Research Of A New Type Of Permanent Magnet Contactor With The Active Tripping Device

Permanent magnet contactor is a contactor of low-power consumption,which characterizes in simple structure,noiselessness and low power consumption.However,there is a congenital defect in the design due to the limit of its working principle,that is,the PM contactor cannot break accordingly when a failure occurred to the control module or the controlled component on the control circuit;or when the coil is malfunctioning or losing power.This congenital defect becomes hidden safety hazard.To solve the congenital defect existing in the present permanent magnet contactor,a new type of permanent magnet contactor is designed.It's composed of a forced breaking protection mechanism,working along with electromagnetic mechanism.It will be forced to break under the actuation of the protection mechanism when the PM contactor malfunctions,effectively solving the coil failure and breaking failure of the PM contactor when losing power,improving the reliability of its performances.This design is significant to ensure the safety of power supply.Firstly,a 3D model of permanent magnet contactor with forced breaking protection mechanism is established by Solid Works software.Based on this model,set up the optimized mathematical models of spring and mechanism,optimize the dynamic and static status by using genetic algorithm to achieve small suction,subtle kinetic energy release,minimum volume and short closing time.Hence,the life of the new type of permanent magnet contactor will be extended.Secondly,intelligent control circuits working cooperatively with new type of permanent magnet are designed.This control circuit is divided into two parts: normal switching circuit and forced breaking circuit.Normal switching circuit realizes the control of normal closing and breaking process by switching thyristor with the control of AVR microprocessor;the forced breaking circuit realizes logical control function by using logical gate circuit constituted by basic electronic components.Lastly,design and set up test platform and analyze experimental results.Test dynamic and static characteristics of the proposed new type of permanent magnet contactor.And test the effectiveness of forced breaking circuit and forced breaking protection mechanism by removing normal switching circuit.Experiment the new type of permanent magnet contactor in actual environment,and the results show that the forced breaking mechanism can achieve mandatory breaking process steadily and effectively when malfunctioning occurs to the contactor.