JP2000221229A - Apparatus and method for detecting partial discharge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a partial discharge signal generated in a power equipment distinctly from a noise by providing a filter at a main noise invading line, and stopping or attenuating a high frequency noise propagating through its lead wire and advancing to the equipment side. SOLUTION: The apparatus for detecting a partial discharge comprises a filter 1 provided at a noise advancing line 4 of a power equipment 5 to stop or attenuate a high frequency noise propagating through its lead wire and advancing to the equipment, a partial discharge sensor 2 provided at a position of the equipment of an opposite side from a position provided with the filter to detect a partial discharge signal generated from the equipment, and a partial discharge measuring instrument 3 for measuring the detected signal. Thus, a measurement of the signal can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial discharge detection device and a partial discharge detection method for monitoring abnormalities and insulation deterioration of an electrical insulation portion of a power device such as a rotating electric machine.

[0002]

2. Description of the Related Art Conventionally, a method of monitoring the state of a device during operation has been used in order to reduce the maintenance cost while ensuring the reliability of the device. 2. Description of the Related Art In electrical equipment such as rotating electric machines such as generators and induction motors, transformers, gas-insulated switches, and power cables, their electrical insulation parts are generally exposed to high voltage and high electric fields, and dielectric breakdown in the electrical insulation parts may occur. Is a major factor in failure. The abnormality or deterioration as a precursor phenomenon of the dielectric breakdown of the electrical insulation part is monitored by detecting a partial discharge generated in the insulation part during operation.

[0003] The measurement of partial discharge of a power device during stoppage is performed in an environment with relatively little noise, such as when the power device is connected to a dedicated power supply and measured independently. However, during operation, since various power devices are connected to the same power supply line or a number of accompanying devices are operating, the partial discharge must be measured in a noisy environment.

As a method of detecting a partial discharge, a partial discharge charge method in which an apparent charge amount when a partial discharge occurs is detected by a coupling capacitor or a ground line CT (CT: current transformer), an electromagnetic field generated by the partial discharge Radiated electromagnetic field method to detect air with an antenna, ultrasonic method to detect minute sound generated by repeated collision of metal foreign objects with the inner wall of the tank by the action of partial discharge and electric field, light emission detection method to detect partial discharge light emission and arc light emission and so on. The above methods are used individually or in combination according to the equipment.

For example, as a method of detecting a partial discharge of a rotating electric machine, a partial discharge charge method or a radiation electromagnetic field method is used, and a high-frequency electric signal generated by the partial discharge is applied to a coupling capacitor and a winding provided on a lead wire of the rotating electric machine. It is detected from the installed resistance temperature detector, the antenna installed inside the rotating electric machine frame, or the ground wire of the frame.

In particular, since a partial discharge signal of a rotating electric machine during operation is usually buried in noise, it is necessary to identify the partial discharge signal as noise and measure only the partial discharge signal. This noise separation is important in insulation monitoring by measuring partial discharge during operation.

As a method of discriminating a partial discharge from a noise and measuring only the partial discharge, for example, Japanese Patent Laid-Open No. 1-1164 is disclosed.
No. 63, a partial discharge measuring device for a rotating electric machine is disclosed.
A partial discharge measuring device is provided at a predetermined position of a lead wire for driving or outputting a rotating electric machine during operation, and a voltage wave and a current wave of a partial discharge and a noise propagation wave propagating through the lead wire are detected and the polarity is detected. The determination is made, the traveling direction of the propagation wave on the lead line is determined from the determined combination of the polarities, the partial discharge is distinguished from the noise, and only the partial discharge is detected.

Further, Japanese Patent Application Laid-Open No. 3-57976 discloses that
A partial discharge sensor designed for partial discharge detection is arranged in the stator slot of the stator winding of a generator, etc., and only the partial discharge generated in the specific stator slot where the partial discharge sensor is installed is limited. A method and an apparatus for performing measurement are disclosed. In this method, a sensor that is designed to be sensitive only to high-frequency signals of 100 MHz or more is sensitive only to a partial discharge signal in the stator slot, and to a noise, the high-frequency signal propagates in the stator slot. Since noise is greatly attenuated, noise is separated by being relatively insensitive.

Japanese Patent Application Laid-Open No. 4-70573 discloses that
A partial discharge measurement method is disclosed in which a frequency spectrum is obtained for a noise signal, a frequency with low noise is selected from the frequency spectrum, and a partial discharge pulse having a certain level or more detected at this frequency is counted.

Further, in US Pat. No. 5,126,677, a noise sensor is provided at a location where noise is generated and invaded, in combination with a partial discharge sensor. A device and a method of controlling the gate of the signal circuit of FIG. 1 to measure only partial discharge are shown.

[0011]

In the conventional partial discharge detecting apparatus and partial discharge detecting method as described above, the partial discharge signal is obtained by utilizing the propagation direction of the signal, the frequency characteristic, the synchronism with the noise sensor output, and the like. Detection is performed separately from noise, but has the following problems.

