DE102011014094A1 - Electric generator for a wind turbine - Google Patents

Abstract

The invention relates to an electric generator for a wind turbine, in particular an internal pole generator for a gearless wind turbine. According to the concept of the invention, at least two sets (7) of pole-forming magnet coils (7.2) and / or permanent magnets (7.1) are arranged on the rotor shaft (5) of the generator to generate at least two separate exciter magnetic fields, with a separate stator () for each exciter magnetic field. 8) can be arranged with associated induction windings. Three or more sets (7) of pole-forming magnet coils (7.2) and / or permanent magnets (7.1) are preferably arranged on the rotor shaft (5) of the generator, so that one, two, three or more separate stators, depending on the electrical power to be installed (8) can be arranged with associated induction windings. The generator according to the invention thus comprises a predetermined constant number of sets (7) of pole-forming magnet coils (7.2) and / or permanent magnets (7.1) and, depending on the power requirement, one, two, three or more stators (8), the number of stators (8 ) is limited to the number of sets (7) of pole-forming magnet coils (7.2) and / or permanent magnets (7.1). The generator according to the invention has a modular structure and can be used for wind power plants of different powers.

Description

The invention relates to an electric generator for a wind turbine, in particular a Innenpolgenerator for a gearless wind turbine.

The effective conversion of wind energy into electrical energy requires wind turbines, which are characterized by high efficiency even in different wind conditions. This problem can best be met with a gearless wind turbine with a synchronous generator. Increasingly, there is a need for wind turbines to have them available for a wide range of power. Often, however, the design of a wind turbine whose performance depends on the performance of the electric generators offered for wind turbines on the market. Especially with small electrical power requirements, the design of a customized wind turbine encounters the problem of a suitable electric generator.

The object of the invention is therefore to provide an electric generator for a wind turbine, which meets a wide power requirement and allows for different wind conditions when used in a gearless wind turbine, a conversion of the offered wind energy into electrical energy with high efficiency.

According to the concept of the invention, the electric generator is designed as Innenpolmaschine, wherein the rotor of the generator directly, d. H. without the interposition of a transmission, is connected to the rotor of the wind turbine and at least two sets of polbildenden magnetic coils and / or permanent magnets for generating at least two separate excitation magnetic fields are arranged on the rotor shaft of the generator and to each field magnetic field, a separate stator with associated induction windings can be arranged.

Preferably, three or more sets of pole-forming magnetic coils and / or permanent magnets are arranged on the rotor shaft of the generator, so that depending on the electrical power to be installed, one, two, three or more separate stators are to be arranged with associated induction windings, wherein a polbildenden Magnetspulen- or Permanent magnet set is assigned to generate a field magnetic field, a stator. A generator according to the invention thus comprises a predetermined constant number of sets of pole forming solenoids and / or permanent magnets for generating a predetermined constant number of exciting magnetic fields and one, two, three or more stators depending on the power requirement, the number of stators being based on the number of sets of pole-forming magnetic coils and / or permanent magnet is limited to the generation of exciting magnetic fields.

Preferably, in each case a set of pole-forming magnetic coils and / or permanent magnets for generating a field magnetic field in a known poling rotationally symmetrical about the rotor shaft, wherein the polbildenden magnetic coils and / or permanent magnets for generating a field magnetic field along a predetermined longitudinal axial portion of the rotor shaft extend. An associated stator with induction windings also surrounds the pole-forming magnet coils and / or permanent magnets in a known manner and also extends in the longitudinal axial direction along a predetermined longitudinal axial section of the rotor shaft.

In each case further sets of pole-forming magnetic coils and / or permanent magnets for generating in each case further excitation magnetic fields are connected in the longitudinal axial direction of the rotor shaft. They may be surrounded by stators with induction windings, depending on the needs of the electrical power to be installed.

A set of pole-forming magnetic coils and / or permanent magnets for generating a field magnetic field and an associated stator with induction coils form a module of a generator according to the invention, which can generate a predetermined electrical power. An electric generator may comprise a plurality of modules, depending on the size of the electrical power to be installed. The maximum possible number of modules that a generator may include depends on the number of sets of pole forming solenoids and / or permanent magnets disposed on the rotor shaft of the generator.

In the formation of the sets of pole-forming magnetic coils and / or permanent magnets for generating the exciting magnetic fields, it is advantageous to form at least one set of permanent magnets, in which case a stator should then be arranged at least around this set. Upon rotation of the rotor shaft, the voltage induced in this stator can then be used to supply the pole-forming magnet coils with the necessary exciting current.

It is understood that the rotor of the wind turbine is to be designed or dimensioned so that the mechanical power generated with the rotor of the installed in the wind turbine electric power of the generator is adjusted.

A power conversion of a wind turbine by adding or removing one or possibly more stators is possible, while of course, the rotor of the wind turbine is to adapt to the new performance parameters.

• • ein elektrischer Generator kann für Windkraftanlagen unterschiedlicher Leistungen eingesetzt werden,
• • eine bestehende Windkraftanlage mit einem erfindungsgemäßen elektrischen Generator kann bei Bedarf im Rahmen des Leistungsbereiches dieses elektrischen Generators auf eine andere Leistung umgestellt werden, wobei lediglich die Statoren des Generators hinzuzufügen oder zu entfernen sind und der Rotor der Windkraftanlage zu verändern ist,
• • die Modulbauweise des elektrischen Generators emöglicht eine effektive und kostengünstige Fertigung von elektrischen Generatoren unterschiedlicher Leistung und
• • der elektrische Generator kann als Synchrongenerator ausgebildet sein, ist für den Einsatz in einer getriebelosen Windkraftanlage geeignet und ermöglicht den Bau von Windkraftanlagen mit einem hohen Wirkungsgrad bei unterschiedlichen Windverhältnissen.

