Nonlinear Model Order Reduction for Feedforward Control of an Air Conditioning System in an Electric Vehicle

Abstract

Air conditioning systems are indispensable in all modern production cars, as they ensure thermal comfort for the passengers. Besides that, extended air conditioning systems allow for additional tasks like tempering the battery in hybrid and electric vehicles. To fulfill these multiple tasks, an advanced control structure has to be applied. Since the components of the air conditioning system are constantly optimized and new structures are developed, an efficient controller design requires a model-based approach to handle the diversity and allow for a fast adaptation to different structures.This paper considers such an approach: For the usage in a two degree of freedom control structure a feedforward controller is derived. This controller is designed as a multiple-input-multiple-output controller with a flatness based approach. To apply the concept on the model of the air conditioning system, a nonlinear model order reduction is performed. The presented reduction method is extended by a frequency scaling on the reduction data and the reduced model is validated with experimental data.