新型电子式过载继电器设计

发布时间：2018-01-14 09:24

本文关键词：新型电子式过载继电器设计　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着科学技术的迅猛发展以及电器元件在各个领域应用的不断深入,人们对在运行中电机的保护要求在不断提高,特别是在现代化、自动化的行业中对电机的保护尤为重要,这就要求控制电机的电器元件具有多种保护功能,其中起过载保护的双金属片式过载继电器准确性差,而电子式过载继电器控制准确,为了满足用户对电子式过载继电器控制准确性的要求,本文研制了一种控制准确、灵敏度高的新型电子式过载继电器。本文研制的新型电子式过载继电器是一种无需辅助电源的、同时具有手动复位和自动复位功能的电子式过载继电器。此继电器由动作机构、辅助触头、电流互感器、控制检测单元和外壳等部分组成,采用数字采样,单片机控制,具有电源指示、脱扣指示,测试按钮,过载保护、断相保护和负载不平衡保护等功能。通过对动作机构原理的介绍,本文提出一种利用电磁理论实现控制回路常开触点和常闭触点转换的方法,以及如何运用异形扭簧实现手动复位和自动复位并存的方法;本文阐述了辅助触头系统设计中重要的两个任务,即触头压力计算和触头材料选择;通过对控制检测单元软硬件设计的阐述,本文介绍了电子式过载继电器中电源产生、信号采集、单片机信号处理以及如何使控制回路实现过载保护、断相保护和自动复位等功能。本文阐述了电子式过载继电器要通过国家强制性产品认证必须进行的几个重要的型式试验,包括辅助触头的接通和分断能力、限制短路电流能力试验、电磁兼容试验以及动作特性试验,分析了影响试验结果的因素以及改进的方法。
[Abstract]:With the rapid development of science and technology and the application of electrical components in various fields, the requirements for the protection of the motor in operation are constantly raised, especially in the modernization. The protection of motor is particularly important in the automation industry, which requires that the electrical components controlling the motor have a variety of protection functions, among which the accuracy of the bimetallic overload relay with overload protection is poor. And the electronic overload relay control is accurate, in order to meet the user's requirements for the electronic overload relay control accuracy, this paper developed an accurate control. A new type of electronic overload relay with high sensitivity is developed in this paper. Electronic overload relay with manual reset and automatic reset. The relay is composed of action mechanism, auxiliary contact, current transformer, control detection unit and shell, etc. It adopts digital sampling. Single-chip microcomputer control, with power indication, tripping indication, test button, overload protection, phase break protection and load imbalance protection and other functions. Through the introduction of the principle of the action mechanism. In this paper, a method to realize the conversion between the normal open contact and the constant closed contact in the control loop by using electromagnetic theory, and the method of how to realize manual reset and automatic reset by using the special-shaped torsion spring are presented. This paper describes two important tasks in the design of auxiliary contact system, namely, the calculation of contact pressure and the selection of contact materials. Through the design of the hardware and software of the control and detection unit, this paper introduces the generation of power supply, signal acquisition, signal processing of single-chip microcomputer and how to realize overload protection in the control loop. This paper describes several important type tests for electronic overload relays to pass the national compulsory product certification, including the ability of connecting and breaking auxiliary contacts. The limited short circuit current capacity test, electromagnetic compatibility test and action characteristic test are analyzed. The factors influencing the test results and the improved method are analyzed.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM58

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