Patent ID: 9461472
Filing Date: 2016-10-04
CPC Classification: H02J,Y02B,Y02P,Y04S

Claim Text:
1. A method for controlling electrical power in a micro-grid, which micro-grid comprises a grid switch that connects the micro-grid to a main grid for receiving power from the main grid, at least one power source including an energy storage, a plurality loads, and at least one controller configured for performing load shedding and configured for controlling the at least one power source, the at least one controller being configured to selectively disconnect each respective load, the method being performed in a grid-connected mode when the micro-grid is connected to the main grid, and in an islanding mode when the connection to the main grid is lost, said method comprising the steps of: determining a load shedding for islanding mode during operation in the grid-connected mode; monitoring the status of the grid switch; entering the islanding mode from the grid-connected mode when the grid switch opens; performing a load shedding upon entering islanding mode by disconnecting one or more of the loads, the load shedding being made in accordance with the determined load shedding; and performing a frequency based regulation by monitoring the frequency in the micro-grid in the grid-connected mode and in the islanding mode, and adjusting the power provided by the energy storage on the basis of variations of the frequency, and performing load shedding on the basis of variations of the frequency, wherein the frequency based load shedding is performed with a faster response than the adjustment of the power provided by the energy storage during islanding mode.