高压直流输电系统后续换相失败风险评估及抑制方法

若引发首次换相失败的交流系统故障未及时清除或恢复阶段控制不当,在直流系统恢复过程中就有可能发生后续换相失败.文中基于换相电压时间面积,分析了导致后续换相失败的直接、间接影响因素,明确了后续换相失败发生机理.为定量评估系统后续换相失败风险,提出了后续换相失败风险指标(SCFRI),并提出了根据风险程度自适应调节触发角的基...

Risk Evaluation and Suppression Methods for Subsequent Commutation Failure of HVDC Transmission System

If the AC system fault causing the first commutation failure is not cleared or improper control is adopted during the fault recovery stage, the subsequent commutation failure may occur in the recovery process of the DC system. Based on the commutation voltage-time area, this paper analyzes the direct and indirect influencing factors leading to the subsequent commutation failure, and clarifies the mechanism of subsequent commutation failure. In order to quantitatively evaluate the risk of subsequent commutation failure, the subsequent commutation failure risk index (SCFRI) is proposed, and an additional control strategy based on SCFRI is proposed to adaptively adjust the triggering angle according to the risk degree. In order to avoid the limitation of additional control range, a coordinated current limiting strategy based on SCFRI is proposed. The two strategies cooperate with each other to effectively suppress the subsequent commutation failure. Taking the CIGRE DC transmission standard model as a testing example, the effectiveness of the proposed SCFRI and suppression strategies is verified.