基于自调节下垂控制的分布式电源并联运行技术

Parallel operation technology of distributed generation based on self-regulation droop control

在孤岛运行模式下,各分布式电源并联运行时输电线路阻抗值存在差异,采用传统的下垂控制难以实现无功功率输出按DG容量比例合理分配。针对该问题,提出一种改进的自调节下垂控制策略,该改进策略在传统无功-电压下垂控制基础上,引入关于输出无功功率的比例积分控制环节后使无功功率输出与线路阻抗无关,从而实现无功功率输出按DG容量比例合理分配,抑制了系统无功环流分量。最后通过Matlab仿真平台搭建DG并联运行仿真模型验证了该改进策略的有效性。

In distributed island mode, each distributed power source operates in parallel. Because of the difference in impedance values of transmission lines, it is difficult to achieve a reasonable distribution of reactive power output in proportion to the DG capacity using traditional droop control. To solve this problem, this paper proposes an improved self-regulating droop control strategy. Based on the traditional reactive-voltage droop control, the improved strategy introduces a proportional-integral control link on the output reactive power. Then, the reactive power output is independent of line impedance. In this way, the reactive power output can be reasonably distributed according to the DG capacity ratio, and the reactive circulating current component of the system is suppressed. Finally, the DG parallel operation simulation model is built by Matlab simulation platform to verify the effectiveness of the improved strategy.