First, according to the method disclosed in Japanese Patent Application Laid-Open No. 1-116463, when a noise signal enters from outside through a lead wire, it is determined that noise is present at the time of entry, but the noise is reflected inside the rotating electric machine. Or when the signal propagates through the winding and comes out of the machine again, it may be detected as partial discharge.

In the method disclosed in Japanese Patent Application Laid-Open No. 3-57976, only partial discharge in a stator slot in which sensors are installed is sensitive, so that a larger number of sensors are installed to monitor a plurality of slots. And the cost increases.

In the method disclosed in Japanese Patent Application Laid-Open No. 4-70573, the frequency with less noise varies with time, day, and season, and the noise is wide in equipment having a complicated signal propagation path such as a rotating electric machine. By having a frequency spectrum that overlaps over the frequency band,
It is considered difficult to reliably separate the partial discharge signal from noise.

Further, in the method described in US Pat. No. 5,126,677, it is necessary to install a noise sensor so as to detect only harmful noise that affects partial discharge measurement. Is effective only for the noise generated by the noise source.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a filter is provided on a main intrusion line of noise to prevent or attenuate high-frequency noise that propagates through the lead and travels to the power equipment side. By doing so, a partial discharge signal generated in the power device is detected separately from noise.

As a result, only partial discharge is detected by a sensor installed in or around a power device, and based on this, a partial discharge detection that can more accurately know insulation abnormality and insulation deterioration in the power device. It is an object to obtain an apparatus and a partial discharge detection method.

[0018]

A partial discharge detecting device according to the present invention is provided on a noise entry line of a power device, and a filter that blocks or attenuates high frequency noise that propagates through the noise entry line and enters the power device. And a partial discharge sensor that is provided at a position on the power device side opposite to a position where the filter is provided and detects a partial discharge signal generated by the power device, and measures the detected partial discharge signal. And a partial discharge measuring device.

Further, in the partial discharge detection device according to the present invention, the electric power device is a rotating electric machine, and the filter is provided on a lead wire for driving or outputting the rotating electric machine, and propagates through the leading wire. To prevent or attenuate high-frequency noise traveling to the rotating electric machine side, and the partial discharge sensor is provided inside the rotating electric machine, on a lead wire on the rotating electric machine side from a filter, or on a propagation path of a partial discharge signal to ground. It is installed to detect a partial discharge signal generated in the rotating electric machine during operation and stoppage in distinction from the high-frequency noise.

Further, in the partial discharge detection device according to the present invention, the partial discharge sensor is a coupling capacitor installed on a lead wire on the rotating electric machine side from the filter, and the partial discharge sensor is stopped by the coupling capacitor during stop and during operation. This is to detect a signal.

Further, in the partial discharge detection device according to the present invention, the partial discharge sensor is a high-voltage high-frequency current transformer installed on a lead wire closer to the rotating electric machine than the filter. It detects a partial discharge signal during stop and operation.

Further, in the partial discharge detection device according to the present invention, the partial discharge sensor is a temperature measuring resistor provided in a winding of the rotating electric machine, and a partial discharge signal coupled to the temperature measuring resistor is provided. Is detected during stop and operation.

Further, in the partial discharge detection device according to the present invention, the partial discharge sensor is an antenna installed in the rotating electric machine, and the partial discharge sensor detects a partial discharge signal during stop and operation by the antenna. is there.

Also, in the partial discharge detection device according to the present invention, the partial discharge sensor is a high-frequency current transformer installed on a ground wire of the rotating electric machine, and the high-frequency current transformer stops and operates during the operation. This is for detecting a partial discharge signal.

Further, in the partial discharge detection device according to the present invention, the partial discharge sensor is a surface voltmeter or a surface ammeter installed on a frame of the rotating electric machine, and is stopped by the surface voltmeter or the surface ammeter. And detecting a partial discharge signal during operation.

Further, in the partial discharge detection device according to the present invention, the power device is a rotating electric machine, and the filter is provided on a lead wire for driving or outputting the rotating electric machine, and propagates through the lead wire. To prevent or attenuate high-frequency noise traveling to the rotating electric machine side, and the partial discharge sensor is provided inside the rotating electric machine, on a lead wire on the rotating electric machine side from a filter, or on a propagation path of a partial discharge signal to ground. Installed, detects a partial discharge signal generated in the rotating electric machine during operation and stoppage, the partial discharge measuring device utilizes the difference in frequency characteristics between the partial discharge signal and the noise signal, and uses two different frequency bands. Is to discriminate between partial discharge and noise from the correlation characteristic of the signal intensity at

In the partial discharge detecting device according to the present invention, the filter is constituted by passing a lead wire through a hollow ferrite.

Further, in the partial discharge detection device according to the present invention, the filter is constituted by the inductance by forming a coil with the lead wire itself.

Further, in the partial discharge detection device according to the present invention, the filter is configured by connecting a capacitor to the lead wire.

