Initial position estimation for permanent magnet synchronous motor rotor based on double integral controller of speed loop
LU Jie-ying
WEN Cheng
LI Jin-hui
SU Wei-zhou
Abstract：The estimation of the initial position of a permanent magnet synchronous motor rotor plays an important role in the vector control of the motor and ensuring operational accuracy.A method for initial position estimation of permanent magnet synchronous motor rotor with incremental encoders based on a speed loop dual integral controller is proposed.By analyzing the mechanism of the motor's speed loop/current loop and identification experiments,the transfer functions of the speed loop object under different initial electrical angle estimation errors are obtained.Based on the uncertainty characteristics of such transfer functions,the speed loop robust controller is proposed.Then,the specific trapezoid current of d-ax is is designed for the special requirements of initial position estimation.Based on coordinate transformation in vector control,the d-axis given current signal is converted into an external input signal of the q-axis current loop,and the initial position estimation problem is transformed into the tracking problem of the speed loop.Accurate estimation of the motor rotor's initial position is achieved by designing the speed loop dual integral controller.It also meets the requirement of small impact and displacement during the estimation.The experimental results show that this method is robust to the estimation errors generated by different initial position estimation.The electrical angle estimation error is less than 1.5° and the electrical angle displacement of the motor dose not exceed 2°,indicating it has high detection accuracy and low displacement and impact during the initial position estimation.
Keywords：initial position estimationpermanent magnet synchronous motordouble integral controllervector control
Publication Date：2025-09-30
Online Publishing Date：2025-10-28(First online date of this platform, not the publication date of the document)
Pages：13( 1733-1745 )