Microgrid smooth switch control method and strategy based on composite energy storage

Abstract

The invention relates to a microgrid smooth switch control method and strategy based on composite energy storage. According to the invention, a low voltage microgrid containing a plurality kinds of distributed power supplies is arranged, a public connecting point PCC in the low voltage microgrid, the distributed power supplies and the switches of all branches are monitored by a microgrid energy management system EMS, and the microgrid energy management system EMS detects the on / off state of the public connecting point PCC of the microgrid to judge whether the low voltage microgrid is located at an isolated island operation state or a grid-connected operation state. The microgrid smooth switch control method is characterized in that a composite energy storage unit composed of a supercapacitor and a storage battery is arranged in the low voltage microgrid containing the plurality kinds of distributed power supplies, and the composite energy storage unit is used for performing microgrid smooth switch control on the basis of the monitoring of the microgrid energy management system EMS on the low voltage microgrid. According to the invention, the composite energy storage characteristics are fully utilized to greatly improve the power supply reliability and power supply quality of the microgrid under a switch emergency state to facilitate the generalization and application of the microgrid.

Description

technical field [0001] The invention relates to a micro-grid smooth switching control method, in particular to a micro-grid smooth switching control method and strategy based on composite energy storage. It belongs to the technical field of electric power transmission and distribution. Background technique [0002] The microgrid has two operating modes: grid-connected and island-connected. Under normal circumstances, the microgrid and the public distribution network operate in parallel, and its voltage and frequency stability are supported by the public distribution network. When the distribution network or the microgrid fails , the point of public connection (PCC) between the microgrid and the distribution network will be disconnected immediately, and the microgrid will change from the grid-connected operation state to the island operation state. For most microgrids, the output of distributed power generation using renewable resources in the microgrid cannot fully meet the...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the serious decline in power quality caused by the power shortage when the micro-grid is switched from grid-connected to unplanned island in the prior art, and the problem that the micro-grid and the public distribution network are not synchronized when the micro-grid is grid-connected problem, to provide a micro-grid smooth switching control method and strategy based on composite energy storage

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