Drive Motor/Generator: Description and Operation

IMA Motor
The motor is a synchronous AC type that serves three functions: it converts kinetic energy into electrical energy, it assists the engine during acceleration, and it starts the engine.

The motor is located between the engine and the transmission. It consists of a three-phase coil stator and a permanent magnet rotor that is directly connected to the engine crankshaft. Three commutation sensors are mounted inside the housing to detect the position of the rotor.




MCM (Motor Control Module)
The MCM controls the amount of assist that the motor produces and the amount of regenerative power that the motor absorbs based on input from the ECM and the BCM. The MCM convents 144 V DC power into three-phase AC power required during assist, and converts AC power into DC power during regeneration.

The MCM also communicates with the PGM tester via the 16P data link connector for better serviceability. If any sensors or circuits in the IMA system are abnormal, the MCM turns on the IMA system indicator to warn the driver that there is a problem.




MDM (Motor Driver Module)
The MDM consists of the MPI module, voltage converter module, capacitor, and the U/V/W phase motor current sensors. The voltage converter acts as a preamplifier for the IGBTs. The IGBTs are used to transfer electrical energy to the motor from the 144 V battery and vice versa. The IGBTs are activated by the MCM based on the amount of assist/regeneration is needed. The voltage converter module monitors voltage and temperature of the MDM, and sends this information to the MCM.