18-phase wind generator direct current grid-connected structure and control method thereof

The technology of a wind turbine and a control method is applied to the DC grid-connected structure of an 18-phase wind turbine and its control field, and can solve the problems of low speed of high-power direct-drive permanent magnet wind turbine, difficult to increase terminal voltage, and different output voltages, etc. , to achieve the effect of reducing wire diameter, reducing insulation level and voltage stability

CN108092257AActive Publication Date: 2018-05-29HUNAN UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2018-05-29

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Abstract

The invention discloses an 18-phase wind generator direct current grid-connected structure and a control method thereof. The structure comprises a 18-phase direct drive permanent magnet wind power generator, six three-phase uncontrollable rectifying bridges, 6m parallel isolation type full bridge DC-DC converters and 6m half bridge sub modules; each set of three-phase alternating current windingsof the 18-phase generator passes through one corresponding three-phase uncontrollable rectifying bridge to be subjected to current conversion and then to be connected to m parallel isolation type fullbridge DC-DC converters; each DC-DC converter is connected with one half-bridge sub module; the positive electrodes and negative electrodes at the output ends of the 6m half bridge sub modules are connected in sequence, and finally are connected with an electric reactor in series to form a series circuit to be connected to a direct current power transmission network; the parallel isolation type full bridge DC-DC converters adopt the maximum power tracking control, and the half bridge sub modules are controlled through direct current transmission current. By virtue of the structure, the voltage level of the generator stator winding is lowered, system stability is improved, and the construction cost of a power plant is lowered.
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Description

technical field

[0001] The invention belongs to the technical field of wind power generation, and in particular relates to a DC grid-connected structure of an 18-phase wind power generator and a control method thereof. Background technique

[0002] With the development of society, energy issues have become increasingly prominent. Seeking various new energy sources to replace the increasingly depleted traditional fossil energy sources has become a research hotspot in various countries.

[0003] As a clean energy, wind energy has great development potential. There are huge wind energy resources in the sea, so the relevant issues of offshore wind farms have attracted a large number of scholars at home and abroad to study. The main challenge of offshore wind farms is how to transmit the generated electricity to land in an efficient and economical way.

[0004] Traditional high-voltage AC transmission requires parallel connection of additional reactive power compensators to ab...

Examples

Embodiment Construction

[0053] The present invention will be further described below in conjunction with the accompanying drawings.

[0054] Figure 4 It is a DC grid-connected structure diagram of 18-phase wind turbines, which includes 18-phase direct-drive permanent magnet wind turbines, 6 three-phase uncontrolled rectifier bridges, 6m parallel isolated full-bridge DC-DC converters and 6m half-bridges submodule. The rotor of the 18-phase generator is coaxially connected with the wind turbine installed in the wind farm. The stator of the 18-phase generator has 18 windings, and every 3 windings form a set of three-phase AC windings, and a total of 6 sets of three-phase AC windings are formed. Each set of windings is commutated by a three-phase uncontrolled rectifier bridge, and then connected to m parallel isolated full-bridge DC-DC converters. Each parallel isolated full-bridge DC-DC converter is connected to a half-bridge sub-module. The positive and negative poles of the output terminals of th...