Circuit/System Description

The power inverter module, often referred to as the drive motor generator power inverter module, contains the motor control modules and the hybrid/EV powertrain control module 1. Each motor control module operates its respective drive motor based upon hybrid/EV powertrain control module 1 commands. Each motor control module controls the speed, direction and output torque of its respective drive motor through the sequencing actuation of high current switching transistors called insulated gate bipolar transistors. Each drive motor operates utilizing 3-phase alternating current (AC) electricity. Each insulated gate bipolar transistor operates a single phase of the drive motor. Each phase is individually identified as U, V and W. Each motor control module monitors the current of each phase in order to detect power inverter module over current conditions.

Because all the motor generator phase circuits are electrically joined together, they should each flow about the same amount of current. The motor control modules perform a mathematical calculation to verify that the phase current sensors are accurate. If the U-V-W phase current sensors indicate about the same amount of phase current, the sum of the calculation should be near zero. If the U-V-W phase currents are not similar, this DTC will set.