JPS61128177A - Apparatus for locating partial discharge generation position - Google Patents

Abstract

PURPOSE:To enhance accuracy, by providing a high speed analogue signal processing circuit for generating an output signal by judging that partial discharge was generated in the mark section corresponding to a section pulse and a display circuit for displaying a location section. CONSTITUTION:Operation circuits, for example, multiplier circuits 41-44 are respectively provided to a location apparatus corresponding to pulse generation circuits 31-34 and, only to multiplier circuits 41-44 to which the respective output section pulses of the pulse generation circuits 31-34 and the output propagation wave line of a partial discharge measuring device 11 were inputted as input signals, the output propagation waves amplified by multiplying the section pulses are outputted. Position display circuits 51-55 are also provided to the location apparatus corresponding to the multiplier circuits 41-44 and triggered by the output propagation waves and the position display circuit corresponding to a location section where partial discharge was generated can lights or issue alarm sound to make it possible to know the location section. By this method, a min. locating distance can be shortened by almost one figure and accuracy can be enhanced.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] Locating device for internal partial discharge occurrence position of high voltage electrical appliances having longitudinal extensions such as gas insulated electrical appliances, gas insulated cables, and electric cables, especially for external devices. The present invention relates to a partial discharge occurrence position locating device with a noise discrimination function.

[Prior art and its problems]

The method for locating the location of partial discharge in this type of electrical appliance is as follows:
A method is known that utilizes the fact that the detection time difference between the direct propagation wave and the reflected propagation wave of a partial discharge pulse is determined by the length to both ends of the electrical appliance under test, the generation position, and the distance between the detection ends.

FIG. 5 is an explanatory diagram for explaining the above-mentioned orientation method, and shows an example in which a gas insulated hermetic switchgear (hereinafter referred to as GLS) is used as a test device. In the figure, the high-voltage charging parts G, I, and S are connected to high-voltage conductors 1. Disconnector 2. No circuit breaker 3, etc., and live parts are grounded through insulating spacers 4 and metal sheaths 5.
6.7.8, etc., and an insulating gas such as SF or gas is filled in the pot metal sheaths 5 to 8.
Insulation between live parts and metal sheath is maintained. Further, both terminals of the high voltage charging section are led out of the metal sheath by, for example, a power cable 9 and connected to an external power system. A discharge pulse detection circuit 10 and a partial discharge measuring device 111 are installed on one terminal side of G=S configured in this way.
A location location result is provided. Now, assume that an internal partial discharge occurs at a location 14 indicated by an arrow in the figure. At this time, the discharge (current) pulse generated by the partial discharge is divided into left and right parts of the high voltage conductor 1, and both terminal parts 15 and 16
However, the propagation wave of the discharge pulse propagating through the conductor has a propagation speed To determined by a distribution constant consisting of the inductance of the conductor and the distributed capacitance between the sheath and the conductor.
(G L S case 3 x 10'1/B),
In addition, since the distribution constant changes suddenly at both end portions 15 and 16, a part of the discharge pulse is reflected, changes direction, becomes a reflected propagation wave, and propagates in the high voltage conductor in the opposite direction again.

FIG. 6 shows pulse trains of directly propagating waves and reflected propagating waves detected by the detection circuit 10. In the figure, pulse P
17 is the detector installation terminal 1 from the discharge pulse generation position 14
The direct propagation wave, pulse P18, which directly propagated toward the terminal 15, is a discharge pulse that travels from the position 14 toward the anti-detector installation terminal 16, is reflected at the terminal 16, and is detected at the terminal 15. The pulse P19 is the second wave of the reflected propagation wave detected by the terminal 15 after the direct propagation wave P17 propagates back and forth between the two terminals 15 and 16, and the pulse P20 is the first wave of the reflected propagation wave. This is the third wave of the reflected propagation wave that is reflected back and forth between the terminals and detected again at the terminal 15.

Now, the distance to position 14 measured along the center line of the high voltage conductor starting from the reflective terminal 16 is 1z, and both terminals 15
．． If the distance between 16 and 16 is t, then in FIG.
Pulse P18°PI3 for 17. P2O detection delay time 'r1. T.

T becomes as follows.

Tl = 2ts/V.

T,=2t/v.

'r, =='r□+T.

Therefore, by measuring the detection delay time T1 or T of the reflected propagation wave with respect to the direct propagation wave P17, the distance tz or t-t from either terminal to the discharge occurrence position can be determined.
You can know z. However, since the propagation speed vO of the discharge pulse in the gas-insulated electric appliance is extremely fast, 3×10 − /8, it is necessary to obtain a positioning accuracy of, for example, a minimum positioning distance of 1 −.

