A Vector Control Based Supercapacitor Current Control Algorithm for Fuel Cell and Battery - Supercapacitor Integrated Electric Vehicles

While driving an electric vehicle, one of the prominent factor which plays a vital role in determining vehicle performance, is load variation. In order to achieve the load levelling, satisfactory recovery of braking energy and for better performance in transient load conditions, the energy storage systems like batteries and supercapacitors must be employed in fuel cell electric vehicles. In this paper, fuel cell stack is integrated with battery and supercapacitor at DC link of the motor drive system for driving the induction motor. The fuel cell is directly connected to the DC link, while battery and supercapacitor are connected through bidirectional New boost converter. The battery in the New boost converter is responsible for the dc link voltage stabilization and supercapacitor deals with load transients. The field oriented vector control of the induction motor is utilized on the drive side to achieve the diverse vehicle speed and load torque demands. Here, a new strategy is introduced for the supercapacitor reference current calculation in the New boost converter, from the torque and flux producing components of the induction motor stator reference currents Ig*, and IL to meet the transient speed and load variations. The analysis of the integrated system along with power sharing among fuel cell, battery and supercapacitor for the diverse vehicle speed and load torque variations is carried out in MATLAB/Simulink, and corresponding simulation results are reported.