Field weakening speed expansion control of permanent magnet synchronous motors based on stochastic gradient descent

In order to improve the rated speed of permanent magnet synchronous motors (PMSMs) and solve its lag problem of output voltage decline information in the weak magnetic region, this study proposed an algorithm of weak magnetic expansion speed control of PMSMS based on stochastic gradient descent. We analyze the principle of PMSMS steady-state operation, establish the PMSMS mathematical model, and carry out the coordinate transformation using static three-/two-phase method. On this basis, we put forward a method of weak magnetic expansion speed control for PMSMs, which overcomes its direction information delay of rated speed and output voltage. In addition, we conducted simulation experiments in Matlab/Simulink to test the performance of this algorithm by comparing with the maximum torque/current control method. The results demonstrated that this control method can improve the rated speed of PMSMs and overcome the problem of low control accuracy caused by the lag information of output voltage direction decline information in the weak magnetic region.