Vol: 1 Issue: 1
MODELING AND CONTROL OF DC-DC BIDIRECTIONAL CONVERTER FOR ELECTRIC VEHICLE (EV) DRIVE SYSTEM
Okon E. Ekpenyong, Eko J. Akpama, Emmanuel E. Effiong
Abstract:
In order to reduce carbon emission from the usage of internal combustion engine vehicles, researchers and Engineers has put efforts in recent time in electric vehicle technologies. This paper presents modelling and control of electric vehicle drive system using a bi-directional DC-DC converter. The drive system is comprised of Lithium-ion batteries, bi-directional half bridge Buck boost DC-DC converter, Fuzzy logic controller and DC machine. The provision for energy regeneration is achieved by using half bridge non isolated DC-DC converter. The initial State of Charge (SOC) is set at 85% where the discharge current is 19.5A during motor mode. The nominal voltage of battery stack is set at 380V with maximum capacity of 100Ah. The rated power of DC machine is set to 250HP with 500V armature voltage and 300V field voltage. The operating mode of power converter is determined according to the torque values of DC machine which is operated in motor and generator modes. The bi-directional DC-DC converter is controlled with Fuzzy logic controller in both modes. Fuzzy logic controller has been implemented for charge control. The system model has been simulated in the MATLAB/SIMULINK. The various waveforms corresponding to the motor speed, armature current, SOC, battery voltage and the battery current during simulation has been plotted and evaluated. From Simulation result verification, its shows that the proposed converter with Fuzzy logic controller is effective and efficient in charging system for Electric Vehicle.
Keywords: Bi-directional DC-DC converter, DC machine, Fuzzy logic controller (FLC), PWM