A light-storage independent microgrid topology for interconnected operation

Abstract

The invention relates to an independent light-storage micro-grid topology for interconnected operation. The independent light-storage micro-grid topology is formed by connecting an energy storage system, a distributed photovoltaic power generation system and a load in parallel; and the distributed photovoltaic power generation system and the load are connected with an AC bus in parallel. The independent light-storage micro-grid topology is characterized in that the output end of an energy storage battery pack in the energy storage system is connected to one end of an isolating switch; the other end of the isolating switch is connected with the input end of a DC / DC converter; the output end of the DC / DC converter is connected with the DC side of a DC / AC energy storage converter, and the connecting line is taken as a DC bus of independent light-storage micro-grids; and the AC output of the DC / AC energy storage converter is taken as an AC bus of independent light-storage micro-grids. When the independent light-storage micro-grids work independently, the DC / DC converter controls the voltage of the DC bus of the independent light-storage micro-grids, and the DC / AC energy storage converter controls the voltage of the AC bus of the independent light-storage micro-grids; when the independent light-storage micro-grids are interconnected, the two independent light-storage micro-grids are connected in parallel by utilizing an interconnecting switch; and the DC / DC converter controls the voltages of the micro-grids by adopting an active voltage droop control method.

Description

technical field [0001] The invention relates to an optical-storage independent micro-grid topology suitable for interconnection operation. Background technique [0002] At the beginning of this century, with the support of the national power transmission to the countryside and the Guangming Project, a large number of independent photovoltaic power supply systems have been widely promoted in Tibet and other areas without electricity but rich in light resources. This kind of system solves the power consumption problem of local residents to a certain extent, but it is not scalable and flexible, and cannot meet the usage demand when the load increases. With the development of distributed generation technology, an independent microgrid technology with greater flexibility and scalability has become a more effective power supply solution than independent power supply systems. [0003] Photovoltaic storage microgrid refers to a small power generation / distribution / power consumption ...

AI Technical Summary

Problems solved by technology

However, the line parameters of the microgrid and the large-scale transmission network are very different. Affected by the change of the line parameters, the droop characteristics have the uncertainty of active power-frequency, reactive power-voltage and active power-voltage, reactive power-frequency. The unavoidable harmonic influence after the parallel connection of transformers brings many disadvantages to the AC parallel system

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