Enhanced Performance DC Microgrid Control Scheme with Li-Ion Battery System for Electric Vehicle Applications

This paper proposes an advanced DC micro grid to-pology and the respective control algorithm that provides en-hanced equalization and dynamic performance of the Li-ion bat-tery storage system (BSS) in electric vehicle applications. The sug-gested control scheme is a hybrid energy storage system that con-sists of Li-ion batteries for the main energy reservoir in back-to-back connection with an auxiliary energy storage system (AESS) of supercapacitors (SCs) or Li-ion battery cells. The AESS improves the battery cell-to-cell equalization and provides energy support to any weak or problematic cells and also, enhances the dynamic performance of the vehicle by providing reinforcing en-ergy during a fast vehicle acceleration and energy saving by ab-sorbing any excess energy during abrupt braking of the vehicle. The battery cell equalization is realized through the Cell Equalizer Controller (CEC). The energy flow through the AESS is managed by a DC-DC converter combined with a matrix switch system which connects the AESS with any battery cell that needs support detected by the Cell Ageing Estimator (CAE). Selective simulation results are presented to validate the operating improvements of the proposed DC micro grid control scheme with Li-ion battery.