The Maximum Torque Current Ratio Control Of Permanent Magnet Synchronous Motor Based On Parameter Self-correction

With the development of power electronic devices and power conversion technology,permanent magnet synchronous motors(PMSM)have been widely used in a variety of industrial applicationgeneration,and industrial servo drives.The permanent magnets of interior permanent s such as electric vehicles,new energy power magnet synchronous motors(IPMSM)are buried into the rotor,and its q-axis inductance is significantly larger than the d-axis inductance,which lead to reluctance torque.To fully utilize the reluctance torque of IPMSM,the maximum torque per ampere(MTPA)control strategy is proposed.However,motor parameters such as d-q axis inductance,permanent magnet flux linkage vary with the operating conditions such as rotor temperature and magnetic saturation,it is difficult to calculated accurate MTPA points with torque equation and constant parameters.Therefore,how to deal with the parameter variation problem and obtain the MTPA angle accurately and quickly has always been a research hotspot of scholars all over the world.In this thesis,the development of frequency conversion Technology of PMSM and the research status of MTPA control are described firstly,the existing problems in the existing MTPA control methods are found by comparing and analyzing the advantages and disadvantages of each MTPA control methods.Secondly,the mathematic model of IPMSM is established and the parameters variation characteristics of IPMSM are analyzed.By explaining the principle of MTPA control,The problems of the MTPA angle calculation method and the virtual signal injection method are compared and analyzed.Then a novel MTPA control method for IPMSM drives based on controller parameters self-Tuning is proposed.The calculated error between the actual parameter and the set one in the torque equation can be calculated as an average by current loop proportional and integral(PI)regulator with feedforward decoupling control strategy and compensated by adding it.Then the MTPA current angle is calculated directly from the compensated torque equation instead of signal processing method with bandpass filter,lowpass filter and integral regulator.Finally,The effectiveness of the proposed method is verified by Matlab/Simulink and experiments under various operating conditions on a prototype 20kW IPMSM drive system with TMS320F28335.The experimental results of the proposed approach show fast dynamic response,the steady-state accuracy of the MTPA current angle is guaranteed at the same time.Moreover,the proposed method is simple and computationally efficient.