Control for Electrical Coolant Valve in Engine Thermal Management Module

Hyundai-Kia Motor Company recently developed a multi-way, electrical coolant valve for engine thermal management module (TMM). The main purposes of the TMM are to boost fuel economy by accelerating engine warm-up and also to enhance engine thermal efficiency by actively controlling the operating temperature. In addition to those, the system can improve vehicle heating and cooling performance as well. The electrical coolant valve is a key component in the TMM as it modulates the amount of coolant flow to individual components in cooling system such as engine oil heat exchanger, heater core, and radiator. The coolant flow modulation is done by controlling the electric valve’s position with using an electric motor attached to the valve. The objective of the valve control is to manage coolant temperature at a desired level that varies depending on vehicle’s operating condition.

This paper discusses the control algorithm developed for controlling electrical coolant valve. The algorithm is designed to force engine coolant temperature to robustly follow the desired temperature target under disturbance from engine operating condition variation. In order to deal with the time delay between valve action and the actual impact on temperature change, the controller utilizes two water temperature sensors located at the inlet and the outlet of engine water jacket circuitry. The result acquired through actual prototype vehicle tests is also demonstrated.