Optimized Supervision of Variable Displacement Compressor for Automotive Air Conditioning

The aim of this paper is to establish the optimized control of external variable displacement compressor (EVDC) for the automotive air conditioning (AC) system in various operating modes. The control logic was developed, calibrated and experimentally verified on test vehicle. The developed control strategy ensures the stability of AC system while achieving the desired climate control and yielding the maximum possible fuel economy. The influence of cooling load, compressor speed and icing of evaporator have been investigated theoretically and validated with test data. The proposed control strategy ensures the safety of compressor and stabilizes the AC system under high engine torque demand, cold start conditions, engine shutdown or under electrical failures reported by on board diagnostics services (OBD). The results reveal improved thermal comfort and improvement in fuel economy with the use of established baseline control logic presented in the paper.