1205同步发电机电气试验和继电保护设计

摘要

随着科技的进步和经济的不断发展，我国用电量需求越来越大。各地区和城镇的供电系统容量呈逐年递增的趋势，大容量的发电机组也在不断的增加。电力系统中，同步发电机是最为核心的部分，发电机是否能长期稳定的运行对于整个电力系统的安全来说起着决定性的作用。由于发电机在设计和制造过程中，不可避免的会存在一定的问题，因此发电机投入使用之前应该先按照规定进行相关的电气试验，以防止带有故障的发电机被投入使用。发电机长期不停地运行的过程中热、磁、电、摩擦、震动等因素都会给发电机带来潜在的危害，大容量发电机复杂的内部结构给其故障检测和继电保护都带来了极大的挑战。人们对电网的稳定性和安全性的要求越来越高，传统的电气故障检测和继电保护不能满足现代电力系统的需求，因此亟需深入地研究同步发电机的故障检测方法，研究在线检测电网中发电机的电气量的方法和研究电网中大型发电机进行继电保护。

本论文首先对同步发电机的进行了研究，了解同步发电机的现场实际运用状况，发现越来越多的大容量发电机在电力系统中被投入使用，然而现在国内几乎没有针对大型同步发电机完整的从故障试验到继电保护的研究，本论文结合大型同步发电机的特点，根据同步发电机的内部物理结构，数学模型以及工作原理，对同步发电机进行了故障分析，并详细对定子绝缘故障和转子绕组匝间短路的检测方法进行了介绍。在分析发电机故障成因和现象的基础上，设计出一套在线监测系统，包括了硬件结构部分和软件设计部分，该监测系统能够实时对电力系统中发电机的各个重要电气量进行检测。论文还对电力系统中大型发电机的继电保护进行了设计，包括整体保护方案的设计和主保护，接地保护的详细设计，并提出发电机主保护的优化配置方案。

关键词：同步发电机 故障 电气试验 继电保护

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Abstract

With the advancement of technology and the development of economy, China's demand for electricity is growing. Power supply is increasing every year in various regions and large-capacity generators constantly increasing. In the power system, synchronous generator is the most central part. Whether the generator can be operated stably plays a decisive role for security of the entire power system. The generator will be some damaged in the design and manufacturing process inevitably. Therefore, the generator need to be tests before it be putted into use to prevent faulty. Generators need to keep long-time operation and the heat, magnetism, electricity, friction, vibration, will cause damage to the generator. The large-capacity generators has complex internal structure, therefore, fault detection and protection are very difficult. People have become increasingly demanding for stability and security of the grid. The traditional electrical fault detection and protection can’t meet the needs of modern power systems. Therefore, study of synchronous generator fault detection method and large generator protection in-depth is very urgent.

This paper studies the synchronous generator and understands the actual situation use of synchronous generators. The study find that more and more large-capacity generators to be used in the power system. However, there was almost no complete study of large synchronous generator including electrical test and protection. This study based on the characteristics of large generators. Analysis fault conditions of synchronous generator according to the internal physical structure, mathematical models and principle of work. This paper describes the detection method of stator insulation fault and Rotor winding inter-turn short circuit fault detailedly. A set of on-line monitoring system was designed in this paper. The monitoring system includes the hardware design and software design. It can detect the status of the generator in real time. It also designed a protection scheme about large generator, including the design of the overall protection scheme, grounding protection design, etc. It presents an optimization method about generator main protection in the end of the paper.

Key Words: Synchronous Generator，Fault，Electrical test， Protection

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目录

摘要 ................................................................................................................................... I Abstract ............................................................................................................................ II 目录 ................................................................................................................................ III 图表目录 ........................................................................................................................ VI 第1章 绪论 .................................................................................................................... 1 1.1 课题背景与意义 ................................................................................................... 1 1.2 国内外研究现状 ................................................................................................... 2 1.2.1 同步发电机电气故障及试验的研究现状 ................................................... 2 1.2.2 同步发电机继电保护研究现状 ................................................................... 4 1.4 研究目标与研究内容 ........................................................................................... 6 1.4.1 研究目标 ....................................................................................................... 6 1.4.2 研究内容 ....................................................................................................... 6 第2章 同步发电机的电气试验 .................................................................................... 8 2.1 同步发电机的基本理论 ....................................................................................... 8 2.1.1 同步发电机的分类 ....................................................................................... 8 2.1.2 同步发电机物理模型 ................................................................................... 8 2.1.3 同步发电机工作原理 ................................................................................... 9 2.2 同步发电机的电气故障现象及原因分析 ......................................................... 11 2.3 同步发电机运行特性测试 ................................................................................. 11 2.3.1 空载特性试验 ............................................................................................. 12 2.3.2 短路特性试验 ............................................................................................. 13 2.3.3 负载特性试验 ............................................................................................. 13 2.4 定子绕组绝缘测试 ............................................................................................. 14 2.4.1 定子绕组介质损耗测试 ............................................................................. 14 2.4.2 定子绕组局部放电测试 ............................................................................. 15 2.5 转子绕组匝间短路测试 ..................................................................................... 16 2.6 STC-5型同步发电机电气试验测试及分析 ...................................................... 16 2.6.1 STC-5型同步发电机额定参数 .................................................................. 16

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2.6.2 STC-5型同步发电机空载特性测试 .......................................................... 16 2.6.3 STC-5型同步发电机短路特性测试 .......................................................... 17 2.6.4 STC-5型同步发电机转子绕组匝间短路故障测试 .................................. 18 2.6.5 试验结果分析............................................................................................. 19 2.7 本章小结 ............................................................................................................. 20 第3章 同步发电机在线监测系统设计 ...................................................................... 21 3.1 同步发电机在线监测现状 ................................................................................. 21 3.2 需求分析 ............................................................................................................. 21 3.2.1 功能需求分析............................................................................................. 22 3.2.2 非功能需求分析......................................................................................... 23 3.2.3 可行性分析................................................................................................. 23 3.3 硬件设计 ............................................................................................................. 24 3.3.1 硬件连接电路设计..................................................................................... 24 3.3.2 数据采集方案设计..................................................................................... 25 3.3.3 模拟量采集电路设计................................................................................. 25 3.3.4 数字量采集电路设计................................................................................. 25 3.4 软件设计 ............................................................................................................. 26 3.4.1 软件整体方案设计..................................................................................... 26 3.4.2 功能模块设计............................................................................................. 26 3.5 本章小结 ............................................................................................................. 27 第4章 同步发电机的继电保护设计 .......................................................................... 28 4.1 发电机保护 ......................................................................................................... 28 4.1.1 发电机主保护............................................................................................. 28 4.1.2 发电机定子接地保护................................................................................. 29 4.1.3 异常运行保护............................................................................................. 30 4.2大型发电机继电保护设计 ................................................................................. 30 4.2.1 总体方案设计............................................................................................. 30 4.2.2 发电机主保护设计..................................................................................... 31 4.2.3 接地保护设计............................................................................................. 32 4.2.4 异常保护设计............................................................................................. 33

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