抵御浙江电网多馈入直流系统持续换相失败措施

Measures for Continuous Commutation Failures of Multi-Infeed HVDC System in Zhejiang Power Grid

针对浙江电网多馈入直流系统可能由于交流系统故障引起的持续换相失败问题,以换相失败本质为理论依据,在搭建系统模型的基础上验证了大容量静止无功发生器(static var generator,SVG)、调相机在抑制持续换相失败中的作用,同时提出采用电压时间面积法优化直流控制保护降低直流持续换相失败的概率,该方法可在交流系统接地故障时通过对熄弧角的控制抑制多回直流输电系统持续换相失败,最后通过系统试验验证了面积法的改善性能。

Aiming at the multi-infeed HVDC continuous commutation failure problem caused by AC system fault in Zhejiang power grid, based on the essence of commutation failures, this paper establishes a typical systematic model to verify the effects of large capacity static var generator （SVG） and synchronous condenser on suppressing the commutation failure. At the same time, this paper adopts voltage-time area method to optimize DC control and protect system, in order to reduce the probability of DC continuous commutation failure. This method can control extinction angle to reduce the continuous commutation failure of multi-infeed HVDC during the grounding fault in AC system. At last, this paper verifies the improvement of voltage-time area method through system test.