Research On MTPA Control Strategy Of Built-in Permanent Magnet Synchronous Motor Based On Disturbance Observation Method

In recent years,with the progress of modern society,the rapid develop ment of power electronic technology,the price of permanent magnet materials has dropped,built-in permanent magnet synchronous motor(Interior Permanent Magnet Synchronous Motor,IPMSM)with its good performance is widely used in automotive power transmission,new Energy development and utilization,military and civilian commercial ships,railway transportation and other fields.The IPMSM produces unique reluctance torque due to the obvious difference in dq axis inductance.In order to make full use of the reluctance torque,the maximum torque current ratio control strategy(Maximum Torque Per Ampere,MTPA).However,traditional MTPA control strategies mostly rely on motor parameters such as dq axis inductance,stator resistance and permanent magnet flux li nkage,and these parameters will change with changes in motor operating conditions and external operating environment,resulting in current vector angle accuracy under MTPA control strategy Decrease,so that it can not meet the high performance requirement s of the motor drive system.How to get rid of the parameter dependence of the motor,improve the accuracy of the optimal stator vector angle under the system MTPA control strategy,and quickly and accurately obtain the optimal stator current vector angle under the MTPA control strategy is a hot topic for domestic and foreign researchers.This article first clarifies the development and application fields of built-in permanent magnet synchronous motors,leads to the current domestic and foreign research status of MTPA control strategies,classifies and analyzes the current main control strategies,and finds that the current MTPA control strategies cannot take into account dynamic performance at the same time.And static stability,this article is roughly divided into two categories based on whether the MTPA control strategy depends on the dq axis inductance,stator resistance,permanent magnet flux and other motor parameters.In this paper,based on the IPMSM structure,Clarke Transformation and Park Transformation,a mathematical model of IPMSM in a rotating synchronous coordinate system is established,and its control system is analyzed one by one.Based on the analysis of the mathematical model,the traditional direct formula calculation method,signal inje ction method and other control strategies are discussed,and the error analysis of the virtual signal injection method is carried out.Taking the direct formula calculation method and the virtual signal injection method as examples,the theory is analyzed through Matlab/Simulink software The data is simulated and compared and analyzed to verify the advantages and disadvantages of these methods.On this basis,this paper introduces the disturbance observation method algorithm,and proposes an intelligent search method based on the disturbance observation method.This article first uses a fixed step to search.When certain parameters of the motor change due to environmental factors,this MTPA strategy will hardly be affected.It can get rid of the dependence o n the motor parameters,but the optimal value is prone to oscillations.The problem is that the "jagging" phenomenon appears,and the accuracy is relatively poor.This paper proposes a variable step size strategy based on the search accuracy problem.Accor ding to the system,the matching search step size is randomly determined,but the calculation time is too long.At the end of this article,combining the advantages of direct formula calculation method,simple calculation and high accuracy of results,a co mprehensive method is proposed by combining the fixed-step search method based on the disturbance observation method and the direct formula calculation method.The above strategies are analyzed by Matlab/Simulink.A comparative analysis of simulation exper iments is carried out to verify the effectiveness of the theoretical analysis,and to compare the aforementioned methods to highlight their advantages.The results show that the MTPA control strategy based on the disturbance observation method is little affected by certain motor parameters,and the comprehensive method greatly improves the accuracy of the MTPA’s optimal stator vector angle,with less calculation time and better system dynamics.Responsiveness and torque output capability.