汽轮发电机灭磁电阻选择  

Selecting Appropriate De-excitation Resistors for Turbine Generators

作　　者：许其品[1] 杨铭[1] 徐蓉[1] 

机构地区：[1]国电南瑞科技股份有限公司,江苏省南京市210061

出　　处：《电力系统自动化》2013年第6期125-129,共5页Automation of Electric Power Systems

摘　　要：从发电机灭磁的目的着手,分析了影响发电机内电势下降速度的因素,利用MATLAB对汽轮发电机内部短路故障时采用不同灭磁电阻及灭磁方式的灭磁进行了仿真。据此得出发电机灭磁设计中灭磁电阻的阻值或残压选择的依据,即所选灭磁电阻应使灭磁回路的时间常数略小于发电机dq轴阻尼绕组时间常数中的较大者。此时既能保证灭磁所需磁场断路器的弧压在安全范围内,又能尽可能地减小发电机故障点电弧的发热量,真正起到保护发电机的作用,对于发电机组灭磁标准的制定具有指导意义。This paper analyzes the factors which affect the drop speed of internal potential of synchronous generators according to the purpose of de-excitation.The processes of de-excitation with different resistors and different approaches are simulated using MATLAB when turbine generator internal short circuit occurs.According to the analysis,the selection criteria of the de-excitation resistor or residual pressure in the de-excitation design of a generator are obtained.That is,the selected de-excitation resistance should make the time constant of the de-excitation circuit a bit less than the bigger one between the time constant of the dq axis damp windings of the generator.At this stage,with the proposed selection criteria,the arc pressure of the DC field breaker required by de-excitation can be in a safe range;and the heat output of the electric arc at the fault point of the stator can be minimized as well.Protection of the generator can thus be real.It also provides significant guidance for modifying the de-excitation standard.

关 键 词：灭磁 时间常数 励磁绕组 阻尼绕组 直流磁场断路器 

分 类 号：TM311[电气工程—电机]