一种抑制后续换相失败的电流偏差控制参数整定方法

基于电网换相换流器的高压直流输电(LCC-HVDC)系统若发生后续换相失败,将严重影响交直流混联电网的安全稳定运行。针对LCC-HVDC系统故障恢复过程中电流偏差控制作用阶段易再次发生换相失败问题，对电流偏差控制参数与换相失败之间的关系进行理论分析，发现此阶段系统若不发生换相失败，逆变侧LCC直流电压和交流换相电压需满足一定的约束关系，且该约束关系受电流偏差控制参数直接影响。然后，基于理论分析结果，提出一种电流偏差控制参数整定方法，可改善系统故障恢复过程中对直流电压恢复速度和程度的控制要求，使系统更易满足直流电压与交流换相电压稳定运行约束关系，以降低后续换相失败概率。最后，利用PSCAD/EMTDC仿真平台CIGRE标准测试模型验证了理论分析的正确性以及参数整定方法的有效性。

A current deviation control parameter tuning method to suppress subsequent commutation failure

If the subsequent commutation failure occurs in the line commutated converter based high voltage direct current (LCC-HVDC) transmission system, it will have a seriously negative impact on the safe and stable operation of the AC-DC hybrid power grid. Aiming at the problem of commutation failure during the current deviation control stage in the fault recovery process of LCC-HVDC system, the relationship between current deviation control parameter and commutation failure is analyzed theoretically. It could be found that if the system does not have commutation failure at this stage, the DC voltage and AC commutation voltage of LCC at the inverter side need to meet certain constraints, and the constraints are directly affected by the current deviation control parameter. Then, based on the theoretical analysis results, a current deviation control parameter tuning method is proposed，which can improve the control requirement of DC voltage recovery speed and degree in the fault recovery process of system. The method makes it easier for the system to meet the stable operation constraints between DC voltage and AC commutation voltage, so as to reduce the probability of subsequent commutation failure. Finally, The CIGRE standard test model in PSCAD/EMTDC simulation platform is used to verify the correctness of the theoretical analysis and the effectiveness of the parameter tuning method.