• Y. VARA LAKSHMI
• K. SURESH KUMAR

In electric vehicle (EV) energy storage systems, a large number of battery cells are usually connected in series to enhance the output voltage for motor driving. The difference in electrochemical characters will cause state-of-charge (SOC) and terminal voltage imbalance between different cells. In this paper, a hybrid cascaded multilevel converter which involves both battery energy management and motor drives is proposed for EV. In the proposed topology, each battery cell can be controlled to be connected into the circuit or to be bypassed by a half-bridge converter. All halfbridges are cascaded to output a staircase shape dc voltage. Then, an H-bridge converter is used to change the direction of the dc bus voltages to make up ac voltages. The outputs of the converter are ultilevel voltages with less harmonics and lower dv/dt, which is helpful to improve the performance of the motor drives. By separate control according to the SOCof each cell, the energy utilization ratio of the batteries can be improved. The imbalance of terminal voltage and SOC can also be avoided, fault-tolerant can be easily realized by modular cascaded circuit, so the life of the battery stack will be extended. Simulation and experiments are implemented to verify the performance of the proposed converter..

STATE OF CHARGE, BATTERY SYSTEMS, ELECTRIC VEHICLE, HYBRID CASCADED MULTILEVEL CONVERTER.

"HYBRID CONVERTERS FOR THREE PHASE BATTERY STORAGE SYSTEM FOR GRID APPLICAITONS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 8, page no.1043-1051, August-2018, Available :http://www.jetir.org/papers/JETIR1808153.pdf

"HYBRID CONVERTERS FOR THREE PHASE BATTERY STORAGE SYSTEM FOR GRID APPLICAITONS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 8, page no. pp1043-1051, August-2018, Available at : http://www.jetir.org/papers/JETIR1808153.pdf