Controlling a wind turbine network switch

Abstract

The invention relates to controlling a wind turbine network switch. In a first wind turbine operation mode the network switch is in a first configuration in which controller input data received at the network switch from external to the wind turbine is permitted to flow through the network switch to the controller, and in which controller output data received at the network switch from the controller is permitted to flow through the network switch. In a second wind turbine operation mode the network switch is in a second configuration differing from the first configuration in that controller input data is blocked from flowing through the network switch to the controller. Upon receiving user input at the operation mode selector to change from the first to the second operation mode, the operation mode selector transmits a signal to the network switch to change from the first to the second configuration.

Description

[0001] CONTROLLING A WIND TURBINE NETWORK SWITCH

[0002] TECHNICAL FIELD

[0003] The invention relates to controlling a network switch of a wind turbine. In particular, the invention relates to controlling the wind turbine network switch to change between a first configuration, in which flow of data is permitted through the network switch to and from a controller of the wind turbine, and a second configuration, in which data flow through the network switch from the controller is permitted but data flow through the network switch to the controller is blocked.

[0004] BACKGROUND

[0005] Wind turbines are used to capture energy in the wind as it flows past them, and to generate electrical power from the captured energy, e.g. to be supplied to an electrical grid. Wind turbines operate in a variety of conditions, e.g. environmental conditions, and monitoring and controlling operational parameters of a wind turbine in view of such conditions is needed to achieve optimal wind turbine performance, e.g. maximising power production and / or minimising wind turbine component loading.

[0006] Wind turbines may be located in relatively remote or inaccessible locations, onshore or offshore. Monitoring and control of wind turbine operation may typically be performed from locations remote from the wind turbine via suitable data flows across a communications network.

[0007] In certain circumstances, it is necessary to halt operation of a wind turbine, such as when service personnel are present at or in the wind turbine, e.g. to perform maintenance. A known way to achieve this is by de-energising the wind turbine system using a main circuit breaker or a physical switch at the wind turbine to disconnect the wind turbine from remote communication. This ensures that remote control of the wind turbine is prevented, e.g. to prevent the wind turbine being started unexpectedly while service personnel are present at the wind turbine. However, this also means that data, e.g. diagnostic data, cannot be communicated from the wind turbine to, for instance, a control system remote from the wind turbine. It is desired to continue monitoring wind turbine conditions and parameters during maintenance. One known way to address this is to provide a wind turbine system with two networks for communication (see WO 2010 / 125140). One of the networks may be for receiving control data at the wind turbine from a remote location, and may be disconnected from external communication during maintenance or service of the wind turbine. Another of the networks may be for providing monitoring data, e.g. to locations external to the wind turbine, and may remain connected during wind turbine maintenance.

[0008] There remains a need for wind turbine systems that allow for monitoring wind turbine parameters and conditions when wind turbine operation is halted, e.g. when service personnel are at the wind turbine site. It is against this background to which the present invention is set.

[0009] SUMMARY OF THE INVENTION

[0010] According to an aspect of the present invention there is provided a control system for a wind turbine. The control system comprises a controller, an operation mode selector, and a network switch.

[0011] In a first operation mode of a plurality of operation modes of the wind turbine the network switch is in a first configuration in which controller input data received at the network switch from external to the wind turbine is permitted to flow through the network switch to the controller, and in which controller output data received at the network switch from the controller is permitted to flow through the network switch.

[0012] In a second operation mode of the plurality of operation modes the network switch is in a second configuration in which controller input data received at the network switch from external to the wind turbine is blocked or suppressed from flowing through the network switch to the controller, and in which controller output data received at the network switch from the controller is permitted to flow through the network switch.

[0013] The operation mode selector is configured to receive user input indicative of user selection to change between different ones of the plurality of operation modes of the wind turbine. Upon receiving user input indicating user selection to change from the first operation mode to the second operation mode, the operation mode selector is configured to transmit an instruction signal to the network switch to change from the first configuration to the second configuration. In some examples, upon receiving user input indicating user selection to change from the second operation mode to the first operation mode, the operation mode selector may be configured to transmit a further instruction signal to the network switch to change from the second configuration to the first configuration.

