Power outage detection system for smart grid using finite state machines

• US 8,930,455 B2
• Filed: 12/22/2011
• Issued: 01/06/2015
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: Itron Networked Solutions, Inc. (Itron, Inc.)
• Original Assignee: Silver Spring Networks, Inc. (Itron, Inc.)
• Inventors: Kan, Daniel, Serai, Harleen
• Primary Examiner(s): BAROT, BHARAT
• Application Number:
  US13/334,210
• Publication Number:
  US 20130166641A1
• Time in Patent Office: 1,111 Days
• Field of Search: 709203-205, 702 57- 58, 702 60- 62
• US Class Current: 709/204
• CPC Class Codes: H02J 13/00006 characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
• CPC Class Codes: H02J 3/0012 Contingency detection
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/52 Outage or fault management, e.g. fault detection or location
• CPC Class Codes: Y04S 40/12 characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment

Abstract

A power outage detection system. The system includes a device configured to increment a reboot counter when the device is powered up, and to transmit a first message when the device loses power and a second message when the device is powered up, and a back office system. The first message includes the value of the reboot counter and a timestamp, and the second message includes the value of the reboot counter. The back office system includes a finite state machine configured to receive the first and second messages. The finite state machine determines if the received first message is valid using the value of the reboot counter and the timestamp, and determines if the received second message is valid using the value of the reboot counter. The finite state machine then outputs an accurate indication of the state of the device.

Claims

1. A power outage detection system, the system comprising:

a device configured to;

increment a reboot counter when the device is powered up, and

transmit a first message when the device loses power and a second message when the device is powered up, the first message including the value of the reboot counter and a timestamp, the second message including the value of the reboot counter; and

a back office system including a finite state machine configured to;

receive the first and second messages,

determine if the received first message is valid based on the value of the reboot counter and the timestamp,

determine if the received second message is valid based on the value of the reboot counter, and

output an accurate indication of the state of the device.

2. The power outage detection system of claim 1, wherein the finite state machine is further configured to:

save the value of the reboot counter,

determine that a received first message is valid when the value of the reboot counter in the received first message is equal to or greater than the saved reboot counter value, and

determine that a received second message is valid when the value of the reboot counter in the received second message is greater than the saved reboot counter value.

3. The power outage detection system of claim 1, further comprising an outage processing system configured to receive an indication of the state of the device from the finite state machine, and to track the states of a plurality of devices.

4. The power outage detection system as set forth in claim 1, wherein the device transmits the first and second messages to the back office system via a wireless mesh network.

5. The power outage detection system as set forth in claim 1, further comprising a domain name system server, the device registering with the domain name server when the device is powered up.

6. The power outage detection system as set forth in claim 1, further comprising the back office system pinging the device, the device responding to the ping when the device is powered on.

7. The power outage detection system of claim 1, wherein the state of the device is determined to be an online state when power to the device is not lost, a momentary state when there is a power outage that has not lasted longer than a predefined time duration, or a sustained state when there has been a power outage for more than the predefined time duration.

8. The power outage detection system of claim 7, wherein the finite state machine transitions from the online state to the momentary state when a valid first message is received and a difference between the timestamp and the current time is less than the predefined time duration.

9. The power outage detection system of claim 7, wherein the finite state machine transitions from the momentary state to the online state when a valid second message is received.

10. The power outage detection system of claim 7, wherein the finite state machine transitions from the momentary state to the sustained state when the difference between the timestamp and the current time exceeds the predefined time duration without receiving a valid second message.

11. The power outage detection system of claim 7, wherein the finite state machine transitions from the sustained state to the momentary state when a valid first message is received and a difference between the timestamp and the current time is less than the predefined time duration.

12. The power outage detection system of claim 7, wherein the finite state machine transitions from the sustained state to the online state when a valid second message is received.

13. The power outage detection system of claim 7, wherein the finite state machine transitions to the online state of the device when the timestamp of a registration message is more recent than the timestamp of a valid first message.

14. A method of determining a state of a device based on a message received from the device, the method comprising:

receiving a message from the device, the message having a first type including a reboot counter and a timestamp or a second type including the reboot counter;

transitioning the state of the device, via a processor, from online to momentary when a valid first type message is received and a difference between the timestamp and the current time is less than a predefined time duration;

transitioning the state of the device from momentary to online when a valid second type message is received;

transitioning the state of the device from momentary to sustained when the difference between the timestamp and the current time exceeds a predefined time duration without receiving a valid second type message;

transitioning the state of the device from sustained to momentary when a valid first type message is received and a difference between the timestamp and the current time is less than a predefined time duration; and

transitioning the state of the device from sustained to online when a valid second type message is received.

15. The method as set forth in claim 14, further comprising:

determining that a first type message is valid when the received reboot counter is greater than or equal to a stored reboot counter; and

determining that a second type message is valid when the received reboot counter is greater than the stored reboot counter.

16. The method as set forth in claim 14, further comprising transitioning the state of the device to online when a ping response is received with a timestamp more recent than the timestamp of a received valid first type message.

17. The method as set forth in claim 14, further comprising receiving an indication of the state of the device at an outage processing system, the outage processing system configured to track the states of a plurality of devices.

18. The method as set forth in claim 14, wherein the message is received via a wireless mesh network.

19. The method as set forth in claim 14, further comprising registering, by the device, with a domain name system server when the device is powered up.

20. The method as set forth in claim 14, further comprising incrementing the reboot counter upon power up.