基于区域电网稳定性的220kV主变高中后备保护失效分析  

Analysis of Backup Protection Failure on High and Medium Voltage Sides of 220kV Main Transformer Based on Regional Power Grid Stability

作　　者：徐宇 杨永志 陈劲秋 Xu Yu;Yang Yongzhi;Chen Jinqiu(Kunming Power Supply Bureau,Yunnan Power Grid Co.,Ltd.,Kunming 650011,China)

机构地区：[1]云南电网有限责任公司昆明供电局,云南昆明650011

出　　处：《云南电力技术》2022年第4期69-72,共4页Yunnan Electric Power

摘　　要：介绍了云南电网220 kV降压变后备保护对区域电网安稳装置的意义及保护整定原则,提出整定原则中主变高中压侧后备保护的复压过流保护整定存在的电网风险。结合厂站的短路电流理论计算及实例,分析了主变高中压侧后备保护失效问题,并提出220 kV主变中压侧复压方向过流保护取消方向元件的措施,探讨了以主变高中压侧差电流为判据的后备保护方法。实例证明,该方法可有效改善主变后备保护功能。This paper introduces the significance and the setting principle of the backup protection of 220 kV step-down transformer in Yunnan power grid,and proposes the grid risk of compound voltage directional over-current protection setting of backup protection on high and medium voltage-side of the main transformer in the setting principle.Combined with the theoretical calculation and example of short-circuit currents of specific substation,the backup protection failure on the high and medium voltage sides of the main transformer is analyzed.The measures to cancel the directional elements for the compound voltage directional over-current protection on the medium voltage side of 220 kV main transformer are put forward,and a new backup protection mthod based on the high-medium voltage side differential current of the main transformer is discussed.The example proves that this method can effectively improve the backup protection function of the main transformer.

关 键 词：主变后备保护 后备保护失效 复压方向 

分 类 号：TM74[电气工程—电力系统及自动化]