Double-fed wind generation set converter topological structure for flexible direct-current electricity transmission system

Abstract

The invention relates to a double-fed wind generation set converter topological structure for a flexible direct-current electricity transmission system and belongs to the technical field of wind power generation. The topological structure comprises a stator side converter, a machine side converter and a net side DC-DC converter. One end of the stator side converter is connected with a stator of a wind generator, and the other end of the stator side converter is connected with the machine side converter and the net side DC-DC converter respectively. The other end of the machine side converter is connected with a rotor of the wind generator. The other end of the net side DC-DC converter is connected with a high-voltage direct-current bus through a high-voltage direct-current cable, and double-fed wind generation set flexible direct-current electricity transmission grid connection generating is achieved. Machine side converter control is easy and flexible, the rated power is small, an extra storage battery does not need to be used as an inversion power supply, meanwhile, a boosting electricity transformer and a box-type substation are of no need, occupied space is small, cost is low, consumption is small, and the double-fed wind generation set converter topological structure is especially suitable for offshore wind power.

Description

technical field [0001] The invention relates to a converter, in particular to a converter used in a doubly-fed wind power generating set of a flexible direct current transmission system, and belongs to the technical field of wind power generation. Background technique [0002] At present, megawatt-level wind turbines generally output 690V50Hz AC power through AC-DC-AC converters, and after being boosted by a step-up transformer, they are connected to the AC busbar and connected to the grid. Its disadvantages are: step-up transformers and box-type substations are required, which require a large area, high costs, and high losses, which especially restrict the development of offshore wind power. [0003] In order to solve the above problems, the applicant of this patent filed a Chinese patent application with the patent number ZL 201320114072.X, disclosing a topological structure of a high-voltage DC converter for double-fed wind turbines. A converter and a grid-side DC-DC...

AI Technical Summary

Problems solved by technology

Its disadvantages are: step-up transformers and box-type substations are required, which require a large area, high cost, and high loss, which especially restricts the development of offshore wind power.

Although this structure can fundamentally solve the problem of doubly-fed wind turbines connected to the grid with high-voltage DC, an additional battery is required to provide inverter power for the machine-side converter when the doubly-fed wind turbines start, and the control is not flexible enough , high cost, not conducive to popularization and application

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