Patent ID: 7908877
Filing Date: 2011-03-22
Classification: B60H,B60L,B60W,F02N,Y02T

Abstract:
1. A method of controlling a HVAC system for a hybrid vehicle having a refrigerant compressor driven only by an engine, the method comprising the steps of: (a) determining a requested air conditioning operating point for a passenger compartment; (b) estimating a time to reach the requested air conditioning operating point; (c) based on steps (a) and (b), estimating a maximum allowed compressor off time; (d) determining if the maximum allowed compressor off time is greater than a minimum allowed engine off time; (e) if the maximum allowed compressor off time is greater than the minimum allowed engine off time, determining if the vehicle is entering an allowable engine off mode; (f) if the vehicle is in the allowable engine off mode, commencing engine shut-off mode; (g) if the engine shut-off mode is anticipated, prior to commencing the engine shut-off mode, adjusting at least one component of the HVAC system to maximize cooling of the passenger compartment with minimum energy usage; and (h) if the engine shut-off mode is commenced, monitoring the HVAC system to determine when engine restart is needed to maintain thermal comfort in the passenger compartment.