[0014] In some examples, upon receiving the user input indicating user selection to change from the first operation mode to the second operation mode, the operation mode selector may be configured to transmit a controller instruction signal to the controller to instruct the controller to change its state from a first state corresponding to the first configuration of the network switch to a second state corresponding to the second configuration of the network switch.

[0015] The controller input data and controller output data may be received at respective communication ports of the network switch. The instruction signal from the operation mode selector may be received at an input / output port of the network switch.

[0016] The controller output data may comprise wind turbine diagnostic data (or other monitoring, reporting or supervisory data).

[0017] The controller output data may flow through the network switch to one or more external systems external to the wind turbine. Optionally, the one or more external systems may include a wind turbine diagnostic system.

[0018] The controller output data may flow through the network switch to one or more user terminals at or in the wind turbine.

[0019] The controller input data may comprise wind turbine control data for instructing the controller to cause a change to operation of the wind turbine.

[0020] The wind turbine control data may be for instructing the controller to start-up operation of the wind turbine.

[0021] The controller input data may be received at the network switch from a remote control system, remote from the wind turbine, for controlling operation of the wind turbine. The controller input data may be received at the network switch from a wind farm controller for controlling operation of a wind farm comprising the wind turbine.

[0022] The first operation mode of the wind turbine may be a normal operation mode in which a rotor and rotor blades of the wind turbine are permitted to rotate about a rotational axis of the wind turbine to capture energy from wind in the vicinity of the wind turbine.

[0023] The second operation mode of the wind turbine may be an operation mode that is appropriate for implementation when one or more personnel are in or at the wind turbine. Optionally, the wind turbine may be shut down in the second operation mode.

[0024] In some examples, to change from the first configuration to the second configuration the network switch may be configured to change an access control list (ACL) of the network switch.

[0025] The network switch may be positioned in a tower of the wind turbine.

[0026] The operation mode selector may comprise a physical actuator arranged for actuation by a user.

[0027] The operation mode selector may be positioned in the wind turbine.

[0028] According to another aspect of the invention there is provided a wind turbine comprising a control system as defined above.

[0029] According to another aspect of the invention there is provided a method for controlling a wind turbine. The wind turbine comprises a controller, an operation mode selector, and a network switch. The method comprises, at the operation mode selector, receiving user input indicative of user selection to change from a first operation mode of the wind turbine to a second operation mode of the wind turbine. The method comprises, upon receiving the user input, transmitting an instruction signal from the operation mode selector to the network switch to instruct the network switch to change from the first configuration to the second configuration. In the first configuration of the network switch, controller input data received at the network switch from external to the wind turbine is permitted to flow through the network switch to the controller, and controller output data received at the network switch from the controller is permitted to flow through the network switch. In the second configuration of the network switch, controller input data received at the network switch from external to the wind turbine is blocked from flowing through the network switch to the controller, and controller output data received at the network switch from the controller is permitted to flow through the network switch.

[0030] According to another aspect of the invention there is provided a non-transitory, computer readable storage medium storing instructions thereon that, when executed by one or more computer processors, causes the one or more computer processors to perform the method defined above.

[0031] BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Examples of the invention will now be described with reference to the accompanying figures, in which:

[0033] Figure 1 schematically illustrates a wind turbine in accordance with an aspect of the invention;

[0034] Figure 2 is a schematic section view of the wind turbine of Figure 1 , including a schematic illustration of a control system of the wind turbine in accordance with an aspect of the invention; and

[0035] Figure 3 shows the steps of a method performed by the control system of Figure 2 in accordance with an aspect of the invention.

