Research Of Design Of Controller For Vacuum Circuit-breaker Based On PIC

Vacuum circuit breaker is a very important equipment in the power system, it is important to protect the safety of operation of distribution network. In recent years, with the development of smart grid, the distribution network has also gradually developed its intelligence process. However, the traditional control of vacuum circuit breaker is controlled by relay. In recent years, the controller of the breaker based on MCU is also developed. But it also has less function and the the electromagnetic environment is very complex, in actual operation. In actual operation the false action caused by electromagnetic interference is sometimes happened. Therefore, developing a controller which has abundant function and high anti-interference is very meaningful and valuable.To begin with, the functions and features as well as the development trend of the circuit breaker controller oriented to the smart grid have been analyzed on the basis of the introduction of the research background and situation of the issue, and designed a controller for circuit breaker take the microprocessor PIC16F877A as the core based on the current research status of vacuum circuit breaker. The idea of modularization has been used when design the controller, which would simplify the designing of the controller and it would debug the controller easier. Overall design and function analysis are carried on in the paper. The characteristic of hardware system is considered in the software system and the MPLAB V8.80 is used in the designing of software system. The idea of modularization has also been used when design the software system, independent interfaces are in the software system for developing in the future. The modules of display, sampling, signal processing, self-checking and storage are all consisted in the designing of software system. Hardware and software system are designed in this paper, filter, source of voltage, LCD, execution mode of closing coils and storage mode are all inside the hardware system.The paper analyzed the complex electromagnetic environment of the controller. Hardware and software anti-interference measures are also researched and an electro-magnetic shield is designed based on the controller. Simulation of the electro-magnetic environment and optimal designs of controller by using the HFSS has been done, and designed a model of the shield. The material, thickness, size of ventilation holes are all simulated in this software and take the optimal solution.The experiments of basic function and anti-interference were done in this paper. The filter, source of voltage, LCD, execution mode of closing coil are all tested in basic function experiments. The results show that each module realizes their expected functions. The contrast experiments of anti-interference have been done in the condition of strong electric and magnetic field. The results show that measures of anti-interference in hardware and software system could realize the function of electromagnetic shielding.