THERMAL FUSE PROTECTION OF A FORM COIL GENERATOR OF A WIND POWER PLANT

Abstract

A generator of a gearless wind power installation, with a rotor and a stator, wherein at least the rotor or the stator is provided with a fuse wire, for detecting a local temperature increase, and wherein the fuse wire comprises an electrically conducting material and the electrically conducting material melts when a predetermined temperature is reached, and thereby brings about an interruption of the electrical conduction, in order thereby to detect the local temperature increase.

Claims

1. A generator of a gearless wind power installation, comprising: a rotor and a stator, wherein at least one of the rotor or the stator is provided with a fuse wire for detecting a local temperature increase, and wherein the fuse wire comprises an electrically conducting material that melts when a predetermined temperature is reached, and thereby interrupts electrical conduction of the fuse wire to detect the local temperature increase.

2. The generator as claimed in claim 1, wherein the fuse wire is located around the stator in an approximately circular manner.

3. The generator as claimed in claim 1, wherein the stator has stator windings that are made up of form-wound coils, wherein the form-wound coils are coupled to one another at coil contact points, and wherein the fuse wire is located along the coil contact points of the stator to detect whether a temperature increase occurs at a coil contact point.

4. The generator as claimed in claim 1, wherein the electrically conducting material of the fuse wire is accommodated in a sheathing in such a way that, in the event the electrically conducting material melts, the electrically conducting material flows in the sheathing in such a way to interrupt the electrical conductivity of the fuse wire.

5. The generator as claimed in claim 4, wherein the sheathing of the fuse wire is configured to withstand a higher temperature than the predetermined temperature.

6. The generator as claimed in claim 1, wherein the predetermined temperature lies in a range of 160 C.-200 C.

7. The generator as claimed in claim 1, wherein the generator is a ring generator.

8. A generator of a gearless wind power installation, comprising: a rotor and a stator, wherein: at least one of the rotor or the stator is provided with an optical waveguide for detecting a local temperature increase, and wherein: the optical waveguide is configured to transmit light waves that are monitored by way of a lightwave evaluation; and wherein the transmission of the light waves through the optical waveguide changes when a predetermined temperature is reached or exceeded and this change is detected by the lightwave evaluation.

9. A fuse wire for detecting a local temperature increase at a generator of a gearless wind power installation, wherein the fuse wire comprises an electrically conducting material and the electrically conducting material melts when a predetermined temperature is reached and, as a result, brings about an interruption of the electrical line, in order thereby to detect the local temperature increase.

10. The fuse wire as claimed in claim 9, wherein the fuse wire is located around component of a generator.

11. A method comprising: thermally monitoring coil contact points in a generator of a gearless wind power installation, wherein a fuse wire is led along the coil contacts points, wherein thermally monitoring coil contact points includes measuring conductivity of the fuse wire while the wind power installation is operating, and generating a warning signal in the event the conductivity of the fuse wire deteriorates.

12. The method as claimed in claim 11, wherein when a warning signal is generated, the wind power installation is stopped and the generator is electrically disconnected from electrical terminals.

13. The method as claimed in claim 11, wherein the warning signal is provided to a remote monitoring center.

14. The method as claimed in claim 11, wherein generating the warning signal occurs in the event the conductivity of the fuse wire is interrupted.

15. The generator as claimed in claim 6, wherein the predetermined temperature is a range of 170 C.-190 C.

16. The generator as claimed in claim 6, wherein the predetermined temperature is 180 C.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0038] The invention is explained in more detail below by way of example on the basis of embodiments with reference to accompanying figures.

[0039] FIG. 1 shows a wind energy installation schematically in a perspective view.

[0040] FIG. 2 schematically shows a ring generator of a gearless wind power installation.

[0041] FIG. 3 shows a detail of a contact region of form-wound coils of a stator of a gearless wind energy installation in a perspective view.

[0042] FIG. 4 shows a block diagram for a system for monitoring.

DETAILED DESCRIPTION

[0043] FIG. 1 shows a wind power installation 100 with a tower 102 and a nacelle 104. Arranged on the nacelle 104 is a rotor 106 with three rotor blades 108 and a spinner 110. During operation, the rotor 106 is set in a rotating movement by the wind and thereby drives a generator in the nacelle 104.

