Research On Intelligentized Technology Of Circuit Breaker Based On Microprocessor

The low voltage circuit breaker is a switch apparatus which is used for connecting or cutting the electric power system and keeping the system from all kinds of malfunction. It is widely applied in many kinds of power supply system because it has many protection functions against malfunction such as over loading, short circuit, creepage, earthing and so on. When the circumstances such as over loading, short circuit or lack of voltage comes forth, it can cut automatically. So it is the main apparatus and has important function in the power system. Besides having the functions of the traditional circuit breaker, the intelligent circuit breakers can show diversified parameters (current, voltage, power, power factor etc). Parameters of many protecting functions can also be showed, set and changed. The malfunction parameters of the protection circuit's acting can be saved in the nonvolatile memorizer so that they can be demanded. So compared to the traditional circuit breaker, the intelligent one has the higher capability vs price ratio, and it is much fitter to the development of modern power system.The hard core of the intelligent circuit breaker is intelligent measure and control unit. It takes on many protection functions such as protection, alarming, show and control. Furthermore, it can realize the four telecontrol of remote sensing, remote adjusting , remote controlling and remote communicating through network card or interface conversion parts. In the network system, it can be watched and controlled via mainframe.The research content of this task is intelligentized technology of circuit breaker. This thesis introduces the hardware design and the software realization for the intelligent circuit breaker on the central of microprocessor 80C196KC. The hardware design is made up of microprocessor least system, on-off quantum input circuit, the transformation circuit for the current and voltage, communication unit etc. The central part of the circuit breaker is the microprocessor. It can measure and calculate the current and voltage, thereby, judge the breaker's action according to the prearranged apparatus like breaking mode etc, and transfer the apparatus to the mainframe, and execute the mainframe's orders. The rated current and breaking mode can not only be set and changed by the bits dial switches connected on the input or output interface of the microprocessor, but can also be changed by the mainframe. This breaker can communicate with the mainframe, so the mainframe can read the apparatus message of the breaker and control the working status of the breaker. Virtual value breaking is adopted in this thesis.