Battery SOC estimation program, wireless transit system, and method of charging the battery

摘要

Occurrence of overcharging and over discharging of batteries mounted on vehicles that travel on tracks in a wireless transit system is prevented by estimating a state of charge (SOC) of the batteries with accuracy. An equivalent circuit of the battery is composed of three circuit elements connected in series, including (i) a first component resistance R1 (ii) a component circuit which includes a capacitance C and a second component resistance R2 connected in parallel and (iii) an open circuit voltage of the battery. The open circuit voltage of the equivalent circuit is calculated using R1 calculated from measurements of current and voltage of the battery, as well as values k=R2/R1 and τ=C×R2. The SOC if the battery is calculated from the open circuit voltage.