System for monitoring the current drawn from traction batteries in electric vehicles and hybrid vehicles

摘要

The invention relates to a battery current monitoring system for traction batteries in electric vehicles and hybrid vehicles, in which battery current monitoring system the maximum battery current is monitored in order to avoid damage to the battery as a result of overheating due to excessively high battery currents and, if appropriate, the said maximum battery current is reduced to a normal value which is permitted for continuous operation. Monitoring is activated if the battery current exceeds a prescribed limit value. The battery current is however not reduced until the battery temperature exceeds a prescribed limit value. It is also proposed not to use the measured average battery temperature as the control variable, but rather to use a reference temperature calculated on the basis of heat balances for individual reaction zones of the battery. The monitoring is terminated as soon as both the average and the calculated battery temperatures drop below a prescribed uncritical value.