An energy control method for a multi-port AC-DC hybrid microgrid system

Abstract

The invention discloses an energy control method for a multi-port AC-DC hybrid micro-grid system, comprising: controlling a modular multilevel converter and a dual-active full bridge through total energy control and AC output current control according to the AC loop in the model The converter, the capacitor voltage in the sub-module, and the output current of the AC side are controlled; according to the DC circuit in the model, the sum of the capacitor voltages of the upper and lower bridge arms of each phase is controlled through phase-to-phase energy control, and the circulating current is obtained The DC component of the reference; through the inter-arm energy control, the difference between the sub-module capacitor voltages between the upper and lower bridge arms in the same phase is balanced, and the fundamental frequency AC component of the circulating current reference is obtained; the modular multi-level is controlled by the circulating current controller The DC and fundamental frequency AC components in the converter are tracked, the inherent double frequency current is suppressed, and the capacitance energy in the bridge arm is adjusted; the modulation signal of the sub-module is adjusted through phase-shifted carrier modulation to realize the capacitance of the sub-module voltage balance.

Description

technical field [0001] The invention relates to the technical field of a multi-level converter applied to a micro-grid system, in particular to an energy control method for a multi-port AC-DC hybrid micro-grid system. Background technique [0002] In recent years, with the rapid development of the global economy, the consumption of coal, oil and other energy is also increasing. The extensive use of traditional energy makes it face the problem of supply shortage, and also brings a series of negative impacts on the environment. Renewable energy has the characteristics of clean, efficient and renewable, which has attracted great attention worldwide. With the support of the governments of various countries, distributed power generation technology has developed rapidly. At present, relatively mature technologies include: photovoltaic power generation, fuel cell power generation, micro gas turbine power generation, wind power generation, etc. [1] . In the past decade, academic ...

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Problems solved by technology

However, with the development of industries such as ships and mines, traditional low-voltage power cannot meet their power supply needs, and the demand for various medium-voltage DC power is further increasing. Medium-voltage DC microgrids have gradually become the main source of power supply for the above occasions [9][10]

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