Experimental Investigations Of Time Characteristic Parameters For Electromagnetic Relays Based On Raspberry Pi

The electromagnetic relay is an automatic switch with isolated function,which is widely used in the high-speed train.The reliability of electromagnetic relay affects the reliability and the stability of the high-speed train control system.The performance of the electromagnetic relay would degrade with working duration grows.It has been determined that most of failure problems occurred in electromagnetic relay is resulted from electrical contact issues.However,the mechanical characteristic parameters measurement of electromagnetic relay is almost impossible due to its completely sealed housing.The variation of mechanical parameters would be described by measuring the time characteristic parameters of high-speed train electromagnetic relay.Therefore,the investigation of the time characteristic parameters would be of great help to understand the possible electromagnetic failure reasons resulted by its mechanical structure.In this paper,a novel test rig based on raspberry pi is designed.The test rig consists of hardware system and software system.The hardware system is composed of signal processing unit,acquisition and control unit,which has the function of processing and collecting the voltage and current signals of electromagnetic relay.The software system is developed in python,which mainly realizes the control of the hardware system and the real-time display and storage of the acquisition signals.The electrical characteristic parameters and time characteristic parameters of the electromagnetic relay are experimental investigated explicitly with the novel test rig.Time characteristics parameters include breaking time,making time,release time,return time and their homogeneity.In order to more explicitly interpret the relationship between time parameter t and operation number x,t=g([e^f（x）])is established to fit the experimental data.The effects of operation number and coil voltage on the time characteristic parameters of the electromagnetic relay are discussed.The degradation physical model is present to better understand the relationship between time characteristic parameters and mechanical characteristic parameters of the high-speed train electromagnetic relay.The research of this subject gives the experimental method of time characteristic parameters research of the high-speed train electromagnetic relay.The research conclusion provides a new idea for improving the reliable operation time of the high-speed train electromagnetic relay.The novel test rig in this paper can also be applied to the study of time characteristic parameters of other sealing electron products.