On/off-grid control method for microgrid with a plurality of distributed power supplies

Abstract

The invention provides an on / off-grid control method for a microgrid with a plurality of distributed power supplies. When the microgrid is on on-grid operation, a central controller of the microgrid can continuously carry out isolated island detection. When the microgrid is detected to be in an isolated island operation state, isolated island operation control is carried out according to a preset strategy. When the microgrid is in an off-grid operation state, the central controller of the microgrid can start an on-grid process to achieve the positive sequence voltage amplitude of the large power grid side, the frequency of the large power grid side, the frequency of the microgrid side, the voltage of the large power grid side, the voltage of the microgrid side, the voltage phase angle value of the large power grid side and the voltage phase angle value of the microgrid side. Whether the microgrid is suitable for on-grid operation is judged by comparing the relationship between correlation values and preset values. If on yes judgment, the central controller of the microgrid can control the breakers to be switched on to achieve grid connection. The control method can achieve the on / off-grid control on the microgrid with distributed power supplies, avoids long-time off-grid operation of the mcirogrid and can timely break the mcirogrid to enable the microgrid to operate normally when a larger power grid is broken down.

Description

technical field [0001] The invention relates to a micro-grid integration / off-grid control method with multiple distributed power sources. Background technique [0002] Distributed power generation has extensive economic and social benefits. Today, when energy is increasingly scarce, the country vigorously advocates distributed power generation, especially the use of solar energy, and photovoltaic power generation has been vigorously developed. While distributed power generation is self-sufficient, the excess power needs to be input into the public grid for use by other users. Correspondingly, when distributed power generation cannot meet its own supply, the public grid is required to provide power support, but the distributed power generation stand-alone Higher input cost and difficult to control. The microgrid combines distributed power sources, loads and control devices to form a controllable small power generation and distribution system, which can effectively solve the ...

AI Technical Summary

Problems solved by technology

While distributed power generation is self-sufficient, the excess power needs to be input into the public grid for use by other users. Correspondingly, when distributed power generation cannot meet its own supply, the public grid is required to provide power support, but the distributed power generation stand-alone High input cost, difficult to control

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