利用虚拟电抗抑制直流输电连续换相失败 控制方法.pdf

中国科技论文在线 利用虚拟电抗抑制直流输电连续换相失败 控制方法# 郭春义，李春华* 5 （华北电力大学新能源电力系统国家重点实验室，北京 102206 ） 摘要：针对传统直流输电逆变侧易发生换相失败及连续换相失败问题，分析了影响系统换相 的关键因素，提出了一种故障期间限制直流电流上升速率和上升幅值的虚拟电抗限流方法。 给出了虚拟电抗的工作原理，设计了稳态及故障下的控制策略，最后，将虚拟电抗限流思想 10 应用于PSCAD/EMTDC 下的CIGRE 标准测试模型中，进行正常及故障仿真，仿真结果表明， 基于虚拟电抗的故障电流抑制方法能在一定程度上限制故障电流的上升速率及上升幅值，有 效降低了直流系统连续换相失败发生的概率，利于系统故障恢复。 关键词：传统直流输电；换相连续失败；虚拟电抗；控制器限流 中图分类号：TM721 15 Virtual Reactor Concept based Continuous Commutation Failure Mitigation Method for HVDC GUO Chunyi, LIChunhua (North China Electric Power University,State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources,Beijing 102206) 20 Abstract: To reduce the continuous commutation failure probability of Line-Commutated-Converter based High Voltage Direct Current (LCC-HVDC), the main reason that causes commutation failure is analyzed. A concept named virtual-reactor is proposed to limit the rise speed and amplitude of DC current. The working operation of virtual-reactor is presented and the control strategy of it is given. Finally, the proposed ideal added in VDCOL(voltage 25 dependent current order limiter) is developed in PSCAD/EMTDC, and the steady state and transient performances of it is analyzed. Simulation results show that the proposed control using virtual-reactor can mitigate the continuous commutation failure effectively under AC faults condition, which can improve the recovery performances of HVDC systems Key words: LCC-HVDC; continuous commutation failure; virtual reactor; DC current-limiting 30 control 0 引言 自1987年舟山直流输电工程投入运行开始，我国的高压直流输电技术的研