US20060164100A1 - Method and system for measuring partial discharge - Google Patents
Method and system for measuring partial discharge Download PDFInfo
- Publication number
- US20060164100A1 US20060164100A1 US11/386,715 US38671506A US2006164100A1 US 20060164100 A1 US20060164100 A1 US 20060164100A1 US 38671506 A US38671506 A US 38671506A US 2006164100 A1 US2006164100 A1 US 2006164100A1
- Authority
- US
- United States
- Prior art keywords
- voltage
- operating voltage
- partial discharge
- spectrum analyzer
- input terminal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1254—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of gas-insulated power appliances or vacuum gaps
Definitions
- the present invention relates to a partial discharge measurement method and a system, and specifically to a partial discharge measurement method and a system suitable for measuring partial discharge which results from an insulation defect in a container filled with insulating gas used as an insulation material.
- the gas insulated device such as a gas circuit breaker, gas insulated switchgear and gas insulated bus, which is used in a transmission and delivery system is structured such that a high-voltage conductor is encased in a sealed metal container filled with an insulating gas and is supported by an insulating support medium. If a defect, such as a metal particle, is present in the sealed metal container, a high electric field is formed locally at the tip of the particle, causing a partial discharge to occur. If the partial discharge continues to exist, mechanical deterioration inside the device may occur, which may eventually result in a breakdown. In view of such circumstances, to conduct preventive maintenance of gas insulated devices, early detection of partial discharge which indicates a preliminary breakdown is important.
- the pattern of the partial discharge signal depends on the phase of the rated voltage applied to a high-voltage conductor, for example, an alternating voltage (operating voltage) of 60,000 to 500,000 volts (50/60 Hz). Therefore, the operating voltage is synchronized with the partial discharge signal (see Japanese Patent Laid-Open No. Hei 09(1997)-80111).
- the objective of the present invention is to compensate a phase shift prior to the measurement of partial discharge when there is a phase shift in the measurement system where partial discharge is to be measured.
- the present invention detects voltages of the conductor encased in the container; converts the waveform of the operating voltage (alternating voltage), among detected voltages, applied to the conductor by using a signal converter circuit; inputs the converted operating voltage into the measuring instrument; detects the phase difference between the measuring instrument's power-supply voltage and the operating voltage based on the inputted operating voltage; compensates the phase of the time axis displayed on the measuring instrument's screen according to the detected phase difference; and inputs the detected voltage into the compensated measuring instrument as it is, thereby displaying partial discharge information on the measuring instrument's screen.
- a voltage phase shift associated with input impedance of the signal converter circuit it is possible to further accurately compensate phase shifts by considering the voltage phase shift and compensating the phase of the time axis displayed on the screen of the measuring instrument.
- partial discharge can be accurately measured.
- FIG. 1 is a block diagram of a partial discharge measuring device according to a first embodiment of the present invention.
- FIG. 2 is a side cross-sectional view of the major portion when the partial discharge measuring device is installed in the gas insulated device.
- FIG. 3 shows waveforms taken at various portions of the signal converter circuit and the display screen of the spectrum analyzer.
- FIG. 4 is a block diagram of a partial discharge measuring device according to a second embodiment of the present invention.
- FIG. 5 is a block diagram of a partial discharge measuring device according to a third embodiment of the present invention.
- FIG. 6 is a block diagram of a partial discharge measuring device according to a fourth embodiment of the present invention.
- FIG. 7 is an explanatory drawing showing the configuration in which a phase difference is obtained by using an oscilloscope.
- FIG. 1 is a block diagram of a partial discharge measuring device according to a first embodiment of the present invention
- FIG. 2 is a side cross-sectional view of the major portion when the partial discharge measuring device is installed in an gas insulated device.
- the partial discharge measuring device 10 is installed in the vicinity of the metal container 16 , which encases a high-voltage conductor 14 and an insulation material, so as to measure one phase of the high-voltage conductor 14 which is a gas insulated bus connected to a gas circuit breaker 12 .
- One end of the high-voltage conductor 14 is connected to an electrode of the gas circuit breaker 12 , and the other end is exposed to the atmosphere via an arrester 18 and a bushing 20 .
- 60,000 to 500,000 volt alternating voltage is applied to the high-voltage conductor 14 as an operating voltage.
- the high-voltage conductor 14 is supported by an annular insulating support medium 22 , and the insulating support medium is fixed to the metal container 16 .
- the metal container 16 is cylindrically structured, and one end in the axial direction is connected to the switchgear encasing container 12 a which encases the gas circuit breaker (gas insulated switchgear) 12 .
- a gas or a gas mixture consisting of a main gas and at least one sub gas is sealed under high pressure.
- a hand hole 24 is created in the body of the metal container 16 , and a flange 26 is mounted at the bottom of the hand hole 24 so as to close the hand hole 24 and seal the metal container 16 .
- a circular-disc antenna 28 is contained in the hand hole 24 as a voltage sensor, and a coaxial cable 30 is connected to the central portion of the antenna 28 .
- the coaxial cable 30 is exposed to the atmosphere from the metal container 16 via a sealed terminal 32 provided on the flange 26 .
- the antenna 28 uses a floating capacitor C 1 located between the antenna 28 and the high-voltage conductor 14 and another floating capacitor C 2 located between the antenna 28 and the flange 26 and detects the voltage electrostatically divided by the floating capacitors C 1 and C 2 , and then outputs the detected voltage to the coaxial cable 30 .
- the other end of the coaxial cable 30 in the axial direction is connected to the changeover switch 34 which can switch between the A-side and the B-side.
- the A-side of the changeover switch 34 is connected to a coaxial cable 36 and the B-side of the changeover switch 34 is connected to a coaxial cable 37 .
- the coaxial cable 36 is connected to a coaxial cable 39 via a signal converter circuit 38 .
- the coaxial cable 39 is connected to the A-side of the changeover switch 42
- the coaxial cable 37 is connected to the B-side of the changeover switch 42 .
- the changeover switch 42 can switch between the A-side and the B-side and is connected to a spectrum analyzer 46 via a coaxial cable 44 .
- the spectrum analyzer 46 is configured as a measuring instrument which displays input information on its screen.
