Research On Online Parameter Identification And State Observation Technology Of Permanent Magnet Synchronous Traction Motor

Permanent magnet synchronous motors have gradually been widely used in the rail transportation industry because of their significant advantages such as light weight,high efficiency and wide speed range.In the train drive control system,the design of the current loop and speed loop and the dynamic adjustment performance of the system all depend on the accuracy of the motor parameters.However,when the motor is installed for the first time,due to the difference between the design parameters and the actual values,it is easy to cause the initial value settings of the parameters in the regulator to be inaccurate;The changes of the motor’s stator resistance,direct axis and quadrature axis inductance and other parameters will also change under the influence of temperature,magnetic saturation and other factors,but the traditional regulator cannot be corrected in real time as the parameters change.Therefore,in order to improve the accuracy and stability of the vector control system,it is very necessary to conduct online parameter identification and state observation research on permanent magnet synchronous motors.The use of built-in permanent magnet synchronous motors is more common in traction locomotives,so this article takes this as the main subject to study the above problems.This paper first analyzes the principle of vector control technology for permanent magnet synchronous motors,and builds a simulation model of vector control system based on id = 0 in Matlab / Simulink and verifies its accuracy,which has laid a solid foundation for the online parameter identification algorithm research.At the same time,the factors that cause the changes of the motor parameters are simply analyzed.In order to verify the impact of the changes on the vector control system and the feasibility of the online parameter identification algorithm,the original permanent magnet synchronous motor model in the Matlab / Simulink model library was Improvements,real-time modification can be changed online,and a method for measuring the stator resistance,quadrature-axis inductance,direct-axis inductance and permanent magnet flux linkage parameters of the inverter by operating condition control of the inverter is proposed.Then it focuses on the principle of online identification algorithm for permanent magnet synchronous motor based on model reference adaptation and recursive least square method.The corresponding observer is designed to identify the main parameters of the motor in real time.When the parameters of the motor and the regulator are fixed values or linear changes,the MRAS algorithm is verified under various working conditions.The experimental comparison shows that the online parameter identification results are fed back to the control link.Among them,the main technical parameters of the motor are modified in real time to improve The performance of the vector control system plays a role.In order to avoid the influence caused by the lack of rank of the MRAS algorithm,the recursive least square method was used for online step-by-step identification,and the accuracy and feasibility of the algorithm were verified by Matlab / Simulink simulation.Finally,the development process and software and hardware system of the d SPACE realtime simulation platform are introduced.Based on this platform,a permanent magnet synchronous motor vector control system is designed.And on this basis,the initial value measurement module of permanent magnet flux linkage is built.Experiments show that the vector control system proposed in this paper and the initial value identification algorithm of permanent magnet flux linkage are feasible.