Independent micro-grid layered coordinated control method based on different time scales

Abstract

The invention discloses an independent micro-grid layered coordinated control method based on different time scales. The method comprises the following steps of (1), according to the dynamic characteristics of voltage and frequency of an independent micro-grid system, dividing the fluctuation range of the voltage and frequency into three areas of A, B and C, wherein the area A represents that the deviation of the voltage and frequency is in a normal fluctuation range, the area B represents that the deviation of the voltage and frequency slightly exceeds the normal fluctuation range, and the area C represents that the deviation of the voltage and frequency seriously exceeds the normal fluctuation range; (2) monitoring and collecting the voltage U, the frequency f and the power P of the bus of the independent micro-grid, and determining the areas where the U and the f are located; (3) if the U and the f are located in the area A, keeping a storage battery energy storage system and a diesel generating set away from an adjustment process, if the U and the f are located in the area B, enabling the storage battery energy storage system in charge of primary control to participate in the adjustment process to achieve system power balance, and if the U and the f are located in the area C, enabling a secondary control diesel generator to participate in the adjustment process to achieve system power balance; (4) repeatedly collecting the U, the f and the P until the U and the f are determined to be located in the area A.

Description

technical field [0001] The present invention relates to micro-grid operation control technology, more specifically, relates to a layered coordination control method for independent micro-grids based on different time scales. Background technique [0002] An independent microgrid refers to a small power system that is isolated from the external large power grid and operates independently. Microgrid transferred to stand-alone operation mode. Existing research and practice have shown that an independent microgrid that integrates intermittent renewable energy sources such as wind and light and multiple mixed energy sources such as battery energy storage systems can effectively reduce the randomness and intermittent nature of high-permeability intermittent power sources such as wind and light. It can also be used as an effective way to solve the power demand in remote areas such as islands. [0003] Coordinated control among different types of distributed power sources in an in...

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Problems solved by technology

"Control of parallel inverters in distributed AC power systems with consideration of line impedance effect" (Tuladhar A, Jin H., Unger T., et. a1. Control of parallel inverters in distributed AC power systems with consideration of line impedance effect [J ].IEEE Transactions on Industry Applications,2000,36(1):131-138.) This article proposes to improve the accuracy of load power distribution based on the parallel control of multi-micro power inverters based on P-f and Q-V droop control methods, but The power quality of an independent microgrid system is still affected by factors such as different power levels, line impedance, and inverter design parameters of each micropower source in the system

The Chinese invention patent application with the application number 201310625717.0 proposes an independent micro-grid coordinated control method based on curve control, which ensures that the battery can work normally for a long time and prolongs the service life of the generator, but does not improve the power quality of the micro-grid system

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