In the partial discharge detection method according to the present invention, a filter provided on a lead wire for driving or outputting a rotating electrical machine prevents or eliminates high-frequency noise that propagates through the leading wire and proceeds to the rotating electrical machine. Attenuating step, by the partial discharge sensor installed on the lead-out line on the rotary electric machine side from the filter, on the rotary electric machine side from the filter, or on the propagation path of the partial discharge signal to the ground, during the operation and during the stop in the rotary electric machine Detecting the generated partial discharge signal.

Further, in the partial discharge detection method according to the present invention, the partial discharge measuring device utilizes the difference in the frequency characteristics of the partial discharge signal and the noise signal, and uses the partial characteristic of the correlation between the signal intensities in two different frequency bands. The method further includes the step of identifying discharge and noise.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 A partial discharge detection device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 1 of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, 1 is a filter, 2 is a partial discharge sensor, 3 is a partial discharge measuring device, 4 is a noise intrusion line,
Reference numeral 5 denotes a power device.

Next, the operation of the partial discharge detection device according to the first embodiment will be described with reference to the drawings.

The measurement of the partial discharge of the power equipment during stoppage, such as that performed during a shipping test or periodic inspection, is performed in a relatively noise-free environment, such as when the power equipment is connected to a dedicated power supply and measured independently. . However, during operation, since various power devices are connected to the same power supply line or a number of accompanying devices are operating, the partial discharge must be measured in a noisy environment.

The noise penetration line 4 is, for example, a power device 5
And the leader line connecting the other devices. By installing the filter 1 on the noise intrusion line 4, it is possible to prevent or attenuate a noise signal generated in another power device.

The partial discharge signal generated in the power device 5 is detected by the partial discharge sensor 2 installed at a position closer to the power device 5 than the filter 1 inside or outside the power device. Since the detected signal has already been subjected to noise removal or attenuation, the partial discharge signal can be easily measured by the partial discharge measuring device 3.

Embodiment 2 Embodiment 2 A partial discharge detection device according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 2 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 2 of the present invention.

In FIG. 2, 1 is a filter, 2 is a partial discharge sensor, 3 is a partial discharge measuring device, 4a is a lead wire, 5a
Is a rotating electric machine.

Next, the operation of the partial discharge detecting device according to the second embodiment will be described with reference to the drawings. FIG. 3 shows a partial discharge signal a1 measured at the generator winding of the partial discharge detection device according to the second embodiment of the present invention.
FIG. 5 is a diagram illustrating frequency characteristics of a noise signal and a noise signal b1. In the figure, the horizontal axis is frequency (MHz), and the vertical axis is signal strength (d
Bm).

Among rotary electric machines, high-voltage induction motors, water turbine generators, and small turbine generators do not themselves have a noise source. Therefore, a noise signal detected by a partial discharge sensor installed in the rotary electric machine is external. This is due to the intrusion of something generated by the device.

There are various types of noise signals detected, such as partial discharges generated in other devices, air corona, thyristor switching noise, and the like. It is.

As shown in FIG. 3, the signal strength is the noise b
1 is larger than the partial discharge a1, but the frequency characteristic is
The partial discharge signal a1 attenuates slowly with frequency, whereas the noise signal b1 attenuates rapidly as the frequency increases. This indicates that high-frequency components are particularly attenuated in the process in which the noise signal propagates and enters the rotating electric machine.

Therefore, if the detection band is increased to some extent, S
It is conceivable that the partial discharge can be detected with good / N, but in reality, the problem of the sensitivity of the detection system including the sensor becomes severe, and the attenuation from the occurrence of the partial discharge to the arrival at the sensor increases. Therefore, it is not necessarily a good method, for example, that the measurable range is limited to the vicinity of the sensor. Rather, it is more effective to suppress the intrusion of noise.

By providing a filter 1 for blocking or attenuating a noise signal on the lead wire 4a, only the partial discharge signal can be effectively measured.
In particular, the effect of the present invention is great for partial discharge measurement during operation with much noise accompanying the operation of other power devices.

In the second embodiment, the rotating electric machine 5a
Although the case has been described, a power device such as a transformer, a gas insulated switch, or a power cable, which can monitor the internal insulation state by partial discharge, may have the same effect.

Embodiment 3 Embodiment 3 A partial discharge detection device according to Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 4 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 3 of the present invention.

In FIG. 4, 1 is a filter, 2a is a coupling capacitor, 3 is a partial discharge measuring device, 4a is a lead wire,
a is a rotating electric machine.

The coupling capacitor 2a blocks a commercial frequency component propagating through the lead wire 4a, that is, a low-frequency component of a high voltage, and passes a high-frequency component of a partial discharge signal or a noise signal. The frequency characteristic of signal detection by the coupling capacitor 2a is determined by the relationship between the capacity of the coupling capacitor 2a and the input impedance of the partial discharge measuring device 3 (or the detection impedance of the partial discharge measuring device 3).
It is possible to detect signals of Hz to several hundred MHz.

