Method for controlling energy storage converters in large-scale off-grid micro-grid

Abstract

The invention relates to a method for controlling energy storage converters in a large-scale off-grid micro-grid. The method includes the steps of firstly, setting up the large-scale off-grid micro-grid; secondly, conducting primary frequency modulation on the off-grid micro-grid by means of an energy storage power station through a Droop work mode; thirdly, conducting secondary frequency modulation on the off-grid micro-grid; fourthly, conducting thrice frequency modulation on the off-grid micro-grid through a micro-grid energy management module; fifthly, conducting master and slave control on the multiple energy storage converters in the energy storage power station. According to the method, by means of flexible control over the energy storage converters, the problem of reliable power supply for independent power supply systems in remote electricity-free areas or island grids or other areas can be effectively solved, and the power supply systems can independently run in a safe, stable and economical mode. The method is applied to the multi-energy complementation alternating current bus shared type off-grid micro-grid, the multi-machine parallel operation of the energy storage power station is achieved through high-speed master and slave communication in the energy storage power station, and safe, stable and economical running of the micro-grid is achieved through interstation peer-to-peer control of the energy storage power station.

Description

technical field [0001] The invention belongs to the operation and control technology of a microgrid, and specifically relates to a control method for an energy storage converter in a large-scale off-grid microgrid Background technique [0002] A microgrid is a collection of distributed power sources, energy storage units, loads, and control and protection devices. It is an autonomous system capable of self-control, protection, and management. According to the connection relationship between the micro-grid and the large power grid, the micro-grid is divided into a networked micro-grid and an off-grid micro-grid. For the networked micro-grid, the energy storage system in the system operates in the P-Q mode and directly performs charging and discharging according to the dispatching instructions. Control; for off-grid microgrids, the energy storage system in the system may be a single-point large-capacity access, may be multi-point decentralized access, may need to be coordinate...

AI Technical Summary

Problems solved by technology

In some large-scale off-grid micro-grid applications, the energy storage system is optimized according to the decentralized access of new energy and system loads. Each energy storage station coordinates with the energy management module of the micro-grid through the monitoring system. For this type of microgrid, during the process of new energy output fluctuations and system load fluctuations in the system, the energy management module of the system needs to take into account multiple constraints at the same time to issue scheduling instructions to each energy storage station, and the operation instructions of the energy storage system are completely dependent on energy management. Modules, on the one hand, rely heavily on the communication network, and the short-term paralysis of the communication network can directly affect the stable operation of the system. On the other hand, the control strategy of the energy management module is too complicated, and at the same time, the construction cost of the system is greatly increased, which restricts distributed new energy and microgrid. healthy and orderly development of

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