METHOD FOR ESTABLISHING A DATA CONNECTION TO A WIND FARM AND WIND FARM COMMUNICATION SYSTEM

Description

[0001] The invention relates to the field of communication between a wind farm and a participant outside the wind farm via a data connection. Such data connections to a wind farm are often necessary for remote maintenance access to components of the wind farm. A common procedure for such remote maintenance access to a component in the wind farm is therefore for a participant to establish a network connection or data connection from outside the wind farm in order to contact the component to be maintained.

[0002] For this purpose, wind farms often have communication units connected to an external network and providing ports for the participants. Network participants can then access these ports and establish a connection with the communication unit. The communication unit then connects individual components to the participant via an internal network.

[0003] From the network’s perspective, each component must be accessible from the outside.

[0004] This is often achieved through network address translation, or NAT for short. NAT translates from public IP addresses to internal IP addresses. In any case, the components must be configured accordingly to gain access to them from outside. Another alternative is to align internal and public IP addresses, so that all internal components are assigned a public IP address. These solutions are therefore only possible with considerable configuration effort.

[0005] Another problem is that with both of these solutions, every component is accessible via an external network, and additional measures must be taken to ensure at least a minimum level of security, namely IT security or information security. This is achieved through the use of security systems such as firewalls and the like.

[0006] Setting up firewalls or other security measures is manageable as long as only a single company or participant performs remote maintenance of individual components. However, given the complexity of the various components installed in a wind farm, wind turbine manufacturers can no longer manufacture and maintain all of them themselves. Therefore, components from third-party manufacturers are increasingly being used in wind farms or within wind turbines. Access to these components, for example, for remote maintenance, is therefore regularly provided by the third-party manufacturers themselves. Qualified support, for example, in the event of a fault, or changes to the configuration, is often only possible in full and within a reasonable timeframe by the third-party manufacturer themselves.Providing access or a data connection for a large number of different participants significantly increases the complexity of the data connection requirements, for example, for remote maintenance. Implementation effort therefore either compromises security or increases the costs of commissioning and even the operating costs themselves.

[0007] Document DE 10 2011 109 678 A1 relates to a communication system that establishes a secure data connection between a mobile device and a computer device for a home automation system, allowing the mobile device to retrieve data, such as videos, from the computer unit. To establish the connection, the communication system additionally comprises a server device that sends an access request from the mobile phone to the computer unit, with the computer unit establishing the connection with the mobile phone based on the request.

[0008] The document US 2005 / 0238034 A1 similarly describes the establishment of a secure communication connection between a server and a client using a so-called "session control server" (SCS).

[0009] The object of the present invention is therefore to address the deficiencies of the prior art. In particular, it should be possible to establish a data connection with a wind farm, especially for remote maintenance, that enables different participants in a data network connected to the wind farm to establish a data connection that ensures the required level of security. The aim is to find an alternative to the prior art.

[0010] For this purpose, a method according to the invention as claimed in claim 1 is proposed.

[0011] The method is used to establish a data connection between a communication unit of a wind farm and a subscriber via an external data network.

[0012] A data network is referred to as external because it is located at least partially outside the wind farm and thus serves to enable communication with the wind farm from participants located outside the wind farm. Accordingly, a wind farm is provided which comprises a communications unit. Participants outside the wind farm are also provided. The participant and the communications unit can establish a data connection via the external data network. In this case, the data network preferably refers to a physical network which is formed, for example, by cables, in particular copper cables, fiber optic cables or wirelessly, such as radio, or combinations thereof. The data connection then describes the state of the data network when it is configured or set up in such a way that data can be exchanged between the communications unit and the participant.

[0013] The method initially involves establishing a data connection between the communication unit and a predefined server via the external data network by the communication unit. The communication unit initiates the establishment of a data connection in order to establish a data connection between the communication unit and a predefined server via the external data network. The predefined server describes a server that is predefined, for example, in the communication unit. Predefining is performed, for example, by storing a fixed IP address in the communication unit that is assigned to the server.

[0014] Furthermore, in a further step, an access planning request is received by the communication unit from the predefined server. The access planning request is received by the communication unit via the external data network. The access planning request includes an identification of a participant in the external data network. This means that the access planning request preferably contains data with which a participant who is connected or connectable to the external data network can be identified. Here, too, such data can include, for example, IP addresses or the like.

