Advanced Thermal System Control Optimization on Ricardo �CONNECT HEV� Democar

Abstract

In the context of the improvement of energy management optimisation on PHEV applications, thermal management is playing a great role. The electrical energy absorbed by the electric ancillaries to heat up or cool down the electric components and the cabin can be as high as the electrical energy required to move the vehicle. PHEV presents a high level of complexity of the cooling/heating circuit architecture with several circuits and multiple pumps and valves due to the presence of high temperature, low temperature and cold temperature cooling circuits. Those circuits can be coupled or not depending on the ambient temperature and driving conditions. In order to minimise the electrical energy used to heat up or cool down components and cabin using electric heater and/or heat pump, waste heat recovery from electric components, electric air conditioning compressor with chiller. The paper will present the novel thermal management system architecture installed on a PHEV (Ricardo CONNECT HEV democar, C-SUV, gasoline) using multiple coolant valves, heat pump and waste heat recovery, with its benefit in term of fuel consumption (up to 3%) and EV range improvement (up to 10-15%) thanks to the use of Model Based Development (vehicle and powertrain 1D thermo-hydraulic models). The advanced thermal control for energy management optimisation will also be presented. The control is developed with a holistic approach using model predictive control and optimal control approaches instead of using a local optimisation of the control of each actuator. These advanced control techniques have the additional benefit of reducing calibration effort whilst delivering efficiency gains compared to heuristic or rule-based controllers. The multi temperature cooling circuit and the control integration will be shown on Ricardo CONNECT HEV democar during the conference.