Using travel-time as means for improving the accuracy of Simple Network Time Protocol

1. A computer program product, comprising:

a non-transitory computer readable medium; and

computer program instructions recorded on the computer readable medium and executable by a processor for carrying out a method comprising

sending a time inquiry from at least one device in a substation to a time provider;

receiving a message including a reference time from the time provider;

evaluating an accuracy of the reference time by comparing the reference time with calculations based on prior communications between the at least one device and the time provider;

improving accuracy of simple network time protocol, whereby if the accuracy of the reference time is less than a threshold value improving the accuracy of the reference time by sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization; and

utilizing the reference time for synchronization of the at least one device in the substation,

wherein if the accuracy of the reference time is greater than a threshold value, the method further comprises:

determining if the accuracy of the reference time is less than an increased threshold value and increasing the threshold value of the accuracy is within the increased threshold value;

calculating an offset value based on time values;

utilizing the offset to synchronize the at least one device; and

putting the at least one device to sleep for a period of time.

2. A system for performing a process for improving accuracy of simple network time protocol, the system comprising:

a processor operable to execute computer program instructions; and

a memory operable to store computer program instructions executable by the processor, for performing the steps of:

sending a time inquiry from at least one device in a substation to a time provider;

receiving a message including a reference time from the time provider;

evaluating an accuracy of the reference time by comparing the reference time with calculations based on prior communications between the at least one device and the time provider;

improving accuracy of simple network time protocol, whereby if the accuracy of the reference time is less than a threshold value improving the accuracy of the reference time by sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization; and

utilizing the reference time for synchronization of the at least one device in the substation,

wherein if the accuracy of the reference time is greater than a threshold value, the method further comprises:

determining if the accuracy of the reference time is less than an increased threshold value and increasing the threshold value of the accuracy is within the increased threshold value;

calculating an offset value based on time values;

utilizing the offset to synchronize the at least one device; and

putting the at least one device to sleep for a period of time.

3. A method for improving accuracy of simple network time protocol, comprising:

sending a time inquiry from at least one device in a substation to a time provider;

receiving a message including a reference time from the time provider;

evaluating an accuracy of the reference time by comparing the reference time with calculations based on prior communications between the at least one device and the time provider;

if the accuracy of the reference time is less than a threshold value improving the accuracy of the reference time by sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization; and

utilizing the reference time for synchronization of the at least one device in the substation

wherein if the accuracy of the reference time is greater than a threshold value, the method further comprises:

determining if the accuracy of the reference time is less than an increased threshold value and increasing the threshold value of the accuracy is within the increased threshold value;

calculating an offset value based on time values;

utilizing the offset to synchronize the at least one device; and

putting the at least one device to sleep for a period of time.

4. The method according to claim 3 , wherein the time inquiry is sent from an intelligent electronic device.

5. The method according to claim 4 , wherein evaluating the accuracy of the reference time comprises comparing a travel time of the message including the reference time with a predetermined value, the method further comprising:

generating a packet including the time inquiry;

putting the packet onto a stack in a time provider in the intelligent electronic device (T 1 );

taking the packet from the stack in the time-provider (T 2 );

putting the packet onto the stack in the time-provider (T 3 ); and

receiving the packet from the stack in the intelligent electronic device (T 4 ), wherein the travel time is computed according to the formula (T 2 −T 1 )+(T 4 −T 3 ).

6. The method according to claim 3 , further comprising:

time stamping at least one of events or disturbances utilizing the reference time.

7. The method according to claim 3 , the devices are synchronized to within about 10 ms.

8. The method according to claim 3 , wherein evaluating the accuracy of the reference time comprises comparing a travel time of the message including the reference time with a calculated value.

9. The method according to claim 3 , wherein the devices are synchronized to within about 1 ms.

10. A method for improving accuracy of simple network time protocol, comprising:

sending a time inquiry from at least one device in a substation to a time provider;

receiving a message including a reference time from the time provider;

evaluating an accuracy of the reference time by comparing the reference time with calculations based on prior communications between the at least one device and the time provider;

if the accuracy of the reference time is less than a threshold value improving the accuracy of the reference time by sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization; and

utilizing the reference time for synchronization of the at least one device in the substation

wherein if the accuracy of the reference time is less than a threshold value, the method further comprises:

decreasing the threshold value and putting the at least one device to sleep prior to sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization.

11. A computer program product, comprising:

a non-transitory computer readable medium; and

computer program instructions recorded on the computer readable medium and executable by a processor for carrying out a method comprising

sending a time inquiry from at least one device in a substation to a time provider;

receiving a message including a reference time from the time provider;

evaluating an accuracy of the reference time by comparing the reference time with calculations based on prior communications between the at least one device and the time provider;

improving accuracy of simple network time protocol, whereby if the accuracy of the reference time is less than a threshold value improving the accuracy of the reference time by sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization; and

utilizing the reference time for synchronization of the at least one device in the substation,

wherein if the accuracy of the reference time is less than a threshold value, the method further comprises:

decreasing the threshold value and putting the at least one device to sleep prior to sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization.

12. A system for performing a process for improving accuracy of simple network time protocol, the system comprising:

a processor operable to execute computer program instructions; and

a memory operable to store computer program instructions executable by the processor, for performing the steps of:

sending a time inquiry from at least one device in a substation to a time provider;

receiving a message including a reference time from the time provider;

evaluating an accuracy of the reference time by comparing the reference time with calculations based on prior communications between the at least one device and the time provider;

improving accuracy of simple network time protocol, whereby if the accuracy of the reference time is less than a threshold value improving the accuracy of the reference time by sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization; and

utilizing the reference time for synchronization of the at least one device in the substation,

wherein if the accuracy of the reference time is less than a threshold value, the method further comprises:

decreasing the threshold value and putting the at least one device to sleep prior to sending a second time inquiry from the at least one device in the substation to the time provider, wherein a second message including a second reference time from the time provider is received, the accuracy of the second reference time, if evaluating the accuracy of the second reference time is less than a threshold value improving the accuracy of the second reference time, and utilizing the second reference time for synchronization.