances to control reactive power accurate sharing was proposed. The strategy used the established communication to facilitate the adjustment of the adaptive virtual impedance to compensate for the voltage drop caused by different feeders of the distributed generation units. At a given load operating point,if the virtual impedance adjustment was completed,even if the communication was interrupted,the precision of the reactive power still could be achieved. After the communication was interrupted,if the load point was changed,the reactive power was declined,but it was still better than the traditional droop controller. In addition,the new control strategy of reactive power was not affected by the impact of the communication delay,and also did not require the information of the feeder impedance. So,it was easy to implement. Finally,some tests had been done in a 2 kV·A microgrid network experiment platform. And the experimental results prove the effectiveness of the new control strategy.%当微电网运行在孤岛模式时,每个发电单元都需要实现较好的负载均分.针对这个问题,提出了一种结合通讯和虚拟阻抗的无功功率精确均分控制策略.该策略利用建立的通讯来促进自适应虚拟阻抗的调整,以补偿不同馈线导致的电压下降.在给定的负载工作点,如果虚拟阻抗调整完毕,即使通讯中断也可以实现精准的无功功率均分.通讯中断后,如果负载点变化,无功功率均分度有所下降,但仍好于传统的下垂控制.此外,新型控制策略的无功功率均分度不受到通信延迟的影响,同时也不需要馈线阻抗的信息,易于实施.最后,通过2 kV·A微网试验平台对控制策略的有效性进行了试验验证.
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