A rotor double-winding structure of a megawatt doubly-fed wind turbine

Abstract

A rotor double-winding structure of a megawatt doubly-fed wind power generator, the rotor slot adopts a semi-closed slot, the rotor winding adopts a stacked loose embedded winding, and the winding has two sets of three-phase symmetrical windings. The number of parallel branches of the first set of windings is 1. The number of parallel branches of the second set of windings is 2, and the corresponding phases of the two sets of windings are connected in series to form a star connection. The structure of the first set of windings is a double-layer stacked winding with unequal turns and unequal spacing, which is used to improve the non-sinusoidal magnetic potential formed by the hard coil of the wave winding; the second set of windings is a short-pitch stacked winding, three-phase symmetrical, mutually The electrical angle difference is 120°, the pitch of this set of windings is small, the wire is saved, and it is used to resist the distortion of the sinusoidal current supplied by the frequency converter. The invention improves the disadvantages of poor power generation quality, many headgears and poor reliability of the conventional wave winding hard winding, greatly reduces the magnetic potential harmonic, and the rotor magnetic potential waveform is highly sinusoidal to reduce harmonic loss and heat generation. Reduce temperature rise, improve power generation quality, efficiency, reliability and economy.

Description

technical field [0001] The invention relates to a motor winding, in particular to a double-winding structure of a rotor of a megawatt double-fed wind power generator. Background technique [0002] In megawatt-class doubly-fed wind turbines, the conventional rotor winding adopts wave winding hard winding form, which has the following disadvantages: [0003] 1. The rotor core must adopt semi-open slots, the slots are large, and the tooth harmonics are large; [0004] 2. The hard winding of the 2-wave winding has poor processability, and there are many headgears, so there are many quality risks; [0005] The leakage reactance of the 3-wave winding is small, and the harmonic suppression of the inverter current supply is poor; [0006] The sinusoidality of the magnetic potential waveform of the 4-wave winding is poor, and the rotor magnetic potential waveform contains rich harmonics, which leads to large loss, severe heat generation, high temperature, and poor quality of the ge...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a double-winding structure of the rotor of a megawatt doubly-fed wind power generator to improve the defects of poor power generation quality, many headgears and poor reliability in the hard winding of the conventional wave winding, which makes the magnetic potential harmonic Greatly reduced, the rotor magnetic potential waveform is highly sinusoidal to reduce harmonic losses, reduce heat generation, reduce temperature rise, improve power generation quality and efficiency, and improve reliability and economy

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