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Title:
SYSTEM FOR MARKING A TOWER AND METHOD FOR INSTALLING AND OPERATING SUCH A SYSTEM
Document Type and Number:
WIPO Patent Application WO/2018/190714
Kind Code:
A1
Abstract:
A system for marking a tower, such as a tower of a wind turbine, has a light fixture for emitting light marking the tower and a power supply for controlling voltage and amperage supplied to the light fixture. The light fixture has a plurality of light sources. Power supply conductors are connected between the power supply outside of the housing and the light fixture for electrically connecting the power supply to the light sources. Of a set of light sources for performing a marking function, a first light source performs the marking function and at least one second, spare light source is also for performing the same marking function in the event of failure of the first light source.

Inventors:
GOEDKNEGT PIETER GERARDUS (NL)
LEEUWANGH THOMAS (NL)
Application Number:
PCT/NL2018/050227
Publication Date:
October 18, 2018
Filing Date:
April 12, 2018
Export Citation:
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Assignee:
ORGA HOLDING B V (NL)
International Classes:
F03D80/10; F21W111/00
Domestic Patent References:
WO2001014789A12001-03-01
WO2016046045A12016-03-31
WO2006077084A12006-07-27
Foreign References:
US1955616A1934-04-17
DE202012003935U12013-07-22
DE102013110857A12015-04-02
EP1544460A22005-06-22
EP2908007A12015-08-19
EP3088637A12016-11-02
US1955616A1934-04-17
Attorney, Agent or Firm:
JANSEN, C.M. (NL)
Download PDF:
Claims:
CLAIMS

1. A system for marking a tower, such as a tower of a wind turbine, comprising a hght fixture for emitting light marking the tower and a power supply for controlling voltage and amperage supplied to the light fixture, wherein:

the light fixture comprises a plurality of hght sources in at least one light housing;

the power supply located outside of the housing;

power supply conductors are connected between the power supply and the hght fixture for electrically connecting the power supply to the light sources; wherein the light sources include a set of light sources for performing a marking function, of which set at least a first light source performs said marldng function and at least one second, spare light source for performing said marking function; and

wherein the light system is arranged for supplying power to either said at least one first light source or to said at least one second light source.

2. A system source according to claim 1, wherein the power supply

comprises a power supply circuitry and is arranged for connecting said circuitry to either said at least one first light source or to said at least one second light source.

3. A system according to claim 1 or claim 2, wherein the power supply conductors comprise a plurality of electrically separate pair of conductors, each of said light sources being electrically connected to at least one of said pairs of conductors, so as to be electrically separate from the at least one other light source, at least when one of said light sources is in operation.

4. A system according to claim 3, wherein the at least one pair of conductors connected to an inactive one of the hght sources is disconnected from contacts of the power supply circuitry and each connector of said pair is connectable to one of said contacts after disconnection of conductors of a connected pair from said contacts.

5. A system according to any of the preceding claims, wherein the light sources are arranged in a common housing. 6. A system according to any of the preceding claims, wherein the housing is permanently sealed including a permanent seal to a cable in which said pairs of conductors are arranged in electrical isolation from each other.

7. A system according to any of the preceding claims, wherein the light sources have a predetermined stationary position.

8. A tower provided with a system according to any of the preceding claims, wherein the housing is mounted to the outside of the tower, the power supply is arranged inside the tower and said conductors extend from said housing to said power supply through a hole in a wall of said tower.

9. A method of providing a tower with a system according to any of the claims 1-7, comprising:

feeding said conductor pairs through a hole in a wall of the tower from outside the tower into the tower;

mounting said housing to an outer surface of said tower;

mounting said power supply in said tower; and

connecting a pair of said conductors to said power supply.

10. A method of operating a system according to any of the preceding claims, wherein, in response to malfunction or non functioning of a first one of the hght sources, either a second one of the light sources is activated or at least the power supply circuitry is repaired or replaced by another power supply circuitry.

11. A method according to claim 10, wherein the system is a system

according to at least claim 4 and wherein activation of another one of said hght sources includes connecting a conductor pair connected to said other one of said light sources to said pair of contacts of said power supply circuitry.

Description:
Title: System for marking a tower and method for installing and operating such a system

FIELD AND BACKGROUND OF THE INVENTION

The invention relates to system for marking a tower, such as a tower of a wind turbine, to a tower provided with such a system, to a method for installing such a system and to a method of operating such a system.

For marking a tower as an obstacle easily discernible by aviation and, if the tower is located offshore, by ships, lights are mounted to the tower. Examples of such lights are described in WOO 1/14789 and WO2016/046045.

