Abstract: The low-voltage breaker is a kind of switch electrical appliance. It can get on and cut the distribution circuit and protect all kinds of faults. It can be widely used in the low-voltage distribution system. The releaser executes the function of breaker. The traditional releasers always are electromagnetic and it is not easy to control their trait. The task uses the microelectronics technology and single-chip technology and utilizes microprocessor to develop the mini-intelligence releaser. It can not only fulfill the function of releasing, i.e. fulfill the protecting function which is pre-designed, but also select the parameters of motion, i.e. it can realize protecting in the multi-situations. Furthermore, by using the normal serial interface RS-232C,we make the intelligence releaser realize communication with PC computer. By using the bus system, the target of remote controlling is realized. All of them strengethen the releaser's functions and make it accord with requirements of distribution system.
The basic principles of the design are accounted detailedly, the selective bases and the operational principle of the hardwares are introduced chiefly and the design reasons and program means of the softwares are recommend in this thesis.
Key words: breaker; releaser; true-rms; communicat