Hybrid energy storage-containing photovoltaic DC micro-grid coordinated control method

Abstract

A hybrid energy storage-containing photovoltaic DC micro-grid coordinated control method comprises the following steps of: establishing a control strategy of a photovoltaic power generation system, and enabling the photovoltaic power generation system to operate in an MPPT mode and a CVC mode; dividing the operation mode of a DC micro-grid into a plurality of working modes; establishing a low-pass filter model to distribute power borne by a hybrid energy storage system; calculating the working currents of a super-capacitor and a storage battery according to the power and terminal voltage borne by the super-capacitor and the storage battery respectively; designing the control mode of a bidirectional DC / DC converter by comparing the charging and discharging current reference value of an energy storage device with the actual working current; and when the photovoltaic power generation system and the energy storage device in the DC micro-grid are not enough to stabilize power fluctuation in the system, or the energy storage device fails and cannot participate in adjustment, integrating the DC micro-grid into a large power grid through the bidirectional DC / DC converter. According to the method, complex parameter setting and mass calculation can be avoided, the service life of the energy storage device is considered while control is flexible, and the operation economical efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of micro-grid control, in particular to a coordinated control method for a photovoltaic DC micro-grid with hybrid energy storage. Background technique [0002] In recent years, the penetration rate of distributed new energy generation represented by wind energy and solar energy has been increasing, and countries all over the world have paid more attention to the development of new energy. However, wind energy and solar energy have intermittent and random characteristics, resulting in The output power has the defects of discontinuity and instability. If it is directly connected to the power grid without adopting an appropriate control strategy, it will have a great impact on the safe and reliable operation of the power grid. [0003] The urgent need for low-carbon energy has promoted the development of micro-grids. Micro-grids are a new type of power grid that combines distributed power sources, energy storag...

AI Technical Summary

Problems solved by technology

[0005] However, it is difficult for a single energy storage device to meet the characteristics of high energy density, high power density and long service life, which requires combining two or more different energy storage elements into a hybrid energy storage system. Under the strategy, the advantages of each energy storage device are brought into play, and the advantages are complementary, which can restrain the power fluctuation of the microgrid.

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