Two-layer nonlinear control of DC–DC buck converters with meshed network topology

In this paper, we analyse a buck converter network containing arbitrary, up to mild regularity assumptions, loads. Our analysis begins with the primary controller where we propose a novel decentralised Lyapunov function for the interconnection between currents and a bounded integrator. We leverage on this result to study the network as a cascaded interconnection between voltages and bounded currents. We, in addition, propose a distributed optimal secondary control framework to steer voltages close to their nominal operating values. We employ the properties of the Laplacian kernel to show recursive feasibility and input-to-state stability of the closed loop. We demonstrate our results in a meshed topology network containing 6 power converters, each converter feeding an individual constant power load with values changing arbitrarily within a pre-specified range.