Power electronic transformer applied to distribution network

Abstract

The invention relates to an electric power electronic transformer applied to a distribution network, which is divided into an input level, an isolation level and an output level. The isolation level uses a power converter with a bridge topology structure to adapt to the requirement of different voltage levels of input; the isolation level uses a form that a plurality of high-frequency transformers respectively carry out isolation, transformation and energy transmission; and the output level has two topology structures, wherein the first structure is formed by parallel connection of the power converter with the bridge topology structure, and the second structure is formed by cascade connection of the power converter with the bridge topology structure, and simultaneously an LC wave filter is connected to improve the voltage-current waveform quality. The complete appliance totally uses mature power devices, is formed by combining basic power units and can be flexibly applied to distribution network lines with different voltage levels. The transformer can automatically regulate line output voltage to stably output voltage, thereby inhibiting voltage quality problems of voltage falling, rising as well as flickering, overvoltage, undervoltage and the like.

Description

technical field [0001] The invention relates to a power electronic transformer used in a power distribution network, and belongs to the technical field of application of power electronics in power systems. Background technique [0002] Since the power transformer was invented in the 19th century, it has become the basic component equipment of the power transmission and distribution system, and the quantity is huge. At present, the traditional power transformer usually adopts iron core oil-immersed type, which has the advantages of simple manufacturing process and high reliability, but the disadvantages are also very obvious, including: large volume and weight, high no-load loss, and the threat of transformer oil to the environment. Its main function is voltage transformation and isolation, and its function is relatively single. When the iron core is saturated, harmonics will be generated, and it will also cause a large excitation inrush current when it is put into the power ...

AI Technical Summary

Problems solved by technology

At present, the traditional power transformer usually adopts iron core oil-immersed type, which has the advantages of simple manufacturing process and high reliability, but the disadvantages are also very obvious, including: large volume and weight, high no-load loss, and the threat of transformer oil to the environment. Its main function is voltage transformation and isolation, and its function is relatively single. When the iron core is saturated, harmonics will be generated, and when it is put into the power grid, it will also cause a large excitation inrush current

The shortcomings and single function of traditional power transformers are difficult to meet the needs and goals of future power grid construction

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