毕业样板论文(《变电站断路器机械特性监测系统设计》)

毕业设计样板论文

《变电站断路器机械特性监测系统设计》

摘 要

对电力设备进行在线监测，是实现设备预知性维修的前提，是保证设备安全可靠运行的关键，也是对传统离线预防性试验的重大补充和新的发展。高压断路器所造成的事故无论是在次数，还是在事故所造成的停电时间上都占据总量60％以上。因此，及时了解断路器的工作状态对提高供电可靠性有决定性意义；并可以大大减少盲目定期检修带来的资金浪费。

本文论述了断路器机械特性参数的监测方法；提出根据断路器生产厂家提供的断路器额定短路电流分断次数，计算每次分闸对应的触头电寿命损耗，预测触头电寿命；提出根据断路器壳体温度和断路器周围空气温度结合断路器的热阻来计算断路器主触头稳态温升的方

法，并根据此时的负荷电流间接计算主触头回路的电阻；在实现在线监测的系统的设计上本文选用了美国 TI 公司最新推出的一种功能强大的单片机MSP430。在系统设计时充分考虑到由于该单片机的低供电电压（1.8～3.6V）给设计所带来的特殊问题，并予以解决。在通讯模块设计中根据RS-485 通信芯片MAX1480B 的特殊结构，解决了不同工作电压芯片RS-485 通信芯片MAX1480 与单片机MSP430 的接口问题，并给出了MAX1480 与MSP430 芯片直接联接的接线方案。

关键词：断路器 在线监测 机械特性 触头电寿命 触头温度

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On-line Monitoring of HVCB

HVCBon-linemonitoring

Abstract

isessentialforpredictingmaintenance and as a

supplement to the traditional off-line preventive maintenance is the key factor of its reliable operation. In fact,

the faults on HVCB account for over 60 percent both in number and duration of all the faults occurring in a substation. Therefore, on-line monitoring ofHVCB could significantly improvepower supply reliability and greatly reduce the expense for regular overhaul.

In this thesis, the inspecting methods of HVCB mechanical characteristics are discussed. According the shut-off times of HVCB at rated short circuit given by manufacturer,the contacts life loss can be calculated for each operation, and the remaining life can be forecast. In this thesis, an indirect method is proposed for determining the main contact temperature based on the breaker shell temperature, air circumference temperature and breaker’s heat resistance, and furthermore, determining the main contact esistance provided the load current is know. The on-line monitoring ris implemented with MSP430, a new Single Chip Microcomputer by Texas Instrument, with its lower supply voltagerange of this chip （1.8～3.6V）is well treated. In the design of communication module, interfacing problem caused by different voltage supply levels (MAX1480 and MSP430) is carefully solved, and a connection scheme is devised in this paper as well.

Kywords: HVCB On-line Monitoring Mechanical Characteristic Touch

Electricity Endurance Touch Temperature

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目 录

第1章 绪 论..........................................................1

1.1 电力设备在线监测................................................... 1 1.1.1 电力设备在线监测技术发展史.................................... 1 1.1.2 电力设备在线监测技术展望...................................... 2 1.1.3 在线监测系统的基本要求........................................ 2 1.2 高压断路器在线监测................................................. 2

1.2.1 高压断路器在线监测技术发展史.................................. 2 1.2.2 国内外高压断路器在线监测技术现状............................... 3 1.3 论文主要工作及取得的成果........................................... 3 第2章 在线监测方案设计................................................5 2.1 机械特性在线监测................................................... 5 2.1.1 机械特性在线监测的必要性...................................... 5 2.1.2 机械特性参数的标定............................................ 5 2.1.3 机械特性参数的采集........................................... 8 2.1.4 机械特性参数的确定........................................... 9 2.1.5 机械故障诊断................................................. 10 2.2 触头电寿命在线监测................................................ 10 2.2.1 分闸电流数据采集及算法....................................... 11 2.2.2 灭弧触头电寿命预测原理....................................... 17

2.3 主触头导电性能在线监测方法的探讨.................................. 19 2.3.1 断路器的发热与散热........................................... 19

2.3.2 主触头温度和主回路电阻间接算法................................ 22 第3章 硬件设计.......................................................24

3.1 硬件系统组成概述.................................................. 24

3.2 新一代单片机MSP430简介........................................... 25 3.3 各功能模块设计.................................................... 26

第4章 软件设计.......................................................32

4.1 硬件级驱动软件设计................................................ 32

4.1.1 WTD定时器中断服务程序流程.................................... 32 4.1.2 A/D 中断服务程序流程.......................................... 32 4.1.3 状态量输入中断服务程序流程................................... 33 4.1.4 TA、TB计数器捕获中断服务程序流程............................. 34 4.1.5 DS1820数据采集子程序......................................... 35 4.2 功能模块级软件设计................................................ 35 4.2.1 合闸记录子程序............................................... 35 4.2.2 分闸记录子程序............................................... 36 4.3 系统级软件设计.................................................... 37 第5章 数据通信...................................................... 39

5.1 RS-485 串行通信的特点............................................. 39 5.2 MSP430 串行通信的特点............................................. 39 5.3 RS-485通信接口芯片MAX1480B....................................... 40 5.4 存在的问题及解决方案.............................................. 40 5.4.1 存在的问题................................................... 40 5.4.2 问题分析..................................................... 41

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