Apparatus and method for diagnosis of power appliances

• US 5,253,180 A
• Filed: 05/16/1990
• Issued: 10/12/1993
• Est. Priority Date: 06/02/1989
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tagawa, Yoshinori, Okumura, Kiyoshi, Yamagiwa, Tokio
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): Ramirez, Ellis B.
• Application Number:
  US07/524,455
• Time in Patent Office: 1,245 Days
• Field of Search: 364/485, 364/551.01, 324/536, 324/541, 324/544, 324/557, 324/630
• US Class Current: 702/59
• CPC Class Codes: G01R 19/16571 comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current G01R19/16514, G01R19/16519, G01R19/16528, G01R19/16533, G01R19/1659 take precedence; measuring currents by using elements sensitive to the magnetic field generated G01R15/14; measuring earth resistance G01R27/18; testing for leakage or short circuits in electrical apparatus G01R31/52
• CPC Class Codes: G01R 31/1254 of gas-insulated power appliances or vacuum gaps testing switches G01R31/327; detecting electrical or mechanical defects in encased switchgear H02B13/065
• CPC Class Codes: G01R 31/50 Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections testing of sparking plugs H01T13/58

Abstract

A power appliance diagnosis apparatus includes a plurality of detectors provided on outer surfaces of gas-insulated casings of a power appliance for detecting the state of an insulating function and/or a current conduction function of the power appliance, a switch for time-divisionally taking in detection signals of the plurality of detectors, a frequency analyzer for performing frequency analysis on the detection signals taken in by the switch, and a controller for performing switching control of the switch.

Claims

1. An apparatus for performing diagnosis of a power appliance, the power appliance including current conduction appliances housed in gas-insulated casings, the apparatus comprising:

a plurality of detectors disposed on one gas-insulated casing of the power appliance for respectively detecting a plurality of mutually different phenomena respectively indicative of a plurality of mutually different conditions of the power appliance, and for respectively outputting a plurality of detection signals indicative of the respective detected phenomena;

switching means for receiving the detection signals from the detectors, and for sequentially outputting each of the detection signals in response to a switching control signal;

control means for generating a switching control signal for controlling the switching means to sequentially output each of the detections signals, and for supplying the switching control signal to the switching means;

a frequency analyzer for sequentially performing frequency analysis of the detection signals sequentially output from the switching means and for sequentially outputting frequency-analyzed signals indicative of respective results of the frequency analysis of the detection signals sequentially output from the switching means; and

means for diagnosing the mutually different conditions of the power appliance based on the frequency-analyzed signals sequentially output from the frequency analyzer.

2. An apparatus according to claim 1, wherein the plurality of detectors include at least two detectors selected from a detector for detecting a phenomenon indicative of partial electric discharge in the one gas-insulated casing, a detectro for detecting a phenomenon indicative of abnormal current conduction in the one gas-insulated casing, and a detector for detecting a phenomenon indicative of mixing of foreign matter in the one gas-insulated casing.

3. An apparatus according to claim 2, wherein the switching means is constituted by a single switch.

4. An apparatus according to claim 3, wherein the switch is disposed in a local panel provided in a vicinity of the power appliance.

5. An apparatus according to claim 1, wherein the switching means is constituted by a single switch.

6. An apparatus according to claim 5, wherein the switch is disposed in a local panel provided in a vicinity of the power appliance.

7. An apparatus for performing diagnosis of a power appliance, the power appliance including switches and current conduction appliances housed in gas-insulated casings, the apparatus comprising:

a plurality of detectors disposed on one gas-insulated casing of the power appliance for respectively detecting a plurality of mutually different phenomena indicative of at least one of an insulating function of the power appliance and a current conduction function of the power appliance, and for respectively outputting a plurality of detection signals indicative of the respective detected phenomena;

switching means for receiving the detection signals from the detectors, and for sequentially outputting each of the detection signals in response to a first switching control signal;

control means for generating a first switching control signal for controlling the switching means to sequentially output each of the detections signals, and for supplying the first switching control signal to the switching means;

a frequency analyzer for sequentially performing frequency analysis of the detection signals sequentially output from the switching means and for sequentially outputting frequency-analyzed signals indicative of respective results of the frequency analysis of the detection signals sequentially output from the switching means; and

means for diagnosing at lest one of the insulating function of the power appliance and the current conduction function of the power appliance based on the frequency-analyzed signals sequentially output from the frequency analyzer.

8. An apparatus according to claim 7, wherein the plurality of detectors include at least two detectors selected from a detectro for detecting a phenomenon indicative of partial electric discharge in the one gas-insulated casing, a detectro for detecting a phenomenon indicative of abnormal current conduction in the one gas-insulated casing, and a detector for detecting a phenomenon indicative of mixing of foreign matter in the one gas-insulated casing.

