动态无功补偿装置提高多馈入直流恢复的布点方法

交直流混联系统中交流系统短路故障发生后,由于交流系统电压不能恢复或持续降低而引起多回直流输电系统连续发生多次换相失败甚至闭锁,采用动态无功补偿装置提高多馈入直流换相失败过程中电压恢复。分析了不同地点及程度交流故障下不同补偿装置直流恢复速度,从多馈入直流间相互影响的交互作用因子出发,计及不同直流传输功率故障后对系统稳定性的影响,定义了多馈入直流交互影响权重系数,确定动态无功补偿装置补偿区域边界,考虑动态无功—电压灵敏度以确定动态无功最佳补偿地点,制定了工程实用的多馈入直流系统动态无功补偿装置布点方案。大电网仿真结果表明,在同等容量的动态无功补偿装置下,推荐方案能有效减少交流故障引起的多馈入直流同时换相失败。

Site Selection for Dynamic Reactive Power Compensation and Improvement of Recovery from Commutation Failures in Multi-infeed HVDC System

In order to choose the suitable point of dynamic reactive power compensation equipments and improve the ability of recovering from DC commutation failures, a method of installing dynamic reactive power compensation equipments is adopted with the price of stability for commutation failures taken into account. The internal relation between multi-infeed interaction factor and commutation failures are analysed so that the effects between DC can be judged in advance. The boundary of dynamic reactive power zone is determined, and the sensitivity of commutation failures is defined. The proportion of multi-infeed DC influence is considered to quickly determine the best compensation position. Plenty of grid simulation results show that for the same capacity of dynamic reactive power compensation equipments, the recommended scheme can effectively reduce commutation failures taking place on several multi-infeed DC lines due to AC faults.