JP4879072B2 - Partial discharge detector for gas insulated switchgear - Google Patents

Description

  The present invention relates to a partial discharge detection device for detecting a partial discharge generated inside a gas insulated switchgear.

  For example, as described in Patent Document 1, in order to detect a partial discharge generated inside a gas-insulated switchgear, a partial discharge detection device including a capacitor voltage-dividing signal detection unit is used. The configuration and operation of a conventional partial discharge detection device will be described below based on the conventional technology described in Patent Document 1.

  In the gas insulated switchgear, a central conductor passes through a gas insulating container filled with an insulating gas, and the central conductor is supported by an insulating spacer that partitions the gas insulating container. The gas insulating container is grounded. A main circuit voltage having a commercial frequency is applied to the center conductor. For example, when a partial discharge is generated by a metal protrusion on the center conductor, an electromagnetic wave signal excited by the partial discharge propagates inside the gas insulating container along the center conductor. A signal in which the electromagnetic wave signal excited by the partial discharge and the main circuit voltage signal are superimposed is detected by a capacitor voltage dividing type voltage detector. The voltage divider type voltage detector is configured to include a floating electrode, which is insulated by forming a virtual capacitor with the center conductor, and between the grounded side of the gas insulating container. It is insulated by forming a capacitor or virtual capacitor.

  The output signal from the capacitor-divided signal detector is input to the signal separator, where it is separated into a partial discharge signal and a main circuit voltage phase signal. Subsequently, the partial discharge signal and the main circuit voltage phase signal separated by the signal separation unit are output to the calculation unit, and the partial discharge signal synchronized with the main circuit voltage is measured by the calculation unit. The signal separation unit and the calculation unit are driven by electric power supplied from an external main power source provided outside the partial discharge detection device.

Japanese Patent Laid-Open No. 04-215075

  In the conventional partial discharge detection device of the gas insulated switchgear described above, an external main power source for driving the signal separation unit and the calculation unit is necessary to detect the partial discharge generated in the gas insulation container. In actual gas insulation containers, hundreds or more of voltage divider type voltage detectors may be installed. In that case, the number of signal separation units and calculation units equal to the number of installed signal detection units. However, it is necessary to supply an external main power source to each of them, and there is a problem that the configuration of the device becomes complicated.

  In addition, when the signal separation unit and the calculation unit are configured as portable devices that can be carried, an external main power source is required to drive the device. Therefore, each time the portable device is connected to the signal detector, the external main power source is connected. Therefore, there is a problem that it takes time for measurement.

  The present invention has been made in view of the above, and is necessary for driving a device in a partial-capacitance partial discharge detector for detecting a partial discharge generated in a gas-insulated switchgear. It is an object of the present invention to obtain a partial discharge detection device of a gas insulated switchgear that can supply power without using an external main power supply.

In order to solve the above-described problems and achieve the object, a partial discharge detection device for a gas-insulated switchgear according to the present invention includes a gas-insulated container filled with an insulating gas and grounded, and an interior of the gas-insulated container. And a central conductor supported by an insulating spacer that extends along the longitudinal direction and is applied with a main circuit voltage and partitions the gas insulating container, and detects a partial discharge generated inside the gas-insulated switchgear. An electromagnetic wave signal and a main circuit voltage signal generated by a partial discharge generated in the gas insulation container using a floating electrode provided between the gas insulation container and the central conductor. And a capacitor voltage detector that detects a signal with a voltage superimposed on the floating electrode, and a voltage detected by the voltage divider voltage detector. A signal separation unit that separates the partial discharge signal and the main circuit voltage phase signal, and an arithmetic unit that calculates a partial discharge signal synchronized with the main circuit voltage based on the partial discharge signal and the main circuit voltage phase signal When, from the voltage detected by the voltage detector of the capacitive divider pressure type, by taking out a voltage obtained by dividing the main circuit voltage divided to generate a power supply voltage for driving the signal separation unit and the arithmetic unit The power supply voltage is supplied through a first power supply line connecting between itself and the signal separation unit, and the power supply is supplied through a second power supply line connecting between the device and the calculation unit. And an internal power supply for supplying voltage .

