Patent ID: 9018865
Filing Date: 2015-04-28
Classification: B60L,H01M,H02J,Y02E,Y02T

Abstract:
1. A vehicle comprising: a rechargeable energy storage system (RESS); an electric traction motor having an output shaft, wherein the traction motor draws energy from the RESS and outputs drive torque to the output shaft to propel the vehicle; a high-voltage component; a high-voltage direct current (HVDC) bus that electrically connects the RESS to the high-voltage component, wherein the HVDC bus includes a positive rail and a negative rail; a passive discharge circuit that is electrically connected across the positive and negative rails, wherein the passive discharge circuit includes: a microprocessor in electrical communication with the passive discharge circuit wherein the photodiode of the optocoupler is connected between the processor and electrical ground; wherein the microprocessor provides an output signal at a first voltage level of 5VDC to the optocoupler that opens the semiconductor switch and prevents discharge of the HVDC bus across the discharge resistor when the microprocessor is operating normally, and at a default second voltage level of 0VDC to the optocoupler that closes the semiconductor switch, which is held closed via the zener diode, to activate the passive discharge circuit only in the presence of a predetermined vehicle condition to thereby passively discharge the HVDC bus across the discharge resistor, and wherein the predetermined vehicle condition is a condition in which a 12VDC auxiliary voltage is temporarily lost aboard the vehicle.