智能塑壳断路器过流保护技术的研究

发布时间：2018-03-23 07:21

本文选题：智能断路器　切入点：过流保护　出处：《河北工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：社会经济快速发展,用电量不断增长,对供电质量和供电可靠性的要求越来越高。然而过电流现象在供电与用电系统中普遍存在,容易引起事故,带来巨大的经济损失。断路器作为一种广泛应用于供电用电系统中的重要保护电器,在过电流保护中起着不可替代的作用,因此本文对智能塑壳断路器的过流保护技术进行了研究。首先,对断路器的发展现状和过流保护技术的应用现状进行了介绍,并详细叙述了智能塑壳断路器过流保护工作原理。其次,对硬件电路进行了设计,包括电流信号变换电路、单片机及其外围电路、辅助电路。电流信号变换电路的动态响应时间决定了过流保护特性,特别是在短路电流下响应时间和短时过电流下误动作问题。通过对电流信号变换电路的设计、计算和实测,使电流信号变换电路达到设计要求。对信号变换电路进行了仿真和实测,分析了相关测试结果并计算了误差,结果表明电流信号变换电路满足设计要求,为单片机提供准确的电流信号。再次,基于ATMEGA64单片机进行了软件编程。采用模块化的设计思路,编写了各功能模块的应用程序。深入研究了电流互感器的输出特性,特别是大电流下进入饱和区的输出特性。采用MATLAB对电流互感器的输出特性进行拟合,得到其变化规律,并在信号处理程序中进行饱和特性的补偿,提高了电流检测精度,满足保护特性设计要求。最后,对过载长延时保护、短路短延时保护、短路瞬时保护进行了实验,实验结果证明所设计断路器的过流保护满足实际使用的要求。
[Abstract]:With the rapid development of social economy and the continuous increase of electricity consumption, the demand for power supply quality and reliability is becoming higher and higher. However, the phenomenon of overcurrent is common in the power supply and power system, which can easily lead to accidents. As an important protective appliance widely used in power supply system, circuit breaker plays an irreplaceable role in over-current protection. Therefore, the overcurrent protection technology of intelligent plastic case circuit breaker is studied in this paper. Firstly, the development status of circuit breaker and the application status of over-current protection technology are introduced. The working principle of overcurrent protection for intelligent plastic case circuit breaker is described in detail. Secondly, the hardware circuit is designed, including current signal conversion circuit, single chip microcomputer and its peripheral circuit. Auxiliary circuits. The dynamic response time of current signal conversion circuit determines the characteristics of over-current protection, especially the response time under short-circuit current and the problem of misoperation under short-time over-current. Through the design, calculation and measurement of current signal conversion circuit, The current signal conversion circuit is simulated and measured, the related test results are analyzed and the error is calculated. The results show that the current signal conversion circuit meets the design requirements. Thirdly, the software program based on ATMEGA64 single chip computer is carried out. The application program of each function module is compiled by using the modular design idea. The output characteristics of the current transformer are deeply studied. MATLAB is used to fit the output characteristics of the current transformer, and the variation law is obtained. The saturation characteristic is compensated in the signal processing program, and the accuracy of current detection is improved. Finally, experiments on overload long delay protection, short circuit short delay protection and short circuit instantaneous protection are carried out. The experimental results show that the over-current protection of the designed circuit breaker meets the practical requirements.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM561

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