- the spectrum analyzer 46 has frequency domain analysis and phase domain analysis functions. It is possible to obtain the position of the zero cross of the operating voltage displayed on the screen by carrying out phase domain analysis using a spectrum analyzer 46 by setting the integral multiple of the operating voltage cycle (50/60 Hz) as a horizontal axis.
- the time axis displayed on the screen of the spectrum analyzer 46 in the phase domain analysis usually synchronizes with the phase of the power supply (outlet power supply) of the spectrum analyzer 46 . Accordingly, if there is a phase difference between an operating voltage applied to the high-voltage conductor 14 and a power supply voltage of the spectrum analyzer 46 , it is not possible to accurately detect the zero cross of the operating voltage.
- changeover switches 34 and 42 are switched to the A-side, and the voltage detected by the antenna 28 is inputted into a signal converter circuit 38 via a coaxial cable 30 , changeover switch 34 , and a coaxial cable 36 .
- the signal converter circuit 38 has a function which converts the signal detected by the antenna 28 into a square-wave which has a steep and constant gradient at the zero cross of the operating voltage.
- the signal converter circuit 38 is equipped with a comparator (not shown) which responds to an operating voltage detected by the antenna 28 and converts the waveform of the operating voltage into a square-wave as shown in FIG. 3 ( a ), a half-wave rectification circuit (not shown) which half-wave rectifies the square-wave outputted by the comparator as shown in FIG. 3 ( b ), and an oscillation circuit (not shown) which converts the voltage outputted by the half-wave rectification circuit into a voltage of any frequency higher than the operating voltage as shown in FIG. 3 ( c ).
- a comparator not shown
- a half-wave rectification circuit which half-wave rectifies the square-wave outputted by the comparator as shown in FIG. 3 ( b )
- an oscillation circuit not shown
- the above-mentioned arbitrary frequency component can be detected by the spectrum analyzer 46 , and preferably, the frequency component is different from a frequency component contained in the partial discharge electromagnetic wave.
- the signal converter circuit 38 responds to an operating voltage detected by an antenna 28 , creates a square-wave signal which has a steep and constant gradient at the zero cross of the operating voltage, and can convert the square-wave signal into a signal of higher frequency than that of the operating voltage, and outputs the signal.
- the spectrum analyzer 46 carries out phase domain analysis of the inputted signal. In this case, phase domain analysis of the frequency which is identical to the oscillation frequency of the signal converter circuit 38 is executed. Once the phase domain analysis is done, as shown in FIG. 3 ( d ), it is possible to accurately detect the phase difference ⁇ between an operating voltage and a power supply voltage of the spectrum analyzer 46 .
- changeover switches 34 and 42 are switched to the B-side to measure partial discharge, and the voltage detected by the antenna 28 is inputted into the spectrum analyzer 46 via a coaxial cable 30 , changeover switch 34 , coaxial cable 37 , changeover switch 42 , and a coaxial cable 44 .
- the screen is displayed on which the horizontal axis indicates frequency and the vertical axis indicates signal intensity. An image which shows peak frequency in the area where partial discharge has occurred appears on the screen.
- an amplifier to amplify the signal detected by the antenna 28 .
- a dipole-type antenna can be used as the antenna 28 . In this case, among dipole-type antennas, if a half-wave length dipole antenna in which the antenna length is principally equivalent to the half-wave length of the detected electromagnetic wave is used, the partial discharge electromagnetic wave resonates or almost resonates with the antenna, thereby making it possible to effectively detect electromagnetic waves.
- antennas 28 a and 28 b which have the same function as an antenna 28 are encased in hand holes 24 a and 24 b , respectively, and each antenna 28 a and 28 b is connected to a spectrum analyzer 46 via a coaxial cable 30 a or 30 b , and a signal converter circuit 38 and a delay circuit 40 are inserted in the middle of the coaxial cable 30 b .
- the other configuration is the same as that shown in FIG. 1 .
- the lengths of the coaxial cables 30 a and 30 b are the same.
- the antenna 28 a functions as a voltage sensor to detect partial discharge
- the antenna 28 b functions as a voltage sensor to detect an operating voltage applied to the high-voltage conductor 14 .
- the operating voltage signal detected by the antenna 28 b is formed into a waveform by a signal converter circuit 38 , and delayed by the delay circuit 40 by the amount of the voltage phase shift (phase difference) ⁇ associated with input impedance of the comparator of the signal converter circuit 38 , and then the signal is inputted into a spectrum analyzer 46 .
- the operating voltage signal is inputted into the spectrum analyzer 46 as an external trigger signal, and in response to the external trigger signal, partial discharge signals detected by the antenna 28 a are sequentially inputted into the spectrum analyzer 46 and are scanned by the spectrum analyzer 46 in synchronization with the operating voltage phase. Then, by executing phase domain analysis to detect the partial discharge signal by the spectrum analyzer 46 , it is possible to highly accurately detect the pattern of partial discharge with regard to the operating voltage phase.
- an electromagnetic wave sensor 50 which is disposed around the insulating support medium 22 and detects an operating voltage applied to the high-voltage conductor 14 is used, and instead of using a spectrum analyzer 46 , an oscilloscope 52 is used.
- the other configuration is the same as that shown in FIG. 4 .
- This embodiment uses an oscilloscope 52 as a measuring instrument which displays input information on its screen. Accordingly, a coaxial cable 30 a is connected to a measurement signal input terminal of the oscilloscope 52 , and a coaxial cable 30 b is connected to a trigger signal input terminal of the oscilloscope 52 .
- the operating voltage signal detected by an electromagnetic wave sensor 50 functions as a trigger, and partial discharge signals detected by an antenna 28 a are sequentially displayed on the screen of the oscilloscope 52 .
- the operating voltage signal is delayed in the delay circuit 40 by the amount of the phase shift (phase difference) ⁇ , it is possible to detect the partial discharge signal using the zero cross of the operating voltage as a trigger position. As a result, it is possible to synchronize the operating voltage with the partial discharge signal.
