Study On Text System For The Motion Charactistics Of Contactor

AC contactor is a very important and widely used low-voltage electrical device, it is mainly used to switch on and off the load circuit, its electrical life and reliability are always been the top priority. It will cause wear on the contacts during it works, contact wear will not only affect the operating frequency of exchanges and contacts, but also directly affect the life of AC contactor, which could be reflected from the AC contactor motion characteristics.Therefore, the motion characteristics of AC contactor testing has become an important issue.In the past, the AC contactor motion characteristics test focused on the simulation analysis and rough measurement, the measurement accuracy is often less than the requirement for optimizing the design of AC contactor. In order to meet the accuracy and efficiency measurement, this paper designed an AC contactor motion characteristics test system.First, in the paper the hardware of AC contactor motion characteristics test system is designed. The testing system is consisted of data acquisition circuit, zero-crossing detection circuit, trigger circuit, the contact time characteristics detecting circuit and the contact displacement characteristics detecting circuit. Multifunction high-speed data acquisition card is used for data acquisition circuit, the zero-crossing detection circuit is consisted of high performance voltage transformer and voltage comparator, the trigger circuit is consisted of the optocoupler and triac, the contact time characteristics are reflected by the changes of the voltage in the load, the contact displacement characteristics are detected by the high-precision laser displacement sensor.Secondly, in the paper the software part of the AC contactor motion characteristics test system is designed. The test system software acquisition is in the LabVIEW development environment, it has the front panel, acquisition and control processing, the preparation of the block diagram and data processing playback of several parts, it is easy of human-computer interaction.Finally, experiment the contacts motion characteristics with the test system. AC contactor operation time, time jitter and displacement characteristics at different voltage and phase angle during closing time are tested with the equipment. The resulting data were analyzed and discussed in the last.This test system can realize AC contactor election phase closing, it also can detect thetime characteristic of AC contactor with the contact displacement characteristics, this reflects the bounce situation and movement characteristics of the contact.