Research On Coordinating Control Of Parallel DC/DC Converters In DC Micro-Grid

For DC micro-grid,the micro-sources are connected to the DC bus through power electronic converters which are connected in parallel.Exploring the interaction between these parallel power electronic converters is not only an important condition to ensure the stable operation of DC micro-grid,but also a necessary premise to research the capacity of DC micro-grid.As for now,most people make analysis in the power system,such as Trend analysis and Fault detection and Relay protection and so on.In the daily life,it can charge with the phone,computer,battery and other charges at the same time through the board,and can maintain a stable operation.That for a DC micro-grid,we want to know how many power electronic converters the DC bus can be connected,this tropic is from the perspectives of power electronics in DC micro-grid.Firstly,this paper analyzes the power electronic converters from these parts such as working principle,small signal modeling and control strategy.By simulating the parallel power electronic converters in Matlab,and using the droop control to suppress the circulating current generated in the parallel converters,real-time digital simulation and hardware in the loop system are realized by real-time simulation platform OPALRT to confirm the validity of the theoretical analysis and the effectiveness of the control strategy.Finally,the stability of the parallel power electronic converters in the DC micro-grid is analyzed from the aspects of input filter,photovoltaic output system and converter performance in droop control.