A hierarchical coordinated control method for independent microgrids based on different time scales

Abstract

The invention discloses a hierarchical coordination control method for an independent micro-grid based on different time scales, which includes the following steps: (1) According to the dynamic characteristics of the voltage and frequency of the independent micro-grid system, the fluctuation ranges of the voltage and frequency are divided into A , B and C three types of areas, A area indicates that the voltage and frequency deviation is within the normal fluctuation range, B area indicates that the voltage and frequency deviation slightly exceeds the normal fluctuation range, and C area indicates that the voltage and frequency deviation seriously exceeds the normal fluctuation range; (2) real-time Monitor and collect the voltage value U, frequency value f and power P on the independent microgrid bus, and judge the area where U and f are located; (3) if U and f are in area A, the battery energy storage system and diesel generator set will not Participate in regulation; if U and f are in area B, the battery energy storage system in charge of primary control participates in regulation to achieve system power balance; if U and f are in area C, diesel generators in secondary control participate in regulation to achieve system power Balance; (4) Repeat the collection of U, f and P until it is judged that U and f are in the A area.

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 by using P-f and Q-V droop control methods to improve the accuracy of load power distribution, but the independent micro-grid system Power quality is still affected by factors such as different power levels of each microsource in the system, line impedance and inverter design parameters

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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