[0015] In a further step, a data connection is established by the communication unit. This data connection is established between the communication unit and the identified participant. This means that the access planning request specifies a participant to the communication unit based on their identification, with whom a data connection is then established in a subsequent step. This data connection is established, preferably automatically, by the communication unit. Furthermore, this data connection is a data connection via the external data network.

[0016] Furthermore, requests to establish a data connection received from the external data network by the communication unit are discarded or rejected, i.e., ignored. The communication unit therefore discards or rejects every request to establish a data connection that it receives. Alternatively, the communication unit is not visible to participants of the external data network for requests to establish a data connection. Accordingly, the communication unit preferably does not provide any ports for establishing a data connection with the communication unit.

[0017] Accordingly, a communications unit is proposed which is arranged in a wind farm and provides a possibility for exchanging data with the wind farm from outside the wind farm, in particular for remote maintenance access. However, this communications unit is either invisible to other participants in the external data network or does not respond to requests to establish a data connection. In this respect, a participant in the external data network cannot initiate a data connection with the communications unit. Nevertheless, the communications unit itself establishes a data connection with a predefined server, which is also a participant in the external data network, for example, and receives access planning requests from this server. These access planning requests contain data with which a participant other than the server can be identified, one who, for example, requires remote maintenance access.The communication unit then establishes or initiates a data connection with the identified participant.

[0018] This creates a special level of security, as not just any participant in the external data network can gain access to the wind farm by establishing a data connection. Instead, a participant must first be announced by the server. Establishing data connections is only possible at the initiative of the communications unit. The server thus represents a type of filter that can be used to exclude unauthorized participants from the outset, even if they have access to access data such as passwords for the communications unit. A participant seeking access to a wind farm must therefore always go through the predefined server, greatly reducing the risk of hacker attacks.Furthermore, a communication unit has been created that is located in the wind farm and can thus also coordinate access within the wind farm, so that a translation of the network addresses is no longer necessary.

[0019] According to a first embodiment, the data connection between the communication unit and the predefined server is continuously maintained by the communication unit via the external data network. In the event of a disruption, the communication unit automatically reestablishes the data connection between the communication unit and the predefined server.

[0020] The data connection between the communication unit and the predefined server via the external data network therefore exists essentially at all times, so that access planning requests can be transmitted to the communication unit from the predefined server essentially at any time, for example, if short-term access to the wind farm is desired or necessary by a participant in the external network. In this respect, the communication unit can be immediately informed of such access planning requests and can essentially instantly establish a data connection to a participant identified via the access planning request. This enables particularly short-term access to the wind farm.

[0021] According to a further embodiment, the data connection between the communication unit and the predefined server is established via the external data network by the communication unit at predetermined times, at predetermined intervals, or upon request, for example, by a service employee on-site at the communication unit itself. In this case, new access planning requests are preferably received after the connection has been established, and the data connection is particularly preferably interrupted again after receipt.

[0022] This implementation accepts that the data connection between the communication unit and the predefined server does not need to be maintained continuously. While this eliminates the possibility of a participant accessing the wind farm for a short time, the system's security is further increased, as an existing data connection between the communication unit and the predefined server, which would potentially be vulnerable, would only be established for short periods of time.

[0023] According to the invention, the access planning request includes a time window. The time window is defined, for example, by a start time and a duration, or by a start time and an end time. The times include, for example, a date and a time, and the duration is specified in seconds, minutes, and / or hours. Depending on this time window, the communication unit then establishes a data connection with the subscriber identified by the access planning information at the beginning of the time window. Furthermore, the communication unit automatically terminates the data connection after the specified duration or at the end time.

[0024] This enables precise planning of access to the wind farm. An operator of the identified participant, for example, a service employee of a third-party provider, can wait for the communication unit to establish a data connection with the participant at a predefined time, particularly one specified by the operator. The operator then has the option of accessing the wind farm via the participant using the communication unit.

[0025] According to a further embodiment, the communication unit is connected to several components of the wind farm via an internal data network. The communication unit thus also serves, in particular, as a gateway. The access planning request includes information about at least one of the components in the wind farm. Furthermore, the communication unit establishes a data connection via the data network with the component specified in the access planning request.

[0026] The communication unit thus preferably also serves as a gateway to connect the identified participant with the specified predefined component of an access planning request via two data connections, namely, via the external data network on the one hand, and via the internal data network on the other. Remote access to the component in the wind farm by a participant in the external data network is thus possible without complex configuration, since, for example, network address translation can be omitted.