On the other hand, the winding of the rotary electric machine 5a has a potential gradient from the maximum potential to the ground potential from the line side to the neutral point side, and the partial discharge is caused near the line side where the highest voltage is applied to the insulator. It tends to occur near the leader line. Therefore, such a partial discharge signal can be detected with high sensitivity with little attenuation by the coupling capacitor 2a provided at the portion of the lead wire 4a closest to the rotary electric machine 5a.

The attenuation factor of the signal propagating through the rotating electric machine winding and the lead wire increases as the frequency increases. Therefore, in general, the noise signal is a signal in which the high-frequency component is greatly attenuated while propagating from the generation source to the coupling capacitor installed in the device to be measured. On the other hand, since the distance from the partial discharge source to the coupling capacitor is relatively short, attenuation of the high frequency component of the partial discharge signal is relatively small. Therefore,
The filter particularly attenuates the high-frequency component of the noise signal and sets the detection band of the measuring instrument to such a high frequency, thereby enabling a partial discharge measurement with a good S / N.

Embodiment 4 FIG. Embodiment 4 A partial discharge detection device according to Embodiment 4 of the present invention will be described with reference to the drawings. FIG. 5 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 4 of the present invention.

In FIG. 5, 1 is a filter, 2b is a high-voltage high-frequency current transformer, 3 is a partial discharge measuring device, 4a is a lead wire, and 5a is a rotating electric machine.

The high-voltage high-frequency current transformer 2b has characteristics of low sensitivity to a signal of a commercial frequency and high sensitivity to a high-frequency signal. Since it has a high voltage resistance and can be mounted during energization, it can be temporarily installed even when it is urgently required to measure partial discharge during operation, in addition to being installed constantly.

Further, as described in the third embodiment, by installing the high-voltage high-frequency current transformer 2b at the portion of the lead wire 4a closest to the rotating electric machine 5a, such a partial discharge signal can be reduced. Detection can be performed with high sensitivity during attenuation. Therefore, by taking this embodiment, it is possible to realize a partial discharge detection device that can be applied to the rotating electric machine 5a in which the partial discharge sensor is not installed in advance.

Embodiment 5 Embodiment 5 A partial discharge detection device according to Embodiment 5 of the present invention will be described with reference to the drawings. FIG. 6 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 5 of the present invention.

In FIG. 6, 1 is a filter, 2c is a resistance temperature detector, 3 is a partial discharge measuring device, 4a is a lead wire, and 5a is a rotating electric machine.

The temperature measuring resistor 2c has a shape of an elongated plate with a temperature measuring element such as platinum and a lead wire fixed by FRP or the like, and is used to monitor the winding temperature during operation of the rotary electric machine 5a. The rotary electric machine 5a is previously installed in the stator slot at the time of manufacturing the rotating electric machine 5a.

Although the resistance temperature detector 2c is not designed as a sensor for detecting discharge, the frequency characteristics and the sensitivity itself are inferior to those of the dedicated sensor. Sufficient detection is possible for high frequency components of the discharge. On the other hand, although the high-frequency component of the noise signal is detected after being greatly attenuated, the high-frequency component cannot be ignored when the intensity of the noise increases. Therefore, by taking this embodiment, it is possible to measure a partial discharge signal propagating through the winding of the rotating electric machine with good S / N without newly installing a sensor for detecting partial discharge inside the rotating electric machine. .

Embodiment 6 FIG. Embodiment 6 A partial discharge detection device according to Embodiment 6 of the present invention will be described with reference to the drawings. FIG. 7 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 6 of the present invention.

In FIG. 7, 1 is a filter, 2d is an antenna, 3 is a partial discharge measuring device, 4a is a lead wire, and 5a is a rotating electric machine.

The partial discharge generated in the rotating electric machine 5a radiates an electromagnetic wave during the generation and propagation of the discharge current. Since the rotating electric machine 5a is surrounded by a metal frame, the rotating electric machine 5a has an effect of blocking electromagnetic wave noise from the outside, and the electromagnetic wave due to the partial discharge generated inside is reflected and propagates around.

Therefore, detection can be performed with a certain degree of sensitivity without largely depending on the position where the discharge occurs. That is, partial discharge of the entire winding can be monitored even with one antenna 2d. Therefore, by taking this embodiment, it is possible to realize a partial discharge detection device capable of monitoring a partial discharge of the entire winding with a minimum number of antennas.

Embodiment 7 FIG. A partial discharge detection device according to Embodiment 7 of the present invention will be described with reference to the drawings. FIG. 8 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 7 of the present invention.

In FIG. 8, 1 is a filter, 2e is a high-frequency current transformer, 3 is a partial discharge measuring device, 4a is a lead wire, 5a
Is a rotating electric machine.

When a partial discharge occurs, the discharge current flows from the high voltage portion to the ground, and finally flows from the rotating electric machine frame at the ground potential to the ground through the ground wire. Since this ground wire is always at the ground potential, the operation of installing the high-frequency current transformer during operation is very safe and simple.

