Microgrid Power Balance Control Method

Abstract

The invention relates to a microgrid power balance control method. An energy storage device is connected to the microgrid through a bi-directional inverter. When the microgrid is operated in the isolated grid state, the V-f control mode is adopted, the energy storage device is used to provide voltage source support for a micro source in the microgrid, and provide power support according to the output of the micro source and the load change. The specific working mode comprises the following steps: (1) when the micro source output power is equal to the power required by a load, the output of the energy storage device is approximate to zero, and the power required by the loaded is completely supplied by the micro source; (2) when the micro source output power is greater than the power required by the loaded, the energy storage device is controlled so as to be charged to absorb the surplus power of the micro source after the load is satisfied; (3) and when the micro source output power is less than the power required by the loaded, the energy storage device is controlled so as to be discharged to supplement the insufficient portion of the micro source output power. According to the invention, the isolated grid and connected grid smooth switching can be realized, and the power supply interruption problem when the connected grid state is changed into the isolated grid state can be solved, so that a guarantee is provided for the operation of the microgrid in various steady states and transient states.

Description

technical field [0001] The invention belongs to the technical field of micro-grid stability control, and in particular relates to a power balance control method in a micro-grid centered on adjusting energy storage equipment. Background technique [0002] The stable operation of the microgrid is the prerequisite for the safe, reliable operation and benefit of the microgrid. The microgrid must be grid-connected and connected, the isolated grid is stable, the isolation is fast enough, seamless switching, and the plug-and-play of the microgrid can be truly realized in order to give full play to its benefits. Due to the common characteristics of low overload capacity, small inertia or no inertia in micro-grid distributed power generation, and the sudden change of load in micro-grid, it is easy to cause micro-grid system oscillation or even collapse, which seriously restricts the development and application of micro-grid. In order to improve this situation, energy storage devices...

AI Technical Summary

Problems solved by technology

Due to the common characteristics of low overload capacity, small inertia or no inertia of micro-grid distributed power generation, and the sudden change of load in micro-grid, it is easy to cause micro-grid system oscillation or even collapse, which seriously restricts the development and application of micro-grid.

In order to improve this situation, energy storage devices are usually used in the current microgrid structure to maintain the transient stability of the system and provide voltage and frequency support for the microgrid when necessary. , A mature control method that can meet the stable operation requirements of the microgrid in various operating modes

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