Sensorless Control With MTPA Control Of Five-phase Permanent Magnet Motor Based On Signal Injection

Increasing energy problems and people’s increasing demand for the quality of life have led to the emergence of a new energy industry,and it has gradually become a part of the development of human society.In recent years,researchers in many fields have attached great importance to the new energy industry,which has directly promoted the rapid development of the industry.The multi-phase interior permanent magnet synchronous motor（IPMSM）not only has the advantages of high torque density,high power factor and wide speed regulation area of three-phase IPMSM,but also has higher control freedom,better torque output performance and other advantages.As a result,this type of motor is also widely used in new energy vehicles,but as the price of rare earth materials rises,the cost of the motor is getting higher and higher.Therefore,how to reduce the hardware cost in the motor control system has gradually become a hot issue,such as replacing the position encoder of the motor with a variety of sensorless control algorithms.In the zero-low speeds sensorless control algorithm based on high-frequency signal injection,in order to prevent coupling between signals and maximize control accuracy,i_d=0control method is generally used,but this control method ignores the reluctance torque of IPMSM,so that the motor loses more energy under the same load torque.The maximum torque per ampere（MTPA）control method not only makes full use of this part of the reluctance torque,but also greatly reduces the loss of the motor.Therefore,this article mainly focuses on the study of the combination of the sensorless control at zero-low speeds and the MTPA control.According to the problem of coupling of high-frequency signals injected into the two algorithms,a novel dual-space signal injection method is proposed.According to the decoupling of the fundamental wave space and the third harmonic space of the five-phase IPMSM,the virtual signal and the actual signal are injected into the two spaces,and the MTPA point and rotor position information are obtained at the same time.On the premise that the two control algorithms can be realized at the same time,good control accuracy and dynamic performance can also be obtained.Finally,the feasibility of the method proposed in this paper is verified by simulation and experiment.The main research points of this paper are listed as follow:（1）Several existing control methods combining sensorless control and the MTPA control are introduced,and their advantages and disadvantages are briefly analyzed.（2）The common types of IPMSM are briefly described,and the coordinate transformation and mathematical model between three space coordinate systems of the five-phase motor are derived.On this basis,the decoupling control of the five-phase IPMSM in the dual rotation space,the MTPA control of the virtual signal injection into the fundamental space and the principle and implementation method of the position sensorless control of the actual signal injection into the third harmonic space are introduced respectively.Then a dual-space signal injection MTPA control of five-phase motor with sensorless control algorithm is proposed.（3）The Simulink model of the proposed algorithm is built,then its structure is analyzed in detail,and the model is used for simulation to verify the control effect and dynamic performance of the proposed algorithm.（4）The signal acquisition and processing functions of the real-time simulation control system are introduced,and the hardware circuit composition and function of each module related to it are analyzed in detail.This system is used to experiment with the method proposed in this paper,and the control effect and dynamic performance of the proposed algorithm are verified.