System for testing of intelligent electronic devices with digital communications

• US 20020173927A1
• Filed: 05/21/2001
• Published: 11/21/2002
• Est. Priority Date: 05/21/2001
• Status: Active Grant

• Current Assignee: OMICRON electronics GmbH, Omnicron Electronics Corp. USA
• Original Assignee: OMICRON electronics GmbH
• Inventors: Vandiver, Benton
• Granted Patent: US 6,795,789 B2
• Time in Patent Office: Days
• US Class Current: 702/122
• CPC Class Codes: G01R 31/3272 Apparatus, systems or circuits therefor G01R31/3275 takes precedence
• CPC Class Codes: G06F 11/2294 by remote test

Abstract

The test system provides conventional analog outputs that allowing application of power system conditions simulation to a device under test. The test device has a communication interface which sends and receives digital communication to and from protection relays, control devices, and meters, known as intelligent electronic devices (IEDs). The test device interacts with the devices under test over a direct communication link or a substation local area network. The communication protocol includes digital communication to send and receive messages which simulate virtual switching and control equipment status and other intelligent electronic device (IED) data and status. The test system monitors the operation of the IED device under test based on the IED digital communication data received and the contained control signal status utilizing the digital communication interface as a substitute for the conventional hard-wiring of IED binary inputs and outputs.

Claims

1. A method for testing electric power devices employing data exchange over a digital communications link, the method comprising the steps of:

applying a test stimulus from a testing device to a power device under test;

receiving in the testing device over digital signal lines test status information from the power device under test, the test status information generated by the device under test in response to application of the test stimulus, the test status information further communicated over the digital communications link; and

synchronizing the received status information with the application of the test stimulus to form synchronized status information.

2. The method of claim 1, further comprising:

determining a device under test response from the synchronized status information.

3. The method of claim 2, further comprising:

adjusting the test stimulus in response to the device under test response.

4. The method of claim 3, wherein all the method steps are recursively repeated to perform a multiple power system condition test sequence.

5. The method of claim 2, further comprising:

developing device under test performance evaluation utilizing the device under test response.

6. The method of claim 1, wherein the digital communications link is a local area network.

7. The method of claim 1, wherein the device under test is an electric power system protection device.

8. The method of claim 1, wherein the test stimulus comprises analog currents and voltages to simulate power system conditions applied to the device under test.

9. The method of claim 1, wherein the test stimulus comprises simulated power system status information in data packet form transmitted to the device under test over the digital communications link.

10. The method of claim 1, wherein the test status information is communicated over the digital communications link in the form of digital data packets.

11. The method of claim 1, wherein the testing device operates as a virtual intelligent electronic device providing virtual control or status information to the device under test.

12. The method of claim 1, wherein the testing device received status information from the device under test in response to interaction between the device under test and other intelligent electronic devices.

13. The method of claim 1, wherein the digital communications link is a digital serial communications link connected to the testing device and a single device under test.

15. The test system of claim 14, the code in memory further directing the processor to perform the step of:

determining a device under test response from the synchronized status information.

16. The test system of claim 15, the code in memory further directing the processor to perform the step of:

adjusting the test signals in response to the device under test response.

17. The test system of claim 16, wherein all the test system steps directed by the code in memory are recursively repeated to perform a multiple power system condition test sequence.

18. The test system of claim 15, the code in memory further directing the processor to perform the step of:

developing device under test performance evaluation utilizing the device under test response.

19. The test system of claim 14, wherein the digital communications link is a local area network.

20. The test system of claim 14, wherein the device under test is an electric power system protection device.

21. The test system of claim 14, wherein the test signals comprise analog current and voltage waveforms to simulate power system conditions applied to the device under test over analog signal lines.

22. The test system of claim 14, wherein the test signals comprise simulated power system status information in digital data form transmitted to the device under test over the digital communications link.

23. The test system of claim 14, wherein the test status information is communicated over the digital communications link in the form of digital data packets.

24. The test system of claim 14, wherein the testing device operates as a virtual intelligent electronic device providing virtual control or status information to the device under test.

25. The test system of claim 14, wherein the testing device received status information from the device under test in response to interaction between the device under test and other intelligent electronic devices.

26. The test system of claim 14, wherein the digital communications link is a digital serial communications link connected to the testing device and a single device under test.

28. The test device of claim 27, the code in memory further directing the processor to perform the step of:

determining a device under test response from the synchronized status information.

29. The test device of claim 28, the code in memory further directing the processor to perform the step of:

adjusting the test stimulus in response to the device under test response.

30. The test device of claim 29, wherein all the test device steps directed by the code in memory are recursively repeated to perform a multiple power system condition test sequence.

31. The test device of claim 28, the code in memory further directing the processor to perform the step of:

developing device under test performance evaluation utilizing the device under test response.

32. The test device of claim 27, wherein the digital communications link is a local area network.

33. The test device of claim 27, wherein the device under test is an electric power system protection device.

34. The test device of claim 27, wherein the test stimulus comprise analog current and voltage waveforms to simulate power system conditions applied to the device under test over analog signal lines.

35. The test device of claim 27, wherein the test stimulus comprise simulated power system status information in digital data form transmitted to the device under test over the digital communications link.

36. The test device of claim 27, wherein the test status information is communicated over the digital communications link in the form of digital data packets.

37. The test device of claim 27, wherein the testing device operates as a virtual intelligent electronic device providing virtual control or status information to the device under test.

38. The test device of claim 27, wherein the digital communications link is a digital serial communications link connected to the testing device and a single device under test.

39. The test device of claim 27, wherein the testing device received status information from the device under test in response to interaction between the device under test and other intelligent electronic devices.

14. A test system for testing electric power devices employing data exchange over a digital communications link, comprising:

at least one power device under test, comprising;

a plurality of analog inputs for receiving simulated test signals;

at least one digital input/output port for receiving and transmitting digital data packets;

a status register for storing status information of the power device under test;

a testing device coupled to power device under test through analog and digital communications lines, comprising;

a processor;

an analog signal generator for outputting simulated test signals over the analog communications lines;

a memory coupled to the processor having computer readable code embodied therein for transacting digital communications with the power device under test, the code for directing the processor to perform the steps of;

receiving status information in the form of digital data packets from the power device under test in response to application of simulated test signals; and

synchronizing the received status information with the simulated test signals to form synchronized status information.

27. A power protection and control test device for communicating the status of simulated substation or protection and control equipment over a digital communications link from the test device to one or more intelligent electronic devices in a power system, comprising:

a testing device coupled to a device under test in the power system through a digital communications lines, comprising;

a processor;

a memory coupled to the processor having computer readable code embodied therein for transacting digital communications with the device under test, the code for directing the processor to perform the steps of;

transmitting a test stimulus to the device under test;

receiving status information in the form of digital data packets from the power device under test in response to application of the test stimulus; and

synchronizing the received status information with the test stimulus to form synchronized status information.