Katium-power-converter-based Li-ion battery charger for railway applications: control-oriented modelling
Résumé
This paper aims at obtaining a suitable model of a Katium-power-converter-based battery charger, to further serve for control design purpose for railway applications. The Katium converter represents a particular DC-DC power converter topology. In the considered application a Katium converter operates as a Li-ion battery charger and a low-voltage power supply for a load composed of a resistive part and a constant-power part. Starting from the bilinear nature of the system model, a family of linear parameter-varying models is obtained by linearization around successive operating points, which mainly depend on the load power to be supplied. The modeling approach further relies upon the observation that the battery current regulation problem is a disturbance-rejection problem, where both constant and periodic disturbances act on the system. The obtained state-space model is validated by MATLAB®/Simulink® numerical simulation, providing a sound starting point for control strategy design.