[0036] DETAILED DESCRIPTION

[0037] Figure 1 illustrates, in a schematic view, an example of a wind turbine 10. The wind turbine 10 includes a tower 102, a nacelle 103 disposed at the apex of, or atop, the tower 102, and a rotor 104 operatively coupled to a generator housed inside the nacelle 103. In addition to the generator, the nacelle 103 houses other components required for converting wind energy into electrical energy and various components needed to operate, control, and optimise the performance of the wind turbine 10. The rotor 104 of the wind turbine 10 includes a central hub 105 and three rotor blades 106 that project outwardly from the central hub 105. With additional reference to Figure 2 - which illustrates a schematic sectional view of the wind turbine 10 - the wind turbine 10 comprises a control system, generally indicated by reference numeral 20. The control system 20 may be placed inside the nacelle 103 or distributed at a number of communicatively connected locations inside (or externally to) the turbine 10. The control system 20 comprises a main controller 201 - also referred to as a wind turbine controller or, simply, controller - connected via an internal communication network 202 to a number of distributed controller nodes 203. The communication network 202 may further comprise a number of communication switches 204 between the controller 201 and communication nodes 203. Each distributed controller node 203 may be connected to a number of sensors 22 for monitoring one or more operational parameters of the wind turbine 10.

[0038] The wind turbine 10 may be included among a collection of other wind turbines belonging to a wind power plant, also referred to as a wind farm or wind park, that serves as a power generating plant connected by transmission lines with a power grid.

[0039] The control system 20 thus may comprise a number of elements, including at least one controller with a processor and a memory, so that the processor is capable of executing computing tasks based on instructions stored in the memory. The control system 20 may, via a network switch 205 and an external communication network 24, be connected to an external or remote computing system 26, such as a central controller, a supervising control and data acquisition (SCADA) system, or other type of controller / system. In this manner, sensor readings, control data, etc., may be made available at the external computing system 26, via the internal communication network 202 and the external communication network 24.

[0040] The network switch 205 is configured to receive and send communications signals or data via the external communications network 24. In particular, control signals or data 24a may be received from the external computing system 26 via the external network 24 at the network switch 205, and monitoring signals or data 24b, e.g. diagnostic data, may be received via the network switch 205 and the network 24 at the external computing system 26.

[0041] The control data 24a may flow through the network switch 205 to the controller 201 via the internal communication network 202 as control data 202a. The monitoring data flowing through the network switch 205 to the external network 24 may be received at the switch 205 from the controller 201 via the internal network 202 as monitoring data 202b.

[0042] The wind turbine 10 may further include a local monitoring / diagnostics module or system 107. In the illustrated example, the local diagnostics module 107 is located in the tower 102 of the wind turbine 10; however, it will be understood that in different examples the local diagnostics module 107 may be located elsewhere in or near to the wind turbine 10, e.g. in the nacelle 103. The monitoring data 202b from the controller 201 may be communicated, via the network switch 205 and internal communication network 202, to the local diagnostics module 107. The local diagnostics module 107 may include one or more user terminals where service personnel at the wind turbine 10 can view and analyse the received monitoring data 202b from the controller 201.

[0043] The wind turbine 10 is operable in a number of different operation modes. For instance, in a so-called normal operation mode the wind turbine 10 may produce power for the grid. In such a mode, the rotor 104 and rotor blades 106 of the wind turbine 10 may be permitted to rotate about a rotational axis of the wind turbine 10 to capture energy from wind in the vicinity of the wind turbine 10. Such a wind turbine operation mode is not suitable for implementation when service personnel are present in or at the wind turbine 10.

[0044] Another operation mode of the wind turbine may be a so-called ‘person in turbine’ mode. In such a mode, the wind turbine 10 will typically not produce power for the grid. Indeed, in such an operation mode the wind turbine 10 may be stopped or shut down. In this case, the rotor 104 and rotor blades 106 do not rotate about the wind turbine rotational axis and so do not capture wind energy for power generation. For instance, the rotor 104 may be locked in position by engaging a rotor lock in such an operation mode. The person in turbine operation mode may be regarded as an operation mode that is suitable for implementation when service personnel are present in or at the wind turbine 10.