[0027] Particularly preferably, data is transmitted from the identified participant to a component of the wind farm and / or from the component to the identified participant by means of the communication unit.

[0028] According to a further embodiment, the identified subscriber is a computer with a unique network address in the external data network, in particular an IP address. The access planning request includes the subscriber's network address and, in particular, login data for the subscriber. With the access planning request, the communication unit thus receives unique information to establish a data connection with the identified subscriber.

[0029] According to a further embodiment, the server is a computer or is connected to a computer in order to enter access planning requests or receive them from a subscriber. The access planning requests are preferably entered via a further data connection, such as an internet connection to the computer, with the computer passing the access planning request to the server. The server can preferably be referred to as a broker. Particularly preferably, an input mask is provided in the computer which can be filled out by an external subscriber. The mask contains, for example, a query about a subscriber to be identified, in particular in the form of an IP address, login data which preferably comprises a user name and a password or a certificate, a time window in which the data connection is to be established and / or a component of a wind farm which is to be accessed.

[0030] This provides a simple way to create access planning requests.

[0031] According to one embodiment, the access planning request is automatically or manually approved before being forwarded to the server, or the access planning request is rejected. This preferably occurs after a security check. This creates a further security aspect, according to which an access planning request submitted by a participant requesting, for example, remote maintenance access is either automatically checked against predefined criteria or according to which a service employee reviews the access planning request and then manually approves it. This provides a further safeguard against unauthorized access to a wind farm.

[0032] According to a further embodiment, the access scheduling request received by the server is checked before the access scheduling request is made available for retrieval by a communications unit. A plausibility check of an access scheduling request can thus be performed in the server. This ensures that no access scheduling requests are passed to the communications unit that contain incorrect login data or the like, or that request access during time slots for which a maximum number of data connections is already scheduled.

[0033] The invention further comprises a system with a communications unit for establishing a data connection between the communications unit and a subscriber via a data network external to the wind farm. The system is configured to use the communications unit to establish a data connection between the communications unit and a predefined server via the external data network. Furthermore, the communications unit is configured to receive at least one access planning request from the predefined server via the external data network. The access planning request includes data that identifies a subscriber of the external data network.

[0034] In addition, the system's communication unit is configured to establish a data connection between the communication unit and the identified participant identified by the access planning request. The communication unit is further configured to discard or reject requests for establishing a data connection received from the external data network. Alternatively, the communication unit is configured to be invisible to requests for establishing a data connection in the external network.

[0035] The communication unit can thus preferably be referred to as the A-subscriber, and the other subscribers of the external data network as the B-subscribers. This means that the communication unit is always the unit that initiates a connection, whereas an identified subscriber is always the subscriber that was called or selected by the A-subscriber to initiate the connection. The communication unit is designed so that it can never function as a B-subscriber.

[0036] Furthermore, according to one embodiment, the communication unit is configured such that it constantly maintains a data connection with the predefined server and automatically re-establishes it in the event of a termination.

[0037] According to a further embodiment, the communication unit is set up or configured to establish a data connection between the communication unit and the predefined server via the external data network at predetermined times, at predetermined intervals or upon request, wherein in particular new access planning requests are received after the data connection has been established and particularly preferably the data connection is interrupted again after receiving.

[0038] According to a further embodiment, the system comprises at least one component of the wind farm, and the communication unit is connected to the component via an internal data network. Preferably, the communication unit is configured or set up to transmit data between the component and an identified participant.

[0039] According to a further embodiment, the system comprises the predefined server and preferably a computer, wherein the computer is configured to receive access planning requests and, in particular after an automatic or manual security check, to provide them to the server for retrieval by the communication unit.

[0040] According to a further embodiment, the system comprises the server and a plurality of communication units, each of which is assigned to one of a plurality of wind farms.

[0041] Furthermore, the invention relates to a server for providing access planning requests, which in particular each comprise data to identify a subscriber of an external network, describe a component of a wind farm and specify a time window in which a data connection is to be established between the subscriber and the component.

[0042] The invention also includes a wind farm with an embodiment of the aforementioned system.

[0043] Further embodiments are illustrated in the figures, which show: Figure 1 shows a wind turbine, Figure 2 shows a wind farm, Figure 3 shows an embodiment of the system and Figure 4 shows an embodiment of the steps of the method.

[0044] Figure 1 shows a wind turbine 100 with a tower 102 and a nacelle 104. A rotor 106 with three rotor blades 108 and a spinner 110 is arranged on the nacelle 104. During operation, the rotor 106 is set into rotation by the wind and thereby drives a generator in the nacelle 104.

