Design Of Intelligent Control System For Control And Protection Switch

With the development of electrical technology and information technology, intelligentelectrical devices are widely used. Intelligent electrical devices introduce microprocessor、sensors and communication system based on triditional appliances, so the PC can runreal-time monitoring on electrical appliances. The microprocessor that the switchintroduced maks itself has a certain ability to make decision. Control command andparameter information can not transfer without the support of communication system. Itrequires communication system has robust and real-time. Triditional switchcommunication module used485bus.485bus is master-slave communication mode. Ahostuses polling mode to ask every slave by turn whether it has information to transfer. A hostcan have at most32slaves, and the slaves must be the same type. with wirelesscommucation rising, using wireless communication as switch communication module ispossible now. Wireless don’t have to lay out wires. This will make it more convenient inthe mountains, large factories and other complex environment. Wireless communication ismuch easier to do post-maintenance, it juse have to replace communication mode and thecommunication mode has larger amount of nodes. Since the switch is more centralizedapplications, so the use of short-range wireless communication network is appropriate.Among all kinds of technology of short-distance wireless communication network, ZigBeehas a low power, low cost, low complexity, self-organization, large network capacitycharacteristic, so using ZigBee as thecommunication module of intelligent switches.The main work of this article is as follows:(1)Designed the control module hardware circuit, communication module used amicroprocessor to control RF chip, SCM is PIC18f46k22, RF chip is CC2420. MCU andRF chip used SPI to communicate, used altium designer to design the schematic diagramand PCB, then soldered circuit board.(2)Designed the antenna balun matching circuit and adjust simulation parameters byADS to achieve the best match.(3)Used program MPLAB to program the communication modules and the touchscreen control C codes, achieved the control of switch on and of the switch parameterswriting and reading. (4)Tested ZigBee nodes transmission performance in open areas and enclosed spacewith obstructions using the circuit board, then ran a comparative analysis of the twoproperties.