分布式多能互补微电网协调控制策略

Study on coordination control strategy of distributed hybrid power in micro grid

微电网可以整合各类分布式电源并为当地负荷提供绿色能源,因而成为世界各国研究的热点。由于微电网运行惯性小、模式多、内部电源特性差异大,而增加了网内公共点电压频率的稳定难度,其控制问题异常复杂。文章提出了基于分布式电源层的改进下垂控制策略,在传统下垂控制的基础上增加前馈调节与比例积分控制机制,从而改变了下垂系数,增大了功率调节范围,加快了公共点频率电压的稳定速度,使微电网并网时实现功率输出的指定控制、孤岛时按负荷的需求分配功率。文章还采用电力系统仿真软件PSCAD/EMTDC V4.4验证了所提方案的可行性。

Microgrid has become research hotspot around the world, because it can integrate all kinds of distributed generation （DG） and supply green energy for local load. But micro grid has small inertia, more operation modes and great difference of internal power characteristic, it is diffi- cult to stabilize voltage and frequency of the common point, which causes many extremely compli- cated control problems. In this paper an improved droop control strategies which add feed-forward and PI control based on conventional droop control is proposed, the strategies change droop coeffi- cient, enlarge range of power adjustment, accelerate steady speed of common point frequency volt- age, improve the control accuracy, achieve a specified control for power output when microgrid is connected to grid and distribute power according to requirement of load on islanding mode. Finally PSCAD/EMTDC V4.4 is used to verify feasibility of the proposed scheme.