Timestamping in wind turbines

1. A method of collecting event data in a wind park installation including a plurality of wind turbines, the method comprising:

providing a plurality of wind turbines, each of the plurality of wind turbines including a respective satellite-based clock;

distributing a first time signal from the respective satellite-based clock to a node in the wind turbine for each wind turbine in the plurality of wind turbines;

detecting respective events by the node happening in a subsystem connected to the node;

collecting respective pieces of event data by the node comprising an information about the respective events;

for each piece of collected event data, adding a timestamp to the respective pieces of collected event data characterizing a corresponding instant of time when the event was detected;

storing the timestamped event data;

providing a central time server in a substation of the wind park installation and distributing a second time signal from the central time server to the node of each wind turbine, wherein accuracy of the first time signal from the respective satellite-based clock is higher relative to accuracy of the second time signal from the central time server;

wherein the adding of the timestamp to the respective pieces of collected event data comprises adding a first timestamp based on the first time signal and a second timestamp based on the second time signal;

based on a time accuracy requirement associated with each respective piece of event data, selecting the first timestamp based on the first time signal for respective pieces of event data associated with a first time accuracy requirement, and selecting the second timestamp based on the second time signal for respective pieces of event data associated with a second time accuracy requirement, wherein the second time accuracy requirement is less than the first time accuracy requirement.

2. The method of claim 1 , wherein the respective satellite-based clock is a Global Positioning System based clock.

3. The method of claim 2 , wherein the respective Global Positional System based clock in each of the plurality of wind turbines is a Pulse Per Second clock of the GPS receiver.

4. The method of claim 1 ,

further comprising providing a local time server in each of the wind turbines, and

wherein distributing the first time signal includes synchronizing the local time server to the respective satellite-based clock and providing the first time signal from the synchronized local time server to the node.

5. The method of claim 4 , wherein providing the first time signal from the synchronized local time server to the node is done by means of Precision Time Protocol.

6. The method of claim 1 , wherein distributing the second time signal is done by means of Network Time Protocol.

7. The method of claim 1 , further comprising providing a local clock in the node of each wind turbine and synchronizing the local clock to the central time server.

8. The method of claim 1 ,

wherein each wind turbine comprises a first group of nodes and a second group of nodes, and

wherein the first group of nodes add the first timestamp to the respective collected event data collected by the first group of nodes and the second group of nodes add the second timestamp to the respective collected event data collected by the second group of nodes.

9. The method of claim 1 ,

further comprising combining the first and the second time signals to create a third time signal,

wherein adding the timestamp comprises adding a third timestamp based on the third time signal.

10. A plurality of wind turbines in a wind park installation, each of the plurality of wind turbines comprising:

a respective satellite-based clock comprising a respective Global Positioning System (GPS) receiver;

a node adapted to detect events happening in a subsystem connected to the node, to collect event data comprising an information about the events, to add a timestamp to each piece of collected event data characterizing a corresponding instant of time when the event was detected and to store the timestamped event data;

providing a central time server in a substation of the wind park installation and distributing a time signal from the central time server to the node of each wind turbine, wherein accuracy of a time signal from the respective satellite-based clock is higher relative to accuracy of the time signal from the central time server;

wherein an adding of the timestamp to the respective pieces of collected event data comprises adding a first timestamp based on the time signal from the respective satellite-based clock and a second timestamp based on the time signal from the central time server; and

based on a time accuracy requirement associated with each respective piece of event data, selecting the first timestamp based on the time signal from the respective satellite-based clock for respective pieces of event data associated with a first time accuracy requirement, and selecting the second timestamp based on the time signal from the central time server for respective pieces of event data associated with a second time accuracy requirement, wherein the second time accuracy requirement is less than the first time accuracy requirement.