馈入弱交流系统的直流输电换相失败恢复特性对 输电能力的影响分析

摘要

A major problem in the operation of HVDC infeeded to a weak AC system is that the faults occurred in the receiving AC system may cause commutation failures of the inverters, and in the event of faults removal, the receiving system will be further weakened, so that the AC/DC system will be difficult to restore to a stable operation state, and even may lead to DC system blocking.Based on electromagnetic transient simulations, this paper studies the characteristics of commutation failures of a DC transmission system infeeded to a weak AC system induced by AC faults near the inverter station, as well as the fault recovery characteristics of the AC/DC system with further weakened receiving systems.The HVDC transmission capability of the steady-state operation is evaluated by the dynamic process of fault recovery.The analysis method can be used as an evaluation method to check the steady-state transmission capability of HVDC transmission systems in actual operations.%馈入弱交流系统的直流输电在运行中面临的一个主要问题,是受端交流系统故障可能引发逆变器换相失败,且在故障清除时往往导致受端系统进一步变弱,使交直流系统难以恢复稳定运行,甚至最终导致直流系统闭锁.本文基于电磁暂态仿真,研究馈入弱交流系统的直流输电在逆变站近区故障导致换相失败以及受端系统进一步变弱情况下的故障恢复特性,以故障恢复动态过程结果评估直流输电系统的稳态运行输送能力.所采用的分析方法可用于实际运行中直流输电输送能力的校核.