However, since the partial discharge signal is greatly attenuated while reaching the ground line, it is very important to suppress the noise signal and distinguish the partial discharge signal from the noise signal. Therefore, by adopting the present embodiment, it is possible to realize a partial discharge detection device capable of suppressing a noise signal and easily monitoring a partial discharge signal of the rotating electric machine.

Embodiment 8 FIG. Embodiment 8 A partial discharge detection device according to Embodiment 8 of the present invention will be described with reference to the drawings. FIG. 9 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 8 of the present invention.

In FIG. 9, 1 is a filter, 2f is a surface voltmeter or surface ammeter, 3 is a partial discharge measuring device, 4a
Is a lead wire, and 5a is a rotating electric machine.

As described in the seventh embodiment,
The current also flows through the rotating electric machine frame due to the occurrence of the partial discharge. Therefore, it is possible to measure a change in potential due to the current or the current itself with a surface voltmeter or a surface ammeter.

Further, since the rotating electric machine frame is maintained at the ground potential, the operation such as mounting the sensor is safe and simple. However, since the surface current due to partial discharge is very weak, it is important to suppress noise for detection. Therefore, by taking this embodiment, it is possible to realize a partial discharge detection device capable of easily monitoring a partial discharge signal of rotating electric machine 5a.

Embodiment 9 FIG. Embodiment 9 A partial discharge detection device according to Embodiment 9 of the present invention will be described with reference to the drawings. FIG. 10 is a diagram showing an example of a frequency spectrum of a partial discharge signal and a noise signal before and after a filter by a partial discharge detection device according to Embodiment 9 of the present invention, and two frequency bands. FIG. 11 is a diagram showing the correlation between the intensity of the two frequency bands of the partial discharge signal and the noise signal by the partial discharge detection device according to Embodiment 9 of the present invention. The configuration is the same as in the first embodiment.

FIG. 10 (a) shows the partial discharge signal a1 measured at the generator winding when no filter is installed.
And the frequency spectrum of the noise signal b1. The horizontal axis is frequency (MHz) and the vertical axis is signal strength (dBm). Further, c indicates a frequency band on the low frequency side, and d indicates a frequency band on the high frequency side.

As shown in the figure, the signal intensity of the noise signal b1 is larger than that of the partial discharge signal a1, but the frequency spectrum shows that the partial discharge signal a1 attenuates gradually with the frequency, while the noise signal b1 attenuates slowly. b1 rapidly attenuates as the frequency increases.

As a method of distinguishing between the partial discharge signal a1 and the noise signal b1 by utilizing the difference in frequency spectrum, the partial discharge measuring device 3 uses two frequency band components for each partial discharge pulse or noise pulse. There is a method of extracting a group having a strong low-frequency component as noise and a group having a strong high frequency as a partial discharge from the correlation of the intensities.

FIG. 11 schematically shows the correlation between the intensities of the two frequency bands. Here, the horizontal axis is the intensity of the frequency band component on the low frequency side, and the vertical axis is the intensity of the frequency band component on the high frequency side.

As shown in FIG. 11, a partial discharge group a3 and a noise signal group b3 are identified. Both the partial discharge signal and the noise signal vary in frequency spectrum and intensity depending on the type of source and the signal propagation path (signal generation position) for each pulse. Therefore, depending on the noise environment of the rotating electrical machine or the state of occurrence of partial discharge, the two groups may overlap and it may be difficult to distinguish between the two groups.

If a high-frequency cutoff filter (low-pass filter) for attenuating high-frequency components is installed on a noise intrusion line, a noise spectrum b2 as shown in FIG. 10B is detected. Due to the high-frequency attenuation characteristics of the filter, the frequency spectrum b2 of the noise signal after filtering has a sharper attenuation of the intensity with respect to frequency than the original frequency spectrum b1.

The correlation between the intensities of the two frequency bands at this time is as shown in a two-band correlation plot b4 after filtering the noise signal in FIG. 11, and the correlation with the two-band correlation plot a3 of the partial discharge signal. Identification becomes clearer.

The method of distinguishing between partial discharge and noise from the correlation between the bands is effective as long as the distribution of both can be distinguished even if the intensity of the noise signal is considerably larger than the intensity of the partial discharge signal. . Therefore, by adopting the present embodiment, even when the intensity of the noise signal is considerably higher than the intensity of the partial discharge signal, it is possible to realize a partial discharge detection device having a good S / N.

Embodiment 10 FIG. Embodiment 1 of the present invention
The partial discharge detection device according to 0 will be described with reference to the drawings. FIG. 12 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 10 of the present invention.

In FIG. 12, 1a is a ferrite core,
2 is a partial discharge sensor, 3 is a partial discharge measuring device, 4a is a lead wire, and 5a is a rotating electric machine.

