考虑换相失败相互影响的多馈入高压直流系统换相失败判断方法

Commutation Failure Judgment Method for Multi-Infeed HVDC Systems Considering the Interaction of Commutation Failures

在多馈入高压直流系统(MIDC)中,逆变站换相失败的相互影响是引发换相失败传递的重要因素。该文详细分析逆变站换相失败期间的暂态特性,并根据开关函数模型及动态相量理论推导直流系统向交流系统注入的换相失败分量;进而研究在交流系统故障及换相失败双重影响下各逆变站换相电压的解析计算方法;在此基础上,通过对比各换流阀的最大换相面积与其关断所需的最小换相面积,提出针对多馈入高压直流系统的换相失败判断分析方法;最后,通过所建多馈入高压直流系统模型的仿真结果,验证了该文方法的有效性。

In the multi-infeed high-voltage DC system(MIDC),the interaction among inverter stations is an important factor that triggers the propagation of commutation failure.In this paper,the transient characteristics of inverter station during commutation failure are analyzed in detail,and the commutation failure component is derived by the switching function model and the dynamic phasor theory.Then,the analytical calculation method is studied to reflect the commutation voltage of each inverter station,considering the mutual influence of AC system fault and commutation failure.On this basis,by comparing the maximum commutation area of each converter valve with the minimum commutation area required for turning off,a commutation failure judgement method is proposed.Finally,the simulation results verify the proposed method.