[0045] Although only two wind turbine operation modes are outlined above, it will be understood that the wind turbine 10 may be operable in any suitable number of different operation modes. For the purposes of the present disclosure, these operation modes may be split into a first set of one or more operation modes that are not suitable for implementation when wind turbine maintenance is being performed, e.g. service personnel are present at the wind turbine 10, and a second set of one or more operation modes that are suitable for implementation when wind turbine maintenance is being performed. Changing operation of the wind turbine 10 between different wind turbine operation modes may be performed or initiated in a number of different ways. For instance, this can be performed from a location remote from the wind turbine 10, such as from the external computing system 26. In such a case, an instruction or command to change the wind turbine operation mode is communicated as control data 24a from the external computing system 26 to the wind turbine network switch 205 via the external network 24, and through the network switch 205 to the controller 201 as control data 202a via the internal network 202. Upon receiving the command, the controller 201 may transmit one or more control signals to control one or more components of the wind turbine 10 in a manner required to change to the relevant operation mode. For instance, to change to an operation mode in which the wind turbine 10 is shut down or stopped, the controller 201 may control the rotor lock for locking the rotor 104 in place to engage so that the rotor 104 cannot rotate about the wind turbine 10 rotational axis. The control data 24a may include any suitable control signals for controlling operation of the wind turbine 10, e.g. to instruct the wind turbine to start up or to shut down, to set one or more operational setpoints for power productions, etc.

[0046] The wind turbine control system 20 includes an operation mode selector 206. In the illustrated example, the operation mode selector 206 is located in the wind turbine tower 102; however, it will be understood that in different examples it may be located elsewhere, e.g. in the nacelle 103. The operation mode selector 206 allows for service personnel present at the wind turbine 10 to change the operation mode of the wind turbine 10.

[0047] The provision of such an operation mode selector is required for compliance with certain standards / directives covering machinery including wind turbine machinery. In particular, Annex 1 of the Machinery Directive 2006 / 42 / EC states: “If machinery has been designed and constructed to allow its use in several control or operating modes requiring different protective measures and / or work procedures, it must be fitted with a mode selector which can be locked in each position. Each position of the selector must be clearly identifiable and must correspond to a single operating or control mode."

[0048] The operation mode selector 206 may include a physical actuator or switch that can be actuated by a user, e.g. service personnel, to instruct the wind turbine 10 to change from one operation mode to another. In known arrangements, a wind turbine operation mode selector may be actuated to disconnect the wind turbine from remote communication by de-energising the wind turbine system.

[0049] Examples of the present invention are advantageous in that communication between a wind turbine and one or more remote systems can be maintained during wind turbine maintenance while still adhering to requirements for compliance with certain directives, such as the directive outlined above. In particular, the wind turbine and remote system can remain in communication during wind turbine maintenance such that monitoring data, such as diagnostic data, can be communicated from the wind turbine to the remote system, but that the remote system cannot control operation of the wind turbine. This means that diagnostic visibility, e.g. SCADA functionality, of the wind turbine is maintained from remote locations while it is still suitable for people to be present in the wind turbine. Examples of the invention benefit from not needing to provide separate communication networks in order to achieve the above effects. Instead, the invention makes use of a logical (software) approach / implementation.

[0050] The beneficial effects of the invention are achieved using the network switch 205 of the wind turbine control system 20, specifically in that the network switch 205 is reconfigurable to take different configurations in different operation modes of the wind turbine 10. Different communication paths between different systems / modules through the network switch 205 are permitted or blocked in different configurations of the network switch 205. This is discussed in greater detail below.

[0051] In a first configuration of the network switch 205, data flow from the wind turbine internal communication network 202 to the external communication network 24, or to another part of the internal communication network 202 via the network switch 205, is permitted. In the first configuration, data flow from the external communication network 24 to the internal communication network 202 is also permitted.

