Research On Controller Of Control And Protective Switching Device And Automatic Calibration System

With the industry’s increasingly complex environment,the traditional thermal magnetic tripcircuit breaker has been unable to meet the market and technology requirements.And the newmulti-functional low-voltage electircal based on microelecronics,industrial bus technology andcomputer netoworks is gradually replace the traditional electrical equipment.just because of thisbackground ,the new Control and Protective Switching Device(hereinafter referred as CPS)cameinto being.This paper first took CPS and control system that combined with traditional discretecomponents into comparement,and then analysised its domestic andinternational developments,atlast ,the research significanse was also mentionedBased on the current mass production of CPS,the core controller in its production processneeds a series of aging tests. in this paper,according to the basic principle of CPS ,we proposed anautomatic calibration system based on RS-485 bus,analysised the principles and reliability ofRS-485,discussesed the structure of RS-485 and the MODBUS protocol content in details,designedhighly efficient and stable communication network.According to the actual needs of CPS,in this paper we proposed a feature based on the inversetime characteristics,discussed the industry rules of inverse time characteristics,and also analysisedthe inverse time algorithm according to characteristics of microprocessor protection,and finallyachieving the function wiht MCU.At the same time,for the overrall design of CPS ,we analysisedthe hardware circuit ,software code ,the principles and structure of the parts attribute in details.Inorder to meet the demands of different manufacturers ,we added the manufaturers hidden menu andself-calibration function to the CPS.According to the national standard GB14048.9 of"voltage switchgear,control equipment andmulti-function device : control and protective switching devices",we adopted industrial personalcomputer software to manage the stable temperature aging shelf of CPS,the test items includedcircuit board’s automatically loop detection and aging test in the different environments.Crossplatform application and UI design were used to manage the personal computer’s monitorsoftware,also in the paper the mechanisim of Qt’s data transmission was introduced.In order tomonitor the CPS,the PC software communicated with every aging shelf by the RS-485 bus,in thisway ,the PC can provide users the detailed inspection process and reports.Finally,the paper summarized the design results of CPS and its automatic calibrationsystem,analysised the current status of the product and the shortage,and pointed out the design direction in future by studying the latest developments..