FIG. 7 is a block diagram showing the circuit configuration of a conventional position locating device. In the figure, the location device that receives the detection pulse signal of the detection circuit 10 includes a sampling unit 21 that samples the instantaneous value of the detection pulse, and an A/C converter that digitally converts the output voltage of the sampling unit 21.
A D converter 22, a counter unit 25 that measures the detection time difference T1, and an arithmetic processing unit 24, 25.2 that stores the output signal of the counter unit and calculates the occurrence position tZ.
6 and a mini-computer consisting of a display unit 27 that displays the calculation results. Therefore, the minimum orientation distance in the above-mentioned device is determined by the minimum counting time of the digital counter 23, the data transmission time, the calculation processing time, the stop/reset/set time of the digital counter 23, etc., and the detected pulse train is processed in real time. However, it is difficult to perform off-time processing, and in the case of off-time processing, only a distance outside the minimum 10-odd range can be obtained. Therefore, when the test object is a conductor with a conductor length of about 10 to 30 m between both terminal parts, such as GbS, there is a problem that an effective positioning result cannot be obtained.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned situation, and it is an object of the present invention to provide a partial discharge occurrence position locating device that has high locating accuracy of the discharge occurrence position and has a function of discriminating intermittent external noise.

[Key points of the invention]

The present invention divides a test sealed electrical appliance that extends in the length direction into a plurality of locating sections in advance, and is provided corresponding to the number of locating sections, and is triggered by a directly propagating wave. A pulse generation circuit that outputs interval pulses ordered from the anti-detector installation end to the orientation interval layer with the pulse width determined by the round trip propagation time (hereinafter simply referred to as propagation time) of the partial discharge pulse, and this pulse generation circuit corresponds to the pulse generation circuit. The structure is configured to include an arithmetic and display circuit that determines that a partial discharge has occurred within the specified locating section and outputs a display signal when the section pulse and the reflected propagation wave are input. It is possible to locate the discharge pulse generation position from the positioning section to which the pulse generation position belongs or from the opposite end of the detector installation.

[Embodiments of the invention]

The present invention will be explained below based on one embodiment.

Fig. 1 is a block diagram of a locating device showing an embodiment of the present invention, and shows an example of a case where the sealed electrical appliance under test is divided into four locating sections (sections), and each circuit is connected to a high-speed Linear C etc. It is composed of an analog signal processing circuit. In the figure, the previously proposed partial discharge measuring device (Japanese Patent Application No. 1983-011583) is used as the detection circuit 10 and the partial discharge measuring device 11, and the pulse width is 10 seconds. The sixth pulse with a low noise and narrow pulse width is removed except for the output pulse of the order of magnitude and intermittent external noise with a pulse width of the same degree as this output pulse.
A propagating wave pulse train as shown in the figure is input to the location device. 31 to 34 are provided corresponding to the number of location sections, and are triggered by the output direct propagation wave of the partial discharge measuring device 11, and the propagation time of the partial discharge pulse corresponding to the length of the location section is reflected as its pulse width. This is a pulse generation circuit that outputs interval pulses ordered in the orientation interval layer from the detector installation end. For example, with the pulse generation circuit 31 on the opposite detector installation end side, interval pulses P3 are output in the order of 31, 32, 33, 34.
1, P32. P33. Output P34. 41-44
is an arithmetic circuit, such as a multiplication circuit, and a pulse generation circuit 3
1 to 64, the output section pulses of the respective pulse generating circuits and the output propagation wave train of the partial discharge measuring device 11 are used as input signals, and the section pulses and the propagation waves are input to the multiplication circuits in a superimposed manner. An amplified output propagation wave is output by multiplying only the interval pulse. 5
Reference numerals 1 to 54 are position display circuits provided corresponding to the multiplication circuits 41 to 44, respectively. For example, the position display circuit corresponding to the location section where partial discharge has occurred triggered by the output propagation wave lights up or sounds an alarm. By emitting , it is possible to know the location area where partial discharge has occurred. 55
Reference numeral 56 denotes a measuring section, which is configured to add the output propagation waves of the multiplier circuits 41 to 44 through an addition port M55 to convert them into a pulse train, and to observe the pulse train using a measuring circuit 56 such as an oscilloscope.

