Relay-to-relay direct communication system and method in an electric power system

• US 7,463,467 B2
• Filed: 08/25/2005
• Issued: 12/09/2008
• Est. Priority Date: 07/06/2001
• Status: Expired due to Term

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Lee, Tony J., Dolezilek, David J.
• Primary Examiner(s): Sherry; Michael J
• Assistant Examiner(s): THOMAS, LUCY M
• Application Number:
  US11/211,816
• Publication Number:
  US 20050280965A1
• Time in Patent Office: 1,202 Days
• Field of Search: 361/64
• US Class Current: 361/64
• CPC Class Codes: H02H 1/0061 concerning transmission of signals transmission of measured quantities or switching orders; sectionalised protection involving signal transmission between at least two stations H02H7/261; comparison of the voltage or current values at two spaced portions of a single system H02H3/28; transferring the output of a sensing member to another variable G01D5/00; electrical measuring arrangements using modulation of electromagnetic waves, e.g. light beams G01R15/24, G01R15/26
• CPC Class Codes: H02H 3/05 with means for increasing reliability, e.g. redundancy arrangements for logic circuits H03K19/003
• CPC Class Codes: H02H 7/261 involving signal transmission between at least two stations transmission of signals in general H02H1/0061
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/16 Electric power substations

Abstract

Provided is a system relay-to-relay direct communication system and method in a power system. The relay-to-relay direct communication system includes a first protective relay having a first transmit module where the first transmit module includes a first microcontroller adapted to provide a plurality of data channels. Each of the plurality of data channels is associated with channel data having a variety of bit-lengths. The relay-to-relay direct communication system also includes a second protective relay directly coupled to the first protective relay via a communication link. The second protective relay includes a first receive module where the first receive module including a second microcontroller adapted to provide the plurality of data channels. A speed of receipt of the channel data by the first receive module is adjustable based on an assignment of the channel data to the plurality of data channels of the first transmit module.

Claims

1. A relay-to-relay direct communication system in a power system, the relay-to-relay direct communication system comprising:

a first protective relay including a first transmit module, the first transmit module including a first microcontroller adapted to provide a plurality of data channels, each of the plurality of data channels associated with channel data having a variety of bit-lengths; and

a second protective relay directly coupled to the first protective relay via a communication link, the second protective relay including a first receive module, the first receive module including a second microcontroller adapted to provide the plurality of data channels, wherein a speed of receipt of the channel data associated with a particular data channel of the plurality of data channels as a plurality of serial messages by the first receive module is adjustable based on an assignment of the channel data associated with the particular data channel to multiple data channels of the plurality of data channels of the first transmit module.

2. The relay-to-relay direct communication system of claim 1, wherein the first protective relay further comprises a second receive module and the second protective relay further comprises a second transmit module to enable bi-directional transmission.

3. The relay-to-relay direct communication system of claim 2, wherein each of the first and second relays further includes a transmit and receive interface means adapted to convert between bytes of channel data bits and the plurality of serial messages transmitted via the communication link, the bytes of channel data bits corresponding to the channel data.

4. The relay-to-relay direct communication system of claim 3, wherein each of the plurality of serial messages includes a number of fixed formatted characters that include the channel data bits.

5. The relay-to-relay direct communication system of claim 3, wherein subsequent to receipt by the first receive module, each of the plurality of serial messages are decoded and parallelized to form a decoded message, sequential decoded messages re-forming the channel data.

6. The relay-to-relay direct communication system of claim 1, wherein the channel data is selected from the group consisting of single-bit output status indication bits, digitized analog values, digitized virtual terminal data and synchronization information.

7. The relay-to-relay direct communication system of claim 6, wherein one of the plurality of data channels is a synchronization channel including the synchronization information if the assignment of the channel data includes an assignment of digitized analog values or digitized virtual terminal data to at least one of the plurality of data channels.

8. The relay-to-relay direct communication system of claim 6, wherein the assignment of the channel data to the plurality of data channels includes assignment of two of any of the output status indication bits, the digitized analog values and the digitized virtual terminal data to one data channel of the plurality of data channels.

9. The relay-to-relay direct communication system of claim 6, wherein the assignment of the channel data to the plurality of data channels includes assignment of one of the output status indication bits, the digitized analog values and the digitized virtual terminal data to at least two data channels of the plurality of data channels.

10. The relay-to-relay direct communication system of claim 6, wherein each of the plurality of serial messages is transmitted via the communication link at a predictable rate.

11. The relay-to-relay direct communication system of claim 10, wherein each of the first and second microcontrollers is further adapted to provide communication link monitoring capability via detection of corrupted serial messages of the plurality of serial messages.

12. The relay-to-relay direct communication system of claim 10, wherein each of the first and second microcontrollers is further adapted to provide communication link monitoring capability via detection of missing serial messages of the plurality of serial messages.

