Wind turbine having a slip ring transmitter

Abstract

A wind turbine has a slip ring transmitter between a rotor hub and a nacelle for transmitting electrical signals with a data protocol. The slip ring transmitter is equipped with a signal amplifier device on the transmission side and with a signal evaluation device on the reception side. The signal amplifier device amplifies voltage values of signals for transmission via a slip ring transmitter. The signal evaluation device sets signals received via the slip ring transmitter to a value corresponding to the data protocol.

Claims

1. A wind turbine comprising: a rotor hub; a nacelle; a bidirectional slip ring transmitter disposed between said rotor hub and said nacelle and configured to transmit electrical signals therebetween in mutually opposite directions and with a data protocol; said bidirectional slip ring transmitter having a plurality of slip rings and having a first end communicating with said nacelle and a second end communicating with said rotor hub; said bidirectional slip ring transmitter defining mutually adjacent first and second slip ring transmitter units; said plurality of slip rings including a ground slip ring common to both of said first and second slip ring transmitter units; said first slip ring transmitter unit including a first signal amplifier device at said first end configured to amplify voltage values of first applied signals for transmission thereof to said second end via a first slip ring of said plurality of slip rings and said ground slip ring; said first slip ring transmitter unit further including a first signal evaluation device at said second end configured to set signals received via said first slip ring and said ground slip ring to a value corresponding to said data protocol; said second slip ring transmitter unit including a second signal amplifier device at said second end configured to amplify voltage values of second applied signals for transmission thereof to said first end via a second slip ring of said plurality of slip rings and said ground slip ring; and, said second slip ring transmitter unit further including a second signal evaluation device at said first end configured to set signals received via said second slip ring and said ground slip ring to a value corresponding to said data protocol.

2. The wind turbine of claim 1, wherein said data protocol is a field bus protocol in which voltage differences are evaluated.

3. The wind turbine of claim 1, wherein said data protocol is an interbus protocol in which voltage differences are evaluated.

4. The wind turbine of claim 1, wherein each one of said first and second signal amplifier devices is configured to amplify voltage differences applied thereto.

5. The wind turbine of claim 4, wherein the amplified voltage differences lie in an interval having a minimum voltage value and a maximum voltage value; and, said minimum voltage value and said maximum voltage value have opposing polarity.

6. The wind turbine of claim 1, wherein each one of said first and second signal evaluation devices is configured to convert signals applied thereto into an interval predefined by said data protocol.

7. The wind turbine of claim 6, wherein said interval predefined by said data protocol has a minimum voltage value and a maximum voltage value; and, said minimum voltage value and said maximum voltage value have a same polarity.

8. A wind turbine comprising: a rotor hub; a nacelle; a slip ring transmitter disposed between said rotor hub and said nacelle and configured to transmit electrical signals with a data protocol; said slip ring transmitter having a transmission side and a reception side; said slip ring transmitter further having a signal amplifier device on said transmission side and a signal evaluation device on said reception side; said signal amplifier device being configured to amplify voltage values of applied signals for transmission via said slip ring transmitter; said signal evaluation device being configured to set signals received via said slip ring transmitter to a value corresponding to said data protocol; and, wherein said signal evaluation device is configured to evaluate a magnitude of voltage differences and to signal one of a plurality of possible states of said slip ring transmitter in an event of voltage differences being below a predefined minimum difference.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described with reference to the drawings wherein:

(2) FIG. 1 shows a schematic view of a wind turbine having a tower, a nacelle and a rotor; and,

(3) FIG. 2 shows a schematic view of a slip ring transmitter.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

