Precise Torque Control in Flux Weakening Operation Based on Induction Machines System

The induction machines, as one of the main driving systems in electric vehicles(EVs), now are widely used and deeply studied. In most cases the driving system need to act accordingly as the VCU demands a certain torque output. This paper proposes a precise torque control method of Induction Machines (IM). The control algorithm combines flux-weakening control with a 2D look-up table torque controller which ensures the torque precision in a wide speed range. The 2D look-up table is obtained from test results, thus the parameter variation is effectively compensated. Since flux-weakening control is combined, this method is not affected by different DC levels and DC voltage ripple. The proposed torque controller is verified by designed experiments and effective data is required.