[0045] The wind turbine 100 from Figure 1 can also be combined with several wind turbines 100 in a wind farm, as described below with regard to Figure 2 described.

[0046] In Figure 2 A wind farm 112 with, by way of example, three wind turbines 100 is shown. The wind turbines 100 can be identical or different. The wind turbines 100 are thus representative of essentially any number of wind turbines 100 in a wind farm 112. The wind turbines 100 provide their power, namely in particular the generated electricity, via an electrical farm grid 114. The currents or power generated by the individual wind turbines 100 are added together, and a transformer 116 is usually provided, which steps up the voltage in the farm and then feeds it into the supply grid 120 at the feed-in point 118, which is also generally referred to as a PCC.

[0047] Figure 2is only a simplified representation of a wind farm 112, which, for example, does not show any power control, although power control is of course present. The farm network 114 can also be designed differently, for example, by also having a transformer at the output of each wind turbine 100, to name just one other embodiment.

[0048] Figure 3shows a system according to an embodiment of the invention. The system comprises a wind farm 112 with three wind turbines 100 shown as examples. Each of the wind turbines is connected to a communication unit 12 via an internal data network 10. The communication unit 12 is, for example, part of a SCADA system 14 of the wind farm 112. The communication unit 12 can be connected to a plurality of participants 18 via an external data network 16. A data connection 20, established by the communication unit 12, exists with a predefined server 22.

[0049] The predefined server 22 can transmit access planning requests 24 to the communication unit 12 via this data connection 20. The access planning requests 24 are previously transmitted via the external data network 16 from a subscriber 18 to a computer 26. After a security check, the computer 26 transmits the access planning request 24 to the predefined server 22, which then transmits the access planning request 24 to the communication unit 12. The subscriber 18, who identifies himself with the access planning request 24, is then connected to the communication unit 12 by establishing a data connection 30 through the communication unit 12. The predefined subscriber 18 can thus exchange data with the communication unit 12. Establishing a data connection 30 from one of the subscribers 18 to the communication unit 12 is not possible via the external data network 16, which corresponds, for example, to the Internet.The communication unit 12 enables the subscriber 18 to access a component 54 of the wind farm 112 via the data connection 30.

[0050] Figure 4 describes an embodiment of the method for establishing the data connection 30 between the communication unit 12 of the wind farm 112 and a subscriber 18. In step 40, an access planning request 24 is transferred from a subscriber 18 to a computer 26. In step 42, this access planning request 24 is checked by the computer 26. In step 44, the checked access planning request 24 is transmitted to the server 22. The access planning request 24 is stored in the server 22 at least until it is retrieved by the communication unit 12 in step 46.

[0051] Furthermore, for example, in parallel, before, or only after step 46, a data connection 20 is established between the communication unit 12 and the predefined server 22 in step 48. Once the connection is established, the access planning request 24 is transferred to or received from the communication unit 12 in step 50. If the data connection 20 between the communication unit 12 and the predefined server 22 does not yet exist, the access planning request continues to be stored.

[0052] After the access planning request 24 has been transmitted to the communication unit 12, the data of the access planning request 24 are extracted in a step 52. The data comprise a time window 51 during which access to a component 54 of the wind farm 112 is desired. In a step 53, the system then waits until the time window 51 occurs, and in step 56, a data connection 30 is established between a subscriber 18, who is also identified by the data contained in the access planning request 24, and a component 54, which is also named in the access planning request 24. In step 58, data is then exchanged between the component 54 and the subscriber 18. After the time window 51 has expired, the data connection 30 is interrupted in step 60.

[0053] If at any time in a step 62 a subscriber 18 attempts to establish a connection with the communication unit 12, this request is ignored or rejected via a connection establishment in a step 64.

Claims

1. Method for establishing a data connection (30) between a communication unit (12) of a wind farm (112) and a subscriber (18) via a data network (16) external to the wind farm (112), comprising the steps of: - establishing (48) a data connection (20) between the communication unit (12) and a predefined server (22) via the external data network (16) by the communication unit (12), - receiving (50) at least one access scheduling request (24) from the predefined server (22) via the external data network (16) by the communication unit (12), wherein the access scheduling request (24) identifies a subscriber (18) of the external data network (16), - establishing (54) a data connection (30) between the communication unit (12) and the identified subscriber by the communication unit (12), wherein requests received from the external data network (16) for establishing a data connection (20, 30) are discarded or rejected (64) by the communication unit (12) or the communication unit (12) is not visible to subscribers (18) of the external data network (16) for requests for establishing a data connection (30), wherein the access scheduling request (24) comprises a time window (51) and the communication unit (12) executes the establishment of the data connection (20) at the beginning of the time window (51), and the communication unit (12) interrupts the data connection (20) after a duration has elapsed or at the end of the time window (51).

