FUZZY LOGIC CONTROL FOR ENERGY MANAGEMENT SYSTEM OF A HYBRID ELECTRIC VEHICLE

The Hybrid Electric Vehicle (HEV) electric motor is typically powered by a battery pack through power electronics. The fuel consumption in HEV is already lower compared to conventional vehicle. However, there will be a need to control the distribution of torque between the engine and electric motor to further minimize the fuel consumption. With reference to this issues, the purpose of this project is to create a complete HEV using a MATLAB/Simulink tool. From the model created, it will be equipped with a controller for energy management system. The method used is by taking the driver command, the state of charge (SOC) of the battery, the vehicle speed, percentage of throttle and engine efficiency as inputs, a fuzzy logic control for parallel HEV has been developed in a controller to effectively control the torque distribution between Internal Combustion Engine (ICE) and electric motor which is known as In-Wheel Motor (IWM). This research also discusses the methodology for designing a base vehicle model using MATLAB/Simulink. Prior to modelling HEV model, the base vehicle model was validated in terms of the fuel consumption to verify the model. The verified built base model will then be modified to become HEV model by virtually installing IWM at the rear wheels together with a controller inside the trunk. The proposed energy management strategy is implemented on a parallel HEV model and it is then simulated to a selected drive cycles. Since the distribution of torque in HEV model is varied according to the rules set, the fuel consumption is reduced significantly as compared with conventional base vehicle model. The simulation results reveal that, the HEV model built from conventional vehicle model has a significant improvement of 23% in terms of fuel economy as well as maintaining battery SOC within its operation range.