Time distribution device with multi-band antenna
AssigneeSchweitzer Engineering Laboratories, Inc.
InventorsShankar V. Achanta, David E. Whitehead, Henry Loehner
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Abstract
Systems and methods for detecting the failure of a precision time source using an independent time source are disclosed. Additionally, detecting the failure of a GNSS based precision time source based on a calculated location of a GNSS receiver is disclosed. Moreover, the system may be further configured to distribute a time derived from the precision time source as a precision time reference to time dependent devices. In the event of a failure of the precision time source, the system may be configured to distribute a time derived from a second precision time source as the precision time signal during a holdover period.
Claims7
A method comprising:
- receiving at a single, multi-band antenna, a first time signal from a first time source, the first time signal having a corresponding first error bound related to accuracy of the first time signal;
- receiving at the single, multi-band antenna, a second time signal from a second time source separate from the first time source, the second time signal having a corresponding second error bound related to accuracy of the second time signal;
- comparing the first time signal with the second error bound of the second time signal;
- when the first time signal falls outside of the second error bound, determine a failure of the first time signal;
- when the first time signal falls within the second error bound, determine that an error of the first time signal is acceptable relative to the second time signal;
- and
- when the first time signal is determined acceptable, outputting a first output time signal from the first time source to an electronic device (ED) protecting an electric power delivery system using the first output time signal.
The method of 1, further comprising:
- outputting a second output time signal from the second time source in place of the first output time signal in response to detecting a failure of the first time source.
The method of 1, wherein the first and second sources comprise at least two selected from the group consisting of:
- a global navigation satellite system (GNSS), a NIST signal, a WWVB signal, a WWV signal, and combinations thereof.
A time distribution device comprising:
- a multi-band antenna configured to
- receive a first time signal from a first time source, the first time signal having a corresponding first error bound related to accuracy of the first time signal;
- and
- receive a second time signal from a second time source, the second time signal having a corresponding second error bound related to accuracy of the second time signal;
- a time quality module configured to:
- compare the first time signal with the second error bound of the second time signal;
- when the first time signal falls outside of the second error bound, determine a failure of the first time signal;
- and,
- when the first time signal is within the second error bound, determine that an error of the first time signal is acceptable relative to the second time signal;
- and,
- an output configured to provide an output time signal corresponding with the first output time signal when the first time signal is determined acceptable.
Dependencies are inferred from the claim text.