Grid-connected topology structure without transformer based on H-bridge used for wind power generation

Abstract

The present invention relates to a grid-connected topology structure based on H-bridge used for wind power generation without the transformer, which comprises wind generation set, rectification module and inversion module. The wind generating set generates low-voltage alternating current; obtaining the direct voltage through three-phase full-bridge rectification, wherein, said direct-current side voltage is used as direct voltage power supply of each unit in the inversion module; after converting the direct voltage to alternating voltage by the inversion module, directly connected in series with multiple power units and output through alternating current high voltage, then integrated to the power grid through buffer inductance. The grid-connected technology of aerogenerator is used to perform wind power generation grid based on the H-bridge without the transformer. The present invention contributes to the dispensing of the step-up transformer required during the general wind power generation grid, and the great saving of costs. Moreover, as outputting the high voltage through the connection in series with multiple power units, it is possible to output multi-level voltage waveform through modulation algorithm so as to reduce the content of output harmonic wave and the pollution to the power grid produced by wind power generation.

Description

technical field [0001] The invention relates to a grid-connection technology of a wind power generator, in particular to an H-bridge-based wind power grid-connection without a transformer. Background technique [0002] As an energy-saving and environmentally-friendly new energy source, the wind power industry has won historic opportunities for development. Against the backdrop of the financial crisis, the wind power industry has risen against the market and developed rapidly. By the end of 2009, the cumulative installed capacity of wind power in the country had reached 25,800 MW. [0003] However, in my country's wind farms, wind generators basically use general-purpose frequency converters to make their phases the same as those of the grid. Finally, the step-up transformer is used to connect to the grid. This not only leads to the need for a step-up transformer for each wind generator, which is costly, but also makes each wind generator only have 3 levels, the harmonic con...

AI Technical Summary

Problems solved by technology

This not only leads to the need for a step-up transformer for each wind turbine, the cost is huge, but also makes each wind turbine only have 3 levels, the harmonic content is very large, and the multi-grid pollution is serious

[0004] In large-scale wind farms, there are many motors, and each wind generator needs to be controlled individually, which is difficult and cumbersome to control, and it is not easy to form centralized wind power generation control

[0005] The output of wind power generation is two-level or three-level, and the harmonic content is large. After boosting, it cannot be directly connected to the power grid, and an output filter device is required.

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