Feasibility analysis of a class of high-order sliding-mode differentiators for redox flow batteries parameter estimation

P.FORNARO; T.P.PULESTON; PULESTON P.F.; M.SERRA; R. COSTA-CATELLÓ; P.E.BATTAIOTTO

Rio de Janeiro

Congreso; 16th Int. Workshop on Variable Structure Systems - VSS 2022; 2022

This work presents the preliminary findings of a feasibility study for a class of sliding mode differentiators to be used in an on-line parameter estimation methodology for vanadium redox flow batteries (VRFB). Specifically, three high order continuous differentiators are considered: a Standard Differentiator; a Filtering Differentiator, which excels the former by incorporating rejection to large noises small in average; and a Tracking Filtering Differentiator, which produces smooth consistent derivatives while inheriting the noise rejection capabilities from the previous one.To model the vanadium redox flow batteries an equivalent circuit model is employed, whose time varying parameters are estimated by a recursive least squares algorithm with forgetting factor, that requires the VRFB measured voltage and current, together with their derivatives. To assess the performance of the different differentiation algorithms in obtaining reliable values of the VRFB parameters, the storage system is excited with standardised current demand profiles. Finally, representative simulation results are presented and discussed.