Drive Motor Generator Control Module Cooling System

Drive Motor Generator Control Module Cooling System Description and Operation

Hybrid Cooling

The drive motor generator power inverter module (PIM) assembly converts high voltage direct current (DC) electrical energy to 3 phase alternating current (AC) electrical energy. The accessory DC power converter module (APM) converts high voltage DC electric energy into low voltage (14 V) and intermediate voltage (42 V) in order to charge the vehicles accessory battery and supply electric energy to the 42 V power steering system. The APM and PIM are fastened together and are referred to as the drive motor/generator control module assembly. The engine control module (ECM) monitors a temperature sensor in the power electronics cooling system and operates the radiator fan and the power electronics coolant pump in response to power electronics cooling system temperature.

The drive motor/generator control module assembly is cooled with pre-mixed Dexcool(R) circulating through a cooling system that is separate from the engine cooling system.The coolant uses 50/50 mix of Dex-cool and de-ionized water. De-ionized water is required in order to prevent corrosion from effecting heatsink performance. Always use pre-mixed coolant and never use tap water in the power electronics coolant system. The pump system will always be activated when the vehicle is on and propulsion is available. The pump system will also be activated when the vehicle is on and propulsion is not available if the algorithms determine that cooling is needed. The HCP and ECM determine the speed/flow and control the power electronics coolant pump system. This circuit is a single driver control to a relay and both pumps are in parallel powered by a fuse in the auxiliary BEC. The power electronics coolant pump control shall be on during a key crank, after a successful key crank, during a jump assist event or after a key off when the power electronics coolant is extremely hot.