  According to the present invention, the internal power supply unit provided inside the partial discharge detection device extracts the voltage obtained by dividing the main circuit voltage based on the signal output from the voltage dividing type voltage detector. Thus, since the power supply voltage is supplied to the signal separation unit and the calculation unit, the partial discharge can be measured without using an external power supply.

  Embodiments of a partial discharge detection device for a gas insulated switchgear according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing a configuration of a partial discharge detection device according to the present embodiment. As shown in FIG. 1, in this embodiment, a gas insulating container 1 in which an insulating gas is sealed is provided, and the gas insulating container 1 is divided by an insulating spacer 3 in the longitudinal direction. A central conductor 2 extending along the longitudinal direction is provided inside the gas insulating container 1, and the central conductor 2 is supported by an insulating spacer 3. A main circuit voltage having a commercial frequency is applied to the center conductor 2. The gas insulation container 1 is grounded by a ground wire.

  The partial discharge that can be generated inside the gas insulating container 1 is generated, for example, via a metal protrusion formed on the central conductor 2. In FIG. 1, a metal protrusion 30 is formed on the central conductor 2, and a partial discharge 4 is generated through the metal protrusion 30. Further, due to the generation of the partial discharge 4, an electromagnetic wave signal 5 is excited on the central conductor 2, and the electromagnetic wave signal 5 propagates through the central conductor 2.

  The gas insulation container 1 has a voltage-divided capacitor voltage detection that detects a voltage signal in which the main circuit voltage signal and the electromagnetic wave signal 5 insulated from the ground side of the gas insulation container 1 are excited by the partial discharge 4. A vessel 6 is provided. The voltage dividing type voltage detector 6 includes a floating electrode 7 which is insulated by forming a virtual capacitor 31 between the floating conductor 7 and the central conductor 2, and is connected to the ground of the gas insulating container 1. A capacitor 32 is formed between the sides and insulated. As described above, in the capacitor voltage dividing type voltage detector 6, the virtual capacitor 31 and the capacitor 32 constitute a voltage divider, and a divided voltage is generated at both ends of the capacitor 32.

  The capacitor-divided voltage detector 6 is connected to the signal separation unit 10 via the signal line 8 and the signal line 9. In the voltage dividing type voltage detector 6, the signal line 8 is connected to the floating electrode 7, and the signal line 9 is connected to one end of a capacitor 32 that is at the ground potential. The signal separation unit 10 separates the partial discharge signal 12 and the main circuit voltage phase signal 13 from the voltage signal in which the main circuit voltage signal and the electromagnetic wave signal 5 input via the signal line 8 and the signal line 9 are superimposed. To do.

  The signal separation unit 10 is connected to the calculation unit 11, and the partial discharge signal 12 and the main circuit voltage phase signal 13 separated by the signal separation unit 10 are output to the calculation unit 11. The calculation unit 11 calculates a partial discharge signal synchronized with the main circuit voltage based on the partial discharge signal 12 and the main circuit voltage phase signal 13.

  In the present embodiment, an internal power supply unit 17 connected to the branch line 33 branched from the connection line 8 and the branch line 34 branched from the connection line 9 is provided. The internal power supply unit 17 extracts a voltage obtained by dividing the main circuit voltage of the commercial frequency from the output voltage of the voltage dividing type voltage detector 6. The internal power supply unit 17 is connected to the signal separation unit 10 through the power supply line 15 and is connected to the calculation unit 11 through the power supply line 16. The power generated by the internal power supply unit 17 is supplied to the signal separation unit 10 and the calculation unit 11 via the power supply line 15 and the power supply line 16, respectively.