- phase difference ⁇ is compensated by the delay circuit 40 . Therefore, the operating voltage can be synchronized with the partial discharge signal, thereby making it possible to highly accurately measure the partial discharge signal.
- a fourth embodiment of the present invention will be explained with reference to FIG. 6 .
- a coaxial cable 30 which is connected to an antenna 28 is directly connected to a spectrum analyzer 46 , and the spectrum analyzer 46 measures the partial discharge signal detected by the antenna 28 .
- the other configuration is the same as that shown in FIG. 1 .
- an oscilloscope 52 is used to measure phase difference ⁇ between the power supply voltage of the spectrum analyzer 46 and the operating voltage signal applied to the high-voltage conductor 14 , and based on the measured phase difference ⁇ , the position of the time axis displayed on the screen of the spectrum analyzer 46 is compensated so that the phase difference ⁇ becomes 0.
- the voltage detected by the antenna 28 is inputted into the spectrum analyzer 46 , and based on the inputted voltage, partial discharge information is displayed on the screen. Consequently, partial discharge can be accurately measured.
- the VT Voltage Transfer
- the VT Voltage Transfer
- an oscilloscope 52 is used to measure phase difference ⁇ between the power supply voltage of the spectrum analyzer 46 and the operating voltage signal applied to the high-voltage conductor 14 , and based on the measured phase difference ⁇ , the position of the time axis displayed on the screen of the spectrum analyzer 46 is compensated so that the phase difference ⁇ becomes 0.
- the voltage detected by the antenna 28 is inputted into the spectrum analyzer 46 , and based on the inputted voltage, partial discharge information is displayed on the screen. As a result, partial discharge can be accurately measured.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Relating To Insulation (AREA)
Abstract
In the measurement of partial discharge, a voltage detected by the antenna is input into a spectrum analyzer and a phase difference between an operating voltage and a power supply of the spectrum analyzer is obtained by phase domain analysis using the spectrum analyzer. Based on the phase difference and the voltage phase shift associated with input impedance of the signal converter circuit, the time axis displayed on the screen of the spectrum analyzer is compensated. After the compensation has been carried out, the voltage detected by the antenna is input into the spectrum analyzer, the partial discharge pattern which synchronizes with the operating voltage is measured by phase domain analysis using the spectrum analyzer.
Description
- The present application claims priority from Japanese application serial no. 2004-44926, filed on Feb. 20, 2004, the content of which is hereby incorporated by reference into this application.
- The present invention relates to a partial discharge measurement method and a system, and specifically to a partial discharge measurement method and a system suitable for measuring partial discharge which results from an insulation defect in a container filled with insulating gas used as an insulation material.
- The gas insulated device, such as a gas circuit breaker, gas insulated switchgear and gas insulated bus, which is used in a transmission and delivery system is structured such that a high-voltage conductor is encased in a sealed metal container filled with an insulating gas and is supported by an insulating support medium. If a defect, such as a metal particle, is present in the sealed metal container, a high electric field is formed locally at the tip of the particle, causing a partial discharge to occur. If the partial discharge continues to exist, mechanical deterioration inside the device may occur, which may eventually result in a breakdown. In view of such circumstances, to conduct preventive maintenance of gas insulated devices, early detection of partial discharge which indicates a preliminary breakdown is important.
- When detecting partial discharge, a specific pattern of the partial discharge signal is developed, and based on the pattern, the type of defect is identified. In this case, the pattern of the partial discharge signal depends on the phase of the rated voltage applied to a high-voltage conductor, for example, an alternating voltage (operating voltage) of 60,000 to 500,000 volts (50/60 Hz). Therefore, the operating voltage is synchronized with the partial discharge signal (see Japanese Patent Laid-Open No. Hei 09(1997)-80111).
- Conventionally, when detecting a partial discharge signal in a signal processing section using an alternating voltage (operating voltage) as a trigger, the alternating voltage is separated from the partial discharge signal which has superposed on the alternating voltage in the signal detecting section; however, there is no consideration about the fact that the phase of the signal changes depending on the elements that configure the signal detecting section. Accordingly, if the signal which has had its phase changed is processed in the signal processing section, even if a partial discharge signal is detected by using an alternating voltage (operating voltage) as a trigger, it is difficult to detect an accurate pattern of the partial discharge signal.
- The objective of the present invention is to compensate a phase shift prior to the measurement of partial discharge when there is a phase shift in the measurement system where partial discharge is to be measured.
- To achieve the above objective, when measuring partial discharge by using a measuring instrument which displays input information on its screen, the present invention detects voltages of the conductor encased in the container; converts the waveform of the operating voltage (alternating voltage), among detected voltages, applied to the conductor by using a signal converter circuit; inputs the converted operating voltage into the measuring instrument; detects the phase difference between the measuring instrument's power-supply voltage and the operating voltage based on the inputted operating voltage; compensates the phase of the time axis displayed on the measuring instrument's screen according to the detected phase difference; and inputs the detected voltage into the compensated measuring instrument as it is, thereby displaying partial discharge information on the measuring instrument's screen. In this case, if there is a voltage phase shift associated with input impedance of the signal converter circuit, it is possible to further accurately compensate phase shifts by considering the voltage phase shift and compensating the phase of the time axis displayed on the screen of the measuring instrument.
- According to the present invention, partial discharge can be accurately measured.
-
FIG. 1 is a block diagram of a partial discharge measuring device according to a first embodiment of the present invention. -
FIG. 2 is a side cross-sectional view of the major portion when the partial discharge measuring device is installed in the gas insulated device. -
FIG. 3 shows waveforms taken at various portions of the signal converter circuit and the display screen of the spectrum analyzer. -
FIG. 4 is a block diagram of a partial discharge measuring device according to a second embodiment of the present invention. -
FIG. 5 is a block diagram of a partial discharge measuring device according to a third embodiment of the present invention. -
FIG. 6 is a block diagram of a partial discharge measuring device according to a fourth embodiment of the present invention. -
FIG. 7 is an explanatory drawing showing the configuration in which a phase difference is obtained by using an oscilloscope. - Hereafter, an embodiment of the present invention will be explained with reference to the drawings.
