Stabilization of a DC electrical network by damping injection

Abstract

It is well known that interactions between weakly damped LC input filters and constant power loads (CPL) can lead to instability. This paper deals, in particular, with this problem when several CPL are connected to the network through undamped LC filters. The second goal is the energy management. They are mainly achieved by controlling the energy flow between the network and a storage device. The latter is a super-capacitor connected to the network via two DC-DC converters. After Port controlled Hamiltonian (PCH) expression of the system dynamics, they are controlled using the passivity approach. A proof of stability of the controlled system is given. Robustness tests relative to parameters uncertainties are realized and simulation results confirm the validity the proposed approach. This approach has also the advantage of requiring the measurement of only two state variables.