阅读说明：本技术 针对风力涡轮机中的传感器的能量供给 (Energy supply for sensors in wind turbines ) 是由 E·纳格尔 J·妞文豪曾 于 2020-03-16 设计创作，主要内容包括：一种风力涡轮机(1)包括塔台(2)、机舱(3)和至少一个可旋转叶片和至少一个传感器(10),所述至少一个传感器(10)包括能量采集器(11)和用于测量物理变量的感测元件(17)。所述能量采集器(11)包括：接收天线(12),用于接收电磁信号(100)；电储存器(15),用于存储电能且电连接到所述感测元件(17)；整流器(14),电连接在所述天线(12)与所述储存器(15)之间。(A wind turbine (1) comprising a tower (2), a nacelle (3) and at least one rotatable blade and at least one sensor (10), the at least one sensor (10) comprising an energy harvester (11) and a sensing element (17) for measuring a physical variable. The energy harvester (11) comprises: a receiving antenna (12) for receiving an electromagnetic signal (100); an electrical storage (15) for storing electrical energy and electrically connected to the sensing element (17); a rectifier (14) electrically connected between the antenna (12) and the reservoir (15).)

1. Wind turbine (1) comprising a tower (2), a nacelle (3), at least one rotatable blade (4) and at least one sensor (10), the at least one sensor (10) comprising an energy harvester (11) and a sensing element (17) for measuring a physical variable, the energy harvester (11) comprising:

a receiving antenna (12) for receiving an electromagnetic signal (100),

an electrical storage (15) for storing electrical energy and electrically connected to the sensing element (17),

a rectifier (14) electrically connected between the antenna (12) and the reservoir (15).

2. Wind turbine (1) according to claim 1, wherein the energy harvester (11) further comprises: a band-pass filter (13) electrically connected between the receiving antenna (12) and the rectifier (14).

3. Wind turbine (1) according to claim 1 or 2, wherein said sensor (10) further comprises: a control circuit (16) electrically connected between the electrical storage (15) and the sensing element (17).

4. Wind turbine (1) according to claim 3, wherein the sensor (10) further comprises: a sensor transmitter (18) electrically connected to the control circuit (16).

5. Wind turbine (1) according to any of the preceding claims, wherein said electrical storage (15) comprises at least one capacitor (21, 22).

6. Wind turbine (1) according to any of the preceding claims, wherein the rectifier (14) comprises at least one active switch (23).

7. Wind turbine (1) according to any of the preceding claims, wherein the wind turbine further comprises: a transmitter (51, 52) for transmitting the electromagnetic signal (100) to the receiving antenna (12).

8. Wind turbine (1) according to claim 7, wherein said transmitter comprises a transmitting antenna (51).

9. Wind turbine (1) according to claim 7, wherein the transmitter comprises a leaky feeder (52).

10. Wind turbine (1) according to claim 9, wherein said leakage feeder (52) is mounted in at least one of said tower (2) or said nacelle (3) or in said rotatable blades (4).

11. Wind turbine (1) according to any of the preceding claims, wherein the sensor (10) is mounted in the tower (2) or the nacelle (3) or in at least one of the rotatable blades (4).

Technical Field

The present invention relates to an apparatus for providing a supply of energy to sensors mounted on a wind turbine. In particular, but not exclusively, the invention relates to a sensor apparatus for providing an energy supply to a sensor mounted in a blade for a wind turbine.

Background

The power supply of sensors installed inside the wind turbine and in particular inside the wind turbine blades is problematic, since in the event of a lightning strike, the lightning can pass directly through the sensor cable or can be coupled into the sensor cable. In both cases, the sensor may be irreparably damaged.

For this reason, it is known in the art defined above to power the sensor without using a cable. For example, the power supply may be performed by means of optical energy (e.g., emitted by a laser and transmitted through an optical fiber). Alternatively, mechanical energy harvesters are known, for example based on MEMS ("micro-electromechanical systems") technology, which use the kinetic energy of moving parts (e.g. the wind rotor of a wind turbine) to generate electrical energy for the sensors mounted in the wind turbine.

Disclosure of Invention

The scope of the present invention is to provide an alternative to the above described system for powering sensors inside a wind turbine, which achieves a number of advantages with reference to the above cited prior art. For example, according to the present invention, it can be characterized by simplicity, efficiency and cost-effectiveness of construction and maintenance.

This scope is met by the subject matter according to the independent claims. Further advantageous embodiments of the invention are described by the dependent claims.

According to the invention, a wind turbine comprises a tower, a nacelle, at least one rotatable blade and at least one sensor comprising an energy harvester and a sensing element for measuring a physical variable. The energy harvester includes:

a receiving antenna for receiving the electromagnetic signal,

an electrical storage for storing electrical energy and electrically connected to the sensing element,

and a rectifier electrically connected between the antenna and the storage.

