Design And Development Of On-line Monitoring System For Circuit Breaker In Metro Traction Substation

In China, the subway is the focus of urban public transport development. Breaks of the metro traction substation are important equipments that have frequent mechanical and electrical actions, as a result, they are prone to failure. Subway operation departments devote lots of manpower and material resources to the high and low voltage breakers for regular maintenance. These not only increase operating costs, but also cause damage to the breaker itself by human factors, and a hidden danger was caused to the normal operation of the breaker. To solve these problems, this paper designed on-line monitoring system of circuit breaker, it can real-time reflect the operating conditions of breaker, so as to enhance safety and reliability of the power supply system in the subway, provide scientific basis and expert decision-making propose for state maintenance.Under the analysis of the working principle and maintenance of order about the AC and DC circuit breakers, in this paper, I extract the important characteristic parameters, such as vibration, the coil current, current of stored energy motor. In the system design, this paper uses utu2440 core board as the hardware carrier, to use the monitoring system for research and application; utilize Linux2.6.24 core software platform for the development of transplant; apply MAX125 sampling chip extending the functions of AD for data acquisition; and through the RS-485 to transmit the data collected. The monitoring system is rich in expansion port, powerful, manageable, real-time, and supporting multi-task.This study focused on the design of the monitoring unit of the hardware and Linux operating system platform, as well as the data collection function implementation. Hardware design include:data acquisition circuit, LCD liquid crystal display design, and RS-485 communication interface. The design of Linux operating system platform includes the construction of development environment, driver and application programming of ADC, RS-485, LCD, USB interface. This thesis completed the preliminary design of data acquisition system and 485 communication test, also the designed LCD liquid crystal display did the preliminary work for further development of embedded graphical user interface.