Intelligent Air Conditioning System Activation in Passenger Cars with Electrified Powertrains

Abstract

The thermal system of the passenger compartment is one of the main auxiliary loads in vehicles with electrified powertrains. One possibility to reduce the energy consumption of the thermal system is to implement optimization-based thermal management strategies, which are able to minimize the energy consumption, while maintaining passengers' thermal comfort. Focus of the present work is the extension of an existing thermal management strategy by an additional control input determining whether to activate the compressor of the air conditioning system or not. The main modules of the existing strategy are two linear model predictive controllers, for the cases with and without activated air conditioning system, formulated as quadratic programs. The existing strategy is extended by a binary control input describing the status of the air conditioning system, such that both quadratic programs are combined to one mixed-integer nonlinear program (MINLP). This problem is reformulated to a mixed-integer quadratic program (MIQP). Besides the MIQP also a heuristic approach for the activation of the air conditioning system is developed to reduce the computational effort. Both approaches are analyzed and compared to show their advantages.