  Next, the operation of the present embodiment will be described with reference to FIG. 1 and FIGS. 2-1 to 2-4. When the partial discharge 4 is generated inside the gas insulating container 1, the electromagnetic wave signal 5 excited by the partial discharge 4 propagates along the central conductor 2. A main circuit voltage having a commercial frequency is applied to the center conductor 2. The capacitor voltage-divided voltage detector 6 detects a voltage signal in which the partial discharge signal and the main circuit voltage signal are superimposed, and outputs the detected voltage signal to the signal separation unit 10. FIG. 2A is a diagram illustrating an example of the signal 18 output from the voltage dividing type voltage detector 6, and illustrates the waveform of the output voltage between the signal line 8 and the signal line 9. As shown in FIG. 2A, the signal 18 output from the voltage dividing type voltage detector 6 has a waveform in which a high-frequency partial discharge signal and a sinusoidal main circuit voltage signal are superimposed.

  Next, in the signal separation unit 10, the signal 18 output from the voltage dividing type voltage detector 6 is converted into a partial discharge signal 12 shown in FIG. 2-2 and a reference pulse in a specific phase shown in FIG. The signal is separated into a main circuit voltage phase signal 13 and transmitted to the calculation unit 11. The computing unit 11 computes a partial discharge signal synchronized with the main circuit voltage based on the partial discharge signal 12 and the main circuit voltage phase signal 13. Further, in the internal power supply unit 17, as shown in FIG. 2-4, a voltage 19 obtained by dividing the main circuit voltage with a capacitor based on voltage signals input via the branch lines 33 and 34. The power supply voltage is supplied to the signal separation unit 10 and the calculation unit 11 through the power supply line 15 and the power supply line 16, respectively.

  Here, in order to clarify the difference between the present embodiment and the conventional partial discharge detection device, the configuration of the conventional partial discharge detection device will be described with reference to FIG. 4 (see, for example, Patent Document 1). . FIG. 4 is a schematic diagram showing a configuration of a conventional partial discharge detection device. In FIG. 4, the same components as those in FIG. 1 are denoted by the same reference numerals. As shown in FIG. 4, in the conventional partial discharge detection device, power for driving the signal separation unit 10 and the calculation unit 11 is supplied from an external main power supply 14, and this external main power supply 14 is used in the present embodiment. Unlike the partial discharge detection device, power is supplied from the outside. On the other hand, in the present embodiment, the internal power supply unit 17 for driving the signal separation unit 10 and the calculation unit 11 uses the output from the voltage dividing type voltage detector 6.

  According to the present embodiment, the internal power supply unit 17 provided inside the partial discharge detection device divides the main circuit voltage based on the signal 18 output from the voltage divider type voltage detector 6. Since the power supply voltage is supplied to the signal separation unit 10 and the calculation unit 11 by taking out the measured voltage, partial discharge can be measured without using an external main power supply or a storage battery. In particular, when hundreds or more of the voltage dividing type voltage detectors 6 are installed in the actual gas insulation container 1, external main power supplies are provided to the signal separation units 10 and the calculation units 11 corresponding to the number of voltage detectors 6 respectively. Or since it becomes unnecessary to supply a storage battery etc., the structure of an apparatus can be simplified and the partial discharge detection apparatus completely independent with respect to the exterior can be obtained.

Embodiment 2. FIG.
FIG. 3 is a schematic diagram showing the configuration of the partial discharge detection device according to the present embodiment. As shown in FIG. 3, in the present embodiment, the signal separation unit 10, the calculation unit 11, and the internal power supply unit 17 are provided inside a portable device 20 that can be carried. The portable device 20 and the capacitor voltage dividing type voltage detector 6 are connected to the connector 21b provided in the portable device 20, the connection line 8 drawn from the capacitor voltage dividing type voltage detector 6, and the connection line. 9 is performed by connecting the connector 21a connected to the connector 9. Since other configurations are the same as those of the first embodiment shown in FIG. 1, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  Next, the operation of the present embodiment will be described. The operations of the voltage dividing type voltage detector 6, the signal separation unit 10, the calculation unit 11, and the internal power supply unit 17 are the same as those of the first embodiment. In the partial discharge detection operation using the present embodiment, the portable device 20 is attached to and detached from the plurality of partial discharge detectors 6 by attaching and detaching the portable device 20 via the connectors 21a and 21b. carry out. At this time, the internal power supply unit 17 provided in the portable device 20 takes out the power from the capacitor voltage dividing type voltage detector 6 connected at the time of measurement, and the signal is respectively transmitted through the power supply lines 15 and 16. A power supply voltage is supplied to the separation unit 10 and the calculation unit 11.

