| 引用本文: | 雷智威,马俊鹏,王顺亮,等.基于关断角动态方程的直流输电后续换相失败预测方法及优化控制[J].电力系统保护与控制,2025,53(9):14-24.[点击复制] |
| LEI Zhiwei,MA Junpeng,WANG Shunliang,et al.Prediction method and optimal control of subsequent commutation failure in LCC-HVDC system based on dynamic extinction angle equation[J].Power System Protection and Control,2025,53(9):14-24[点击复制] |
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| 摘要: |
| 高压直流输电系统受端交流故障后，易发生后续换相失败，严重影响系统安全运行。为提升抑制后续换相失败发生的能力，提出了一种基于关断角动态方程的预测及优化控制方法。通过解析首次换相失败恢复阶段的直流电流与关断角动态特性，建立了关断角动态微分方程，并结合相图分析法揭示后续换相失败机理，即当关断角降至阈值时其变化率持续为负，导致换相失败。为提升对后续换相失败的抑制能力，提出一种基于关断角动态方程的预测及优化控制方法。设计实时预测判据，依据交流电压有效值及其变化率动态计算关断角趋势。同时，提出动态补偿控制策略，在定关断角控制中引入动态补偿环节实时修正参考值。基于CIGRE标准模型的仿真结果表明，所提预测判据在三相/单相接地故障下的准确率显著优于传统方法，所提出的优化控制策略能够有效地抑制后续换相失败的发生，显著提升了系统的暂态稳定性。 |
| 关键词: 高压直流输电 后续换相失败 关断角补偿 优化控制策略 |
| DOI：10.19783/j.cnki.pspc.241092 |
| 投稿时间：2024-03-31修订日期：2024-09-25 |
| 基金项目:国家自然科学基金青年基金项目资助(52207216) |
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| Prediction method and optimal control of subsequent commutation failure in LCC-HVDC system based on dynamic extinction angle equation |
| LEI Zhiwei,MA Junpeng,WANG Shunliang,JIAO Ning,LIU Tianqi |
| (School of Electrical Engineering, Sichuan University, Chengdu 610065, China) |
| Abstract: |
| In line-commutated converter-based high-voltage direct current (LCC-HVDC) systems, subsequent commutation failures are prone to occur following AC faults at the receiving end, seriously threatening the secure operation of the systems. To enhance the capability of suppressing subsequent commutation failures, this paper proposes a predictive optimization control method based on the dynamic extinction angle equation. By analyzing the dynamic characteristics of DC current and extinction angle during the recovery phase following the initial commutation failure, a differential dynamic equation for the extinction angle is established. Using phase-plane analysis, the mechanism of subsequent commutation failure is revealed: when the extinction angle decreases to a critical threshold and its rate of change remains negative, commutation failure occurs. To improve the suppression capability, a predictive optimization control method based on the dynamic extinction angle equation is proposed. A real-time prediction criterion is designed to dynamically calculate the extinction angle trend using the effective AC voltage magnitude and its rate of change. Simultaneously, a dynamic compensation control strategy is developed, in which a compensation term is added to the fixed extinction angle control to continuously adjust the reference in real time. Simulation results based on the CIGRE benchmark model demonstrate that the proposed prediction criterion achieves significantly higher accuracy than conventional methods under both three-phase and single-phase grounding faults. Moreover, the proposed optimal control strategy effectively suppresses subsequent commutation failures and significantly enhances the system’s transient stability. |
| Key words: LCC-HVDC subsequent commutation failure extinction angle compensation optimal control strategy |
