基于动态等效电路的含DG电力系统电压稳定性分析

Voltage stability analysis of power system with DGs based on dynamic equivalent circuit

分布式电源(Distributed generation,DG)接入电网对电力系统电压稳定有一定影响。首先对DG接入节点内部系统进行综合动态等效,将动态等效电路的分析方法应用于含DG的电力系统。然后将DG视为"负"的负荷,提出DG接入后评价系统静态电压稳定性的广义阻抗模裕度指标。基于广义阻抗模裕度指标,具体分析了DG不同接入方式、出力大小对系统电压稳定性的影响和优化无功补偿的效果。最后通过仿真验证了所提方法是研究含DG电力系统静态电压稳定性的一种实用和方便的方法。

Distributed generation connected to grid will have certain impact on voltage stability of power system. At first, the comprehensive dynamic equivalence circuit of internal grid of DG integrating bus is implemented; and on the basis, the method of dynamic equivalent circuit is further extended to the grid-connected DG which is regarded as a ＂negative＂ load; and general impedance modulus margin index is put forward to evaluate the system static voltage stability. The impacts of the output and their different installation methods of DG on system voltage stability and optimization of reactive power compensation are researched based on general impedance modulus margin index. At the last, the proposed method is proved to be a practical and convenient method that is suitable to study the static voltage stability of grid-connected DG.