FIG. 2 is a signal waveform diagram for explaining the operation of each part in the embodiment shown in FIG.
．． The pulse generation circuit 31 is divided equally into four locating sections with P and Q as boundaries, and the pulse generating circuit 31 is placed in the locating section on the anti-detector installed end 16 side, and then sequentially on the detecting end 14 side in the order of 32° 33.34. The pulse generator 32
This example shows a case where the position of a partial discharge generated at a position 14 between locating sections 0 and 2 corresponding to . In the figure, Wll is the output propagation wave pulse train of the partial discharge measuring device 11, PI3 is the direct propagation wave, and P1
8 is the first wave of the reflected propagation wave from the anti-detector installation end 16, P
19 is the second reflected propagating wave from the anti-detector installation end 16 of the directly propagating wave P17, and P19 is the propagation time for the directly propagating wave P17 to travel back and forth exactly once between the two terminals 15 and 16 of the GLS. T! is output from the partial discharge measuring device 11.

P31 to P34 are the output section signal waveforms of the pulse generators 31 to 64 triggered by the direct propagation wave P17, respectively, where Gi of the propagation wave, round-trip propagation time T of the total length of 3, and the respective pulse widths, They are ranked in the orientation section layer from P31 corresponding to the orientation section on the side of the degree detection device end 16, and are sequentially output without overlapping each other. In this embodiment, an example is shown in which P31 is delayed by a time To corresponding to the pulse width of the directly propagating wave P17, and a section pulse whose pulse width is narrower than the others by the waiting time To is output. There is. W42 is the output propagation wave of the multiplier circuits 41-42, and is multiplied by the propagation wave pulse train P17-P19 indicated by Wll and the interval pulses p31-P34. As a result, P
Propagating wave pulses P17 and PI3 in which overlap with the inter-cis pulse is avoided by generating 31 with a delay of To time
The multiplication result becomes zero and is erased from the output side of the multiplication circuit, and the first wave of the reflected propagation wave, PI3, becomes the interval pulse P32.
is amplified by being multiplied by , and output as W42. P52 is the display signal of the position indicator 52, W4
2, only the indicator 52 lights up or issues an alarm, thereby making it possible to detect that a partial discharge has occurred between the location section 0 and P.

Note that if a noise pulse enters the GAS from both terminals 15 and 16 of the GLS shown in FIG. By configuring the multiplier circuit to output the noise pulse, it is possible to eliminate the noise pulse in the multiplication circuit, and therefore, there is an advantage that it is possible to prevent the noise pulse from being mistakenly recognized as a partial discharge.

FIG. 6 is a block diagram showing a specific example of the pulse generation circuit in the embodiment shown in FIG.
Delay circuit 6 which uses the output propagation wave train W11 of No. 1 as a common input
1 to 64, peak value holding circuits 71 to 74, and differential circuits 81 to 86.
is output.

FIG. 4 is a signal waveform diagram for explaining the operation of the pulse generation circuit in FIG. P71 to P74 shown indicate the output signal waveforms of the peak value holding circuits 71 to 74. In the figure,
The direct propagation wave P17 of the partial discharge pulse input to the delay circuits 61 to 64 is transmitted from time t1 to TO in the delay circuit 61, and from the anti-detector installation end 16 to the corresponding location section in the other delay circuits 62 to 64. The propagation time to the entrance of the input signal K @ T t2%・7% + %'' is delayed by TI and input to the peak value holding circuits 71 to 74, respectively.The peak value holding circuits 71 to 74 hold the peak value of the input signal. detect and hold this peak value until time t,
The held peak value signals W31 to W34 are sent to differential circuits 81 to
8 Output to B. The differential circuits 81 to 83 are configured to output the difference between the output peak value signals of adjacent peak value holding circuits, and the hatched portions of P71 to P73 are erased by passing through the differential circuits 81 to 86. p31. p
32 and P33 are output, and P34 is directly output from the peak value holding circuit 74. As described above, interval pulses P are generated from the pulse generation circuits 31 to 64 in order from the orientation interval side on the anti-detector installation end 16 side, with the pulse width being the propagation time corresponding to the length of the corresponding orientation interval.
31 to P34 can be sequentially output without overlapping each other.

Furthermore, in FIG. 1, if the oscilloscope of the measuring circuit 56 is configured to be triggered by the output pulse of the partial discharge measuring device 11, for example, the detection delay time of the output pulse train of the adder circuit with respect to the directly propagating wave can be measured, so that partial discharge can occur. You can know the location in detail.

As is clear from the above description of the embodiments, since the device of the present invention is constructed with an analog signal processing circuit using a high-speed Linear C or the like, high-speed signal processing is possible compared to a device using a conventional digital signal processing circuit. If possible, it is possible to set the minimum orientation distance to 1 m or less by setting the pulse width of the input propagation wave to about 2 to 5 x 10 seconds. In addition, when applied to locating the partial discharge occurrence position of a GhS with a total length of about 1 o to 301 mm, the time T required for a propagating wave to propagate back and forth between two terminals is about 0.7 to 2 x 10 seconds. Because it is extremely short compared to the time interval between repeated occurrences of discharge pulses and the time interval of external noise,
The probability that multiple discharge pulses or external noise will occur within one orientation time is extremely low. Therefore, it is possible to sufficiently avoid erroneous positioning due to a plurality of pulses being detected close to each other.

