220kv变压器微机保护原理的研究.doc

220kv变压器微机保护技术的研究
摘要
作为电力系统继电保护重要组成部分的变压器继电保护,对保障变压器的安全运行具有十分重要的作用。本文在介绍电力系统微机保护原理及其发展趋势的基础上,对电力系统中大量应用的220/35KV电压等级的变压器的继电保护进行了专门研究, 分析了影响变压器差动保护可靠性和灵敏度的不平衡电流的产生原因和特点,利用微机技术补偿不平衡电流的影响。根据这一类变压器的运行特点,吸取以往各种保护方法的长处,制定了一套适合于220/35KV电压等级的电力变压器保护方案,以差动保护和***保护为主保护,低电压启动的过电流保护为后备保护。以所制定的保护方案为依据,选择了以MCS-96 系列16位单片机8098为核心的变压器微机保护装置的硬件平台,进行保护装置的硬件系统设计和软件模块设计。在硬件设计方面,主要包括数据采集系统、CPU主系统、开关量输入/输出系统及跳闸出口部分等电路的设计。在软件设计方面, 对现有主要的微机保护算法进行了比较、分析,选择具有计算简便、收敛速度快、收敛过程稳定等优点的递推最小二乘算法,满足了变压器保护对算法估计精度和估计速度的要求。
关键词:变压器;差动保护;继电保护;微机保护
Abstract
Transformer relaying protection is one important part of power system relay protection, it is very important to the transformers' safe operation. This paper is on introduce the microprocessor-based protection power system to protect the foundation of the principle and its development trend , to power system inside large quantity application of 220/35KV electric voltage the grade 's transformer of relay protection the specialized researched, and analyze the produce cause and characteristic of the unbalanced current which influence the reliability and sensitivity of transformer differential protection, some puter-based methods pensating the unbalanced current. According to this the transformers' movement characteristics , absorb the strength of the every kind of protection method before , formulation a suitable for 220/35KV electric voltage the grade’s transformer protect the project , with differential protection and protect with gas to main protection , and the low electric voltage is after starting of protect over the electric current for to have the protection . With the established protection the project is a basis , and with the transformer puter-based protection that MCS-96 series 16 single-chip machine 8098 for the core to choice , hardware that protect the device terrace hardware bine the right protect the device the system design and software mold the piece designed. Design the aspect in the hardware , include data collecting system , CPU m