解决超调问题的220kV变电站无功配置方法

针对220 kV变电站单组补偿容量配置偏大、感性与动态无功补偿缺乏引起的电压调控困难问题,提出了220 kV变电站离散与连续相结合的综合无功补偿方案,由一组直接式静止同步补偿器(static synchronous compensator,STATCOM)和采用开关柔性控制技术的并联电容器组组成补偿系统。首先构建了变电站无功补偿调压估算模型和指标——无功超调率,该指标揭示了当前变电站无功补偿配置组数有限和单组容量不宜过大之间的矛盾,使得220 kV变电站采用所提的新型补偿方案成为了解决受端系统的稳态电压控制的精度和暂态电压稳定的超调问题的根本出路。算例表明紧急状态下所提方案能给电网提供有效的动态电压支撑。

A Configuration Method of Reactive Power Compensation for 220 kV Substations to Reduce Voltage Overshoot

In allusion to the difficulty of voltage regulation due to excessive compensation capacity of single compensator set and absence of inductive and dynamic reactive compensation in 220 kV substations,a synthetical reactive power compensation scheme for 220 kV substation,which combines discrete compensation with continuous compensation,is proposed.In the proposed scheme,the compensation system is composed of one set of direct static synchronous compensator(STATCOM) and shunt capacitor banks which can be flexibly switched.Firstly,an evaluation model for reactive power compensation and votlage regulation in 220 kV substation and its evaluation index called reactive power overshoot rate are constructed and such an index reflects the contradiction between finite number of reactive power compensator sets and inadvisability of excessive compensation capacity of single compensator set,thus the proposed compensation configuration scheme becomes a fundamental way to improve the accuracy of steady-state voltage control and reduce the overshoot to ensure transient voltage stability at receiving end.Simulation results of a certain regional power network in Guangdong province show that the proposed method is favorable to steady-state voltage stability control of power network and can provide effective dynamic voltage support under emergency condition.