基于双梯度下降法的内置式永磁同步电动机精确转矩控制

Precise Torque Control of Interior PMSM Based on Double Gradient Descent Method

针对电动汽车内置式永磁同步电动机(IPMSM)给定参考转矩的电流闭环控制系统,为了实现系统宽调速范围内的精确转矩控制,首先分析了基于梯度下降法的弱磁控制策略无法实现指令转矩准确跟踪的原因,引入定子电流指令沿等转矩曲线法向的修正方向,提出了基于双梯度下降法的新型弱磁控制方案,通过对电磁转矩实时估计构成转矩反馈环节,并与基于梯度下降法沿切向修正方向的电压反馈环节相结合,实现IPMSM驱动系统的弱磁控制及宽调速范围内对时变给定参考转矩的准确跟踪控制。最后,通过系统仿真和方案测试验证该弱磁控制策略的合理有效性。

To achieve the precise torque control of an interior permanent magnet synchronous motor （IPMSM） for the electric vehicle over a wide operating region,which was controlled by the current closed-loop in the condition of a given reference torque,the reason why the traditional field weakening control strategy based on the gradient descent method failed to track the reference torque was first analyzed.Then a new field weakening control strategy was presented based on the double gradient descent method by introducing the normal modification direction of constant torque curve.Along this direction,the magnitude of the modification was derived from the torque error between the reference and estimated torque by the torque feedback loop.And the torque feedback loop was combined with the traditional voltage feedback loop in which the current reference was modified by the tangential direction of constant torque and the magnitude of the modification was derived from the output voltage error.Above-mentioned research aims to achieve the field weakening control and achieve the precise torque control of IPMSM drive system over a wide operating region and in the condition of given time-varying reference torque.Finally,the proposed scheme was verified by the simulation results and test results.