Tunnelling time-critical messages between substations over WAN

1. A method of transmitting time-critical messages in an Open Systems Interconnection (OSI) layer 2 network tunnel from a first intelligent electronic device (IED) in a first substation to a second IED in a second substation over a Wide Area Network (WAN), wherein each of the first and second substation comprises an edge IED and is associated with a substation Local Area Network (LAN), wherein each of the time-critical messages comprises message parameters, wherein the method comprises the steps of:

a) providing a translation table comprising corresponding translated values of the message parameters, between the first and/or second substation LAN and the WAN,

b) configuring a virtual IED in the second substation using the translated values of the message parameters, to impersonate the first IED,

c) translating the message parameters according to the translation table, by the edge IED of the first and/or second substation,

d) forwarding the time-critical messages from the first IED to the WAN, and

e) receiving the time-critical messages by the second IED from the WAN.

2. The method according to claim 1 , wherein the step c) is performed by the edge IED in OSI layer 2, and wherein the edge IED is adapted to monitor the OSI layer 2 network tunnel.

3. The method according to claim 2 , further comprising the step of: selecting relevant time-critical messages from the time-critical messages based on the messages parameters, prior to the step c).

4. The method according to claim 3 , wherein the step c) is performed again after step d), and wherein the time-critical messages are GOOSE and/or SV messages.

5. The method according to claim 3 , wherein the step of translating is performed n times, where n is an integer that defines the number of substations to which the time-critical messages are sent via the WAN or that corresponds to the number of redundant pseudo wires via which the time-critical messages are received from the WAN, and wherein the translation table comprises: an egress translation table for transmission of the time-critical messages from a substation LAN towards WAN, and an ingress table for the time-critical messages from the WAN to a substation LAN.

6. The method according to claim 3 , wherein the parameters of the time-critical messages comprises at least one of the following identifiers: MAC, VLAN ID, APPID, svID, goID, or LDName that is within “gocbRef” of GOOSE message and within “dataset” of GOOSE and SV messages, and wherein the virtual IED is defined in a SCD file of the second substation.

7. The method according to claim 1 , further comprising the step of:

selecting relevant time-critical messages from the time-critical messages based on the messages parameters, prior to the step c).

8. The method according to claim 1 , wherein the step c) is performed again after step d).

9. The method according to claim 1 , wherein the time-critical messages are GOOSE and/or SV messages.

10. The method according to claim 1 , wherein the step of translating is performed n times, where n is an integer that defines the number of substations to which the time-critical messages are sent via the WAN or that corresponds to the number of redundant pseudo wires via which the time-critical messages are received from the WAN.

11. The method according to claim 1 , wherein the translation table comprises: an egress translation table for transmission of the time-critical messages from a substation LAN towards WAN, and an ingress table for the time-critical messages from the WAN to a substation LAN.

12. The method according to claim 1 , wherein the parameters of the time-critical messages comprises at least one of the following identifiers: MAC, VLAN ID, APPID, svID, goID, or LDName that is within “gocbRef” of GOOSE message and within “dataset” of GOOSE and SV messages.

13. The method according to claim 1 , wherein the virtual IED is defined in a Substation Configuration Description (SCD) file of the second substation.

14. The method according to claim 13 , comprising the steps of:

importing a configuration file of the edge IED of the second substation into a system engineering tool for the second substation, and obtaining the SCD file of the second substation,

inputting the SCD file into a virtual IED engineering tool comprising means for generating instantiated IED descriptions for the virtual IED and the edge IED.

15. The method according to claim 14 , further comprising the step of:

generating a first instantiated IED description IID for the virtual IED, wherein physical device information proxy name of the virtual IED is set to name of the first IED,

generating an instantiated IED description IID for the edge IED based on channel link defined between communication interface instances of the first and second substation, and

importing the first and second IID into the system engineering tool for the second substation.

16. An apparatus of transmitting time-critical messages in Open Systems Interconnection (OSI) layer 2 network tunnel from a first intelligent electronic device (IED) in a first substation to a second IED in a second substation over a Wide Area Network (WAN), wherein the first and second substation are associated with a first and second substation Local Area Network (LAN) respectively, wherein the apparatus comprises:

an edge device being adapted to translate message parameters of the time-critical messages according to a translation table comprising corresponding translated values of message parameters for the first and/or second substation LAN and the WAN, and

a virtual IED defined in the second substation using the translated values of the message parameters, and adapted to impersonate emulating the first IED.

17. The apparatus according to claim 16 , wherein the edge device comprises a filter adapted to select the relevant time-critical messages prior to translation of the message parameters.

18. The apparatus according to claim 17 , wherein the edge device is adapted to perform the translation of the message parameters n times, where n is an integer that defines the number of substations to which the time-critical messages are sent via the WAN or that corresponds to the number of redundant pseudo wires via which the time-critical messages are received from the WAN.

19. The apparatus according to any one of claim 16 , wherein the edge device is adapted to perform the translation of the message parameters n times, where n is an integer that defines the number of substations to which the time-critical messages are sent via the WAN or that corresponds to the number of redundant pseudo wires via which the time-critical messages are received from the WAN.

20. A system of transmitting time-critical messages in Open Systems Interconnection (OSI) layer 2 network tunnel from a first intelligent electronic device (IED) in a first substation to a second IED in a second substation over a Wide Area Network (WAN), wherein the first and second substation are associated with a first and second substation Local Area Network (LAN) respectively, wherein the system comprises:

a first and second edge IED arranged in the first and second substation LAN respectively, and adapted to translate message parameters of the time-critical messages according to a translation table comprising corresponding translated values of message parameters for the first and/or second substation LAN and the WAN,

a virtual IED defined in the second substation using the translated values of the message parameters, and adapted to impersonate the first IED in the first substation.