The frequency characteristic of the impedance of the ferrite core 1a is determined by the inherent permeability and shape of the ferrite, and the higher the frequency, the higher the impedance. By utilizing this characteristic and passing the lead wire 4a through the hollow ferrite core 1a, the high frequency component of the noise signal can be attenuated.

Therefore, taking the present embodiment, it is possible to monitor the partial discharge signal of the rotating electric machine with good S / N by discriminating the partial discharge signal and the noise signal from the correlation between the signal intensities in two different frequency bands. And a partial discharge detection device capable of performing the above-described operations.

Embodiment 11 FIG. Embodiment 1 of the present invention
1 will be described with reference to the drawings. FIG. 13 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 11 of the present invention.

In FIG. 13, 1b is a coil conductor, 2 is a partial discharge sensor, 3 is a partial discharge measuring device, 4a is a lead wire, and 5a is a rotating electric machine.

The conductor has an inductance even if it is kept straight, but the inductance increases when the conductor is formed into a coil or when a magnetic material is inserted in the coil. Inductance does not contribute to impedance at low frequencies, but does increase at higher frequencies.

Therefore, the high frequency component of the noise can be attenuated by forming the coil conductor 1b in the lead wire 4a so as not to affect the commercial frequency and to increase the impedance in the frequency band of the high frequency noise. Therefore, by taking this embodiment, by distinguishing the partial discharge signal and the noise signal from the correlation between the signal intensities in two different frequency bands, it is possible to monitor the partial discharge signal of the rotating electric machine with good S / N. A discharge detection device can be realized.

Embodiment 12 FIG. Embodiment 1 of the present invention
2 will be described with reference to the drawings. FIG. 14 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 12 of the present invention.

In FIG. 14, 1c is a capacitor, 2 is a partial discharge sensor, 3 is a partial discharge measuring device, 4a is a lead wire, and 5a is a rotating electric machine.

The capacitor 1c is connected to the lead wire 4a,
By grounding the other end of the capacitor 1c, the high-frequency signal propagating through the lead wire 4a flows to the ground, and does not reach the rotating electric machine 5a.

Therefore, taking this embodiment, it is possible to monitor the partial discharge signal of the rotating electric machine with good S / N by distinguishing the partial discharge signal and the noise signal from the correlation between the signal intensities in two different frequency bands. And a partial discharge detection device capable of performing the above-described operations.

[0093]

As described above, the partial discharge detection device according to the present invention is provided on the noise entry line of a power device, and blocks or attenuates high frequency noise that propagates through the noise entry line and enters the power device. A filter, a partial discharge sensor provided at a position on the power device side opposite to a position where the filter is provided, and detecting a partial discharge signal generated in the power device, and measuring the detected partial discharge signal With the provision of the partial discharge measuring device, a partial discharge signal can be easily measured.

Further, as described above, in the partial discharge detection device according to the present invention, the power device is a rotating electric machine, and the filter is provided on a lead wire for driving or outputting the rotating electric machine. High frequency noise that propagates to the rotating electrical machine side by propagating through the lead wire is prevented or attenuated, and the partial discharge sensor is connected to the inside of the rotating electrical machine or a filter on the lead wire side of the rotating electrical machine side or to the ground of the partial discharge signal. Installed on the propagation path, the partial discharge signal generated in the rotating electric machine during operation and stop, and is detected separately from the high-frequency noise, the measurement frequency is set to a high frequency such that the noise attenuation is large. There is an effect that it is possible to effectively measure only the partial discharge signal without the need.

Further, in the partial discharge detection device according to the present invention, as described above, the partial discharge sensor is a coupling capacitor installed on the lead wire on the rotating electric machine side from the filter, and the partial discharge sensor is stopped when the coupling capacitor is stopped. Since the partial discharge signal is detected during operation, the sensor can be installed near the location where partial discharge near the maximum potential of the rotating electrical machine winding is most likely to occur, and the coupling capacitor is suitable for detecting wideband signals Therefore, the effect that the high frequency component of the noise signal is attenuated by the filter and the detection band of the measuring instrument is set to the frequency at which the noise signal is attenuated, whereby the partial discharge having a good S / N can be measured.

Further, as described above, in the partial discharge detection device according to the present invention, the partial discharge sensor is a high-voltage high-frequency current transformer installed on a lead wire closer to the rotary electric machine than the filter, and Since the partial discharge signal is detected during stop and operation by the high-frequency current transformer, the sensor can be installed near the location where partial discharge near the maximum potential of the rotating electrical machine winding is most likely to occur. Since it can be installed, S / N can be installed not only for regular installation but also for urgent measurement of partial discharge during operation.
This has the effect of realizing a good device.

Further, in the partial discharge detecting device according to the present invention, as described above, the partial discharge sensor is a temperature measuring resistor provided in the winding of the rotating electric machine, and the temperature measuring resistor includes Since the coupled partial discharge signal is detected during stoppage and operation, the partial discharge signal propagating through the winding of the rotating electric machine is measured with good S / N without newly installing a sensor for detecting partial discharge inside the rotating electric machine. It has the effect of being able to do so.

