广东多直流输电换相失败对电网稳定运行的影响

Influence of Simultaneous Commutation Failure of Guangdong Multiple HVDC on Power System Secure Operation

本文研究了直流输电换相失败期间直流有功和无功的动态特性,介绍了评估交流系统对直流系统电压支撑能力的3个方面量化指标,从引发多直流换相失败的交流故障区域范围、多直流短路比指标、严重交流故障条件下电网失稳数量分析了广东多直流同时换相失败对电网安全运行的影响。针对广东电网未来日益严重的电压失稳风险,提出了优化直流控制策略、配置动态无功补偿、受端电网结构优化、应用柔性直流输电4个方面的技术措施。

This paper investigates the dynamic characteristics of active power and reactive power during HVDC commutation failure period. The quantitative index for assessing voltage supporting capability of AC system for HVDC system is introduced. The influence of simultaneous commutation failures of Guangdong multiple HVDC on the secure operation of the power grid is analyzed from three aspects： AC area where AC fault may cause multiple HVDC simultaneous commutation failure; multi-infeed effective short circuit ratios and the number of power grid instability under severe AC system failure conditions. Technical countermeasures including HVDC control strategy optimizing, dynamic reactive power compensation installation, AC power grid topology reconfiguration and VSC HVDC utilization are proposed for dealing with voltage instability risk of Guangdong power grid.