Research On Fault Detection System Of Squirrel Cageasynchronous Motor

Asynchronous motor is the most widely used power equipment in industrial production,its running state directly influences the normal production industry,once the fault will lead to paralysis of the entire production system,and even cause great economic losses.Therefore,it is of great significance to study the monitoring and diagnosis system for early detection of the abnormal state.In this paper,the technology of state monitoring and fault diagnosis for asynchronous motor is studied.The research contents are as follows:Firstly,the basic structure and operation principle of the asynchronous motor are studied,and analyzed the causes of common motor electrical faults and mechanical faults,focusing on rotor broken bar,circuit power and stator winding phase failure fault mechanism analyzed,and the detection principle were analyzed.Frequency domain and time-frequency signal analysis methods including Fourier transform,wavelet transform and FSWT transform.Based on the simulation of the rotor broken bar fault signal,the 4 algorithms are analyzed,which provides a reference for the fault feature extraction of asynchronous motor.The signal acquisition and diagnosis system of asynchronous motor is designed.The system architecture includes two aspects: hardware and software.The hardware is composed of measurement system and data acquisition card.The measurement system includes current detection,speed detection and temperature detection of three module,as the front-end module state monitoring system,is composed of sensor,rotary encoder,AD acquisition card and terminal etc..Use PCL-1716 to collect the three-phase stator current and PCL-818 collects the temperature and the motor speed.The system application program is designed and implemented,which realizes the functions of signal acquisition,processing and display,parameter setting,data management,fault diagnosis and so on.The Access database is used to record the current,speed and temperature information,which is convenient for the analysis of the historical data.The motor test platform is built to verify the feasibility of the design and the function of the system.The effectiveness of the fault diagnosis method is verified by the test and analysis of the rotor broken bar,stator winding open circuit and power supply failure of the test bench.