The Study Of Electromagnetic Relay Life Prediction Parameters Detection System

Electromagnetic relays are widely used among aerospace, communications transmission, industrial control and other fields.As control devices, relays’ performance and reliability often determines their systems’ reliability.If we can rely on the beginning of the relay state information to predict its life, it will be a lot of great significance.Relay life prediction models need to establish the relationships of their parameters and their life.This requires a relay testing equipment which can measure various parameters of the relays precisely.This article study on electromagnetic relay parameters detection system which can provide data support for life prediction model.The main work of this article is as follows:(1) Through studying the performance degradation process of electromagnetic relays, the impact of performance degradation of electromagnetic relays on relays’ parameters is analyzed; some typical parameters are selected for detection; the functional requirements of the testing equipment are proposed based on these parameters.(2) By analyzing the functional requirements of the system, specific design plan of this detection system is reasonably established. The hardware structure of experimental device is established by using IPC equipped with high-speed data acquisition card as the hardware core according to the design. The software system is built by graphics language on virtual instrument development platform. The system is simple to operate and has friendly human-computer interaction. Testing equipment calculates the various parameters of DC relays based on the waveform acquired by high-speed data acquisition card and it automatically displays the waveform and parameters. The parameters are stored in the IPC. Through experimental verification, the hardware and software systems of the equipment are proved to work properly. It is able to collect data and calculate, store relays’ various parameters in accordance with the experimental requirements.(3) Specific relay samples are selected to use this system for full life experiment. All parameters and data of the relays are stored in the corresponding electronic documents according to the set procedures. Then the above data are processed and analyzed and the following rules are found: contact resistance is tending to increase; the pick-time is tending to decrease with increasing number of operations; the time constant is tending to significantly increase in the late life of the relay; the over-travel time is tending to decrease with increasing number of operations.