Research Of Intelligent Protection Module Of Variable Current Devices For Large Current DC And Power Electronics

Variable current equipment for large current DC and power electronics is the commondevice in the industrial electronics, and its supporting protection device is always a hot spotfor domestic and foreign research. With the development of microcomputer technology, MCUcontrol has involved in the industrial field. At the moment, it is widely used to the intelligentprotection system with MCU. The intelligent protection module is proposed by reading a largenumber of technical informations and deeply researching technologies, and it includes theMCU-51controller unit, the CPLD subsidiary unit, the peripheral detection and hardwareprotection circuit.This paper is divided two parts of hardware design and software design. The hardwarepart is comprised of MCU-51control unit, CPLD auxiliary module, detection circuit, A/Dconversion circuit, hardware protection circuit, executive action unit and reset circuit,keyboard circuit and LCD display circuit, etc. The software part is comprised of mastercontrolling program and assistant program. When designing hardware circuit, the high costperformance of chips and devices is selected, and the economic and reliable circuit is achieved.In programing, the modularization ideas is adopted to reduce program complexity and increaseprogram transplantation.In conclusion, after experimenting the hardware and simulating the software, the responsetime needs second class for this intelligent protection device, and A/D conversion time needsfor100microsecond, then51MCU could correctly adjust and display the protection threshold,besides CPLD could transmit the correct time logic to MCU. Therefore, this design hasbasically possessed the function with protection, display, alarm, action.