9. An apparatus according to claim 8, wherein the switching means is constituted by a single switch.

10. An apparatus according to claim 9, wherein the mutually different phenomena respectively detected by the detectors appear in the form of frequency components in respective mutually different frequency bands;

wherein the frequency analyzer sequentially changes a frequency band in which it performs frequency analysis to each of the mutually different frequency bands in response to a second switching control signal as it sequentially performs frequency analysis of the detection signals sequentially output from the switching means such that the frequency analyzer performs frequency analysis of the detection signals in the respective frequency bands in which the frequency components of the respective phenomena which the detection signals are indicative of appear; and

wherein the control means generates a second switching control signal for controlling the frequency analyzer to sequentially change a frequency band in which it performs frequency analysis to each of the mutually different frequency bands, and supplies the second switching control signal to the frequency analyzer.

11. An apparatus according to claim 10, wherein the control means includes means for changing the first switching control signal and the second switching control signal to change an interval at which the switching means sequentially outputs each of the detection signals and at which the mutually analyzer sequentially changes a frequency band in which it performs frequency analysis to each of the mutually different frequency bands.

12. An apparatus according to claim 7, wherein the switching means is constituted by a single switch.

13. An apparatus according to claim 12, wherein the mutually different phenomena respectively detected by the detectors appear in the form of frequency components in respective mutually different frequency bands;

wherein the frequency analyzer sequentially changes a frequency band in which it performs frequency analysis to each of the mutually different frequency bands in response to a second switching control signal as it sequentially performs frequency analysis of the detection signals sequentially output from the switching means such that the frequency analyzer performs frequency analysis of the detection signals in the respective frequency bands in which the frequency components of the respective phenomena which the detection signals are indicative of appear; and

wherein the control means generates a second switching control signal for controlling the frequency analyzer to sequentially change a frequency band in which it performs frequency analysis to each of the mutually different frequency bands, and supplies the second switching control signal to the frequency analyzer.

14. An apparatus according to claim 13, wherein the control means includes means for changing the first switching control signal and the second switching control signal to change an interval at which the switching means sequentially outputs each of the detection signals and at which the mutually analyzer sequentially changes a frequency band in which it performs frequency analysis to each of the mutually different frequency bands.

15. An apparatus for performing diagnosis of a first power appliance and a second power appliance, the first power appliance and the second power appliance each including switches and current conduction appliances housed in gas-insulated casings, the apparatus comprising:

a plurality of first detectors disposed on one gas-insulated casing of the first power appliance for respectively detecting a plurality of mutually different phenomena indicative of at least one of an insulating function of the first power appliance and a current conduction function of the first power appliance, and for respectively outputting a plurality of first detection signals indicative of the respective detected phenomena;

a plurality of second detectors disposed on one gas-insulated casing of the second power appliance for respectively detecting a plurality of mutually different phenomena indicative of at least one of an insulating function of the second power appliance and a current conduction function of the second power appliance, and for respectively outputting a plurality of second detection signals indicative of the respective detected phenomena, the second detectors being disposed on the one gas-insulated casing of the second power appliance at respective locations respectively corresponding to respective locations at which the first detectors are disposed on the one gas-insulated casing of the first power appliance;

first switching means for receiving the first detection signals from the first detectors, and for sequentially outputting each of the first detection signals in response to a first switching control signal;

second switching means for receiving the second detection signals from the second detectors, and for sequentially outputting each of the second detection signals in response to a second switching control signal;

first control means for generating a first switching control signal for controlling the first switching means to sequentially output each of the first detections signals, and for supplying the first switching control signal to the first switching means;

second control means for generating a second switching control signal for controlling the second switching means to sequentially output each of the second detections signals, and for supplying the second switching control signal to the second switching means;

a first frequency analyzer for sequentially performing frequency analysis of the first detection signals sequentially output from the first switching means, and for sequentially outputting first frequency-analyzed signals indicative of respective results of the frequency analysis of the first detection signals sequentially output from the first switching means;

a first frequency analyzer for sequentially performing frequency analysis of the first detection signals sequentially output from the first switching means and for sequentially outputting first frequency-analyzed signals indicative of respective results of the frequency analysis of the second detection signals sequentially output from the second switching means; and

means for diagnosing at least one of the insulating function of the first power appliance and the current conduction function of the first power appliance based on the first frequency-analyzed signals sequentially output from the first frequency analyzer, and for diagnosing at least one of the insulating function of the second power appliance and the current conduction function of the second power appliance based on the second frequency-analyzed signals sequentially output from the second frequency analyzer.

