一起发电机低励失磁故障分析  

Analysis of A Generator Under-excitation and Demagnetization Fault

作　　者：刘启德 黄新民 马涛 王廷旺 李小沛 赵立斌 LIU Qide;HUANG Xinmin;MA Tao;WANG Tingwang;LI Xiaopei;ZHAO Libin

机构地区：[1]国网新疆电力有限公司电力科学研究院,新疆乌鲁木齐830011 [2]国网新疆电力有限公司乌鲁木齐供电公司,新疆乌鲁木齐830011

出　　处：《青海电力》2024年第4期72-78,共7页Qinghai Electric Power

摘　　要：针对某水电站一起2台50 MW水力发电机低励失磁跳机事件,分析发电机低励失磁的过程、失磁保护动作逻辑及行为、发生低励失磁的原因。通过绘制发电机失磁保护静稳动作边界曲线、发电机机端测量阻抗轨迹、在Matlab/Simulink仿真平台搭建电力系统单机无穷大仿真模型验证分析的正确性。分析及仿真结果表明某水电站在一管三机的供水方式下,发电机由于水锤效应导致机组功率突升同时产生PSS(电力系统稳定器)无功功率反调,叠加发电机低励失磁保护定值整定错误增大静稳动作范围致使发电机低励失磁保护动作跳闸,最后根据事故原因提出了防止此类事故再次发生的措施。This paper analyzes a demagnetization trip event of two 50 MW hydro generators at a hydropower station.process of generator demagnetization,the demagnetization protection action logic and behavior,and the causes of demagnetization are studied.By drawing the static stability boundary curve of the demagnetization protection,the trajectory of the measured impedance at the generator terminal,and by building a single-machine infinite-bus power system simulation in Matlab/Simulink,the accuracy of the analysis is verified.The analysis and simulation results show that under the water supply mode of one penstock for units at the hydropower station,the water hammer effect causes a sudden increase in unit power,which in turn causes the PSS(power system stabilizer) to reduce reactive power.This,combined with the error in setting the demagnetization protection values,enlarges the static stability action range,leading to the demization protection action and tripping of the generator.Finally,measures to prevent such accidents from happening again are proposed based on the accident analysis.

关 键 词：水力发电机 低励失磁 MATLAB/SIMULINK 水锤效应 电力系统稳定器 无功功率 

分 类 号：TM612[电气工程—电力系统及自动化]