Off-grid control method of micro-grid energy storage device based on power prediction

Abstract

The invention relates to an off-grid control method of a micro-grid energy storage device based on power prediction and adopts a double-loop control strategy. The control of the storage battery adopts voltage to control an external loop and adopts current to control the internal loop; the control of a super capacitor adopts power to control the external loop and adopts the current to control the internal loop. Photovoltaic output power PV and load power PL of different times in a day are determined according to a power prediction curve; a difference value signal P delta of the output power PV and the load power PL is calculated; a DB9 wavelet packet decomposition method is adopted to perform decomposition on the difference value signal P delta to obtain a high frequency part signals Phigh and low frequency part signals Plow; the low frequency part signals Plow is complimented by the output power of the storage battery; and the high frequency part signals Phigh is complimented by the super capacitor output power.

Description

Technical field [0001] The invention belongs to the technical field of microgrid and new energy power generation, and relates to an off-grid control method of a microgrid energy storage device based on power prediction. Background technique [0002] Since the development and application of microgrid control strategies are in their infancy and not yet mature, the safety, reliability and stability of microgrid operation cannot be guaranteed, which greatly hinders the development and large-scale application of microgrids and new energy sources. Further improvements and explorations are needed. At this stage, making full use of the microgrid energy storage equipment-batteries and supercapacitors to control the operation of the microgrid has become a direction of microgrid research. Supercapacitors have the characteristics of high power density, long cycle life, short charging time, high reliability, and low energy density. The storage battery has high energy density and can store ene...

AI Technical Summary

Problems solved by technology

[0002] Since the development and application of microgrid control strategies are in their infancy and immature, the safety, reliability and stability of microgrid operation cannot be guaranteed, which greatly hinders the development and large-scale application of microgrid and new energy. Further improvement and exploration are needed. At this stage, making full use of microgrid energy storage devices—battery and supercapacitor to control the operation of microgrid has become a direction of microgrid research

Supercapacitors have the characteristics of high power density, long cycle life, short charging time, high reliability, and low energy density, while batteries have high energy density and can store energy in large capacities, but they are not suitable for frequent charging and discharging.

The method of combining these two energy storage devices in microgrid control to make their advantages complementary has not yet been combined due to technical reasons.

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