Robust control of a multi-bus DC microgrid based on adaptive Lyapunov function method

Abstract

Abstract Due to the development of power electronic devices, the DC microgrids are competing AC microgrids, and even in some areas, such as efficiency, reliability, stability, DC microgrids are superior. In spite of mentioned advantages, the main technical challenge related to operation of the DC microgrids is to provide a fast and stable voltage regulation. In this paper, a robust control structure is proposed for multi-bus DC microgrids. Adopting master–slave control strategy, an adaptive voltage control scheme is proposed to robustly maintain the master unit voltage at the nominal value. In addition, an adaptive current controller is designed to robustly regulate the current of all the DG units in the grid-connected mode, as well as the slave units in the islanded mode of operation. All of the controllers are designed based on local measurements and are independent with respect to parameters, dynamic, and topology of the DCMG loads. The control scheme is shown to be stable and robust subject to parametric uncertainties and various types of disturbances. The consistent and effectiveness of the proposed control scheme is demonstrated through simulation studies in MATLAB® software environment.

Keywords

• DC microgrid
• DC distributed generation
• Master/slave structure
• Lyapunov control theory