General Design Method of Modified Damping Assignment-PBC in Shipboard Evolutive Microgrids

Passivity based control (PBC) is an appealing solution to control power converters while ensuring the stability of more and more complex and modular electrical systems. However, the original interconnection and damping assignment-PBC (IDA-PBC) controller design method generates singularities in the control-variables leading to their saturation and spikes of current. This article highlights this nondesired phenomenon by applying the original IDA-PBC to the control of a boost converter. A novel controller design is then proposed to remove the singularities of the control-variables while preserving the proof of passivity of the whole controlled system. The proposed method introduces a new damping assignment approach to tune the performances of the system. This design can be applied to a specific subclass of port controlled Hamiltonian (PCH) systems which includes the average models of different converters. To highlight the generalization of the proposed method, it is applied to a 5th-order 2 kW 2-input modular three-level boost converter (MTL-BC), and validated experimentally. The advantage of the controller is presented for a microgrid system (MGS) application compared to other conventional control strategies and how it improves the stability margin in the presence of a constant power load (CPL).