An Hybrid Observer for a two-branch Supercapacitor Model : voltages estimation for SOH and SOC under NEDC and WLTP cycles

In this paper, based on a two-branch model, an online internal voltages estimation method of a supercapacitor is proposed. The goal is to provide a fast and accurate online estimation of such voltages as they are useful for estimating its State Of Health (SOH) and/or State Of Charge (SOC). An hybrid nonlinear observer is designed to estimate voltages using sampled measurements. This kind of observer uses a correction term in the prediction step with the aim of performing with large sampling period, then it is suitable for efficient online estimation. Simulation results highlight good performances of the observer in online parameters estimation in the case of fast dynamics inputs under NEDC and WLTP cycles.