应对直流连续换相失败的紧急控制策略  

An emergency control strategy coping with continuous commutation failure in DC system

作　　者：苏寅生[1] 陈董秀 鲍颜红[2] 姚海成[1] 黄河[1] 任先成[2] 

机构地区：[1]中国南方电网电力调度控制中心,广东广州510623 [2]国网电力科学研究院/南瑞集团公司,江苏南京210003

出　　处：《电力系统保护与控制》2017年第4期126-131,共6页Power System Protection and Control

基　　金：南方电网公司科技项目"南方电网安全稳定综合防御系统建设与实施(二期)";国家电网公司科技项目"计及受端电网约束的特高压直流外送大规模新能源发电送端电网调度运行关键技术研究与应用"

摘　　要：直流输电系统连续换相失败故障可能导致送端电网暂态失稳。连续换相失败造成系统失稳的主要原因是直流输送功率连续性骤降导致发电机累积加速面积大于减速面积。提出了通过安全稳定控制装置紧急控制的应对方案。采用换相失败时间的累加量作为失稳判据和切机方案的匹配依据。如不再发生后续的换相失败,则仅仅采用切机措施保证系统的安全稳定,对于不能恢复的连续换相失败,则需要闭锁相关直流后切机。通过互联交直流电网算例仿真验证了该方案的有效性。Continuous commutation failure of DC transmission system may cause transient instability in AC/DC interconnected power system. The main reason for transient instability is that continuous sudden-reduction of DC power under continuous commutation failure condition results in generator＇s cumulative acceleration area greater than deceleration area. The emergency control scheme for coping with the transient instability problem by security and stability control devices is proposed. The accumulative commutation failure time is adopted as instability criterion and matching variable of the generator tripping scheme. If continuous commutation failure whose duration is less than the blocking threshold value, the generator-tripping measures are adopted to prevent the instability, otherwise, the DC system blocking and generator-tripping measures are adopted simultaneously to ensure the stability. The effectiveness of this method is verified by the case of actual AC/DC interconnected power grid.

关 键 词：连续换相失败 送端电网 紧急控制 切机方案 

分 类 号：TM721.1[电气工程—电力系统及自动化]