Alternating current and direct current mixed micro power grid system and control method thereof

Abstract

The invention discloses an alternating current and direct current mixed micro power grid system and a control method thereof. The system comprises a photovoltaic module, an inverter, a direct-current converter, a storage battery, a super capacitor, an alternating current load, a direct current load, a direct current bus, an alternating current bus, an SVG (scalable vector graphics) and an APF (active power filter) and the like. The control method comprises the following steps: firstly detecting the voltage and frequency of a main network, if the voltage and the frequency are normal, grid-connected operation is adopted in the system, otherwise, isolated island operation is adopted; if the grid-connected operation is adopted in the system, PQ (performance qualification) control is adopted in the inverter, and constant voltage control is adopted in the direct current converter; if the isolated island operation is adopted in the system, V / F control is adopted in the storage inverter with maximum capacity and a super capacitor, the PQ control is adopted in other inverters, and the constant voltage control is adopted in the direct current converter; and finally, the energy storage capacity is enabled to be within an optimum range under the condition that the system is in normal operation. With the adoption of the alternating current and direct current mixed micro power grid system and the control method thereof, the problem of operation control of the alternating current and direct current mixed micro power grid system is solved, the reliability, safety and economy of the system are improved, and the utilization efficiency of renewable energy sources is improved.

Description

technical field [0001] The invention belongs to the technical fields of renewable energy power generation, AC-DC hybrid micro-grid control and micro-grid application, and relates to a micro-grid control method, in particular to an AC-DC hybrid micro-grid system and a control method thereof. Background technique [0002] With the promotion and utilization of renewable energy, the microgrid has developed rapidly due to its advantages of flexible dispatchability, reliability of power supply efficiency, and independence of local electricity demand. The DC microgrid has also attracted widespread attention due to its significant advantages such as high utilization rate of renewable energy and low investment cost. However, since most of the current domestic loads are AC loads, there is less demand for a separate DC microgrid, so it has both The advantages of the AC-DC hybrid microgrid will be born because of this. Due to the complex structure and numerous components of the AC-DC h...

AI Technical Summary

Problems solved by technology

Due to the complex structure and numerous components of the AC-DC hybrid microgrid system, its control is difficult, which limits its development to a certain extent.

[0003] At present, the existing microgrid control methods are mainly aimed at the control of traditional AC microgrids, and these methods cannot complete the control of DC microgrids.

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