Design and model of regenerative battery controller for electric car. Case study in Rwanda

Abstract

This Research presents the design and model of regenerative battery controller for electric vehicles. The proposed solutions address issues related to battery discharging and charging. The direct torque control-switching algorithm has been modified to recover electrical energy from an electric vehicle during braking and deceleration when powered by a permanent magnet synchronous motor, without the use of an additional power converter or other electrical energy storage devices. During the regenerative braking process, a switching sequence is applied to the inverter, which is a universal bridge inverter as selected in MATLAB/Simulink, and which differs from normal operation due to the unique arrangement of switches inside. The new switching sequences are considered to convert wasted energy into electrical energy to charge the battery. State of charge for the battery is used as a performance indicator of the rotor speed variation. Different simulations are conducted to validate the performance of the proposed system, to find the energy used, storage and regenerated as well as accuracy of the designed model. The results show the high capability to solve the problem of low power on the battery supplying the electric vehicle. I t is clear that 95% of regenerated energy was used to recharge the battery and a small portion is wasted as heat since it is not possible to recover all energy.