  According to the present embodiment, the internal power supply unit 17 provided in the portable device 20 when several hundred or more capacitor-divided voltage detectors 6 are installed in an actual gas-insulated container. Therefore, it is not necessary to wire a power line from the external main power supply every time the portable device 20 is connected to the partial discharge detector, and the measurement time can be shortened. Further, since the plurality of partial discharge detectors 6 can be detected by the portable device 20, it is not necessary to provide the configuration as in the first embodiment for each voltage dividing type voltage detector 6 and the cost is reduced. There is an effect that can be done.

1 is a schematic diagram illustrating a configuration of a partial discharge detection device according to a first exemplary embodiment. In Embodiment 1, it is a figure which shows an example of the signal output from the capacitor | condenser voltage dividing type voltage detector. In Embodiment 1, it is a figure which shows an example of the partial discharge signal isolate | separated by the signal separation part. In Embodiment 1, it is a figure which shows an example of the main circuit voltage phase signal isolate | separated by the signal separation part. In Embodiment 1, it is a figure which shows an example of the voltage signal which an internal power supply part produces | generates. FIG. 6 is a schematic diagram illustrating a configuration of a partial discharge detection device according to a second exemplary embodiment. It is a schematic diagram which shows the structure of the conventional partial discharge detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas insulation container 2 Center conductor 3 Insulation spacer 4 Partial discharge 5 Electromagnetic wave signal 6 Capacitor partial pressure type voltage detector 7 Floating electrode 8, 9 Signal line 10 Signal separation part 11 Calculation part 12 Partial discharge signal 13 Main circuit voltage phase signal 14 External main power supply 15, 16 Power supply line 17 Internal power supply 18 Signal 19 Voltage 20 Portable device 21a, 21b Connector

Claims (2)

A gas insulating container filled with an insulating gas and grounded, and supported by an insulating spacer that extends along the longitudinal direction inside the gas insulating container and applies a main circuit voltage and partitions the gas insulating container. A partial discharge detection device for detecting a partial discharge generated inside a gas insulated switchgear comprising a central conductor,
Using the floating electrode provided between the gas insulating container and the central conductor, a signal in which an electromagnetic wave signal generated by a partial discharge generated in the gas insulating container and a main circuit voltage signal are superimposed is used as the floating electrode. A voltage dividing voltage detector that detects the divided voltage generated in
A signal separation unit for separating the partial discharge signal and the main circuit voltage phase signal from the voltage detected by the capacitor voltage dividing type voltage detector;
Based on the partial discharge signal and the main circuit voltage phase signal, an arithmetic unit that calculates a partial discharge signal synchronized with the main circuit voltage;
A power supply voltage for driving the signal separation unit and the arithmetic unit is generated by extracting a voltage obtained by dividing the main circuit voltage from the voltage detected by the capacitor voltage dividing type voltage detector , The power supply voltage is supplied through a first power supply line that connects between the signal separation unit and the signal separation unit, and the power supply voltage is supplied through a second power supply line that connects between itself and the calculation unit. An internal power supply to supply,
A partial discharge detection device for a gas insulated switchgear characterized by comprising:   The partial discharge detection device for a gas-insulated switchgear according to claim 1, wherein the signal separation unit, the calculation unit, and the internal power supply unit are provided in a portable device.

Images