Life Test Technology And Data Processing Of Ac Contactor

AC contactor(hereinafter called as contactor)is one kind of controlling low-voltage electrical appliances which is widely used,and it has advantages in convenience of production and low cost.With the development in modernization of industrial production,the reliability of contactor becomes more and more important.Mechanical life test and electrical life test can be used to test the reliable operation of contactor,and they are also of great importance in testing the performance and quality of contactor.In this paper,the life test technology of contactor is chosen to be the object,and the test conditions and test methods have been studied based on mechanical life and electrical life.The device of life test for contactor has been designed,and life test of contactor is conducted.In order to solve the problem of switching power supply voltage frequently when variable load test is conducted,the main circuit which uses silicon controlled rectifier replace contactor is designed.This circuit can also reduce the noise and improve the operation frequency.The driving circuit which uses MOS transistor to control coil of contactor is designed.This circuit can control the phase angle of making and breaking operation for contactor.The circuit which can monitor the contacts is designed based on the data acquisition card.This monitoring circuit can detect voltage and current during the life test.The system software of the device is designed based on Visual Basic using modular design method.This software can set test parameters,debug the test device and control the life test process automatically.The electrical life test of contactor is conducted and the method of data processing has been studied.The accumulation of Joule integral is taken as a decisive factor to predict the electrical life of contactor.The method of calculating the voltage and current,breaking arcing time and Joule integral of characteristic parameters based on test data is studied.The test result shows that the contact time has an influence on service life of contactor.Through the analysis of the characteristic parameters before the test is conducted,the result shows that the contactor with long contact time has longer service life.