Grid-connection type photovoltaic direct current microgrid system and operational control method therefor

Abstract

The invention discloses a grid-connection type photovoltaic direct current microgrid system and an operational control method therefor. The microgrid system comprises a direct current busbar, a photovoltaic generation unit, an energy storage unit, a capacitor, a mains supply grid side, an energy management unit and a load; the photovoltaic generation unit is connected with the direct current busbar through a first one-way DC / DC converter; the energy storage unit and the capacitor are connected with the direct current busbar through a first bidirectional DC / DC converter and a second bidirectional DC / DC converter separately; the main supply grid side is connected with the direct current busbar through a bidirectional AC / DC converter; and the load is connected with the direct current busbar. According to the operational control method, the power supplies for the mains supply grid side, the photovoltaic generation unit, the energy storage unit and the capacitor are fully coordinated in terms of the power supply sequences and logics, so as to ensure the reliability of power supply and higher economic benefits.

Description

technical field [0001] The invention relates to the field of power grids, in particular to a grid-connected photovoltaic DC microgrid system and an operation control method thereof. Background technique [0002] With the rapid growth of the national economy, the demand for electricity has grown rapidly. For a long time, the power production sector has mainly used the construction of large-scale power plants and ultra-high voltage long-distance transmission lines as solutions, but the investment is large, the construction period is long, and the environment Disadvantages such as pollution have also become increasingly prominent. On the other hand, several large-scale power outages at home and abroad in recent years have also made people aware of the vulnerability of centralized power supply systems. Distributed generation technology (distributed generation, DG) came into being under such circumstances. [0003] Distributed generation technology (DG) has the characteristics ...

AI Technical Summary

Problems solved by technology

The power supply method of hybrid energy storage of batteries and supercapacitors is still seldom used in DC microgrids, and there are various problems in the existing hybrid energy storage solutions, such as many times of charging and discharging of batteries, which is easy to affect the service life, and the configuration of supercapacitors High cost, etc., it is necessary to propose a new hybrid energy storage solution, and at present, there is no complete household grid-connected DC microgrid system solution based on hybrid energy storage

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