Patent ID: 9069044
Filing Date: 2015-06-30
Classification: G01R

Abstract:
1. A battery management system (BMS), comprising: a voltage determination unit to measure a voltage of a battery and to measure a voltage of an inverter, a relay being connected between the battery and the inverter, the voltage determination unit measuring the voltage of the inverter and the voltage of the battery while the relay is being turned off; a current determination unit to measure a current flowing between the battery and the inverter, the current determination unit measuring the current while the relay is being turned off; and a relay defect determination unit to determine whether the relay is defective based on the current and a difference between the voltage of the battery and the voltage of the inverter, the relay defect determination unit determining that the relay is defective if an absolute value of the current is greater than a first critical value and the difference between the voltage of the battery and the voltage of the inverter is less than a second critical value, the relay defect determination unit determining whether a driving voltage of the relay is normal before measuring the current flowing between the battery and the inverter and before measuring the voltage of the battery and the voltage of the inverter.