New On-Line MTPA Angle Search and Control Methods Based on Digital Twins for IPM Synchronous Motor Drives Considering Motor Non-Linearity

Abstract

The main theme of this paper is to propose on-line MTPA angle search and control methods based on digital twins for IPM synchronous motor drives. The proposed method is developed based upon the ECE model, the finite element model of IPM synchronous motor. An on-line MTPA angle search method is developed to achieve the minimization of stator current for the specific output torque and speed. A new IPM synchronous motor control is proposed based upon its digital twins model to consider the non-linearity caused by magnetic saturation of motor which become more relevant especially under heavy load conditions. In the proposed IPM synchronous motor control method, two current controllers and the parameters for decoupling control are tuned on-line to adapt to the variation of motor parameters caused by the non-linearity of motor. Experiment results are shown to support the proposed methods. The motor for the application of electrical scooter with the rated specifications of 2 kW, 2000 rpm, 10 Nm, is used for test and comparison. Comparing with the conventional methods, the test results show the stator current can be reduced up to 17.23 % under 2000 rpm and half load conditions. The efficiency improvement is up to 3.18 %. These results fully confirm the effectiveness of the proposed on-line MTPA angle search and control methods.INDEX TERMS Interior Permanent Magnet (IPM) synchronous motor, maximum torque per Amp (MTPA) control, digital twins, Equivalent Circuit Extraction (ECE) model.