基于单片机的智能低压电动机综合保护器的研究硬件设计 学位论文

毕业设计任务书

河北工程大学

毕业设计（论文）任务书

题目：基于单片机的智能低压电动机综合保护器的研究——硬件设计

学生姓名：李莉学号：050062221

专业班级：电气及其自动化05-22 学院：科信学院

设计起止日期：2009.3.16~2009.5.25

联系实际的题目假想的题目

题目性质：√

技术要求及原始数据：要求低压鼠笼式异步电动机功保护器具有过载、过电流、断相、漏电、短路等保护。过载保护时间滞后时间为60~180s，断相保护动作滞后时间小于1s，短路保护滞后时间小于0.2s。可显示故障时间和类型。动作值的修改。

主要任务： 1 综合保护器总体方案的确定

2系统的软件设计（流程图）

3软件编程和调试

4手工绘制一张1#图纸，用计算机绘制1~2

5撰写并打印设计说明书一份张1#图纸

学生（签字）：系主任（签字）：

指导教师（签字）：院长（签字）：

摘要

摘要

电动机因具有结构简单、价格低廉、使用维护方便等优点，在国民经济各方面被广泛采用。然而，由于供电状态和机械负荷的多变性，使得电动机的故障率较高，不仅会损坏电动机本身，而且会影响整个生产，造成较大的经济损失。因此，电动机的安全运行对保证厂矿企业的正常生产是非常重要的。

本文首先分析了异步电动机的常见故障，以交流采样的方法进行数据采集为依据，采用检测三相电压、三相电流、零序电流的方法，得出了电动机故障的准确判据，确定了各种故障的保护措施，对电动机实现了短路、欠压、断相、漏电、过载等保护功能。

本文以8位单片机AT89C52做微处理器，AT89C52单片机内置256字的RAM和8K 字的ROM，可以进行外部扩展数据存储器和程序存储器，具有性能较好的I/O、运算等功能，有合适的指令系统，能够实现电机智能保护，电路简单，功能齐全。为了实现电机分布检测和控制的要求，控制系统具有便于集中管理和信息共享的特点。

关键词：电动机；智能保护；单片机AT89C52；故障保护

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Abstract

Abstract

Because the electric motor has the structure simply, the price inexpensive, merits and so on use maintenance convenience, is widely used in the national economy various aspects.However, as a result of the power supply condition and the machinery load polytropy, causes electric motor the failure rate to be high, not only can damage electric motor itself, moreover can affect the entire production, creates the big economic loss.Therefore, the electric motor safe operation to guaranteed the factory and mining enterprise the regular production is extremely important.

This article has first analyzed the asynchronous motor common breakdown, take exchanges the sampling method to carry on the data acquisition as the basis, uses the examination three-phase voltage, the three-phase current, the zero foreword electric current method, has obtained the electric motor breakdown accurate criterion, had determined each kind of breakdown protective measures, realized the short circuit to the electric motor, have owed press, break, protection functions and so on the leakage, overload.

This article makes the microprocessor by 8 monolithic integrated circuit AT89C52, in at89C52 monolithic integrated circuit sets at 256 character RAM and 8K character ROM, may carry on exterior expansion data-carrier storage and the program memory, has functions and so on performance good I/O, operation, has the appropriate command system, can realize the electrical machinery intelligence protection, the electric circuit is simple, the function is complete. In order to realize the request which the electrical machinery distribution examines and controls, the control system has is advantageous for the centralized management and the information sharing characteristic.

Keywords:Electric motor; intelligent protection; monolithic integrated circuit AT89C52; fail safe

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