Stabilisation strategy based on feedback linearisation for DC microgrid with multi-converter

Abstract

Power electronic converters have been widely used in power system and the stability issues of DC microgrid with converters will be discussed in this study. Firstly, an equivalent circuit and the corresponding state space model for DC microgrid with DC–DC converters were established. The model shows that the DC microgrid systems with DC–DC bidirectional converter in boost or buck mode is a non-linear system, and the tightly regulated point-of-load converters may destabilise the system because it introduces negative incremental resistance to DC microgrid. Then the method of exact feedback linearisation, which transforms the non-linear system into the linear system by coordinate transformation, was applied to stabilise DC microgrid system, and the stabilisation strategy of non-linear system was determined by designing the feedback coefficient of the linearised system. Finally, the feasibility and effectiveness of the stabilisation strategy for DC microgrid with DC–DC bidirectional converter have been verified by the results of simulation with MATLAB.

Keywords

• DC-DC power convertors
• state-space methods
• feedback
• distributed power generation
• linearisation techniques
• power system stability
• power generation control
• nonlinear systems
• linear systems
• stabilisation strategy
• multiconverter
• power electronic converters
• DC microgrid system
• DC–DC bidirectional converter
• nonlinear system
• point-of-load converters
• linearised system
• power system stability
• feedback linearisation
• buck mode
• boost mode
• negative incremental resistance
• coordinate transformation
• feedback coefficient
• Matlab