FIG. 1 is a block diagram of a partial discharge measuring device according to a first embodiment of the present invention, andFIG. 2 is a side cross-sectional view of the major portion when the partial discharge measuring device is installed in an gas insulated device. - In
FIGS. 1 and 2 , the partialdischarge measuring device 10 is installed in the vicinity of themetal container 16, which encases a high-voltage conductor 14 and an insulation material, so as to measure one phase of the high-voltage conductor 14 which is a gas insulated bus connected to agas circuit breaker 12. One end of the high-voltage conductor 14 is connected to an electrode of thegas circuit breaker 12, and the other end is exposed to the atmosphere via anarrester 18 and abushing 20. For example, 60,000 to 500,000 volt alternating voltage is applied to the high-voltage conductor 14 as an operating voltage. The high-voltage conductor 14 is supported by an annularinsulating support medium 22, and the insulating support medium is fixed to themetal container 16. Themetal container 16 is cylindrically structured, and one end in the axial direction is connected to theswitchgear encasing container 12 a which encases the gas circuit breaker (gas insulated switchgear) 12. In thismetal container 16, as an insulation material, for example, a gas or a gas mixture consisting of a main gas and at least one sub gas is sealed under high pressure. Ahand hole 24 is created in the body of themetal container 16, and aflange 26 is mounted at the bottom of thehand hole 24 so as to close thehand hole 24 and seal themetal container 16. - A circular-
disc antenna 28 is contained in thehand hole 24 as a voltage sensor, and acoaxial cable 30 is connected to the central portion of theantenna 28. Thecoaxial cable 30 is exposed to the atmosphere from themetal container 16 via a sealedterminal 32 provided on theflange 26. When detecting an operating voltage (alternating voltage) applied to the high-voltage conductor 14 and a partial discharge signal which has superposed on the operating voltage, theantenna 28 uses a floating capacitor C1 located between theantenna 28 and the high-voltage conductor 14 and another floating capacitor C2 located between theantenna 28 and theflange 26 and detects the voltage electrostatically divided by the floating capacitors C1 and C2, and then outputs the detected voltage to thecoaxial cable 30. The other end of thecoaxial cable 30 in the axial direction is connected to thechangeover switch 34 which can switch between the A-side and the B-side. The A-side of thechangeover switch 34 is connected to acoaxial cable 36 and the B-side of thechangeover switch 34 is connected to acoaxial cable 37. Thecoaxial cable 36 is connected to acoaxial cable 39 via asignal converter circuit 38. Thecoaxial cable 39 is connected to the A-side of thechangeover switch 42, and thecoaxial cable 37 is connected to the B-side of thechangeover switch 42. Thechangeover switch 42 can switch between the A-side and the B-side and is connected to aspectrum analyzer 46 via acoaxial cable 44. - The
spectrum analyzer 46 is configured as a measuring instrument which displays input information on its screen. Thespectrum analyzer 46 has frequency domain analysis and phase domain analysis functions. It is possible to obtain the position of the zero cross of the operating voltage displayed on the screen by carrying out phase domain analysis using aspectrum analyzer 46 by setting the integral multiple of the operating voltage cycle (50/60 Hz) as a horizontal axis. - However, the time axis displayed on the screen of the
spectrum analyzer 46 in the phase domain analysis usually synchronizes with the phase of the power supply (outlet power supply) of thespectrum analyzer 46. Accordingly, if there is a phase difference between an operating voltage applied to the high-voltage conductor 14 and a power supply voltage of thespectrum analyzer 46, it is not possible to accurately detect the zero cross of the operating voltage. - Therefore, prior to the measurement of the partial discharge signal using a
spectrum analyzer 46, in order to measure the phase difference between an operating voltage of the high-voltage conductor 14 and a power supply voltage of thespectrum analyzer 46,changeover switches antenna 28 is inputted into asignal converter circuit 38 via acoaxial cable 30,changeover switch 34, and acoaxial cable 36. Thesignal converter circuit 38 has a function which converts the signal detected by theantenna 28 into a square-wave which has a steep and constant gradient at the zero cross of the operating voltage. - Specifically, the
signal converter circuit 38 is equipped with a comparator (not shown) which responds to an operating voltage detected by theantenna 28 and converts the waveform of the operating voltage into a square-wave as shown inFIG. 3 (a), a half-wave rectification circuit (not shown) which half-wave rectifies the square-wave outputted by the comparator as shown inFIG. 3 (b), and an oscillation circuit (not shown) which converts the voltage outputted by the half-wave rectification circuit into a voltage of any frequency higher than the operating voltage as shown inFIG. 3 (c). Herein, the above-mentioned arbitrary frequency component can be detected by thespectrum analyzer 46, and preferably, the frequency component is different from a frequency component contained in the partial discharge electromagnetic wave. Thesignal converter circuit 38 responds to an operating voltage detected by anantenna 28, creates a square-wave signal which has a steep and constant gradient at the zero cross of the operating voltage, and can convert the square-wave signal into a signal of higher frequency than that of the operating voltage, and outputs the signal. When a signal outputted by thesignal converter circuit 38 is inputted into thespectrum analyzer 46, thespectrum analyzer 46 carries out phase domain analysis of the inputted signal. In this case, phase domain analysis of the frequency which is identical to the oscillation frequency of thesignal converter circuit 38 is executed. Once the phase domain analysis is done, as shown inFIG. 3 (d), it is possible to accurately detect the phase difference θ between an operating voltage and a power supply voltage of thespectrum analyzer 46. - On the other hand, as shown in
FIG. 3 (a), because input impedance of the comparator in thesignal converter circuit 38 is high (several MΩ), there is a voltage phase shift (phase difference) Φ between the input and output voltages of the comparator. For this reason, when compensating the time axis displayed on the screen of thespectrum analyzer 46, the location of the time axis displayed on the screen of thespectrum analyzer 46 is automatically compensated based on the voltage phase shift (phase difference) Φ associated with input impedance of the comparator and the phase difference θ between the operating voltage and the power supply voltage of thespectrum analyzer 46 so that both the phase difference Φ and the phase difference θ become 0. By carrying out compensation in such a way, it is possible to accurately synchronize the time axis displayed on the screen with the phase of the power supply voltage of thespectrum analyzer 46 in the phase domain analysis of thespectrum analyzer 46. - After the phase compensation has been carried out,
