断路器导电回路电阻智能测试的研究

【作者】 牛文静；

【导师】 李洪春；

【作者基本信息】 大连理工大学 ， 控制理论与控制工程， 2004， 硕士

【摘要】 断路器导电回路电阻是标志断路器质量的主要参数之一，其值的大小直接影响到断路器通载额定工作电流时的温升以及短路状态下的动热稳定性。断路器导电回路电阻主要取决于动、静触头之间的接触电阻。接触电阻一般是微欧级的小电阻。目前最常用的接触电阻测试仪器是微欧仪，这些仪器普遍采用大电流恒流源，因此体积和重量都很大。 本论文提出了一种新的电源方式—脉冲电源，开发了一种新型回路电阻测试仪。脉冲电源的使用使测试仪体积和重量大大减小，便于携带和现场测试使用。仪器在设计中采用了单片机测试控制系统对脉冲电源进行充、放电控制，对数据进行采集、转换和处理，最后用LED数码管显示被测断路器接触电阻值和放电回路电流的峰值。 该仪器的电压、电流信号的测量均采用工程实际中经常使用的四端子接线技术，有效的减少了引线电阻带来的测量误差。在硬件电路中使用了精密的仪用放大器对需要测试的信号进行放大，同时还使用光电耦合器件、继电器和滤波电路等来减小各种干扰。在软件设计中，使用数字滤波等方法来减小系统的测量误差。 经实验检验，本研究开发的新型回路电阻测试仪具有良好的人机界面，操作简单，经济实用。更多还原

【Abstract】 Circuit resistance of breaker is one of the most important parameters which determine the quality of breaker. It can directly affect the temperature rising when the rated current passes through breaker and the moving thermal stability at the over loading moment. The resistance mostly lies on the contact resistance between moving and static contact of breaker. The value of the contact resistance is very small with micro ohm scalar. Micro ohm meter has been used to measure the contact resistance commonly at present. Since the constant-current source is used, the volume and weight of micro ohm meter is very large.In this design, a new instrument using pulse power supply is introduced to measure the contact resistance. The volume and weight of the new instrument is minished and it can be used expediently. In the new instrument a system of MCU is applied to control charging or discharging the pulse power supply, collects convert and operate data, and then display the value of the contract resistance and the peak value of discharging circuit current with LED.In the instrument the measurement of voltage and current adopt the technology of four-terminal connection which is used usually in engineering practice to reduce the system error on collecting signals. In the hardware instrument amplifiers are used to amplify the signals, at the same time Phototubes relay and filter circuit are adopted to reduce interference. In software program of digital filter can be compiled to reduce the measure error.It has been proved by experiments that the new intelligent instrument has a favorable interface, can be handled simply Eind has low cost.更多还原