Research On Induction Motor Temperature Identification Based On Model Reference Adaptive System

As some induction motors need to run under complex conditions(such as submersible motors),due to this type of complex conditions of work induction motor temperature is not easy to measure directly,the motor cavity temperature is not easy to distribute.At this time the temperature rise of the motor is related to the long-term stable operation of the motor safety,which requires the operation of the complex conditions of induction motor temperature monitoring.Especially in the motor load mutation of the moment,the current will be a sudden change,but the motor temperature will not be a mutation.Therefore,this paper studies the above problems,and combines the rotor stator and rotor resistance parameter identification method with the motor equivalent thermal model to realize the on-line identification of the stator and rotor side temperature.The model reference adaptive theory is applied to the parameter identification of the stator and rotor resistance of the motor.According to the mathematical model of the induction motor in the two-phase stationary coordinate system,the voltage and current model of the equivalent rotor flux can be obtained.The reference model and the adjustable model of the stator and rotor resistance identification scheme can be determined by the voltage and current model of the equivalent rotor flux.The work can provide the theoretical basis for the design of the adaptive rate of the rotor.In order to ensure the stability of stator and rotor resistance identification system,the hyperstable inequality is applied to the error equation of fixed rotor resistance identification system,and the respective adaptive rates corresponding to stator and rotor resistance are obtained.Due to the influence of the temperature change of the motor on the rotor resistance,the resistance value of the adaptive rate is corrected by the approximate linear relationship between the motor temperature and the metal resistance,and the stator and rotor resistance scheme with the temperature change of the motor is obtained.Simulation of the model can be verified by modeling and simulation.As the temperature rise of the motor is caused by the loss,according to the induction motor structure induction motor two heat source equivalent thermal model.On the basis of this,the influence factors of the motor cooling system on the motor temperature are considered,and the equivalent thermal model of the induction motor is obtained.The real-time identification of the rotor temperature of the induction motor can be realized by this model.This paper improved the induction motor temperature identification system platform,and improved the algorithm platform.And then carried out a constant load torque,variable load torque,variable voltage load torque and variable frequency load torque experiments to simulate the actual motor operation of the complex conditions.By comparing the experimental identification temperature and the measured temperature under different experimental conditions,the maximum error between the two is less than 8?,and the sudden change of the transient temperature of the load is not abrupt,which shows that the algorithm model has good dynamic followability.It also verifies the feasibility and correctness of the proposed method of motor temperature identification.