changeover switches antenna 28 is inputted into thespectrum analyzer 46 via acoaxial cable 30,changeover switch 34,coaxial cable 37,changeover switch 42, and acoaxial cable 44. If frequency domain analysis is conducted by thespectrum analyzer 46 when voltage detected by theantenna 28 is inputted into thespectrum analyzer 46 without passing through thesignal converter circuit 38, the screen is displayed on which the horizontal axis indicates frequency and the vertical axis indicates signal intensity. An image which shows peak frequency in the area where partial discharge has occurred appears on the screen. By executing phase domain analysis with frequency which shows the peak, it is possible to detect a partial discharge pattern which synchronizes with the operating voltage, thereby making it possible to identify the type of defect based on the pattern. - Thus, in this embodiment, prior to the measurement of partial discharge by using a
spectrum analyzer 46, if there are voltage phase shifts, which are phase differences θ and Φ, in the measurement system, the voltage phases are compensated so that the phase difference becomes 0. As a result, it is possible to accurately measure partial discharge. - If voltage induced in an
antenna 28 is weak, it is preferable to use an amplifier to amplify the signal detected by theantenna 28. Also, a dipole-type antenna can be used as theantenna 28. In this case, among dipole-type antennas, if a half-wave length dipole antenna in which the antenna length is principally equivalent to the half-wave length of the detected electromagnetic wave is used, the partial discharge electromagnetic wave resonates or almost resonates with the antenna, thereby making it possible to effectively detect electromagnetic waves. - Next, a second embodiment of the present invention will be explained with reference to
FIG. 4 . In this embodiment,antennas antenna 28 are encased inhand holes antenna spectrum analyzer 46 via acoaxial cable signal converter circuit 38 and adelay circuit 40 are inserted in the middle of thecoaxial cable 30 b. The other configuration is the same as that shown inFIG. 1 . To equalize the propagation time of each signal that is transmitted throughcoaxial cables coaxial cables - The
antenna 28 a functions as a voltage sensor to detect partial discharge, and theantenna 28 b functions as a voltage sensor to detect an operating voltage applied to the high-voltage conductor 14. The operating voltage signal detected by theantenna 28 b is formed into a waveform by asignal converter circuit 38, and delayed by thedelay circuit 40 by the amount of the voltage phase shift (phase difference) Φ associated with input impedance of the comparator of thesignal converter circuit 38, and then the signal is inputted into aspectrum analyzer 46. The operating voltage signal is inputted into thespectrum analyzer 46 as an external trigger signal, and in response to the external trigger signal, partial discharge signals detected by theantenna 28 a are sequentially inputted into thespectrum analyzer 46 and are scanned by thespectrum analyzer 46 in synchronization with the operating voltage phase. Then, by executing phase domain analysis to detect the partial discharge signal by thespectrum analyzer 46, it is possible to highly accurately detect the pattern of partial discharge with regard to the operating voltage phase. - In this embodiment, if a voltage phase shifts by the amount of the phase difference Φ during the process in which the operating voltage signal is inputted into the
spectrum analyzer 46, the phase of the operating voltage signal is delayed by the amount of the phase difference Φ. Therefore, it is possible to highly accurately detect the pattern of partial discharge with regard to the operating voltage phase. - Next, a third embodiment of the present invention will be explained with reference to
FIG. 5 . In this embodiment, instead of using anantenna 28 b as a voltage sensor, anelectromagnetic wave sensor 50 which is disposed around the insulatingsupport medium 22 and detects an operating voltage applied to the high-voltage conductor 14 is used, and instead of using aspectrum analyzer 46, anoscilloscope 52 is used. The other configuration is the same as that shown inFIG. 4 . This embodiment uses anoscilloscope 52 as a measuring instrument which displays input information on its screen. Accordingly, acoaxial cable 30 a is connected to a measurement signal input terminal of theoscilloscope 52, and acoaxial cable 30 b is connected to a trigger signal input terminal of theoscilloscope 52. - In this embodiment, the operating voltage signal detected by an
electromagnetic wave sensor 50 functions as a trigger, and partial discharge signals detected by anantenna 28 a are sequentially displayed on the screen of theoscilloscope 52. In this case, because the operating voltage signal is delayed in thedelay circuit 40 by the amount of the phase shift (phase difference) Φ, it is possible to detect the partial discharge signal using the zero cross of the operating voltage as a trigger position. As a result, it is possible to synchronize the operating voltage with the partial discharge signal. - In this embodiment, phase difference Φ is compensated by the
delay circuit 40. Therefore, the operating voltage can be synchronized with the partial discharge signal, thereby making it possible to highly accurately measure the partial discharge signal. - Next, a fourth embodiment of the present invention will be explained with reference to
FIG. 6 . In this embodiment, acoaxial cable 30 which is connected to anantenna 28 is directly connected to aspectrum analyzer 46, and thespectrum analyzer 46 measures the partial discharge signal detected by theantenna 28. The other configuration is the same as that shown inFIG. 1 . - In this embodiment, as shown in
FIG. 7 , for example, anoscilloscope 52 is used to measure phase difference θ between the power supply voltage of thespectrum analyzer 46 and the operating voltage signal applied to the high-voltage conductor 14, and based on the measured phase difference θ, the position of the time axis displayed on the screen of thespectrum analyzer 46 is compensated so that the phase difference θ becomes 0. After that, the voltage detected by theantenna 28 is inputted into thespectrum analyzer 46, and based on the inputted voltage, partial discharge information is displayed on the screen. Consequently, partial discharge can be accurately measured. - In
FIG. 7 , to detect an operating voltage signal, for example, the VT (Voltage Transfer) can be used for measurement. When measuring a power supply voltage of thespectrum analyzer 46, it is possible to measure the phase of the power supply voltage by connecting thespectrum analyzer 46 and theoscilloscope 52 to the same power supply. - In this embodiment, prior to the measurement of partial discharge by the
spectrum analyzer 46, anoscilloscope 52 is used to measure phase difference θ between the power supply voltage of thespectrum analyzer 46 and the operating voltage signal applied to the high-voltage conductor 14, and based on the measured phase difference θ, the position of the time axis displayed on the screen of thespectrum analyzer 46 is compensated so that the phase difference θ becomes 0. On the premise that the compensation has been completed, the voltage detected by theantenna 28 is inputted into thespectrum analyzer 46, and based on the inputted voltage, partial discharge information is displayed on the screen. As a result, partial discharge can be accurately measured.
