Self-Scanning System and Evaluation of Dynamic Electrical Performance of Electric Vehicles Using Different Control Systems

The main energy target of an electric vehicle (EV) is reducing the consumption by optimally using battery energy between two successive charges and travelling the greatest possible distance in any dynamic conditions. An EV’s power converter must at all times use the optimal amount of energy supplied from the batteries to fulfil this purpose. It is necessary to change the control strategy of the motors while driving the electric vehicle depending on the operating mode. The definition and selection of optimal intelligent control techniques are determined by the measurement and the determination of operating boundary conditions according to the working modes of the electric vehicle. The EV can operate with one or two motors - all wheel drive (AWD) - depending on the operating mode. The main regimes considered are acceleration, braking, skidding regime by varying the adhesion torque as well as changing the traction system by coupling two motors on the two axles - front and rear – (AWD). This paper presents an innovative technique for detecting the optimal control method of an EV driven by a three-phase inverter depending on the operating regimes of the vehicle. The analysed control strategies were scalar control (U/f), direct torque control (DTC) and field-oriented control (FOC). A comparative study between the different control strategies by measuring and analysing the motor torque and the harmonic spectrum of the stator current is carried out in the paper. The comparative study focuses on determining the optimal values of the global energy parameters of a battery-powered EV using different control algorithms. The result of this comparison determines the strengths and weaknesses of the different techniques by evaluating the energy performance of the EV under imposed dynamic conditions.