13. The relay-to-relay direct communication system of claim 10, wherein each of the first and second microcontrollers is further adapted to calculate communication link availability based on a number of corrupted and missing serial messages of the plurality of serial messages during a time period.

14. The relay-to-relay direct communication system of claim 1, wherein the assignment of the channel data to the plurality of data channels is predetermined during a relay commissioning process.

15. The relay-to-relay direct communication system of claim 1, wherein the assignment of the channel data to the plurality of data channels is dynamically determined during relay operation in the power system.

16. The relay-to-relay direct communication system of claim 1, wherein the plurality of data channels comprises eight data channels.

17. A relay-to-relay direct communication system in a power system, the relay-to-relay direct communication system comprising:

a first protective relay including a first transmit module, the first transmit module including a first microcontroller adapted to provide a plurality of data channels, each of the plurality of data channels associated with channel data having a variety of bit-lengths; and

a second protective relay directly coupled to the first protective relay via a communication link, the second protective relay including a first receive module, the first receive module including a second microcontroller adapted to provide the plurality of data channels, the communication link adapted to transmit a plurality of serial messages at a predictable rate, each of the plurality of serial messages formed using channel data bits corresponding to the channel data,

wherein each of the first and second microcontrollers is further adapted to provide communication link monitoring capability via detection of corrupted serial messages and missing serial messages of the plurality of serial messages, and to calculate communication link availability based on a number of the corrupted and missing serial messages during a time period.

18. The relay-to-relay direct communication system of claim 17, wherein the first protective relay further comprises a second receive module and the second protective relay further comprises a second transmit module to enable bi-directional transmission.

19. The relay-to-relay direct communication system of claim 18, wherein each of the first and second relays further includes a transmit and receive interface means adapted to convert between bytes of the channel data bits and the plurality of serial messages.

20. The relay-to-relay direct communication system of claim 19, wherein each of the plurality of serial messages includes a number of fixed formatted characters that include the channel data bits.

21. The relay-to-relay direct communication system of claim 19, wherein subsequent to receipt by the first receive module, each of the plurality of serial messages are decoded and parallelized to form a decoded message, sequential decoded messages re-forming the channel data.

22. The relay-to-relay direct communication system of claim 17, wherein the channel data is selected from the group consisting of single-bit output status indication bits, digitized analog values, digitized virtual terminal data and synchronization information.

23. The relay-to-relay direct communication system of claim 22, wherein one of the plurality of data channels is a synchronization channel including the synchronization information if the assignment of the channel data includes an assignment of digitized analog values or digitized virtual terminal data to at least one of the plurality of data channels.

24. A relay-to-relay direct communication system in a power system, the relay-to-relay direct communication system comprising:

a first protective relay including a first transmit module, the first transmit module including a first microcontroller adapted to provide a plurality of data channels, each of the plurality of data channels associated with channel data having a variety of bit-lengths; and

a second protective relay directly coupled to the first protective relay via a communication link, the second protective relay including a first receive module, the first receive module including a second microcontroller adapted to provide the plurality of data channels, the communication link adapted to transmit a plurality of serial messages at a predictable rate, each of the plurality of serial messages formed using channel data bits corresponding to the channel data,

wherein a speed of receipt of the channel data by the first receive module is adjustable based on an assignment of the channel data to the plurality of data channels of the first transmit module, and

wherein each of the first and second microcontrollers is further adapted to provide communication link monitoring capability via detection of corrupted serial messages and missing serial messages of the plurality of serial messages, and to calculate communication link availability based on a number of the corrupted and missing serial messages during a time period.

25. The relay-to-relay direct communication system of claim 24, wherein each of the first and second relays further includes a transmit and receive interface means adapted to convert between bytes of channel data bits and the plurality of serial messages transmitted via the communication link.

26. The relay-to-relay direct communication system of claim 25, wherein each of the plurality of serial messages includes a number of fixed formatted characters that include the channels data bits.

27. The relay-to-relay direct communication system of claim 25, wherein subsequent to receipt by the first receive module, each of the plurality of serial messages are decoded and parallelized to form a decoded message, sequential decoded messages re-forming the channel data.

28. The relay-to-relay direct communication system of claim 24, wherein the channel data is selected from the group consisting of single-bit output status indication bits, digitized analog values, digitized virtual terminal data and synchronization information.

29. In a relay-to-relay direct communication system in a power system, the relay-to-relay direct communication system having a first protective relay including a first microcontroller adapted to provide a plurality of data channels and having a second protective relay directly coupled to the first protective relay via a communication link, the second protective relay including a second microcontroller adapted to provide the plurality of data channels, each of the plurality of data channels associated with channel data having a variety of bit-lengths, a method for calculating communication link availability, the method comprising:

converting the channel data into a plurality of serial messages;

transmitting, via the communication link, each of the plurality of serial messages at a predictable rate;

determining an aggregate number of received uncorrupted serial message; and

dividing the aggregate number of uncorrupted serial messages received during a time period by a number of serial messages expected to be received during the time period.