A feedback charge strategy for Li-ion battery cells based on Reference Governor

Abstract

In this paper, we propose a solution for the control of the state-of-charge of a lithium-ion (Li-ion) battery cell. The aim is to design a control scheme able to charge the battery in a fast way while ensuring that the safety constraints of the electrochemical model (ECheM) of the battery are not violated. The proposed solution is based on a novel computationally efficient formulation of the Reference Governor (RG) able to deal with the union of linear constraints and which has been designed on the basis of a reduced ECheM, namely the equivalent-hydraulic model (EHM). Using suitable safety margins, the satisfaction of the constraints on the EHM ensures the satisfaction of the constraints on the full-order ECheM. Simulation results obtained on an accurate simulator show that the proposed method, if compared with classical charge strategies, is able to considerably improve the charge performance while ensuring the satisfaction of the constraints. These findings are validated experimentally on a Li-ion graphite/LCO battery.