(4) FIG. 1 shows a tower 10 of a wind turbine, on which tower 10 a nacelle 12 is arranged. The nacelle 12 is mounted so as to be rotatable about the longitudinal axis of the tower 10 with a rotational connection, and can be oriented with respect to the wind using, for example, a yaw drive. The nacelle 12 bears a rotor hub 14 on which three rotor blades 16 are arranged. Of the rotor blades 16, the rotor blades 16a and 16b are illustrated in a side view. The rotor hub 14 is mounted on a rotor shaft 18. The rotor shaft 18 is rotatably mounted in the nacelle 12 in order to drive a generator therein. For a pitch controller or other control devices provided in the rotor hub such as, for example, a de-icing device, it is necessary to transmit data from the nacelle 12 into the rotatable rotor hub 14. For this purpose, the rotor shaft 18 has a slip ring transmitter. The principle of a slip ring transmitter is illustrated in FIG. 2. FIG. 2 illustrates, for example, five slip rings 20a, 20b, 20c, 20d, 20e which are insulated electrically from one another and rotate with the rotor shaft 18. There are slip ring transmitters with more than five slip rings. Brushes 22a, 22b, 22c, 22d, 22e, via which the voltage signals 30a, 30b, 30c, 30d, 30e are tapped at the slip rings 20a, 20b, 20c, 20d, 20e or applied to the slip rings 20a, 20b, 20c, 20d, 20e, are in mechanical contact with the slip rings 20a, 20b, 20c, 20d, 20e. Slip ring transmitters in which individual wires, carbon brushes, wire bundles or contact plates tap the voltage signals at the slip rings or apply them to the slip rings are also known. A signal amplifier device 24a amplifies the voltage signals applied via the interbus data line 28 and applies them as amplified voltage signals 30d, 30e to the slip rings 20d, 20e. The common reference potential GND 30c, required for the transmission of signals, is passed on from a first assembly 24 to a second assembly 26 via the slip ring 20c and the brush 22c. The first assembly 24 has a signal amplifier device 24a and a signal evaluation device 24b, and the second assembly 26 has a signal amplifier device 26a and a signal evaluation device 26b. The amplified voltage signals 30d, 30e which are tapped at the brushes 22d, 22e are passed onto a signal evaluation device 26b, wherein the latter converts the amplified voltage signals 30d, 30e again into the voltage ranges predefined by the interbus data protocol and outputs them as voltage signals to the interbus data line 32. In the illustrated embodiment, the slip rings 20a, 20b, 20c, 20d, 20e rotate with the rotor shaft 18, and the brushes 22a, 22b, 22c, 22d, 22e are fixedly connected to the nacelle 12.

(5) In the opposing direction of signal flow, a signal amplifier device 26a amplifies the voltage signals applied via the interbus data line 32 and applies them as amplified voltage signals 30a, 30b to the slip rings 20a, 20b via the brushes 22a, 22b. The common reference potential GND 30c required for the transmission of signals is passed on from the assembly 26 to the assembly 24 via the brush 22c and the slip ring 20c. The amplified voltage signals 30a, 30b applied to the slip rings 20a, 20b are passed onto a signal evaluation device 24b, wherein the latter converts the amplified voltage signals 30a, 30b again into the voltage ranges predefined by the interbus data protocol and outputs them as voltage signals to the interbus data line 28.

(6) The transmission of data operates with differential levels, wherein a difference between two voltage signals is continuously evaluated. The interbus protocol provides, for example, that the minimum differential levels have to be exceeded in absolute terms between, in each case, two interbus lines so that an input stage changes into another logical state. Open inputs, to which no defined state is assigned, are connected via electrical resistances in such a way that they reliably change into a defined logical state. In the normal interbus, a transmitter generally uses only positive levels with voltage values of 0 V and 5 V.

(7) The object of the signal amplifier device 24a, 26a is to determine the magnitude of the voltage signals in a normal interbus transmitter. With the logical signal which is determined in this way, two amplifiers are actuated which output a higher output voltage to the slip ring transmitter than the normal interbus transmitter. This also means that possible negative input voltage ranges are used. It is therefore possible, for example, for the amplified voltage signals to be at +12 V to −10 V.

(8) The signal evaluation device 24b, 26b evaluates the voltage signals picked up via the brushes 22a, 22b, 22c, 22d, 22e and converts them again into the voltage ranges predefined by the interbus data protocol. The embodiment shown in FIG. 2 shows a communication device in which data signals flow to the, for example, fixed brushes 22a, 22b, 22c, 22d, 22e via the slip ring transmitter.

(9) It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.