Study On Parameter Identification Of Three-phase Asynchronous Motor

The vector control technology realizes the decoupling of the stator current excitation component and the torque component of the asynchronous motor.The independent control of the two components makes the asynchronous motor obtain the same excellent speed regulation performance as the DC motor.Domestic and foreign scholars have done a lot of research on vector control of asynchronous motor.It is found that the vector control performance is heavily dependent on the parameters of the motor itself.The most influential is the fixed rotor resistance,and the parameters will change continuously during the running of the motor.Aiming at this problem,an asynchronous motor parameter identification method based on vector control process is proposed,and the simulation and experiment are designed to verify the proposed method.The main research contents are as follows:Firstly,for the problems of the traditional asynchronous motor offline parameter identification method,such as difficulty in implementation,large cumulative error,vulnerability to environmental interference,and low accuracy of identification results,a simple operation and identification of all parameters to be identified are proposed.The method is based on the recursive least squares method.The discount factor is added to enhance the correction ability of the algorithm.The pseudo-random sequence with low power consumption and anti-interference is selected as the input excitation signal of the motor,which enhances the system to be identified.Anti-interference ability.The simulation and experimental verification of the proposed offline identification method are carried out.The simulation results demonstrate the feasibility of the proposed method.The experimental results are more accurate than the traditional single-phase experimental identification results,and the error of offline identification results with Siemens S120 inverter is less than 5%,which indicates that the proposed method has high practical value.Secondly,the on-line identification of asynchronous motor parameters often adopts complex algorithms.According to the motor model,the parameter estimation values are obtained through multiple optimizations.This online identification method puts high requirements on the calculation speed of the controller and realizes difficulties.Aiming at this problem,an online identification method of stator and rotor resistance based on dynamic equivalent circuit of three-phase asynchronous motor and energy efficiency analysis of motor is proposed.This method does not require complicated iterative and computational process,and it is identified on the asynchronous motor vector control platform.The method is verified by experiments.The fluctuation range of stator and rotor resistance identification results is less than 0.5?,which proves that the proposed online identification method is simple and reliable,and has certain practical value.Finally,in order to obtain accurate asynchronous motor parameters in real time,the constriction factor particle swarm optimization algorithm is used to simultaneously identify the three parameters of motor stator resistance,rotor resistance and moment of inertia,balance the exploration and search ability of particles,and accelerate the convergence speed.By constructing the online identification model of asynchronous motor parameters and carrying out simulation research,and compared with the standard particle swarm optimization algorithm,the simulation results show that the algorithm has a good identification effect.