A Simple Control Solution for Traction Motor Used in Hybrid Vehicles

Electric motors (EM) are widely used in industry for a large variety of applications, such as traction motors used in electric and hybrid vehicles. In this paper a hybrid electric vehicle is considered, which contains both an internal combustion engine and an EM. Without focusing on the other components of the vehicle, the EM is treated in detail, both regarding modelling aspects and control solutions. After a brief modelling of the plant, two cascade speed control solutions are presented: first a classical PI+PI cascade control solution is presented. Then a correction term is introduced as a PI + a non-homogenous structured PI controller solution. The controllers are developed using the Modulus-Optimum method for the inner loop, and the extended symmetrical optimum method, corrected based on the 2p-SO-method, for the outer loop (for a more efficient disturbance rejection). Simulations were performed using numerical values taken from a real application consisting in a hybrid vehicle prototype, showing satisfactory behaviour.