自适应下垂系数的孤岛微电网无功均分策略

Adaptive droop coefficient-based reactive power sharing strategy for islanded microgrid

在孤岛微电网中,由于线路阻抗的不匹配,常常导致传统的下垂控制无法完成分布式电源(DG)之间无功功率的均分.为了消除DG之间的无功不均分,首先分析了传统下垂控制无法完成无功均分的原因,设计了可自适应调节的无功下垂系数,使无功下垂系数可以满足无功均分的条件,从而解决无功功率无法均分的问题.为了使无功均分控制器具有更高的灵活性和可靠性,设计了动态分布式观测器,并证明了其收敛性.动态分布式观测器可以使DG以分布式的方式更加灵活可靠地获取所需的信息.通过4个不同的算例对所提的控制策略进行验证,仿真结果验证了所提控制策略的优越性和有效性.

In the islanded microgrid,the mismatch in line impedance hinders the traditional droop control from achieving an equal distribution of reactive power among Distributed Generation(DG)sources.To address this problem and enhance the flexibility and reliability of the controller,this paper analyzes the reasons behind the failure of traditional droop control and proposes an adaptive droop coefficient that can be dynamically adjusted to meet the conditions for reactive power sharing.Additionally,a dynamic distributed observer is designed and its convergence is proven,which allows DG sources to obtain necessary information flexibly and reliably in a distributed manner.Finally,the proposed control strategy is verified through simulations in four different scenarios,and the results demonstrate its superiority and effectiveness.