2. Method according to claim 1, wherein the communication unit (12) constantly maintains the data connection (20) between the communication unit (12) and the predefined server (22) via the external data network (16) and automatically re-establishes it (48) in the event of an interruption.

3. Method according to claim 1 or 2, wherein the communication unit (12) establishes the data connection (20) between the communication unit (12) and the predefined server (22) via the external data network (16) at predetermined times, at predetermined intervals or by request, preferably thereupon receives new access scheduling requests (24) and particularly preferably thereupon interrupts the data connection (20) again.

4. Method according to one of the preceding claims, wherein the communication unit (12) is connected to a plurality of components (54) of the wind farm (112) via an internal data network (10) and the access scheduling request (24) comprises an indication of at least one component (54) in the wind farm (112), wherein the communication unit (12) establishes a data connection via the internal data network (10) with the specified component (54), wherein preferably data is transmitted from the identified subscriber (18) to the at least one component (54) of the wind farm (112) and / or transmitted from the component (54) to the identified subscriber (18).

5. Method according to one of the preceding claims, wherein the identified subscriber (18) is a computer with a unique network address, in particular an IP address, and wherein the access scheduling request (24) comprises the network address of the subscriber and in particular login data for the subscriber.

6. Method according to one of the preceding claims, wherein a computer (26) is provided to receive access scheduling requests (24), in particular from a subscriber, in particular via the external data network (16), and the computer (26) transmits the access scheduling request (24) to the server.

7. Method according to claim 6, wherein the access scheduling request (24) is passed from the computer (26) to the server (22) when the access scheduling request (24) is automatically or manually released by or with the computer (26), in particular after a security check.

8. Method according to one of the preceding claims, wherein a received access scheduling request (24) is checked in the server (22) before the access scheduling request (24) is provided for retrieval by the communication unit (12).

9. System comprising a communication unit (12) of a wind farm (112) for establishing a data connection between the communication unit (12) and a subscriber (18) via a data network (16) external to the wind farm, wherein the communication unit (12) is in particular adapted to perform the steps of the method according to any one of claims 1 to 8, wherein the communication unit (12) is adapted for, - establishing a data connection (20) between the communication unit (12) and a predefined server (22) via the external data network (16), - receiving an access scheduling request (24) from the predefined server (22) via the external data network (16), wherein the access scheduling request (24) identifies a subscriber (18) of the external network (16) and comprises a time window (51), - establishing a data connection (30) between the communication unit (12) and the identified subscriber (18), and - to reject or refuse requests received from the external data network for establishing a data connection or to be invisible to subscribers (18) of the external data network (16) for requests for establishing a data connection, wherein the system is adapted for establishing the data connection (16) between the communication unit (12) and the predefined server (22) via the external data network (16) at predetermined times, at predetermined intervals or by request, preferably to receive new access scheduling requests (24) and particularly preferably to interrupt the data connection again, wherein the communication unit (12) is adapted for establishing the data connection (20) at the start of the time window (51) and to interrupt the data connection (20) after a duration has elapsed or at the end of the time window (51).

10. System according to claim 9, wherein the system is adapted for constantly maintaining the data connection (20) between the communication unit (12) and the predefined server (22) via the external data network (16) and for automatically re-establishing it in the event of an interruption.

11. System according to claim 9 or 10, wherein the system further comprises a component (54) of the wind farm (112) and the communication unit (12) is connected to the component (54) of the wind farm (112) via an internal data network (10), wherein the communication unit (12) is arranged for transmitting data between a subscriber (18) and the component (54), in particular designed as a gateway.

12. System according to any one of claims 9 to 11, wherein the system further comprises the server (22) and preferably a computer (26) for receiving the access scheduling requests (24).

13. System according to any one of claims 9 to 12, wherein the system comprises a server for executing the method according to any one of claims 1 to 8.

14. Wind farm comprising a system according to any one of claims 9 to 12, in particular comprising a communication unit (12).