High Voltage Power Allocation Management of Hybrid/Electric Vehicles 2011-01-1022

As the automotive industry moves toward producing more advanced hybrid/electric vehicles, high voltage Rechargeable Energy Storage Systems (RESS) are now being implemented as the main power source of the vehicle, replacing the need for the traditional Internal Combustion Engine (ICE) altogether or just during certain parts of a drive cycle. With this type of architecture, it is becoming a necessity to equip these vehicles with devices that can draw their power from the high voltage (HV) RESS. These HV devices are not only used to support the propulsion of the vehicle but to perform other necessary vehicle functions as well.

With demands of high voltage power from multiple systems ranging from RESS thermal conditioning, cabin thermal conditioning, RESS charging, and vehicle propulsion, power demands can exceed the available power of the vehicle. This creates a perplexing problem of how to manage the high voltage power consumption between the different vehicle systems. This document describes how a controls method to manage the HV loads of a vehicle can be implemented to optimize the use of available power and ensure that power consumption remains within the operating bounds of the RESS. This document will also go into detail regarding when these types of vehicles may get into power constraining conditions and how a control system would manage power allocation in each specific condition.