基于Newton-Raphson搜索算法的永磁同步电机变电感参数最大转矩电流比控制方法

For interior permanent magnet synchronous motor (IPMSM), the maximum torque per ampere control (MTPA) can produce maximum torque output under the minimum current conditions by making full use of the reluctance torque. However, the inductance of IPMSM has magnetic saturation and cross-saturation characteristics, and its parameters vary with current in practice. This requires a lot of tedious calibration and fitting work. In this paper, MTPA searching method with variable inductance parameters is proposed. By constructing inductance look-up-table (LUT) varying with current, a second-order Newton-Raphson (N-R) searching algorithm is used to convert the complex MTPA nonlinear relationship into iterative operation, which can be easily implemented by a microcontroller. In this way, MTPA current distribution accuracy is improved and the calibration work is simplified. The simulation and experiments verify the effectiveness of the proposed method.