A problem associated to such lights is that installation and

maintenance is costly, because reaching locations at the outside of the tower, especially location for obstruction lighting for aviation that are high above the ground or sea level, is cumbersome and requires highly

specialized high altitude climbers and special climbing equipment. In offshore situations high altitude work is often impossible in view of weather circumstances, or at least very expensive.

Various attempts have been made to alleviate this problem. One approach is mounting the light fixtures inside or from the inside of the tower.

EP 1544460 discloses such a solution in which a light source of a hght fixture is installed inside the tower, which allows relatively easy installation and replacement, and fiber optic cables are arranged passing from the hght source, inside of the tower, through the wall of the tower to a light

distributing member on the outside of the tower wall. However, obtaining a required light emitting pattern is difficult to due to the random light distribution exiting fro the fiber optic cable. WO2006/077084 and EP 2908007 describe installing light fixtures from inside the tower through holes or other openings in the tower. However this requires relatively large openings to be made in the tower, which compromises the strength of the tower or requires reinforcements or other measures to compensate therefor. EP 3088637 describes such a measure, which is to leave open such an opening in the wall of the tower in a weld where successive tower sections are welded to each other. However, these solutions require a relatively large hole in the tower through which the light fixture needs to be inserted, which may require additional local

reinforcements of the tower wall. Also, it turned out that ahgning of the hght fixture was rather burdensome due to the installation from the inside, as during installation it is difficult to see what happens with the light at the outside of the tower.

Publication US 1955616 discloses a lamp changing device wherein the electric lamps are mounted on a carrousel that is rotated to successively connect a next electric lamp in a hghting circuit.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solution for marking a tower with one or more lights, which can be operated reliably at low costs and in which adverse effects on the strength of the tower are at least reduced.

According to the invention, this object is achieved by providing a system according to claim 1. The invention can also be embodied in a tower according to claim 9 and in methods according to claims 10 and 11.

Because light sources of a set of light sources for performing a marking function include at least a first hght source performing that marking function and at least one second, spare light source for performing that marking function, and the light system is arranged for supplying power to either the at least one first light source or to the at least one second light source, the need of replacing the light source in the event of malfunction or non-function of that light source is avoided, because the spare light source can be activated as a replacement for the malfunctioning or non-functioning hght source. Moreover, because the power supply is located outside of the housing containing the light source and power supply conductors are connected between the power supply and the light fixture for electrically connecting the power supply to the light sources, the power supply can be installed inside the tower, where functioning of the power supply can easily be checked and replacement or repair of the power supply can be carried out without requiring specialized high altitude climbers and special climbing gear.

The spare light source can be connected to the power supply when it needs to be activated only, so in case of failure of the first light source.

Advantageously, the power supply comprises a power supply circuitry and is arranged for connecting said circuitry to either said at least one first light source or to said at least one second light source to allow to connect either one of the connectors. It may be understood that multiple spare light sources or multiple sets of spare light sources can be available, so that switching to a next spare light source or to a next set of spare light sources can be done multiple times, e.g. one, two, three or more times depending on the number of spare light sources or sets of spare light sources available.

Preferably, the power supply conductors comprise a plurality of electrically separate pair of conductors, each of said light sources being electrically connected to at least one of said pairs of conductors, so as to be electrically separate from the at least one other light source, at least when one of said light sources is in operation. This allows an easy and reliable switching between the first light source and the spare light source, and - eventually - a further spare light source. Preferably, the at least one pair of conductors connected to an inactive one of the light sources is disconnected from contacts of the power supply circuitry and each connector of said pair is connectable to one of said contacts after disconnection of conductors of a connected pair from said contacts.

Advantageously, the light sources are arranged in a common housing. This allows easy installation and handling of the system. Alternatively and/or additionally, multiple light fixtures comprising a light source, can be provided, and said multiple light fixtures can be provided in a common housing. The housing is permanently sealed including a permanent seal to a cable in which said pairs of conductors are arranged in electrical isolation from each other. The pairs of conductors can be arranged in a power supply hose in electrical isolation from each other.

Advantageously, a tower is provided with such a system, wherein the housing is mounted to the outside of the tower, the power supply is arranged inside the tower and said conductors extend from said housing to said power supply through a hole in a wall of said tower.