The significant advantages and features of the invention over the prior art are essentially:

• An electric generator can be used for wind turbines of different capacities,
• An existing wind turbine with an electric generator according to the invention can, if required, be converted to another power within the power range of this electric generator, wherein only the stators of the generator are to be added or removed and the rotor of the wind power plant to be changed,
• • The modular design of the electric generator enables an efficient and cost-effective production of electric generators of different power and efficiency
• • The electric generator can be designed as a synchronous generator, is suitable for use in a gearless wind turbine and allows the construction of wind turbines with high efficiency in different wind conditions.

The objectives and advantages of the invention will be further explained in the following embodiments. The accompanying drawings show in:

1 : A schematic representation of a generator for a wind turbine with two stators and in

2 : A schematic representation of a generator for a wind turbine with a stator.

1 illustrates a trained as Innenpolmaschine synchronous generator for a gearless wind turbine. On a base plate 1 are a front and a rear bearing bracket 2 and 3 with plain bearings 4 for supporting a rotor shaft 5 assembled. At the through the front bearing bracket 2 sweeping end of the rotor shaft 5 is directly without the interposition of a gearbox, the rotor head plate 6 to which the wind turbine rotor blades (not shown) are mounted. Between the bearing mounts 2 and 3 are on the rotor shaft 5 three sentences 7 of pole-forming permanent magnets 7.1 rotationally symmetric about the rotor shaft 5 arranged, in 1 only one sentence 7 the pole-forming permanent magnets 7.1 , namely to the rear bearing plate 3 pointing phrase 7 , is visible. To the front bearing plate 2 pointing phrase 7 pole-forming permanent magnets 7.1 as well as the middle sentence 7 pole-forming permanent magnets 7.1 is each a stator 8th arranged with induction coils. The in 1 illustrated electric generator is designed to form a maximum of three generator modules. These are on the rotor shaft 5 three sentences 7 pole-forming permanent magnets 7.1 arranged to produce three independent excitation magnetic spring. At two sentences 7 the pole-forming permanent magnets 7.1 are each a stator 8th arranged with induction coils. Of the three possible modules of the generator so that two modules are formed. A third stator can be retrofitted if necessary, if the generator is to be upgraded to its maximum capacity. Preferably, the individual generator modules have the same performance characteristics in order to enable rational production. However, identical performance characteristics of the individual generator modules are not a necessary condition for forming a solution according to the invention.

2 illustrates a synchronous generator, also designed as Innenpolmaschine for a gearless wind turbine, in which on the rotor shaft 5 as well as in the 1 generator shown three sentences 7 are arranged by pole-forming magnet, wherein, in contrast to the in 1 shown generator just by one sentence 7 Polbildender magnets a stator 8th is arranged and the polbildenden magnets for generating the field magnetic fields on the one hand in an in 2 visible set as permanent magnets 7.1 and the other one in the other 2 visible sentence 7 the pole-forming magnets as magnetic coils 7.2 are formed. The magnetic coils 7.2 are for the electrical power supply of the magnetic coils 7.2 electrically contacted via slip rings and brushes, not shown. The advantage of forming the pole forming magnets as magnetic coils 7.2 is that when not arranging a stator 8th no exciter current is fed to this set of pole-forming magnets, so that no excitation magnetic field is generated around the set of pole-forming magnets not surrounded by a stator.

LIST OF REFERENCE NUMBERS

1

baseplate

2

front bearing bracket

3

rear bearing bracket

4

bearings

5

rotor shaft

6

Rotor head plate

7

Set of pole-forming magnets

7.1

pole-forming permanent magnets

7.2

pole-forming magnetic coils

8th

stator

Claims (5)

Electric generator for a wind turbine, preferably for a gearless wind turbine, in which the rotor ( 6 ) of the wind turbine directly on the rotor shaft ( 5 ) of the generator, characterized in that on the rotor shaft ( 5 ) of the generator rotationally symmetric at least two sets ( 7 ) of pole-forming magnetic coils ( 7.2 ) and / or permanent magnets ( 7.1 ) are arranged for generating at least two separate excitation magnetic fields and for each field magnetic field a separate stature ( 8th ) can be arranged with associated induction windings. Electric generator according to claim 1, characterized in that the pole-forming magnetic coils ( 7.2 ) and / or permanent magnets ( 7.1 ) rotationally symmetrical about the rotor shaft ( 5 ) are arranged such that each set of magnetic coils ( 7.2 ) and / or permanent magnets ( 7.1 ) for generating a field magnetic field along a predetermined longitudinal axial portion of the rotor shaft ( 5 ), so that each excitation magnetic field only over a predetermined longitudinal axial portion of the rotor shaft ( 5 ). Electric generator according to claim 1 or 2, characterized in that one possibly by one sentence ( 7 ) on polbildenden magnet coils ( 7.2 ) and / or permanent magnets ( 7.1 ) arranged stature 8th this sentence ( 7 ) in the longitudinal axial direction of the rotor shaft ( 5 completely covered. Electric generator according to one of Claims 1 to 4, characterized in that either only sets ( 7 ) on polbildenden magnet coils ( 7.2 ) or only sentences ( 7 ) on pole-forming permanent magnets ( 7.1 ) for generating exciting magnetic fields on a rotor shaft ( 5 ) are arranged. Electric generator according to one of Claims 1 to 4, characterized in that at least one set ( 7 ) on pole-forming permanent magnets ( 7.1 ) for generating a field magnetic field on a rotor shaft ( 5 ) is arranged.

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