초록 ▼

A microprocessor based electric vehicle traction battery monitoring system evaluates the state of charge, interfaces with a traction motor control system, and controls recharging. The state of charge is evaluated during the first part of discharge by integrating the current after compensating it for

A microprocessor based electric vehicle traction battery monitoring system evaluates the state of charge, interfaces with a traction motor control system, and controls recharging. The state of charge is evaluated during the first part of discharge by integrating the current after compensating it for rate of discharge and during the last part of discharge by dividing the battery into sub-packs and evaluating the state of charge from the lowest sub-pack voltage compensated for polarization voltage. The charge storage capacity is also calculated from the lowest sub-pack voltage. The maximum traction motor current is progressively limited during the last part of discharge. During charging, the charge withdrawn is replaced while progressively reducing the charging current and the battery is then charged at a constant current until the rate of rise of the lowest sub-pack voltage falls below a fixed level.

대표청구항 ▼

A battery state of charge evaluator comprising: means responsive to battery voltage for producing a voltage value, means responsive to battery current for producing a current value, means for computing the polarization voltage as a complex function of time and of the current value, the complex funct

A battery state of charge evaluator comprising: means responsive to battery voltage for producing a voltage value, means responsive to battery current for producing a current value, means for computing the polarization voltage as a complex function of time and of the current value, the complex function being determined in accordance with characteristics of the battery being evaluated, means for correcting the voltage value to compensate for the polarization voltage, and means for computing the state of charge of the battery as a function of the corrected voltage value, said function being determined in accordance with the characteristics of the battery being evaluated.