Design For Intelligent Release Of Circuit Breaker Based On DsPIC

Circuit breakers is one of the most important electrical protection appliance for powersystem (?)mainly used for making and breaking circuit and the protection of various types offaults. Release is the core device of the circuit breaker that used to acquire the signal andcontrol the protection action of circuit breaker, and it can achieve overload fault, shortcircuit fault, phase failure, ground fault protection function. After the electromagneticprotection stages and electronic protection stages, at present, the intelligent release withintelligent microcontroller is used as major research and application directions. Intelligentrelease not only achieve the line protection of traditional release (?)b ut also it have thefunctions of display, real-time monitoring and communications. After the function anddevelopment analysis to the domestic and overseas releases, proposed the study ofintelligent release based on dsPIC and Ethernet communications.In this thesis, the development and key technologies of intelligent release aresummarized and introduced firstly, and determine the functional requirements and overalldesign of intelligent release. In hardware circuit design, Microchip's dsPIC completecontrol of the external circuit. Sensing and intelligent release selection, power module,signal acquisition module, communication module and the release drive module areintroduced in detail. In software design, shows the flow chart of main program flow chart,signal acquisition, signal RMS calculations, over-current protection, and Ethernetcommunications in detail. And the power parameters calculation and the theory of variousprotection features are analyzed reasonably.In this thesis, through the hardware simulation, experiment and software test.Achieved release's protection function, and improved the stability and reliability. Thedesign use ENC28J60 Ethernet chip achieve communication, gives a detailed hardwaredesign circuit. Via the implant of TCP/IP protocol stack, using the browser to complete themonitoring of release. Interference problem has been studied in the thesis, hardware and software has taken various measures to ensure the reliable operation of intelligent releasein industrial environments.