Stable control method for switching micro grid grid-connected mode to island operation mode

Abstract

The invention discloses a stable control method for switching a micro grid grid-connected mode to an island operation mode. The method comprises a step of collecting the electrical quantities of a micro grid and a tie line and receiving a command of an upper-level system through a micro grid central controller and a rapid measurement and control unit and obtaining a real-time operation state of the micro grid, a step of calculating the real-time load and power output of a micro grid system when the operation state is a planned island and judging whether source and load are balanced or not, otherwise, switching a main power supply from PQ operation mode to a V / f operation mode when the system satisfies an island criterion, judging whether the system runs normally after a PCC switched is switched off, removing immediately after detecting a failed line if the system is abnormal, and restarting the judgment, and a step of judging whether the source and load are balanced in the micro grid if the system is normal, calculating a power imbalance amount if the source and load are unbalanced, adjusting storage energy output and then judging whether the source and load are balanced again, performing low-voltage / low-frequency load shedding if the source and load are unbalanced, and judging whether the source and load are balanced again. The detection mode is simple, and the stability is good.

Description

technical field [0001] The invention relates to the technical field of micro-grids, in particular to a stable control method for grid-connected micro-grids to island operating modes. Background technique [0002] Traditional primary energy sources such as coal and oil are non-renewable. Improving energy utilization efficiency, developing new energy sources, and strengthening the use of renewable energy sources have become increasingly prominent in the process of rapid economic and social development. Energy demand growth and energy shortages, It is an inevitable choice between energy utilization and environmental protection. [0003] At present, distributed power sources such as photovoltaic power generation, wind power generation, fuel cells, micro gas turbines, and internal combustion engines have made great progress in technology after long-term development. my country plans to have a total installed capacity of generators of nearly 1 billion kilowatts by 2020. Among them...

AI Technical Summary

Problems solved by technology

However, the detection method of this scheme is complicated, the cost is high, and the stability control efficiency is insufficient

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