[0044] FIG. 2 shows a generator 130 schematically in a side view. It has a stator 132 and an electrodynamic rotor 134, which is mounted so as to be rotatable in relation thereto, and is secured with its stator 132 on a bed plate 138 by way of a journal 136. The stator 132 has a stator support 140 and laminated stator cores 142, which form stator poles of the generator 130 and are secured on the stator support 140 by way of a stator ring 144. The electrodynamic rotor 134 has rotor pole shoes 146, which form the rotor poles and are mounted on the journal 136 by way of a rotor support 148 and bearings 150 so as to be rotatable about the axis of rotation 152. The laminated stator cores 142 and rotor pole shoes 146 are separated only by a narrow air gap 154, which is a few mm wide, in particular less than 6 mm, but has a diameter of several meters, in particular more than 4 m. The laminated stator cores 142 and the rotor pole shoes 146 each form a ring and together are also annular, and therefore the generator 130 is a ring generator. In accordance with its purpose, the electrodynamic rotor 134 of the generator 130 rotates together with the rotor hub 156 of the aerodynamic rotor, of which the initial sections of rotor blades 158 are indicated.

[0045] FIG. 3 shows in a perspective view a detail of a generator 300 with various form-wound coils 302, which are connected to one another at various contact points 304. In this case, two adjacent form-wound coils 302 of the same phase are always connected to one another. These form-wound coils 302 may differ from one another in details, the same reference numeral 302 always being used for the sake of better overall clarity. FIG. 3 shows here a detail from a generator 300, which is formed with six phases, in the case of which therefore the stator to which the form-wound coils 302 belong has six phases.

[0046] The contact points 304 also have in this case contact bridges 306, in order to bridge the geometrical distance between form-wound coils. Consequently, at the contact points 304, contact bridges 306 are secured to form-wound coil ends 308, that is in the example are screwed on. The reference numerals 304 for identifying the contact points indicate corresponding screw heads, but the contact points 304 are not restricted to these, but rather also include these form-wound coil ends 308. In any event, any temperature increase in the region of a contact point will also spread to such end portions 308.

[0047] Provided for the temperature monitoring is therefore a fuse wire 310, which here runs around the generator 300 essentially in a circular or annular manner. It is thereby laid in the region of the contact points 304 and lies partially between the contact bridges 306 and on form-wound coil ends 308, which to this extent can still be counted as belonging to the contact points 304. It is consequently evident that the fuse wire 310 can be laid in an easy way, and at the same time is in this case arranged in the vicinity of all the contact points 304.

[0048] The fuse wire 310 has in this case a sheathing, which in the embodiment shown essentially forms a torus. Inside it there is a low-melting wire.

[0049] Provided is a proposal for monitoring temperature increases at form-wound coils of a ring generator of a gearless wind power installation. Such a ring generator with form-wound coils may also be referred to as a form-wound coil generator.

[0050] In connection with a form-wound coil generator, it is inherent in the system that many contact points are required in the stator winding. The reliability of the generator depends on the reliability of all the contacts that are made. Since inadequate contacting can lead to the generator being damaged, it is advisable to detect a deteriorating contact in good time. Provided is a monitoring system that is capable of switching off the generator in good time.

[0051] The invention consequently concerns, in principle and in graphic terms, a fuse of a great size, which however is not heated up by its own current but by heating its vicinity. Consequently, not current but heating is monitored. In a casing tube or casing pipe that conducts heat as well as possible there is a conductor that has a defined melting temperature. This system is wound or laid around all of the contacting points in a preferably circular manner. If one of the contact points heats up to an inadmissible degree, the electrical conductor, which may also be referred to as a core wire, melts and causes an interruption, which is detected and used for switching off the generator.

[0052] As mentioned above, in another embodiment the optical waveguide 400 is configured to transmit light waves and the transmission of light waves is monitored by way of an evaluation unit 402, such as a lightwave evaluation unit. The transmission of the light waves through the optical waveguide 400 changes when a predetermined temperature is reached or exceeded and this change, in particular an interruption of the transmission, can be detected by the evaluation unit 402.

[0053] Excessive heating, even only local excessive heating, of the optical waveguide changes the transmission behavior, and this is sensed by the evaluation unit 402. The evaluation unit 402 includes a sensor, such as an optical sensor 404, configured to sense the changes in the transmission behavior. Particularly an interruption can be detected. However, also a change in the quality of the light signal can be detected, in particular a frequency shift or other frequency change. The use of an optical waveguide thus allows the generator to be monitored over its entire circumference by just one optical waveguide. The evaluation unit may also include a controller 406 coupled to the sensor 404 to indicate that the change has occurred (FIG. 4). The evaluation unit 402 may be used with the fuse wire 310 as discussed above and may include at least one of a sensor and a controller.