Further, as described above, in the partial discharge detection device according to the present invention, the partial discharge sensor is an antenna installed in the rotating electric machine, and the partial discharge signal is output by the antenna during stop and operation. Is detected, the electromagnetic wave due to the partial discharge generated inside the rotating electric machine is reflected, wraps around and propagates, so that the partial discharge of the entire winding can be monitored by the minimum number of antennas.

As described above, in the partial discharge detection device according to the present invention, the partial discharge sensor is a high-frequency current transformer installed on the ground wire of the rotating electric machine, and is stopped by the high-frequency current transformer. Since the partial discharge signal is detected during and during operation, there is an effect that the sensor can be easily attached even during operation of the rotating electric machine.

As described above, in the partial discharge detection device according to the present invention, the partial discharge sensor is a surface voltmeter or a surface ammeter installed on a frame of the rotating electric machine. Since the ammeter detects the partial discharge signal during stop and during operation, there is an effect that the sensor can be easily attached even during operation of the rotating electric machine.

Further, in the partial discharge detection device according to the present invention, as described above, the power device is a rotating electric machine, and the filter is provided on a lead wire for driving or outputting the rotating electric machine. High frequency noise that propagates to the rotating electrical machine side by propagating through the lead wire is prevented or attenuated, and the partial discharge sensor is connected to the inside of the rotating electrical machine or a filter on the lead wire side of the rotating electrical machine side, or to the ground of the partial discharge signal. , Installed on the propagation path, detects the partial discharge signal generated in the rotating electric machine during operation and stop,
The partial discharge measuring device uses the difference in the frequency characteristics of the partial discharge signal and the noise signal, and distinguishes the partial discharge and the noise from the correlation characteristics of the signal intensities in two different frequency bands. Even when the intensity is considerably large as compared with the partial discharge signal, it is possible to measure a partial discharge having a good S / N.

Further, as described above, the partial discharge detection device according to the present invention constitutes the filter by passing the lead wire through the hollow ferrite.
Even when the intensity of the detected noise signal is considerably large as compared with the partial discharge signal, it is possible to measure the partial discharge having a good S / N.

As described above, in the partial discharge detection device according to the present invention, the filter is formed by the inductance by forming the coil with the lead wire itself, so that the intensity of the detected noise signal is reduced by the partial discharge. This has the effect that a partial discharge with a good S / N can be measured even when the signal is considerably larger than the signal.

Further, in the partial discharge detecting device according to the present invention, as described above, since the filter is configured by connecting the capacitor to the lead wire, the intensity of the detected noise signal is compared with the partial discharge signal. Thus, even when the voltage is considerably large, it is possible to measure a partial discharge having a good S / N.

As described above, in the partial discharge detection method according to the present invention, the filter is provided on the lead wire for driving or outputting the rotating electric machine, and propagates through the leading wire to proceed to the rotating electric machine. A step of blocking or attenuating high-frequency noise, and during operation and stoppage by a partial discharge sensor installed inside the rotary electric machine, on a lead line on the rotary electric machine side from the filter, or on a propagation path of a partial discharge signal to ground. Detecting the partial discharge signal generated in the rotating electrical machine, so that only the partial discharge signal can be effectively measured without setting the measurement frequency to a high frequency at which noise attenuation is large. This has the effect.

Further, as described above, the partial discharge detection method according to the present invention utilizes the difference between the frequency characteristics of the partial discharge signal and the noise signal by the partial discharge measuring device to perform
The method further includes the step of distinguishing between partial discharge and noise from the correlation characteristic of the signal intensity in two different frequency bands, so that even if the detected noise signal has a considerably large intensity compared to the partial discharge signal, a portion having a good S / N ratio This has the effect that the discharge can be measured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a configuration of a partial discharge detection device according to a second embodiment of the present invention.

FIG. 3 is a diagram showing an example of a frequency spectrum of a partial discharge signal and a noise signal by a partial discharge detection device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 3 of the present invention.

FIG. 5 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 4 of the present invention.

FIG. 6 is a diagram showing a configuration of a partial discharge detection device according to a fifth embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a partial discharge detection device according to a sixth embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of a partial discharge detection device according to a seventh embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a partial discharge detection device according to an eighth embodiment of the present invention.

FIG. 10 is a diagram showing an example of a frequency spectrum of a partial discharge signal and a noise signal before and after a filter by a partial discharge detection method according to Embodiment 9 of the present invention, and two frequency bands.

FIG. 11 is a diagram showing a correlation between intensity of two frequency bands of a partial discharge signal and a noise signal according to a partial discharge detection method according to Embodiment 9 of the present invention.

FIG. 12 is a diagram showing a configuration of a partial discharge detection device according to a tenth embodiment of the present invention.

FIG. 13 is a diagram showing a configuration of a partial discharge detection device according to an eleventh embodiment of the present invention.

FIG. 14 is a diagram showing a configuration of a partial discharge detection device according to Embodiment 12 of the present invention.

