A kind of AC and DC hybrid power supply system and method

Abstract

The invention relates to an alternating current and direct current hybrid power supply system and method. The system comprises current transformers C1, C2, C3, C4 and C5, diodes D1, D2 and D3, intelligent control switches S1, S2 and S3 and a direct current bus. A principle of prioritizing usage of a local DG is adopted, and a self-adaptive power control strategy based on direct current bus voltage signals is employed; the intelligent control switches S1, S2 and S3 for a three-phase alternating current power grid, the local DG and a local energy storage component are automatically controlled according to a state of the direct current bus voltage signals; supply and demand power balance between the three-phase alternating current power grid, the local DG as well as the local energy storage component and electricity consumption of loads can be effectively regulated and controlled. The method is well compatible with traditional alternating current systems; problems of alternating current stability, voltage and frequency synchronization, reactive power and the like caused by the local DG being connected to a power grid in an alternating current form can be prevented; continuous and high-reliability power supply for local loads can be realized; influence exerted on user side electric energy quality can be reduced, local DG energy utilization efficiency can be improved, and an environment friendliness property is fulfilled.

Description

technical field [0001] The invention relates to the field of power system operation and control, in particular to an AC / DC hybrid power supply method suitable for a distributed power generation system. Background technique [0002] The application of power electronics technology, information technology and frequency conversion technology has made the DC loads such as electric vehicles, information equipment, semiconductor lighting systems, etc. in the urban distribution network increase day by day. Many existing electrical equipment such as computers, televisions, and electronic communication equipment are DC loads in nature, and need to be powered by AC power adapters, which not only causes energy loss, but also increases equipment manufacturing costs. In addition, the power output form of diesel generators, wind power generators, etc. is AC, while the power output form of distributed power sources such as photovoltaics and fuel power generation is DC. In the traditional A...

AI Technical Summary

Problems solved by technology

In the currently proposed AC-DC hybrid power supply system, the AC and DC buses coexist, the AC and DC distributed power sources and loads are connected to the AC and DC buses respectively, and the system is connected to the grid through the AC bus. The power balance relationship between AC and DC sides needs to be considered, and the system structure and control are complex

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