High speed digital transient waveform detection system and method for use in an intelligent electronic device

Patent metadata

Field	Value
Publication number	US-11307227-B2
Application number	US-201414194856-A
Country	US
Kind code	B2
Filing date	Mar 3, 2014
Priority date	Apr 3, 2007
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

A system and a method is provided for the detection and capture, and in particular for an ultra high speed detection and capture, of transients in input voltages by an intelligent electronic device. The system and method detects transients for input voltages in either phase to phase or phase to neutral measurements and permits a user to set threshold levels for detecting transients in input voltages. In an embodiment, the system and method further provides a field programmable gate array as a controller for managing transient detection. The field programmable gate array includes a state machine for determining the state of the sampled signal with respect to a threshold level at a specified waveform sample period.

First claim

What is claimed is:

1. An intelligent electronic device (IED) for detecting at least one transient in at least one voltage waveform of a power distribution system comprising:
at least one analog-to-digital converter configured to sample at least one analog voltage input channel coupled to the power distribution system at a first sampling rate and output digital voltage samples in each of a plurality of successive waveform sample periods, each waveform sample period comprising a predetermined time period, wherein a beginning of each waveform sample period defines a first boundary and an end of each waveform sample period defines a second boundary; and
a transient detection system configured to receive the digital voltage samples from the at least one analog-to-digital converter in each of the plurality of waveform sample periods, the transient detection system including a first state machine configured to detect and store a single peak transient value and a duration value of a transient in each of the plurality of waveform sample periods based on states of the first state machine, wherein the first state machine transitions between different states based on a number of peaks detected in each waveform sample period, a position of the digital voltage samples with respect to a pre-determined transient threshold level, and the position of the digital voltage samples with respect to at least one boundary of each waveform sample period.

2. The IED of claim 1 , wherein the transient detection system includes:
a threshold comparator for detecting whether a digital voltage sample is above the pre-determined transient threshold level;
a duration counter for measuring a duration of a detected transient based on the threshold comparator;
a peak comparator for detecting the peak value of the digital voltage samples that may occur in each of the plurality of waveform sample periods; and
a transient capture memory for storing the digital voltage samples of the at least one analog voltage input channel in each of the plurality of sequential waveform sample periods,
wherein, the first state machine receives inputs from the threshold comparator and the peak comparator to transition between states.

3. The IED of claim 2 , wherein the transient detection system includes a subtractor circuit that receives the digital voltage samples from the at least one analog voltage input channel, wherein the subtractor circuit is configured to determine phase to phase voltages or phase to neutral voltages.

4. The IED of claim 2 , wherein the transient capture memory is one of an internal transient capture memory contained within the transient detection system or an external transient capture memory not contained within the transient detection system.

5. The IED of claim 2 , wherein the transient detection system includes an intermediate holding register for temporarily holding parameter values collected by the first state machine during each of the plurality of waveform sample periods.

6. The IED of claim 5 , wherein the parameter values comprise: (a) a peak transient value, (b) a continuation value for indicating that a transient value remained above the pre-determined transient threshold level when crossing over from one waveform sample period to an adjoining waveform sample period, (c) a new transient value N for indicating that the transient was not a carryover from a previous waveform sample period and (d) a duration value indicating a duration of the peak transient value.

7. The IED of claim 1 , further comprising a waveform capture circuit configured to sample the at least one analog voltage input channel coupled to the power distribution system at a second sampling rate and output digital samples in each of the plurality of sequential waveform sample periods.

8. The IED of claim 7 , wherein the at least one analog-to-digital converter and the waveform capture circuit sample the at least one analog voltage input channel simultaneously, the first sampling rate being faster than the second sampling rate.

9. The IED of claim 8 , further comprising at least one processor configured to produce merged waveform data in each of the plurality of waveform sample periods by combining the single detected peak transient value and associated duration value together with the digital voltage samples of the waveform capture circuit.

10. The IED of claim 8 , wherein the first sampling rate is about 1 Mhz or higher.

11. The IED of claim 8 , wherein the first sampling rate is substantially in the range from 1 MHz to 50 MHz.

12. The IED of claim 2 , wherein the transient detection system is further configured to detect whether a digital voltage sample is below a pre-determined negative transient threshold level.

13. The IED of claim 1 , further comprising at least one processing device configured to determine energy usage data from voltage samples of at least one analog voltage input channel coupled to the power distribution system and a display for displaying the determined energy usage data.

14. The IED of claim 13 , further comprising a communication device for communicating the determined energy usage data to an external device via a communication protocol.

15. The IED of claim 14 , wherein the communication protocol is an Ethernet protocol.

16. The IED of claim 13 , further comprising input/output (I/O) interface for communicating the determined energy usage data to an external device via a pulse output.

17. The IED of claim 1 , further comprising a communication device that communicates data to an external device.

18. The IED of claim 1 , further comprising a web server for communicating data to an external device.

19. The IED of claim 1 , wherein the at least one analog-to-digital converter and the transient detection system are disposed in a socket-type meter form.

20. The IED of claim 1 , wherein the at least one analog-to-digital converter and the transient detection system are disposed in a panel mounted meter form.

21. The IED of claim 1 , wherein the at least one analog-to-digital converter and the transient detection system are disposed in a switchboard meter form.

22. The IED of claim 1 , wherein the at least one analog-to-digital converter and the transient detection system are disposed in a A-base front wired meter form.

23. The IED of claim 1 , wherein the at least one analog-to-digital converter and the transient detection system are disposed in a circuit breaker mounted meter form.

24. The IED of claim 1 , further comprising a touchscreen display configured to display data and receive input commands.

25. The IED of claim 1 , further comprising a communication device configured to couple the IED to a network, wherein the communication device operates on a wireless protocol.

26. The IED of claim 1 , wherein the first sampling rate is about 10 Mhz.

27. The IED of claim 9 , further comprising a web server for communicating the merged waveform data to an external device.

28. The IED of claim of 18 , wherein the data include a transient waveform image.

29. The IED of claim 1 , further comprising a communication device for communicating a transient waveform image to an external device.

30. The IED of claim 1 , further comprising a memory configured to store at least one of a peak transient value, a duration of the transient and/or a time stamp of th

Assignees

• Electro Industries/Gauge Tech

Inventors

• Spanier Joseph
• Zhu Hai
• Wang Wei

Classifications

• G01R19/2513 Primary

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title

• G06F17/40

  Data acquisition and logging (for input to computer G06F3/00) · CPC title

• G01R19/2509 Primary

  Details concerning sampling, digitizing or waveform capturing · CPC title

• G16Z99/00

  Subject matter not provided for in other main groups of this subclass · CPC title

• G01R19/04

  Measuring peak values {or amplitude or envelope} of AC or of pulses · CPC title