[Explanation of symbols]

1 filter, 1a ferrite core, 1b coil,
1c capacitor, 2 partial discharge sensor, 2a coupling capacitor, 2b high-frequency current transformer, 2c resistance temperature detector, 2d
Antenna, 2e high-frequency current transformer, 2f surface voltmeter (surface ammeter), 3 partial discharge measuring instrument, 4 noise intrusion line, 4a lead wire, 5 power equipment, 5a rotating electric machine.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G015 AA06 AA12 AA13 AA14 AA18 CA01 2G036 AA10 AA20 AA24 BA02 BA03 BA05 BA34 BA35 BA43 CA06

Claims (14)

[Claims] Claims: 1. A power device is provided on a noise entry line of a power device,
A filter that blocks or attenuates high-frequency noise that propagates through the noise entry line and enters the power device; and a filter that is provided at a position on the power device side opposite to a position where the filter is provided, and generated by the power device. A partial discharge detection device comprising: a partial discharge sensor that detects a partial discharge signal; and a partial discharge measuring device that measures the detected partial discharge signal. 2. The electric power device is a rotating electric machine, and the filter is provided on a lead wire for driving or outputting the rotating electric machine, and a high-frequency wave propagating through the lead wire and traveling to the rotating electric machine side. Blocks or attenuates noise, and the partial discharge sensor is installed inside the rotary electric machine, on a lead wire on the rotary electric machine side from the filter, or on a propagation path of the partial discharge signal to the ground, and rotates during operation and stop. The partial discharge detection device according to claim 1, wherein a partial discharge signal generated in the electric machine is detected separately from the high-frequency noise. 3. The partial discharge sensor according to claim 1, wherein the partial discharge sensor is a coupling capacitor provided on a lead wire closer to the rotating electric machine than the filter, and detects the partial discharge signal during stop and operation by the coupling capacitor. Item 3. The partial discharge detection device according to Item 2. 4. The partial discharge sensor is a high-voltage high-frequency current transformer installed on a lead wire on the rotary electric machine side of the filter, and outputs a partial discharge signal during stop and operation by the high-voltage high-frequency current transformer. 3. The method according to claim 2, wherein the detection is performed.
The partial discharge detection device according to claim 1. 5. The partial discharge sensor is a resistance temperature detector provided in a winding of the rotating electric machine, and detects a partial discharge signal coupled to the resistance temperature detector during stop and operation. 3. The partial discharge detection device according to claim 2, wherein: 6. The partial discharge sensor according to claim 2, wherein the partial discharge sensor is an antenna installed in the rotating electric machine, and detects a partial discharge signal during stop and operation by the antenna. Detection device. 7. The partial discharge sensor is a high-frequency current transformer installed on a ground wire of the rotating electric machine, and detects the partial discharge signal during stop and operation by the high-frequency current transformer. 3. The partial discharge detection device according to claim 2, wherein: 8. The partial discharge sensor is a surface voltmeter or a surface ammeter installed on a frame of the rotating electric machine, and detects a partial discharge signal during stop and operation by the surface voltmeter or the surface ammeter. 3. The partial discharge detection device according to claim 2, wherein: 9. The electric power device is a rotating electric machine, and the filter is provided on a lead wire for driving or outputting the rotating electric machine, and a high frequency wave propagating through the lead wire and traveling to the rotating electric machine side. Blocks or attenuates noise.The partial discharge sensor is installed inside the rotary electric machine, on a lead wire on the rotary electric machine side from the filter, or on a propagation path to the ground of the partial discharge signal, and rotates during operation and stop. The partial discharge measuring device detects a partial discharge signal generated in the electric machine, and utilizes the difference in the frequency characteristics of the partial discharge signal and the noise signal to determine the partial discharge and the partial discharge from the correlation characteristic of the signal intensity in two different frequency bands. 2. The partial discharge detection device according to claim 1, wherein noise is identified. 10. The partial discharge detection device according to claim 9, wherein the filter is configured by passing a lead wire through a hollow ferrite. 11. The partial discharge detection device according to claim 9, wherein the filter is formed by forming the coil by the lead wire itself. 12. The partial discharge detection device according to claim 9, wherein the filter is configured by connecting a capacitor to a lead line. 13. A step of blocking or attenuating high-frequency noise propagating through the lead-out line and traveling toward the rotating electric machine by a filter provided on a lead-out line for driving or outputting the rotating electric machine; A partial discharge signal generated inside the rotating electric machine during operation and stoppage is detected by a partial discharge sensor installed inside, on a lead wire on the rotating electric machine side from the filter, or on a propagation path of the partial discharge signal to the ground. And a method for detecting partial discharge. 14. The method according to claim 1, further comprising the step of using the difference in the frequency characteristics of the partial discharge signal and the noise signal to distinguish the partial discharge and the noise from the correlation characteristics of the signal intensities in two different frequency bands. 14. The partial discharge detection method according to claim 13, wherein: