Design Of Control And Protective Switching Communication Module Based On Profibus

As an important part of low-voltage apparatus field, switchgear is indispensableprimary equipment in power automatic system, its running state is stable or not, whichimpacts directly the whole system’s safe and steady. As the representative product ofswitchgear, control and protective switching device integrate various traditional discreteprotective apparatus into single equipment, which realizes traditional equipment’ functionscombination, it has small volume, compete functions and simply maintenance, itsprotective precision and safe reliability improve obviously. With the rapid development offieldbus technology and network communication technology, the new generationdevelopment slogan calls communication-capable apparatus. For complying with thisdevelopment trend, control and protective switching need to set up the communicationinterface, and connect with fieldbus to realize the network.In this paper, to adapt that technology development brought more and more highreliability requirement for automatic distribution network, in the premise of looking intolow-voltage apparatus and fieldbus, put forward a communication-capable control andprotective switching network system based on Profibus fieldbus, PC or IPC is designed forupper computer, and connects with multiple control and protective switching throughProfibus fieldbus to realize remote control. Lower computer’s intelligent controller usesmodularized design scheme, take PIC18F452singlechip as the kernel control chip,peripheral circuits consist of line signal detection, control signal output, key-press anddisplay, and communication interface modular etc. The emphasis is the design ofcommunication modular for data exchange between singlechip and upper computerthrough Profibus fieldbus, the transmission data are line voltage and current, protectiveparameters and on-off state etc, the data uses parameter coding form to store, and waits forbeing called at any time. The upper computer uses WinCC software to design themonitoring interface, the interface uses intuitive and image equipment graphics and matching running parameters and state to display, it understands and operates easily, whichrealizes to monitor multiple lower computers’ running state in real time.In the end, debug the system, including the circuit running of intelligent controller’scommunication modular, data exchange between upper and lower computer, and uppercomputer’s interface operation. According to the testing, system’s communicationfunctions realized successfully, which proved the feasibility of design.