Hybrid cascading multi-level static synchronous compensation device and wind turbine generator set power supply system

Abstract

The invention provides a hybrid cascading multi-level static synchronous compensation device and a wind turbine generator set power supply system. The synchronous compensation device comprises a first H-bridge power unit and a second H-bridge power unit. The first H-bridge power unit comprises two parallel-connection bridge arms, wherein each bridge arm comprises two series-connection gate pole turn-off thyristors. The second H-bridge power unit comprises two parallel-connection bridge arms, wherein each bridge arm comprises two series-connection insulated gate bipolar transistors. The characteristics of power devices in the first H-bridge power unit in the synchronous compensation device and the characteristics of power devices in the second H-bridge power unit in the synchronous compensation device are complementary to form a hybrid cascading circuit structure, the aims that the switching frequency of the power devices is reduced and the capacity of the synchronous compensation device is improved can be well achieved, and the synchronous compensation device can be applied in power supply systems of various types, and particularly suitable for the power supply system of a wind turbine generator set with the high megawatt power so as to meet the application requirements of the high-power wind turbine generator set.

Description

technical field [0001] The invention relates to electrical control technology, in particular to a hybrid cascaded multi-level static synchronous compensation device and a wind turbine power supply system. Background technique [0002] Wind power generation is an energy utilization technology that converts wind energy into electrical energy through wind turbines. It is currently the fastest-growing and most potential "green energy" in the field of new energy development. [0003] As wind energy is an intermittent energy source, it has great randomness and uncontrollability. Therefore, during the grid connection process of wind turbines outputting electric energy to the grid, the output voltage of wind turbines fluctuates greatly, and the power factor is low. A large number of harmonics are generated, thus resulting in poor quality of the output power. [0004] In order to improve the quality of the output power of the wind turbine, a Static Var Generator (SVG for short) can ...

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Problems solved by technology

[0005] Wind turbines of different power levels require SVGs with different capacities. By increasing the turn-on or turn-off frequency (also called switching frequency) of power devices in SVG, the capacity of SVG can be increased. However, the switching frequency of power devices is limited by its own Due to the restriction of the nature of the power device, it cannot be increased without limit, and increasing the switching frequency of the power device also increases the loss of the power device. Therefore, the existing SVG has the contradiction between reducing the switching frequency of the power device and increasing the capacity of the device, which cannot meet the requirements of megawatts. Application requirements for high-power wind turbines

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