Advantageously, only a single power supply hose may be provided between the light fixture outside of the tower and the power supply inside of the tower. The single power supply hose may comprise multiple power- supply conductors, typically one conductor for each light source, so e.g. a first cable and a spare cable. Each conductor may be provided with a connector for connection to the power supply inside of the tower. When the first light source is active for marking the tower, the first cable and the first connector are connected to the power supply. In case of failure of the first light source, the first connector can be disconnected from the power supply, and the spare connector can be connected to the power supply such that the spare light source can perform the marking function. In case of failure of the power supply itself, the power supply can easily be exchanged, as it is located in the tower inside.

Advantageously, the light sources have a predetermined stationary position in the at least one light housing. As such, contrary to the prior art lamp changers, there are no moving parts in the housing, which improves the reliability and robustness of the system. Also, the switching between a first light source or a set of first light source and the second spare light source or a set of second spare light sources is done at the power supply, outside of the housing. In particular, this switching is done by disconnecting a pair of conductors of the first light source from the power supply and connecting a pair of conductors from the second light source to the power supply. As such, the light fixture can remain unchanged during the use of the system, and any adaptations, switching or changes can be done outside of the light fixture and housing, namely inside of the wind turbine tower, at the power supply. This provides for easy maintenance and a reliable system, as the maintenance, if any, can be done from inside of the tower. In case of failure, for example the power supply can be exchanged, or for example the pair of conductors can be disconnected and a pair of conductors of the spare hght source can be connected.

Preferably, after manufacturing of the housing with the light sources arranged therein at fixed, predetermined positions, the housing is

permanently sealed. So, after sealing, no amendments, variations, adaptations or changes are possible anymore to the housing, in particular to what is inside of the housing, such as the light sources. The light sources are at a fixed position and remain at that position.

Particular elaborations and embodiments of the invention are set forth in the dependent claims.

Further features, effects and details of the invention appear from the detailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic side view of an example of a tower according to the invention; and Fig. 2 is a schematic representation of a marking system installed in such a tower.

DETAILED DESCRIPTION

It is to be noted that the figures are given by way of exemplary embodiments only. Corresponding elements are designated with

corresponding reference numbers.

In Fig. 1, a wind turbine 1 mounted to a tower 2 is shown. The tower is provided with a system for marking the tower, to make the tower more easily discernible for aviation and, if the tower is located offshore to shipping as well. Inside the tower 2, a stairway 5, which may be helical, is provided, but other climbing facilities or a lift may also be provided. The tower 2 has a wall 6 bounding an interior 7 of the tower 2.

The tower is equipped with light fixtures 3 for emitting light marking the tower 2 and power supplies 4 for controlling voltage and amperage supplied to the respective light fixtures 3. The number and location of the fixtures typically has to meet regulations such as FAA regulations in the United States or the International ICAO regulations.

As is shown in Fig. 2, the light fixture 3 has a plurality of light sources 8a-8c in a housing 9. The hght sources 8a-8c have a predetermined stationary position, meaning that the position of the light sources will not be changed during the use of the system. When switching between the light source, or the set of light sources and the spare light source or the set of spare light sources, the position of the light sources remains the same, as no adaptations or variations are done inside of the housing. Only, the pair of conductors of the (first) light source is disconnected from the power supply, and the pair of conductors of the spare light source is connected to the power supply, and/or the power supply itself is being exchanged or repaired. The light housing 8 is transparent at least in directions in which light (which may also be or include infrared radiation) has to be emitted. The power supply 4 is located outside of the housing 9. Power supply conductors 10.1-10.6 are connected between the power supply 4 and the hght fixture 3 for electrically connecting the power supply 4 to the light sources 8a-8c.

In this example, the light sources 8a-8c form a set of hght sources for performing a marking function. Of this set at a given moment, for instance a first light source 8a performs the marking function, while second and third, spare light sources 8b and 8c are redundant for performing the marking function and accordingly not active. The light system is arranged for supplying power to either the first light source or to the second or third light source.

Because the light sources 8a-8c of a set of light sources include at least a first light source 8a performing that marking function and at least one second, spare light source 8b, 8c for performing the same marking function, and the light system is arranged for supplying power to either the first light source 8a or to one of the spare light sources 8b, 8c, the need of replacing a light source in the event of malfunction or non-function of that hght source 8a is avoided, because one of the spare hght source 8b or 8c can be activated as a replacement for the malfunctioning or non-functioning hght source. After the second light source 8b has taken over the marking function of the first light source 8a, the third light source 8c is still left as a spare in the event of malfunction or non-function of the second light source 8b. The hght sources of a set may also be activated in a different order of succession.

