Circuit/System Description

The power inverter module, often referred to as the drive motor generator power inverter module, contains DC high voltage capacitors and a resistor circuit intended to discharge the electrical energy stored within those capacitors. Whenever the high voltage contactors are opened, the hybrid/EV powertrain control module 1 connects the internal resistor circuit across the capacitor circuit. The level of the high voltage is monitored by the hybrid/EV powertrain control module 1 before and after the resistor circuit has been connected. If the voltage level remains high for too long, the hybrid/EV powertrain control module 1 sets this DTC and then commands the motor control modules to connect the drive motor 3 phase circuits across the DC high voltage positive and negative circuits thereby discharging the capacitors.