Desing And Analysis Of Characteristic For Intelligent AC Contactor With Selsction Angle And Dynamic Control

An intelligent AC contactor is a new type of contactor which has themerits of energy saving, decreased noise and an extended life. In this paper, anintelligent AC contactor with angle selecting is introduced, and its dynamiccharacteristic is researched in both theory and experiment. The results provide atheoretical basis for design of the intelligent AC contactor, and have guidingmeaning in optimizing the dynamic characteristic of the contactor.Based on the conventional CJ40-500contactor, the intelligent controlmodule is designed to produce direct current with energy saving, angleselecting and dynamic control. The selection of components and the design ofhardware and software are based on the operating characteristic of theelectromagnetic system and the requirement of intelligent control.The electromagnetic distribution and calculation are introduced. Thecalculation method of the electromagnetic force is deduced by analyzing theenergy distribution. The dynamic equation set can be established based on the features of control and the electromagnetic principle.An experimental measurement system is designed to test the dynamicprocess of the contactor in a high speed and precision. The voltage controlsubsystem can output voltages according to the requirement of the experiment.A laser displacement sensor of LK-G5000is used to measure the displacementof the contact and the armature. The velocity and acceleration can be calculated.The testing circuit for contact bounces, current, voltage and conditioning isdesigned. The dynamic parameters are collected by a Synchronous dataacquisition system.Duty cycle of PWM is optimized to save energy on the premise ofworking the reliability. The closing angle and other dynamic parameters areobtained by experiments. The consistency and stability of the contactor can beimproved by angle control. The best control scheme in different voltages isobtained to optimize the cooperation of reaction and suction. The closing timeand the contact bounces are reduced drastically by angle selecting and dynamiccontrol. Thus, the life of the contactor can be extended due to that.