一起35kV变压器断线故障分析  

Analysis of a 35kV transformer disconnection fault

作　　者：熊胜辉 林撒迦 刘宏君 Xiong Shenghui;Lin Sajia;Liu Hongjun(CYG SUNRI CO.,LTD.Shenzhen 518057)

机构地区：[1]长园深瑞继保自动化有限公司,广东深圳518057

出　　处：《现代科学仪器》2023年第6期179-184,共6页Modern Scientific Instruments

摘　　要：本文针对一起35kV变压器高压侧单相断线导致低压侧过流保护动作的事故进行机理分析。采用对称分量法对变压器高压侧单相断线情况下的高低压侧电流影响进行分析,结合不同负载特性情况推导出低压侧负荷电流的变化,推导出低压侧过流保护的动作原因,结果表明,变压器高压侧单相断线时,电动机负载由于转差率的差异,负序阻抗相对正序阻抗较小,进而可能会导致低压侧过流保护动作,并通过PSCAD/EMTDC仿真模型进行试验验证。This paper analyzes the mechanism of an accident where a single-phase break on the high-voltage side of a 35kV transformer caused the overcurrent protection on the low-voltage side to operate.Symmetric component method is used to analyze the impact of high and low voltage side currents in the case of single-phase disconnection on the high voltage side of the transformer.Based on different load characteristics,the changes in load currents on the low voltage side are derived,and then deduce the reasons for the action of overcurrent protection on the low voltage side.The results show that when the single-phase disconnection on the high voltage side of the transformer occurs,the negative sequence impedance is relatively small compared to the positive sequence impedance due to the difference in slip rate of the motor load,leading to the low-voltage side overcurrent protection,experiments using PSCAD/EMTDC simulation models verifies its effectiveness of the analysis.

关 键 词：断线故障 变压器保护 电流方向 过流保护 

分 类 号：TM772[电气工程—电力系统及自动化]