Claims (4)
1-12. (canceled)
13. A method of measuring partial discharge, comprising the steps of:
detecting voltages of a conductor encased in a container together with an insulation material, at different locations respectively;
converting a waveform of an operating voltage, among said detected voltages at the one location, applied to said conductor by using a signal converter circuit;
inputting said converted operating voltage, via a delay circuit, into the trigger signal input terminal of a measuring instrument which displays input information on the screen;
inputting the other detected voltage at the other location, into the measurement signal input terminal of said measuring instrument; and
displaying voltage information inputted into said measurement signal input terminal on the screen of said measuring instrument using the operating voltage inputted into said trigger signal input terminal as a trigger.
14. A partial discharge measuring system comprising:
a plurality of voltage detecting means for detecting voltages of a conductor encased in a container together with an insulation material, at different locations respectively;
a signal converter circuit for converting a waveform of an operating voltage, among said detected voltages at the one location, applied to said conductor;
the first inputting means for inputting said converted operating voltage, via a delay circuit, into the trigger signal input terminal of a measuring instrument which displays input information on the screen;
the second inputting means for inputting the other detected voltage at the other location, into the measurement signal input terminal of said measuring instrument; and
a displaying means for displaying voltage information inputted into said measurement signal input terminal on the screen of said measuring instrument using the operating voltage inputted into said trigger signal input terminal as a trigger.
15. A partial discharge measuring system according to claim 14 ,
wherein said signal converter circuit comprising:
a comparator which responds to said operating voltage detected by said voltage detecting means and converts the waveform of said operating voltage to a square-wave;
a half-wave rectification circuit which half-wave rectifies the square-wave outputted by said comparator; and
an oscillation circuit which converts an output voltage of said half-wave rectification circuit into a voltage of higher frequency than that of said operating voltage.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/386,715 US20060164100A1 (en) | 2004-02-20 | 2006-03-23 | Method and system for measuring partial discharge |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004044926A JP4470157B2 (en) | 2004-02-20 | 2004-02-20 | Partial discharge measurement method and apparatus |
JP2004-044926 | 2004-02-20 | ||
US11/048,777 US20050184737A1 (en) | 2004-02-20 | 2005-02-03 | Method and system for measuring partial discharge |
US11/386,715 US20060164100A1 (en) | 2004-02-20 | 2006-03-23 | Method and system for measuring partial discharge |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/048,777 Continuation US20050184737A1 (en) | 2004-02-20 | 2005-02-03 | Method and system for measuring partial discharge |
Publications (1)
Publication Number | Publication Date |
---|---|
US20060164100A1 true US20060164100A1 (en) | 2006-07-27 |
Family
ID=34709155
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/048,777 Abandoned US20050184737A1 (en) | 2004-02-20 | 2005-02-03 | Method and system for measuring partial discharge |
US11/294,409 Active US7256584B2 (en) | 2004-02-20 | 2005-12-06 | Method and system for measuring partial discharge |
US11/386,715 Abandoned US20060164100A1 (en) | 2004-02-20 | 2006-03-23 | Method and system for measuring partial discharge |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/048,777 Abandoned US20050184737A1 (en) | 2004-02-20 | 2005-02-03 | Method and system for measuring partial discharge |
US11/294,409 Active US7256584B2 (en) | 2004-02-20 | 2005-12-06 | Method and system for measuring partial discharge |
Country Status (6)
Country | Link |
---|---|
US (3) | US20050184737A1 (en) |
EP (1) | EP1566646B1 (en) |
JP (1) | JP4470157B2 (en) |
KR (1) | KR101105747B1 (en) |
CN (1) | CN100430744C (en) |
DE (1) | DE602005006860D1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080088314A1 (en) * | 2006-10-13 | 2008-04-17 | Abdelkrim Younsi | Methods and apparatus for analyzing partial discharge in electrical machinery |
WO2009130356A1 (en) * | 2008-04-23 | 2009-10-29 | Universidad Carlos Iii De Madrid | Inductive sensor with galvanic insulation for the detection and measurement of high-frequency current pulses |
US20100176816A1 (en) * | 2009-01-15 | 2010-07-15 | John Horowy | Partial Corona Discharge Detection |
US9329221B2 (en) | 2011-04-06 | 2016-05-03 | Mitsubishi Electric Corporation | Partial discharge sensor |
Families Citing this family (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4470157B2 (en) * | 2004-02-20 | 2010-06-02 | 株式会社日本Aeパワーシステムズ | Partial discharge measurement method and apparatus |
JP4323418B2 (en) * | 2004-12-16 | 2009-09-02 | 株式会社日本Aeパワーシステムズ | Abnormal condition diagnosis method and system for gas insulation equipment |
US7952360B2 (en) * | 2007-03-14 | 2011-05-31 | General Electric Company | Method and system for passively detecting and locating wire harness defects |
US7112968B1 (en) * | 2005-11-30 | 2006-09-26 | Haneron Co., Ltd. | Method and apparatus for detecting a partial discharge in a high-voltage transmission and distribution system |
US7532012B2 (en) * | 2006-07-07 | 2009-05-12 | Ambient Corporation | Detection and monitoring of partial discharge of a power line |