The sensing elements may measure physical variables of interest in the wind turbine, such as vibration, temperature, pressure, humidity or others. The sensor may be mounted in any component of the wind turbine (e.g. any of the blades or the tower or nacelle).

The energy harvester of the present invention is based on harvesting energy from available electromagnetic sources that emit electromagnetic signals in the wind turbine environment. Suitable electromagnetic sources for the energy harvester of the invention may be, for example, radio frequency sources like television and radio. Alternatively, according to an embodiment of the invention, the wind turbine further comprises: a transmitter for transmitting the electromagnetic signal to a receiving antenna of the energy harvester. The transmitter may comprise a transmit antenna or a leaky feeder.

By the term "leaky feeder", it is meant a communication elongate member which leaks electromagnetic waves transmitted along the member. The leaky feeder may be constituted by a leaky coaxial cable or a leaky waveguide or a leaky stripline. The leaky feeder allows the electromagnetic signal to leak out of the leaky feeder along its length and make the electromagnetic signal available to the energy harvester of the sensor.

The energy harvester of the sensor according to the invention allows to avoid the risks associated with the cable connection, in particular during lightning. With other cableless solutions, such as those involving the use of optical energy sources (lasers) and fiber optic cables or MEMS, the energy harvester that harvests energy from electromagnetic signals is characterized by simpler and cheaper components.

According to an embodiment of the present invention, the energy harvester may further include: a band pass filter electrically connected between the receiving antenna and the rectifier. Advantageously, a band pass filter may be used to selectively choose a frequency band among the frequencies available to the energy harvester.

According to an embodiment of the invention, the sensor further comprises: a control circuit electrically connected between the electrical storage and the sensing element. The sensor may further include: a sensor transmitter electrically connected to the control circuit. Advantageously, the sensor transmitter may be used to transmit information, such as measurement data, from the sensor. The leaky feeder may also be arranged to receive information sent by the sensor.

Drawings

The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment. The invention will be described in more detail hereinafter with reference to an example of embodiment but to which the invention is not limited.

Fig. 1 shows a schematic cross section of a wind turbine according to a first embodiment of the invention.

Fig. 2 shows a schematic cross section of a wind turbine according to a second embodiment of the invention.

FIG. 3 shows a schematic cross section of a wind turbine according to other embodiments of the present invention.

FIG. 4 shows a schematic representation of a sensor of a wind turbine according to an embodiment of the invention.

Fig. 5 shows a schematic representation of the circuitry of the first embodiment of the energy harvester comprised in the sensor of fig. 4.

Fig. 6 shows a schematic representation of the circuitry of the second embodiment of the energy harvester comprised in the sensor of fig. 4.

Fig. 7 shows a schematic representation of the circuitry of a third embodiment of the energy harvester comprised in the sensor of fig. 4.

Fig. 8 shows a schematic representation of the circuitry of a fourth embodiment of an energy harvester comprised in the sensor of fig. 4.

Detailed Description

The illustration in the drawings is schematically. It should be noted that in different figures, similar or identical elements are provided with the same reference numerals.

Fig. 1 to 3 show respective embodiments of a wind turbine 1 for generating electricity. The wind turbine 1 comprises one or more sensors 10 according to the invention. The wind turbine 1 comprises: a tower 2 mounted on the ground 8 at one bottom end. At the opposite top end of the tower 2, a nacelle 3 is mounted. The nacelle 3 houses a generator (not shown in the drawings) of the wind turbine 1. Intermediate the tower 2 and the nacelle 3, a yaw angle adjustment device (not shown) is provided, which is capable of rotating the nacelle about a vertical yaw axis Z. The wind turbine 1 further comprises a wind rotor 5 with one or more rotating blades 4 (in the perspective of fig. 1, only two blades 4 are visible). The wind rotor 5 is rotatable about a rotation axis Y for transferring rotational energy to a generator of the nacelle 3. The generation of electric power by the present invention is not a specific object of the present invention and is therefore not described in further detail. In general, the following terms "axial", "radial" and "circumferential" are made with reference to the axis of rotation Y, when not otherwise specified. The blades 4 extend radially with respect to the rotation axis Y.

In the embodiment of fig. 1 to 3, each of the blades 4 comprises two sensors 10 according to the invention. According to other embodiments of the invention, the wind turbine 1 comprises: at least one sensor 10, which may be mounted in any of the tower 2, the nacelle 3, one of the rotatable blades 4 and any other component of the wind turbine. Each sensor 10 includes a receiving antenna 12 for receiving an electromagnetic signal 100.