Since the power supply 4 is located outside of the housing 9

containing the hght sources 8a-8c and power supply conductors 10.1-10.6 are connected between the power supply 4 and the light fixture 3 for electrically connecting the power supply 4 to the light sources 8a-8c, the power supply 4 can be installed inside the tower 2, where functioning of the power supply 4 can easily be checked and replacement or repair of the power supply 4 can be carried out without requiring speciahzed high altitude climbers and/or special climbing gear. Each light source 8a-8c may comprise at least one light emitting element, such as a light emitting diode. The hght source may also comprise a plurality of light emitting elements arranged on a same level of the light source as to obtain a hght emitting pattern as required by rules and regulations, e.g. with a relatively large horizontal spread and a relatively limited vertical spread. The hght emitting elements can be arranged in an array or in a circular or polygonal arrangement.

Many variants are possible.

The number of spare light sources of each set performing a given marking function (which may also be shared with other light sources of other sets simultaneously active) may also be one or larger e.g. three, four or more. Preferably, the assured minimum combined lifetime of the light sources of a set is such that the set lasts at least as long as the lifetime of the tower or time span to a next major overhaul of the tower.

In the present example, the power supply 4 has a power supply circuitry 11 that is arranged for connecting the circuitry 11 to either the first light source 8a or to one of the other, spare hght sources 8b and 8c. Thus, only a single power supply circuitry 11 is needed, which limits costs. Failure of a power supply circuit occurs relatively infrequently and can be solved relatively easily, so that the presence of only one power supply for per set of light sources 8a-8c does not entail important disadvantages. The power supply circuitry 11 has contacts 13.1, 13.2 for connection to a power network or other power source.

The power supply conductors are formed by a plurality of electrically separate pairs of conductors 10.1 with 10.2, 10.3 with 10.4 and 10.5 with 10.6. Each of the hght sources 8a-8c is electrically connected to one of the pairs of conductors 10.1 with 10.2, 10.3 with 10.4 and 10.5 with 10.6, so as to be electrically separate from the other light sources, at least when one of the light sources 8a-8c is in operation. Thus, each light source 8a-8c is coupled to another, associated pair of conductors, so that in the event that malfunction of a light source 8a-8c is caused by malfunction of a conductor in connection with that hght source 8a-8c, changing over to another light source 8a-8c will resolve the malfunction as well, because this also entails switching to supplying power via another one of the pairs of conductors. Accordingly, the likelihood that changing over to another light source 8a-8c will not resolve the malfunction is particularly small.

Reliability of solving malfunctions and non functioning of marking hghts is further particularly high because the pairs of conductors connected to inactive ones of the light sources 8b, 8c are disconnected from contacts 12.1, 12.2 of the power supply circuitry 11 and each connector of these pairs 10.3 with 10.4 and 10.5 with 10.6 is connectable to one of the contacts 12.1, 12.2 after disconnection of conductors of a connected pair 10.1 with 10.2 from the contacts 12.1, 12.2. Thus, when changing over to a different pair of conductors there is no switchgear between the newly connected conductors and the power supply circuitry that is used again and that could have formed a cause of the malfunction of non function of the marking light.

The light sources 8a-8c are arranged in a common housing 9, so that the light fixture is of an efficient construction and can be made reliably weather proof fairly easily.

For reliably shielding the light sources 8a-8c and associated light engine circuitry of each light source reliably from rain, the housing 9 is permanently sealed including a permanent seal 15 to a cable 14 in which the pairs of conductors 10.1-10.6 are arranged in electrical isolation from each other. Preferably the sealing is such that it has a lifetime equal to that of the tower or to the duration of a period between major tower maintenance operations.

For providing a tower 2 with a system according to invention, the conductor pairs 10.1-10.6 are fed through a hole 16 in the wall 6 of the tower 2 from outside the tower 2 to the interior of the tower, the housing 9 is mounted to an outer surface 17 of the tower 2, the power supply 4 is mounted in the tower 2 and a pair of the conductors 10.1-10.6 is connected to the power supply 4. Thus, the housing 9 can be manufactured and sealed under industrial controlled conditions and tested before installation, while a very small hole 16 is sufficient for passing the conductors to the power supply 4 in the interior of the tower. Preferably, the housing 9 and introduction of the cable 14 through the hole 16 is carried out prior to assembly of the tower or at least prior to bringing the tower in an upright position, so that these steps do not have to b carried out at high altitude above the ground or above the sea.

For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include

embodiments having combinations of all or some of the features described. It may be understood that the embodiments shown have the same or similar components, apart from where they are described as being different.

Several features have been described as part of the same or separate embodiments. However, it will be appreciated that the scope of the invention also includes embodiments having combinations of all or some of these features other than the specific combinations of features embodied in the examples.