[0052] That is, in the first configuration of the network switch 205 monitoring data 202b, e.g. wind turbine diagnostic data, output from the controller 201 can flow through the network switch 205 and be communicated as monitoring data 24b to the external computing system 26. The monitoring data 202b output from the controller 201 can also flow through the network switch 205 and be communicated to another system / module of the wind turbine 10 on the internal communication network 202, such as to the local diagnostic module 107. Furthermore, in the first configuration control data 24a output from the external computing system 26 can flow through the network switch 205 and be communicated as control data 202a to the controller 201 .

[0053] In view of the open data communication paths from a remote system / location to the wind turbine 10, and vice versa, the first configuration of the network switch 205 may be regarded as being suitable when the wind turbine 10 is operating in the normal mode of operation. More generally, given that control data may be communicated to the controller 201 from an external system in the first configuration, then the first configuration may be regarded as being suitable when there are no service personnel in or at the wind turbine 10.

[0054] Like in the first configuration, in a second configuration of the network switch 205 data flow from the wind turbine internal communication network 202 to the external communication network 24, or to another part of the internal communication network 202 via the network switch 205, is permitted. However, in contrast to the first configuration, in the second configuration of the network switch 205 data flow from the external communication network 24 is blocked from being communicated to and along the internal communication network 202.

[0055] That is, in the second configuration of the network switch 205 monitoring data 202b output from the controller 201 can flow through the network switch 205 and be communicated as monitoring data 24b to the external computing system 26, and / or can be communicated to another system / module of the wind turbine 10 on the internal communication network 202, such as to the local diagnostic module 107. However, in the second configuration control data 24a output from the external computing system 26 is blocked from flowing through the network switch 205. As such, control data 24a received at the network switch 205 from a remote location is not communicated to the controller 201. This means that remote control of the wind turbine 10 is prevented when the network switch 205 is in the second configuration. For instance, this ensures that unexpected start up of the wind turbine 10 - based on a remote control instruction - does not occur when service personnel are present at the wind turbine 10.

[0056] In view of the open data communication path from the wind turbine controller 201 to a remote location / system, but the closed communication path from the remote system / location to the wind turbine controller 201 , the second configuration of the network switch 205 may be regarded as being suitable when the wind turbine 10 is operating in the ‘person in turbine’ mode of operation. More generally, given that control data is blocked from being communicated to the controller 201 from an external system in the second configuration, then the second configuration may be regarded as being suitable when there are service personnel in or at the wind turbine 10, e.g. during wind turbine maintenance.

[0057] The network switch 205 can be controlled to switch between different configurations in dependence on user input at the operation mode selector 206. In particular, selection of a specific wind turbine operation mode at the mode selector 206 may cause a dynamic reprogramming of the network switch 205 into a different configuration based on the selection.

[0058] Each configuration of the network switch 205 may be implemented as instructions for whether to accept or block data or network traffic received at certain inputs (or input ports) of the switch 205. For instance, an input of the network switch 205 that receives external data 24a from the external network 24 may be configured or programmed to allow the data to flow through the network switch 205 in the first configuration but then reconfigured or reprogrammed to block the input and passage through the network switch 205 of such data in the second configuration. In contrast, an input of the network switch 205 that receives data from the controller 201 may be configured or programmed to allow the data to flow through the network switch 205 in both the first and second configurations.

[0059] The input ports of the network switch 205 that receive control data 24a from external to the wind turbine 10, and that receive monitoring data 202b from the controller 201 , may be communication ports. These communication ports may be Ethernet-based ports that are suitable for handling network-based communications data.

[0060] Changing between different configurations of the network switch 205 may involve changing or updating a filter list, or access control list (ACL), of the network switch 205 that defines whether to forward / pass or block / drop traffic received at each input port of the switch 205. In particular, when the network switch 205 receives a trigger signal 207 from the mode selector 206 indicating a change of selected wind turbine operation mode, this can trigger a response at the network switch 205 to change / update the filter list or ACL list in order to change the switch configuration, as appropriate. Changing from the first to the second configuration may be regarded as using a unidirectional filtering mechanism, where the filtering mechanism is handled through reconfiguration runtime in the switch 205. The input port of the network switch 205 that receives the trigger signal 207 from the mode selector 206 may be an input / output (I / O) port. In contrast to the communication ports of the network switch 205 that handle network-based communications data, the I / O port receiving input from the mode selector 206 may be a discrete port that is suitable for handling binary (on / off) commands. The trigger signal 207 may be an on or off signal depending on which operation mode is selected at the mode selector 206.