In the embodiment of fig. 1, the electromagnetic signal 100 is emitted by a transmitting antenna 51 mounted on the nacelle 3. In the embodiment of fig. 1, the electromagnetic signal 100 is emitted by a transmitting antenna 51 mounted on the nacelle 3.

In the embodiment of fig. 2, electromagnetic signal 100 is emitted by an electromagnetic signal source connected to leaky feeder 52. Leaky feeder 52 allows electromagnetic signal 100 to leak out of the leaky feeder along its length and makes electromagnetic signal 100 available to receiving antenna 12. The leaky feeder 52 is configured as a loop attached to the tower 2. This configuration allows: the emission of electromagnetic signal 100 may be oriented according to any direction about vertical yaw angle Z.

Fig. 3 shows other possible installations of leaky feed lines 52 that emit electromagnetic signals 100. For example, it may be mounted in any of the tower 2, the nacelle 3, the wind rotor 5 and the rotatable blades 4.

The leaky feeder 52 is configured to: a closed loop, as shown in the embodiments of fig. 1 to 3; or arc, extending for less than 360 degrees.

According to other embodiments of the invention (not shown), the wind turbine 1 may comprise any other transmitter for transmitting the electromagnetic signal 100 to the receiving antenna 12. The location of the transmitter may be selected according to an optimization criterion, for example, a location may be selected that minimizes the distance between the transmitter transmitting the electromagnetic signal 100 and the receiving antenna 12.

According to other embodiments of the invention (not shown), the wind turbine 1 does not comprise any transmitter for transmitting the electromagnetic signal 100 to the receiving antenna 12, the electromagnetic signal 100 being emitted by an external electromagnetic signal source. For example, the electromagnetic signal 100 may be emitted by a radio frequency source (like television and radio).

Fig. 4 shows the sensor 10 in more detail. The sensor 10 comprises an energy harvester 11 and a sensing element 17 for measuring a physical variable. The sensing element 17 measures any physical variable relevant in the wind turbine, such as vibration, temperature, pressure, humidity or others. The energy harvester 11 comprises a receiving antenna 12. Attached to the receiving antenna 12, the energy harvester 11 comprises a band-pass filter 13, a rectifier 14 and an electrical storage 15 electrically connected in series, the electrical storage 15 being used to store electrical energy of the electromagnetic signal 100, which is harvested by the receiving antenna 12.

A band pass filter 13 electrically connected between the receiving antenna 12 and the rectifier 14 allows the energy harvester 11 to operate in a selected frequency range (e.g., away from interference risks). Alternatively, instead of the band pass filter 13, a high pass filter may be used to select frequencies above a threshold frequency (e.g. 10 MHz) for avoiding lightning interference. According to other embodiments of the present invention, no filter is present between the receive antenna 12 and the rectifier 14. The electrical storage 15 may comprise at least one capacitor. Alternatively, other electrical storage may be used.

According to the embodiment of fig. 4, the sensor 10 further comprises a control circuit 16 electrically connected between the electrical storage 15 and the sensing element 17. The control circuit 16 may include a CPU, FPGA ("field programmable gate array") and other circuitry for servicing the sensing elements 17. The control circuit 16 may include further circuitry for serving a sensor transmitter 18 electrically connected to the control circuit 16. The sensor transmitter 18 comprises a transmitting antenna for transmitting information (e.g. measurement data) from the sensor 10 to a receiver, which may be provided on the wind turbine 1. The receivers may be provided with respective leaky feeders for receiving information transmitted by the sensors 10. The electrical energy stored in the electrical storage 15 provides power to the control circuit 16, the sensing element 17 and the sensor transmitter 18 when required.

Fig. 5 to 8 show four respective embodiments of the energy harvester 11. All four respective embodiments of fig. 5 to 8 comprise a receiving antenna 12, a rectifier 14 and an electrical storage 15, respectively. The rectifier 14 may comprise one simple diode (fig. 6), two diodes arranged in opposite directions in two respective branches connected in parallel with the receiving antenna 12 (fig. 7), a plurality of diodes (fig. 5) or a plurality of active switches, such as MOSFETs or JFETs. According to other embodiments of the invention (not shown), the energy harvester 11 may comprise any other type of rectifier 14 capable of converting the wave signal provided by the receiving antenna 12 into a DC signal to be transmitted to the electrical storage 15. The electrical storage 15 may comprise, for example, one single capacitor (fig. 5, 6 and 8), two capacitors (fig. 7) or a plurality of capacitors (embodiment not shown). According to other embodiments of the invention (not shown), the energy harvester 11 may comprise any other type of electrical storage 15 capable of storing the energy of the DC signal provided by the rectifier 14.