Research On Parameter Identification System Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor is more and more widely used because of its small size,high power density,excellent starting and control performance.It is especially suitable for mechanical and electrical systems with high-performance requirements for motors such as robots and new energy electric vehicles.In recent years,with the continuous development of control technology,the requirements of upmarket electrical and mechanical system systems for motor performance are also increasing.The precise electromagnetic parameters(stator resistance Rs,linear inductance Ld,,quadrature inductance Lq and permanent magnet flux ?f)can be used to realize the high performance control of permanent magnet synchronous motor but the parameters of the motor are changing in the actual operation process.It is of great significance to study the on-line identification technology of motor electromagnetic parameters in order to achieve high-performance control of permanent magnet synchronous motor.The main content of this paper is the theory and technology research of on-line parameter identification of permanent magnet synchronous motor.Firstly,the mathematical model of permanent magnet synchronous motor in two-phase rotating coordinate system is established and used as the parameter identification model.The parameter identification system of permanent magnet synchronous motor based on vector control technology is constructed.The dynamic-state and steady-state performance of permanent magnet synchronous motor control system is simulated with Matlab software.Secondly,in order to solve the problem of "data saturation" and weak anti-interference ability in least squares method,the performance of parameter identification system of permanent magnet synchronous motor discretized by Pade approximation method is studied by combining multi-innovation method with limited memory least squares method.Aiming at the influence of voltage deviation on the accuracy of parameter identification system,the mechanism of voltage deviation is deeply analyzed and the dead-time compensation method for suppressing voltage deviation is studied.For the problems that current polarity is difficult to accurately judge in dead-time compensation process and characteristic parameters are difficult to obtain,the currents of id*and iq*are transformed into abc coordinates to determine the basis of current polarity.The processing of characteristic parameters is simplified.The simulation results show that the current distortion rate is reduced from 11.42%to 3.76%,the voltage deviation is controlled within 1.5%,and the identification accuracy is improved to 0.6%.This shows that the dead-time compensation method is effective in improving the identification accuracy of parameters.Finally,a parameter identification system is designed and an experimental platform is built.Based on the experimental platform,the dead-time compensation method and multi-innovation limited memory least squares parameter identification algorithm are experimentally validated.The results show that the current distortion rate is reduced to 3.658%after dead-time compensation,and the identification error of electromagnetic parameters is less than 5%,which is in good agreement with the simulation analysis.The rationality and feasibility of the dead-time compensation method and parameter identification algorithm are further verified.