[0061] In some examples of the invention, in addition to a change of wind turbine operation being selected at the mode selector 206 triggering a change of configuration of the network switch 206, a reconfiguration or reprogramming of the controller 201 may also be triggered by such an operation mode selection change. In particular, in response to a change of wind turbine operation mode being selected at the mode selector 206, a further trigger signal 208 may be transmitted from the mode selector 206 to the controller 206 to cause or instruct an appropriate change in configuration, state or operation of the controller 201 . The change instructed by the further trigger signal 208 to the controller 201 may be a matching or corresponding change instructed by the trigger signal 207 to the network switch 205. For instance, when the operation mode selector 206 is actuated to select the second wind turbine operation mode - suitable for implementation when service personnel are present at the wind turbine 10 - the further trigger signal 207 may cause the controller 201 to reprogram such that the controller 201 blocks input of external traffic, e.g. a control signal 202a.

[0062] Figure 3 summarises the steps of a method 30 performed by the wind turbine control system 20 in accordance with examples of the invention. At step 301 , user input is received at the operation mode selector 206, e.g. from service personnel located at the wind turbine 10. The received input may be indicative of a selection of a wind turbine operation mode requested by the user. The input may be in the form of actuation of a physical switch having different positions corresponding to different defined wind turbine operation modes, for instance.

[0063] The user may be able to select between at least a first wind turbine operation mode that is suitable for implementation when there are no service personnel present at the wind turbine 10, e.g. a normal operation mode in which the wind turbine 10 produces power for the grid, and a second wind turbine operation mode that is suitable for implementation when there are service personnel present at the wind turbine 10, e.g. during wind turbine maintenance. At step 302, the method 30 may involve performing a determination as to whether the received user input is indicative of the user requesting a change from the first wind turbine operation mode to the second wind turbine operation mode. In some examples, such a determination may be performed at the mode selector 206.

[0064] If yes, then at step 303 the method 30 involves instructing or causing the network switch 205 to change or update from the first configuration to the second configuration, as defined above. In particular, the trigger signal 207 is sent from the mode selector 206 to the switch 205 to cause appropriate reconfiguration of the switch 205, e.g. by changing the filter list as described above. Note that the first configuration of the network switch 205 is suitable for implementation when the wind turbine 10 is in the first operation mode. Correspondingly, the second configuration of the network switch 205 is suitable for implementation when the wind turbine 10 is in the second operation mode.

[0065] If the determination at step 302 is no, then at step 304 the method 30 may involve performing a determination as to whether the received user input is indicative of the user requesting a change from the second wind turbine operation mode to the first wind turbine operation mode. If yes, then at step 305 the method 30 involves causing the network switch 205 to change from the second configuration to the first configuration, again via transmission of the trigger signal 207 from the mode selector 206 to the network switch 205.

[0066] In the method illustrated in Figure 3, a specific determination as to whether the selected operation mode has changed from the first to the second operation mode, or vice versa, is described (steps 302 and 304). However, it will be understood that in some examples of the invention no such specific determination is made or needed, and that user actuation of the operation mode selector 206 automatically triggers appropriate reconfiguration of the network switch 205 via (automatic) transmission of the trigger signal 207.

[0067] Many modifications may be made to the described examples without departing from the scope of the amended claims.

