Direct-current micro-grid system and control method thereof

Abstract

The invention relates to a direct-current micro-grid system and a control method thereof. The direct-current micro-grid system comprises a direct-current power distribution circuit, a bi-directional AC/DC (alternating current/direct current) rectifying/inverting device, a distributed energy generating device, an energy storing device, direct-current loads, alternating-current loads, a urban microclimate interactive system, a clock interactive system, a micro-grid control system and micro-grid protecting devices, an upper scheduling management system is arranged in the micro-grid control system so as to form layered management for micro-grid energy. The direct-current micro-grid control method includes: entering a grid connection mode or an island model according to working state of a large power grid, and determining the working states of the energy storing device and the distributed energy generating device according to information of the urban microclimate interactive system and the clock interactive system. The direct-current micro-grid system can independently supply power to the alternating-current and the direct-current loads and can be connected with a power grid to generate power according to processed result of urban microclimate interactive information, so that requirements on power supply for users are met, cost is reduced, designing, controlling, operation and maintenance of a micro-grid are benefited, and reliability, economy and efficiency of the micro-grid are effectively improved.

Description

technical field [0001] The invention relates to a DC micro-grid system and a control method thereof, and is mainly applicable to a DC micro-grid system connected to distributed power sources, wind and solar storage, and mains power multi-energy complementary. Background technique [0002] In recent years, with the increasing pressure on global resources and environment, smart grid has become a hot topic in the power industry, and is considered to be a grid development model that will change the future power system. [0003] The microgrid system is a highly independent decentralized power network, which is the basis of the smart grid. The system is composed of any combination of solar photovoltaic power generation, wind power generation, biomass power generation, gas power generation or diesel power generation, fuel cells, battery packs, etc., and then adds metering and control devices to form a self-contained system, independent of large power grids or intermittent and large...

AI Technical Summary

Problems solved by technology

Since the electric energy cannot be stored in the gas turbine system, peak shaving and valley filling as one of the control functions of the microgrid cannot be realized

Secondly, due to the large inertia of the gas turbine, it is impossible to achieve the second-level smooth control target of tie-line power

[0010] 2. When the micro-grid distributed power supply is an energy storage system, due to the limited power of the energy storage system, it is impossible to achieve long-term (such as tens of hours) island operation after a failure of the large power grid

[0011] 3. Existing technologies cannot simultaneously realize the rational configuration and application of megawatt-scale wind turbines and solar photovoltaic power generation devices within the microgrid

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