SVC错位补偿对风机高电压脱网威胁及应对措施

Study on Threat of Wind Turbine Tripping due to Overvoltage Caused by SVC Malposition Compensation and Countermeasures

随着风电并网容量的快速增长,风机脱网已成为电网安全运行的重要威胁,故障清除后恢复过程中出现的高电压则是引发风机脱网的重要因素之一。针对风电场广泛应用的静止无功补偿器(static var compensator,SVC),详细解析了其电压无功暂态响应轨迹的特征,揭示了SVC所具有的"错位补偿"效应及其引发风机高电压脱网的原理,并分析了电压扰动速率、SVC控制参数和触发延迟时间对"错位补偿"效应的影响。在此基础上,提出了SVC变参数控制策略和紧急闭锁控制策略。实际风电场的仿真结果验证了控制策略缓解风机高电压脱网的有效性。

With rapid capacity growth of wind farms connected to grid, large-scale wind turbine tripping has become an important threat to safe operation of power system. High voltage in recovery process is an important factor causing wind turbine tripping. In this paper, static var compensators, widely used in wind farms, and characteristics of their voltage and reactive power transient response are analyzed in detail. Mechanism of ‘malposition compensation’ effect in SVC and its threat to high voltage tripping of wind turbine is disclosed. Impacts of external disturbance rate, SVC control parameters and trigger time delay on malposition compensation are analyzed. On these bases, SVC variable parameter control and emergency lock control strategies are proposed to suppress malposition compensation effect. Simulation results of actual wind farm verify effectiveness of the control strategy in easing threat of wind turbine tripping due to overvoltage.