Analytical modeling of electric drives for vehicle traction control systems

Wheel-torque control bandwidth in vehicle dynamics model is crucial in evaluating optimal tracking ability of tire slip and in analysis of control system stability. Electric drives' control dynamics are influenced by timing of digital control events, e.g. by sampling instant of motor currents. Reflecting this timing in drive analytical models is therefore important for analysis of vehicle traction systems. The paper considers five various transfer-function models including issues of digital control events timing. The aim of the paper is to compare the accuracy of the models in representing dynamics of a Permanent Magnet Synchronous Motor (PMSM) drive. Bode characteristics of the analytical models are compared to these of a reference model. The comparison is made for three commonly used cases of PMSM current sampling. Applicability of presented models has been discussed and frameworks to use specific models have been indicated.