Optimal Power Management of Multiple Battery Units by Power Converter System in Electric Vehicle

Abstract

A concept of multiple fixed and small battery units configuration for a novel Electric Vehicle (EV) architecture is proposed to address the issue of high initial price, lack of space availability, inadequate range and higher energy consumption at a short distance of an EV. To deal with the optimal power flow management of these batteries based on the availability of their State-of-Charge(SoC), a SoC based droop control method is applied over DC/DC Power Converter Systems(PCSs) which interface battery units and electric powertrain. Gradual attainment of uniform power distribution with SoC balancing between these parallel modules is achieved under droop control method. Droop controlling of bi-directional DC/DC converter is performed for both charging and discharging operation. A MATLAB/Simulink model of SoC based droop control included three battery units with bidirectional DC/DC converter system is developed and simulation results at the constant speed of EV are shown to demonstrate and verify the approach. Then federal urban driving schedule of an EV is applied as a load to test the effectiveness of the system.