A MODIFIED BIDIRECTIONAL FLYBACK CONVERTER-BASED ACTIVE CELL BALANCING OF LI-ION BATTERY STRING FOR ELECTRIC VEHICLE APPLICATIONS

An efficient bidirectional flyback converter topology is proposed in this article to enhance the balancing speed and diminish the losses due to leakage reactance and circulating current. The proposed topology has two integrated no-dissipative resistor-capacitor-diodes (RCD) snubber circuits, which are used to reduce leakage reactance and improve the efficiency of the battery charge equalization (BCE) system. The proposed topology will reduce the number of switching devices and circuit complexity when compared to conventional active cell balancing topologies. The proposed system design and step-by-step equalization processes are presented in detail. By using various aspects, such as static state, one cell with the highest state of charge (SOC) value, and one cell with the lowest SOC value, MATLAB simulation software verifies the performance of the proposed topology. The variation in balancing time among each aspect is examined through MATLAB. A comparative chart was presented with various characteristics of the proposed topology and conventional topologies. The simulation result and comparative chart may show the improvement of the proposed topology. This work will extend to charging and discharging functions with suitable parameters for better performance in electric vehicle (EV) applications.