16. An apparatus according to claim 15, wherein the plurality of first detectors and the plurality of second detectors each include at lest two detectors selected from a detector for detecting a phenomenon indicative of partial electric discharge in the one gas-insulated casing, a detector for detecting a phenomenon indicative of abnormal current conduction in the one gas-insulated casing, and a detector for detecting a phenomenon indicative of mixing of foreign matter in the one gas-insulated casing.

17. An apparatus according to claim 16, wherein the mutually different phenomena respectively detected by the first detectors and the second detectors appear in the form of frequency components in respective mutually different frequency bands;

wherein the first frequency analyzer sequentially changes a frequency band in which it performs frequency analysis to each of the mutually different frequency bands in response to a third switching control signal as it sequentially performs frequency analysis of the first detection signals sequentially output from the first switching means such that the first frequency analyzer performs frequency analysis of the first detection signals in the respective frequency bands in which the frequency components of the respective phenomena which the first detection signals are indicative of appear;

wherein the second frequency analyzer sequentially changes a frequency band in which it performs frequency analysis t each of the mutually different frequency bands in response to a fourth control signal as it sequentially performs frequency analysis of the second detection signals sequentially output from the second switching means such that the second frequency analyzer performs frequency analysis of the second detection signals in the respective frequency bands in which the frequency components of the respective phenomena which the second detection signals are indicative of appear; and

wherein the first control means generates a third switching control signal for controlling the first frequency analyzer to sequentially change a frequency band in which it performs frequency analysis to each of the mutually different frequency bands, and supplies the third switching control signal to the first frequency analyzer; and

wherein the second control means generates a fourth switching control signal for controlling the second frequency analyzer to sequentially change a frequency band in which it performs frequency analysis to each of the mutually different frequency bands, and supplies the fourth switching control signal to the second frequency analyzer.

18. An apparatus according to claim 17, wherein the first control means includes means for changing the first switching control signal and the third switching control signal to change an interval at which the first switching means sequentially outputs each of the first detection signals and at which the first mutually analyzer sequentially changes a frequency band in which it performs frequency analysis to each of the mutually different frequency bands;

and

wherein the second control means includes means for changing the second switching control signal and the fourth switching control signal to change an interval at which the second switching means sequentially outputs each of the second detection signals and at which the second mutually analyzer sequentially changes a frequency band in which it performs frequency analysis to each of the mutually different frequency bands.

19. An apparatus according to claim 17, further comprising:

means for determining if an abnormality exists in the first power appliance based on the at least one of the insulating function of the first power appliance and the current conduction function of the first power appliance diagnosed by the diagnosing means, and for determining if an abnormality exists in the second power appliance based on the at least one of the insulating function of the second power appliance and the current conduction function of the second power appliance diagnosed by the diagnosing means; and

means for preventing the first control means from generating the first switching control signal and the third switching control signal if the determining means determines that an abnormality exist in the second power appliance, and for preventing the second control means from generating the second switching control signal and the fourth switching control signal if the determining means determines that an abnormality exists in the first power appliance.

20. A method of performing diagnosis of a power appliance, the power appliance including switches and current conduction appliances housed in gas-insulated casings, the method comprising the steps of:

respectively detecting a plurality of mutually different phenomena indicative of at least one of an insulating function of the power appliance and a current conduction function of the power appliance with a plurality of detectors disposed on one gas-insulated casing of the power appliance, the plurality of detectors respectively outputting a plurality of detection signals indicative of the respective detected phenomena;

sequentially selecting each of the detection signals from the detectors;

sequentially performing frequency analysis of the sequentially selected detection signals with a frequency analyzer, the frequency analyzer sequentially outputting frequency-analyzed signals indicative of respective results of the frequency analysis of the sequentially selected detection signals; and

diagnosing at least one of the insulating function of the power appliance and the current conduction function of the power appliance based on the frequency-analyzed signals sequentially output from the frequency analyzer.

21. A method according to claim 20, wherein the mutually different pehnomena respectively detected by the detectors appear in the form of frequency components in respective mutually different frequency bands;

and

wherein the step of sequentially performing frequency analysis of the sequentially selected detection signals with a frequency analyzer includes sequentially changing a frequency band in which the frequency analyzer performs frequency analysis to each of the mutually different frequency bands while sequentially performing frequency analysis of the sequentially selected detection signals such that the frequency analyzer performs frequency analysis of the detection signals in the respective frequency bands in which the frequency components of the respective pehnomena which the detection signals are indicative of appear.