Study On Breaking-intelligent Technology Of AC Contactor

AC contactor is a class of low voltage electrical apparatus which used commonly. Alarge number of arc will be produced by electromagnetic contactor no matter in the closingcourse or breaking course, especially in the breaking course, so the electrical endurance andreliability of AC contactor will be significantly affected. Under the background of scienceand technology revolution, intelligent breaking ofAC contactor will be an inevitable trend.Firstly, this paper discussed the operating principle of intelligent AC contactorbreaking device, proposed a scheme called zero-current breaking of the three-phase contactby turns, determined the calculation method of voltage, current and power factor. Secondly,the hardware and the software were completed. In the hardware, the MicrochipPIC16F1937is the core of this processer, mainly for zero-current breaking by turns of thethree-phase contact. The acquisition circuit is to capture the three-phase voltage and currentsignals in main circuit, and the communication circuit is used to communicate with the PCby the way of remote control.The software not only completed the AC contactor breakingtask, but also to achieve human-computer interaction task. The human-computer interactiontask can realize real-time monitoring of voltage and current, and change parameters of ACcontactor via PC.Practice has proved that the intelligent AC contactor designed in this paper can realizezero-current breaking of the three-phase contact by turns, and the range of the breakpointscan meet requirements. The intelligent AC contactor has the feature of better accuracy andstability. It has a high practical value.