US20110226503A1 (en) * | 2010-03-17 | 2011-09-22 | Bolin Philip C | Gas insulated busbar particle trap |
EP2395364A1 (en) * | 2010-06-14 | 2011-12-14 | Alstom Technology Ltd | Method for detecting the partial discharges generated in an electric system and electric system with a device for detecting the partial discharges generated therein |
CN102305903B (en) * | 2011-06-03 | 2014-07-23 | 云南电力试验研究院(集团)有限公司 | Partial discharge detection method for pulse current of electrified operation single phase integrated gas insulated switchgear (GIS) |
KR101290294B1 (en) * | 2011-10-31 | 2013-07-26 | 주식회사 효성 | Partial discharge diagnostic system of power apparatus using contactless phase measurement sensor |
FR2987900B1 (en) * | 2012-03-09 | 2015-07-31 | Alstom Technology Ltd | METHOD FOR RECOGNIZING PARTIAL DISCHARGES ISSUED INSIDE AND OUTSIDE AN ELECTRICAL APPARATUS |
JP6116952B2 (en) * | 2013-03-19 | 2017-04-19 | 株式会社東芝 | Partial discharge monitoring system and partial discharge monitoring method |
CN105593693A (en) * | 2013-10-01 | 2016-05-18 | 三菱电机株式会社 | Partial discharge sensor |
US20150142344A1 (en) * | 2013-10-18 | 2015-05-21 | Utilx Corporation | Method and apparatus for measuring partial discharge charge value in frequency domain |
AU2013404355B2 (en) * | 2013-10-29 | 2018-08-09 | Prysmian S.P.A. | Partial discharge detection system and method employing a synthetized synchronization signal |
CN103558524A (en) * | 2013-11-12 | 2014-02-05 | 国网上海市电力公司 | Detection device for partial discharge of switch cabinet |
WO2015190260A1 (en) * | 2014-06-10 | 2015-12-17 | 株式会社日立製作所 | Partial discharge diagnosis system and partial discharge diagnosis method |
FR3024240B1 (en) * | 2014-07-28 | 2018-02-16 | Alstom Technology Ltd | PARTIAL DISCHARGE DETECTION DEVICE WITH FRACTALLY ARCHITECTURED ANTENNA |
CN104237605B (en) * | 2014-09-04 | 2018-01-09 | 兰州空间技术物理研究所 | A kind of high-pressure electrostatic voltage measuring apparatus |
KR101787901B1 (en) * | 2016-06-14 | 2017-11-15 | 엘에스산전 주식회사 | Power equipment diagnostic apparatus |
EP3577475A1 (en) | 2017-03-02 | 2019-12-11 | Rosemount Inc. | Trending functions for partial discharge |
CN106918743A (en) * | 2017-04-12 | 2017-07-04 | 国网四川省电力公司电力科学研究院 | The working voltage phase localization method of the middle single-phase cable termination of pressure |
CA3007729A1 (en) | 2017-06-12 | 2018-12-12 | Vibrosystm Inc. | Method of monitoring partial discharges in a high voltage electric machine, and connection cable therefore |
DE102017217127A1 (en) * | 2017-09-26 | 2019-03-28 | Siemens Aktiengesellschaft | Method and arrangement for detecting partial discharges in an electrical equipment |
US11067639B2 (en) | 2017-11-03 | 2021-07-20 | Rosemount Inc. | Trending functions for predicting the health of electric power assets |
US10794736B2 (en) | 2018-03-15 | 2020-10-06 | Rosemount Inc. | Elimination of floating potential when mounting wireless sensors to insulated conductors |
JP7097017B2 (en) * | 2018-05-14 | 2022-07-07 | 日新電機株式会社 | Partial discharge diagnostic device |
US11181570B2 (en) | 2018-06-15 | 2021-11-23 | Rosemount Inc. | Partial discharge synthesizer |
US10833531B2 (en) | 2018-10-02 | 2020-11-10 | Rosemount Inc. | Electric power generation or distribution asset monitoring |
JP2020099016A (en) * | 2018-12-19 | 2020-06-25 | 株式会社オーケー社鹿児島 | Weak discharge imaging system |
CA3033769A1 (en) | 2019-02-14 | 2020-08-14 | Daniel Pineau | Partial discharge detector and associated method |
US11313895B2 (en) | 2019-09-24 | 2022-04-26 | Rosemount Inc. | Antenna connectivity with shielded twisted pair cable |
CN111044854A (en) * | 2019-12-11 | 2020-04-21 | 国网北京市电力公司 | Partial discharge detection method and device for dry-type equipment and electronic equipment |
CN111044805B (en) * | 2019-12-27 | 2021-12-24 | 中国航空工业集团公司西安飞机设计研究所 | Electrostatic discharge radio frequency noise test method |
CN111157857A (en) * | 2020-01-03 | 2020-05-15 | 天津大学 | Device for testing surface discharge characteristic of low-temperature insulating material with controllable environmental temperature |
CN112731081A (en) * | 2020-12-25 | 2021-04-30 | 国网山东省电力公司电力科学研究院 | Method and device for acquiring partial discharge phase |
JP7482058B2 (en) * | 2021-02-16 | 2024-05-13 | 株式会社東芝 | Partial discharge measurement system and partial discharge measurement method |
CN113358932A (en) * | 2021-05-11 | 2021-09-07 | 北京首钢自动化信息技术有限公司 | Device and method for detecting synchronous phase angle of medium-voltage frequency converter |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5075629A (en) * | 1989-05-11 | 1991-12-24 | Kabushiki Kaisha Toshiba | Partial discharge detecting device for electrical equipments |
US20010040459A1 (en) * | 1999-01-28 | 2001-11-15 | Hitachi, Ltd. | Method of diagnosing partial discharge in gas-insulated apparatus and partial discharge diagnosing syatem for carrying out the same |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04204270A (en) * | 1990-11-30 | 1992-07-24 | Toshiba Corp | Partial-discharge detecting device for gas insulation switching device |
DE4126868A1 (en) * | 1991-08-14 | 1993-02-18 | Asea Brown Boveri | Partial discharge pulse detecting arrangement in gas insulated HV system - contains measurement points at boundaries of sub-regions of system which produce logical direction signals for evaluation of discharge location |
JP3187642B2 (en) * | 1994-02-25 | 2001-07-11 | 関西電力株式会社 | Electrical device abnormality detection method and rotating electrical machine abnormality detection device |
KR100206662B1 (en) * | 1995-08-28 | 1999-07-01 | 변승봉 | Partial discharge measuring method using frequency spectrum analyzer. |
JPH0980111A (en) | 1995-09-14 | 1997-03-28 | Toshiba Corp | Partial discharge detection apparatus |
