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Comparison and Selection of LiFePO4 Battery System in Underground Mine Electric Vehicles

Due to safe and reliable characteristic, two lithium iron phosphate (LiFePO4) batteries and their corresponding battery packs with different capacities have been chosen to make four battery systems for underground mine electric vehicles (UMEVs). The experiments of these batteries and battery packs are conducted to identify their internal resistances, the relationships between open circuit voltage and state of charge during charging/discharging period and capacities at different ambient temperatures. A hybrid simulation approach based on the modified Advanced Vehicle Simulator (ADVISOR) is proposed to compare these four battery systems by integrating the experimental results of these batteries and battery packs into an UMEV model. Then, the simulation of the UMEV is conducted at the specifically designed underground mine driving cycle with variable rolling resistance coefficients and variable uphill/downhill gradients. The results indicate that the battery system with the prismatic cell of 20Ah is the best option for the UMEV among the four battery systems.