Research And Design Of Induction Motor Operating State Monitoring System

Induction motor is widely used in the field of rail transit and industrial control because of its simple structure,high efficiency and high reliability.However,due to various reasons,the induction motor in the long-term operation process may appear a variety of faults,and even cause serious safety accidents.Research shows that the voltage,current,speed and temperature of the induction motor can reflect the running state of the motor.The real-time monitoring of these signals can judge the running state of the motor in a timely and effective manner,which is of great significance to ensure its safe and reliable operation.At present,the research on the state monitoring system of induction motor is mainly based on the data obtained from the monitoring system,and the corresponding fault diagnosis method is studied to evaluate the running state of the motor,while the research on the reliability assessment method of the sensor data collected in the monitoring system is less.Therefore,this paper takes the temperature,voltage,current,torque and speed of two induction motors in the laboratory as the monitoring objects,and builds a real-time monitoring system of the operation state of induction motors.Firstly,the data acquisition accuracy and reliability of the temperature sensor used in the monitoring system are studied.The first is to analyze the non-linear measurement error in the process of Pt100 temperature measurement.The MATLAB simulation shows that the least square piecewise linear fitting method can reduce the error and ensure the accuracy of temperature data acquisition.The second is to solve the problem that the temperature sensor may fail during operation and provide false data.A data fusion method based on Bayesian estimation is used to preprocess the data collected by the multi-temperature sensor,so as to ensure the collected temperature data is accurate and reliable.Then the design and implementation of the monitoring system are introduced in detail.It includes the hardware and software design of temperature acquisition device,voltage acquisition device,current acquisition device and acquisition transmission device,as well as the design of upper computer monitoring software.Finally,the temperature measurement experiment is carried out by using the developed temperature acquisition device.The results show that the accuracy of the temperature measurement device compensated by the least square piecewise linear fitting method can meet the requirements.By using the actual temperature data collected by the monitoring system,a data fusion method based on Bayesian estimation adopted in this paper is verified.The results show that this method can effectively evaluate the reliability of sensor output data and eliminate false data,so as to ensure the accuracy and reliability of monitoring data.And the developed monitoring system has been tested in many aspects.The results show that the system runs normally and can realize the real-time monitoring of the motor running state.The research results not only have practical significance for improving the performance of the induction motor condition monitoring system,but also play an important role in other scientific experiments and teaching demonstrations as an experimental platform,which has good application value.