Maximum torque per ampere current predictive control of interior permanent magnet synchronous motors based on parameter identification

To realize an efficient and accurate control of Interior Permanent Magnet Synchronous Motors (IPMSMs) and solve the effects of the motor parameter changes on the control performance, a method for the Maximum Torque Per Ampere (MTPA) current predictive control of the IPMSM based on online parameter identification was proposed. First, according to the torque characteristic of the IPMSM, an optimal relationship of d- and q-axis currents under the MTPA control was simplified to facilitate engineering calculation. The effects of the motor parameters on the MTPA operating point offset were analyzed. In addition, key parameters q-axis inductance and permanent magnet linkage of rotator, which significantly affect the MTPA algorithm, were adaptively identified based on a reference model to calculate the optimal d-q current distribution in real time. Subsequently, based on the accurately identified parameters and optimal current commands, predictive current control was applied such that the actual current can track the command faster and improve the dynamic performance of the system. The experimental results show that the errors of the online identification of q-axis inductance and permanent magnet linkage of rotator are less than 3% and 3.5%, respectively, and the convergence time is less than 20 ms. The motor can effectively track the MTPA operating point, and the current response time is less than 30 ms, which satisfies the requirements of stable, reliable, efficient, and fast operation of IPMSM systems. © 2020, Science Press. All right reserved.