Claims

CLAIMS1. A control system for a wind turbine, the control system comprising: a controller; an operation mode selector; and a network switch, wherein in a first operation mode of a plurality of operation modes of the wind turbine the network switch is in a first configuration in which controller input data received at the network switch from external to the wind turbine is permitted to flow through the network switch to the controller, and in which controller output data received at the network switch from the controller is permitted to flow through the network switch, wherein in a second operation mode of the plurality of operation modes the network switch is in a second configuration in which controller input data received at the network switch from external to the wind turbine is blocked from flowing through the network switch to the controller, and in which controller output data received at the network switch from the controller is permitted to flow through the network switch, wherein the operation mode selector is configured to receive user input indicative of user selection to change between different ones of the plurality of operation modes of the wind turbine, wherein, upon receiving user input indicating user selection to change from the first operation mode to the second operation mode, the operation mode selector is configured to transmit an instruction signal to the network switch to change from the first configuration to the second configuration.

2. A control system according to Claim 1 , wherein, upon receiving user input indicating user selection to change from the second operation mode to the first operation mode, the operation mode selector is configured to transmit a further instruction signal to the network switch to change from the second configuration to the first configuration.

3. A control system according to Claim 1 or Claim 2, wherein, upon receiving the user input indicating user selection to change from the first operation mode to the second operation mode, the operation mode selector is configured to transmit a controller instruction signal to the controller to instruct the controller to change its state from a first state correspondingto the first configuration of the network switch to a second state corresponding to the second configuration of the network switch.

4. A control system according to any previous claim, wherein the controller input data and controller output data are received at respective communication ports of the network switch, and wherein the instruction signal from the operation mode selector is received at an input / output port of the network switch.

5. A control system according to any previous claim, wherein the controller output data comprises wind turbine diagnostic data.

6. A control system according to any previous claim, wherein the controller output data flows through the network switch to: one or more external systems external to the wind turbine; optionally, when dependent on Claim 4, wherein the one or more external systems includes a wind turbine diagnostic system; or, one or more user terminals at or in the wind turbine.

7. A control system according to any previous claim, wherein the controller input data comprises wind turbine control data for instructing the controller to cause a change to operation of the wind turbine; optionally, wherein the wind turbine control data is for instructing the controller to start-up operation of the wind turbine.

8. A control system according to any previous claim, wherein the controller input data is received at the network switch from: a remote control system, remote from the wind turbine, for controlling operation of the wind turbine; or, a wind farm controller for controlling operation of a wind farm comprising the wind turbine.

9. A control system according to any previous claim, wherein the first operation mode of the wind turbine is a normal operation mode in which a rotor and rotor blades of the wind turbine are permitted to rotate about a rotational axis of the wind turbine to capture energy from wind in the vicinity of the wind turbine.

10. A control system according to any previous claim, wherein the second operation mode of the wind turbine is an operation mode that is appropriate for implementation when one or more personnel are in or at the wind turbine; optionally, wherein the wind turbine is shut down in the second operation mode.

11. A control system according to any previous claim, wherein to change from the first configuration to the second configuration the network switch is configured to change an access control list, ACL, of the network switch.

12. A control system according to any previous claim, wherein the network switch is positioned in a tower of the wind turbine.

13. A control system according to any previous claim, wherein the operation mode selector comprises a physical actuator arranged for actuation by a user.

14. A wind turbine comprising a control system according to any previous claim.

15. A method for controlling a wind turbine, the wind turbine comprising: a controller; an operation mode selector; and a network switch, the method comprising: at the operation mode selector, receiving user input indicative of user selection to change from a first operation mode of the wind turbine to a second operation mode of the wind turbine; upon receiving the user input, transmitting an instruction signal from the operation mode selector to the network switch to instruct the network switch to change from the first configuration to the second configuration, wherein in the first configuration of the network switch, controller input data received at the network switch from external to the wind turbine is permitted to flow through the network switch to the controller, and controller output data received at the network switch from the controller is permitted to flow through the network switch, wherein in the second configuration of the network switch, controller input data received at the network switch from external to the wind turbine is blocked from flowing through thenetwork switch to the controller, and controller output data received at the network switch from the controller is permitted to flow through the network switch.

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