发电厂励磁变故障分析和保护配置分析

Analysis of Fault Analysis and Protection Configuration of Excitation Transformer in Power Plant

在水力、火力发电厂中,发电机端电气设备故障是具有较高障率的,具体的故障情况有发电机PT故障、发电机PT一次保险故障、发电机CT二次回路开路、励磁变故障、励磁变高压侧三相短路、主变低压侧封闭不严进水、封闭母线封闭不严进水等。上述故障中,最常见的会导致发电机定子接地故障,最严重的是励磁变高压侧发生三相短路,将导致发电机设备损坏。本文以北方公司下属某电厂#6机660MW超临界燃煤发电机组发电机跳机事故为例,对发电机端出现的故障进行分析;对故障发现后所进行故障处理,进行相关参数试验;对日常检修工作中暴露的安全生产管理、人员管理等问题进行分析;对暴露的问题从岗位责任、人员管理、事故缺陷问题剖析、工作制度等几个方面进行整改;对发电机端进行保护配置,监测发电机运转情况,发现问题解决问题,减少经济损失。

In hydraulic and thermal power plants,generator terminal electrical equipment is with high disability rate.The specific fault conditions include generator PT fault,generator PT primary insurance fault,generator CT secondary circuit open circuit,excitation transformer fault,three-phase short circuit at the high-voltage side of excitation transformer,lax water inlet at the low-voltage side of main transformer,lax water inlet at the enclosed bus,etc.Among the above-mentioned faults,the most common one will cause a generator stator ground fault,and the most serious one is a three-phase short circuit on the high voltage side of the excitation transformer,which will cause damage to the generator equipment.In this paper,the generator jump accident of unit 6660MW supercritical coal-fired generator set in a subordinate power plant of North Company is taken as an example to analyze the failure of generator end.Conduct relevant parameter test for fault treatment after fault discovery;Analyze the safety production management,personnel management and other problems exposed in the daily maintenance work;Rectify the exposed problems from the aspects of post responsibility,personnel management,accident defect analysis,work system,etc;Protect the generator terminal,monitor the operation of the generator,find problems,solve problems and reduce economic losses.