DE19647686C2 (en) * | 1996-11-07 | 2001-02-15 | Siemens Ag | Device and method for generating an electromagnetic test signal sequence for a partial discharge measuring device |
JPH10170596A (en) | 1996-12-09 | 1998-06-26 | Hitachi Ltd | System for diagnosing insulated apparatus and method for detecting partial discharge |
JP4008102B2 (en) * | 1998-05-13 | 2007-11-14 | 株式会社フジクラ | Dielectric loss tangent measurement method |
JP2001133506A (en) * | 1999-11-01 | 2001-05-18 | Hitachi Ltd | Method and device for diagnosing compressed gas insulation equipment |
JP4470157B2 (en) * | 2004-02-20 | 2010-06-02 | 株式会社日本Aeパワーシステムズ | Partial discharge measurement method and apparatus |
-
2004
- 2004-02-20 JP JP2004044926A patent/JP4470157B2/en not_active Expired - Lifetime
-
2005
- 2005-01-11 CN CNB2005100004963A patent/CN100430744C/en active Active
- 2005-02-03 US US11/048,777 patent/US20050184737A1/en not_active Abandoned
- 2005-02-03 DE DE602005006860T patent/DE602005006860D1/en active Active
- 2005-02-03 EP EP05002312A patent/EP1566646B1/en active Active
- 2005-02-17 KR KR1020050013293A patent/KR101105747B1/en active IP Right Grant
- 2005-12-06 US US11/294,409 patent/US7256584B2/en active Active
-
2006
- 2006-03-23 US US11/386,715 patent/US20060164100A1/en not_active Abandoned
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5075629A (en) * | 1989-05-11 | 1991-12-24 | Kabushiki Kaisha Toshiba | Partial discharge detecting device for electrical equipments |
US20010040459A1 (en) * | 1999-01-28 | 2001-11-15 | Hitachi, Ltd. | Method of diagnosing partial discharge in gas-insulated apparatus and partial discharge diagnosing syatem for carrying out the same |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080088314A1 (en) * | 2006-10-13 | 2008-04-17 | Abdelkrim Younsi | Methods and apparatus for analyzing partial discharge in electrical machinery |
US7579843B2 (en) | 2006-10-13 | 2009-08-25 | General Electric Company | Methods and apparatus for analyzing partial discharge in electrical machinery |
WO2009130356A1 (en) * | 2008-04-23 | 2009-10-29 | Universidad Carlos Iii De Madrid | Inductive sensor with galvanic insulation for the detection and measurement of high-frequency current pulses |
ES2340750A1 (en) * | 2008-04-23 | 2010-06-08 | Universidad Carlos Iii De Madrid | Inductive sensor with galvanic insulation for the detection and measurement of high-frequency current pulses |
US20100176816A1 (en) * | 2009-01-15 | 2010-07-15 | John Horowy | Partial Corona Discharge Detection |
US8193818B2 (en) * | 2009-01-15 | 2012-06-05 | Hamilton Sundstrand Corporation | Partial corona discharge detection |
US9329221B2 (en) | 2011-04-06 | 2016-05-03 | Mitsubishi Electric Corporation | Partial discharge sensor |
Also Published As
Publication number | Publication date |
---|---|
US20060071667A1 (en) | 2006-04-06 |
JP4470157B2 (en) | 2010-06-02 |
EP1566646B1 (en) | 2008-05-21 |
US20050184737A1 (en) | 2005-08-25 |
KR20060042068A (en) | 2006-05-12 |
CN100430744C (en) | 2008-11-05 |
CN1657963A (en) | 2005-08-24 |
US7256584B2 (en) | 2007-08-14 |
DE602005006860D1 (en) | 2008-07-03 |
JP2005233837A (en) | 2005-09-02 |
EP1566646A1 (en) | 2005-08-24 |
KR101105747B1 (en) | 2012-01-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7256584B2 (en) | Method and system for measuring partial discharge | |
KR100614952B1 (en) | A method and device for detecting a partial discharge in an electrical device | |
EP2466324B1 (en) | Combined measuring and detection system | |
US6424162B1 (en) | Insulated device diagnosing system that prepares detection data from partial discharge signal such that periodic elements are given to different specific frequencies of the partial discharge signal | |
JP3914278B2 (en) | Discharge measuring device | |
US20070139056A1 (en) | Partial discharge detection apparatus and detection method of electrical rotating machine | |
AU714368B2 (en) | Measuring system for partial discharges | |
US20080001610A1 (en) | Apparatus and method of water absorption test for generator stator winding insulator using cross capacitance | |
US10018666B2 (en) | Partial discharge monitoring system and partial discharge monitoring method | |
KR101385318B1 (en) | Apparatus for diagnosing partial discharge and method therefor | |
JP2001133506A (en) | Method and device for diagnosing compressed gas insulation equipment | |
JP4740421B2 (en) | Partial discharge site location method for three-phase gas insulation equipment | |
Ahmed et al. | On-line partial discharge detection in cables | |
JPH10255564A (en) | Shield effect testing instrument and inspection device, shield effect testing sheet, and static-electricity coupler | |
EP2395364A1 (en) | Method for detecting the partial discharges generated in an electric system and electric system with a device for detecting the partial discharges generated therein | |
KR100383177B1 (en) | Sensor and system for measuring oil deterioration in distribution transformer | |
JP2023032488A (en) | Partial discharge detection method and partial discharge detection device | |
JP2003185697A (en) | Electric apparatus and its interior diagnosing apparatus | |
JP3231557B2 (en) | Partial discharge measurement adapter and partial discharge measurement method | |
Gataullin et al. | Pre-Breakdown Condition of Insulation Recognition by Partial Discharges Characteristics | |
CN113740421A (en) | Cable defect detection device | |
JPH1026650A (en) | Partial-discharge diagnosis method for gas insulated equipment | |
JPH06230067A (en) | Insulation diagnosing device | |
JPH06160456A (en) | Non-contact circuit route inspection device | |
JP2000055974A (en) | Measuring method for partial discharge at cable end connection part |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |