Direct Torque Control of IPMSMs by Nonlinear Optimal Control Technique

This book deals with design and analysis of direct torque control (DTC) system for interior permanent magnet synchronous motors (IPMSMs) in electric vehicle (EV) applications. First, dynamics equations of the IPMSMs are transformed to a suitable form that makes a nonlinear optimal DTC technique applicable. Because of being constructed in stationary reference frame, the proposed direct torque controller is not only simpler but also more robust than the conventional PI direct torque controller which requires an estimated stator position information and Park transformation. Based on a nonlinear control technique, which approximates the optimal solution to the Hamilton-Jacobi-Bellman equation, the proposed DTC scheme can effectively handle the nonlinearities of the IPMSM drive systems. Finally, the proposed DTC scheme is simulated on MATLAB/Simulink software and implemented on a prototype IPMSM with a TMS320F28335 DSP.