变电站电压无功控制对静态电压稳定的影响分析

摘要

Voltage and reactive power control (VQC) of substation determines capacitors or reactors switching and on-load tap changers (OLTC) automatically by on-line monitoring the load side bus voltage and high-voltage side reactive power injection. It is an important measure of maintaining voltage quality of power grid. According to nine-areas control diagram rule of substation VQC, this paper establishes a continuation power flow model including actions of VQC, and analyzes the impact of substation VQC on steady state voltage stability of Guangdong Power Grid. And a new type of bifurcation induced by OLTC regulation is founded, and it is called OLTC regulation induced bifurcation. A test on Guangdong Power Grid illustrates that VQC action can maintain voltage quality of substations and enhance steady state voltage stability margin, but may induce system bifurcation under heavy loading conditions, and lead to voltage collapse.%　　变电站电压无功控制(VQC)通过在线监视负荷侧电压和高压侧注入无功来决定站内电容器电抗器的投切和主变抽头的调整,它是一种提高电压质量的重要手段。根据变电站 VQC 模块的九区控制图规则,建立考虑 VQC 动作的连续潮流计算模型,分析其对广东电网静态电压稳定性的影响,并观察到一种由 VQC 策略中 OLTC 动作引起的电压失稳分岔情况,称为 OLTC调节诱导分岔。通过对广东电网的仿真分析表明,VQC 调控能够维持变电站电压质量,提高静态电压稳定负荷裕度,但在重负荷条件下可能发生由于 VQC 的动作而引起的系统分岔,从而导致电压失稳。