Furthermore, in the present invention, it is also possible to configure the apparatus to use the sealed electrical appliance under test as one location section and to discriminate between intermittent external noise and internal discharge.

[Effects of the Invention] As described above, the present invention divides a test sealed electrical appliance that has a partial discharge detection device on one end side and extends in the length direction into a plurality of locating sections in advance, and determines the length of each locating section. With the propagation time of the partial discharge pulse corresponding to the pulse width and the direct propagation wave of the partial discharge pulse) pulses for the number of location sections that are subjected to IJ gar and sequentially output the section pulses ordered in the order of the location sections from the side opposite to the detector installation side. a generation circuit, which is provided corresponding to the pulse generation circuit, and determines that a partial discharge has occurred within the specified section corresponding to the section pulse when the section pulse and the reflected propagation wave from the partial discharge measuring device are input. An arithmetic circuit consisting of a high-speed analog signal processing circuit that outputs an output signal based on the location information, and a display circuit that optically or acoustically displays the corresponding location section are provided. As a result, the restriction on the minimum orientation distance due to the time required for data transfer and calculation time, which was a problem with conventional orientation devices using digital calculation circuits, has been eliminated, and the minimum orientation distance can be shortened by almost an order of magnitude. It is possible to provide a device that can locate the occurrence position of a partial discharge in a relatively short sealed electric appliance with a distance of about 10 to 301 degrees with an accuracy of one to several degrees. In addition, by shortening the pulse width of the section pulse corresponding to the orientation section on the side opposite to the detector installation end by a predetermined period of time and configuring it to occur later than the trigger pulse of the directly propagating wave, etc., it is possible to It is possible to discriminately eliminate external noise that enters from both terminals and its round-trip reflected propagation waves using a multiplication circuit, and it is possible to provide a locating device that has a function of discriminating intermittent external noise. Furthermore, by providing a measurement circuit that can observe the output pulses of the arithmetic circuit as a pulse train, it becomes possible to precisely locate the partial discharge occurrence position as necessary.
A device with high location accuracy can be provided.

Note that the partial discharge occurrence position locating device of the present invention is not limited to locating the position of partial discharge, but also detects contact failure of high current contacts such as disconnectors and circuit breakers included in the high voltage charging part of the electrical equipment under test. By detecting the generated spark as a propagating wave, it can also be used as a locating device for the location where contact failure occurs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of an embodiment of the present invention;
2 is a signal waveform diagram in the embodiment shown in FIG. 1, FIG. 6 is a specific configuration diagram of the pulse generation circuit in the embodiment shown in FIG. 1, and FIG. 4 is a signal waveform diagram of the pulse generation circuit in the embodiment shown in FIG. 3. Figure 5 is a schematic side sectional view of the sealed electrical appliance under test, Figure 6 is the pulse train of the propagating wave of the partial discharge pulse in the appliance shown in Figure 5,
The figure is a block diagram showing the circuit configuration of a conventional position locating device. 1.2.3... High voltage charging part, 5.6.7.8...
Metal sheath, 9...Terminal part (electric cable), 10.
...Detection circuit, 11...Partial discharge measuring device, 12...
Position locating device, 14... Partial discharge occurrence position, 15...
・Detector installation end, 16... Anti-detector installation end, ○, P,
Q: Boundary position of the location section, 31-34: Pulse generation circuit, 41-44: Arithmetic circuit (multiplying circuit), 5
1-54...Position display circuit, 55.56...Measuring section, 61-64...Delay circuit, 71-74...Peak value holding circuit, 81-86...Differential circuit, P17 ...
Direct propagation wave, P18. PI3...Reflected propagation wave, P31
~P34...Section pulse, T,...Period, TO...
・Delay time. Time T. Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1) A detector that is installed at one end of a sealed electrical appliance that extends in the length direction and detects the directly propagating wave of the internal partial discharge pulse of the sealed electrical appliance and the reflected propagating wave with the other terminal as the reflection end. In order to locate the occurrence position of an internal partial discharge, the partial discharge pulse propagation time is triggered by a directly propagating wave and corresponds to the length of the section of the sealed appliance to be located, and the pulse width is used to locate from the counter-detector installation end. A pulse generation circuit for a specified number of sections that outputs section pulses ordered in the order of sections, and an arithmetic and display circuit that is provided corresponding to this pulse generation circuit and outputs when the section pulses and reflected propagation waves are input. A partial discharge occurrence position locating device comprising: