Compensating the Thermally Derated Torque for Six-Phase Induction Machine Based Electric Drive System Using Linear Parameter Varying Control

Multiphase induction machine posses the several advantages compared to three-phase induction machine when used in the Electric Drive System (EDS) of Electric Vehicles (EV). The performance of an EDS in extreme working conditions is extremely compromised. An electric drive suffers from torque derating as its parameters change due to the rise in operating and ambient temperatures. The performance of commonly used Field-oriented Control (FOC) in the EDS of EV is deteriorated under the vast variations in the rotor and stator resistances due to the change in the operating conditions. In this work, a robust Linear Parameters Varying (LPV) based FOC technique is proposed to estimate the thermally derated torque and flux to improve the performance of EDS when it operated in harsh environment. The performance of the proposed control technique is verified and investigated for the electric drive of a passenger bus (class-4) used in urban transportation. The Federal Urban Driving Schedule (FUDS) is adopted for the simulation experiment and validation of the proposed approach. The nonlinear simulation results show the capability of the proposed technique to accurately estimate and track the derated torque and flux demands in a six-phase Induction Machine (IM) based EDS.