Mixed micro-grid system based on power electronic transformer and power control method of system

Abstract

The invention provides an AC and DC mixed micro-grid system based on a power electronic transformer and a power control method of the system. The system comprises a main grid, an AC micro grid, a DC micro grid and the power electronic transformer. According to the operation states and power requirements of the AC micro grid and the DC micro grid, the power electronic transformer adjusts the power of the AC micro grid and the DC micro grid in a mixed sagging method. Thus, the power of the main grid, the AC micro grid and the DC micro grid can be rapidly and accurately adjusted, it is ensured that the frequency of the AC micro grid and the bus voltage of the DC micro grid are stable, and stable operation of the AC and DC mixed micro-grid after access of distributed energy is realized.

Description

technical field [0001] The invention relates to the field of power electronics, in particular to an AC-DC hybrid microgrid system and a power control method based on a power electronic transformer. Background technique [0002] The network access requirements of distributed energy resources (DER) promote the continuous development of power systems, and microgrids are an effective solution to realize large-scale intermittent DER access. DER is connected in the form of DC, which can save a lot of commutation links, and does not require phase and frequency tracking, and the controllability and reliability will be greatly improved. DC is an ideal access form for DER. In recent years, DC microgrids have gradually gained people's attention. However, at this stage, the main body of the power grid is still in the form of AC, and AC access is still the main form of DER grid connection. The hybrid microgrid with AC and DC coexistence will be the microgrid structure that will exist fo...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the defects in the prior art, the present invention provides an AC / DC hybrid microgrid system and a power control method based on a power electronic transformer, which realizes the energy coordinated control among the main grid, the AC microgrid, and the DC microgrid, and ensures that the AC The frequency stability of the micro-grid and the bus voltage of the DC micro-grid are stable to solve the problem of stable operation of the AC-DC hybrid micro-grid after distributed energy access

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