JPS5910125A - Internal part discharge monitor for high voltage stational device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention continuously monitors and measures whether or not an internal abnormality occurs in a high-voltage stationary electrical appliance while the electrical appliance is in operation or in an energized state.
The present invention relates to a monitoring device that can issue an alarm and take necessary countermeasures such as stopping the operation of electrical appliances when an abnormality is detected.

Insulation deterioration due to local insulation breakdown as an internal abnormality in oil-immersed transformers and other high-voltage stationary electric appliances, that is, partial discharge, can progress to full-scale dielectric breakdown if it continues for a long time, causing large-scale damage to the electric appliance. It may lead to an accident.

Therefore, we continuously monitor the condition of electrical appliances, detect this partial discharge as soon as it occurs, and take necessary measures such as internal inspection of the electrical appliance.

It is necessary to prevent accidents involving electrical appliances.

And the monitoring device generally has a
External noise such as external discharge, switching noise, radio noise, etc. generated from power transmission lines, bushings, etc.
It is necessary to have a function that can clearly distinguish electrical discharge from internal electrical discharge.
In addition to being able to accurately determine these things, it is also required to be easy to handle and inexpensive.

This method uses two different physical quantities, electric pulses and ultrasonic pulses, to detect internal discharge pulses and external noise, and distinguishes between internal discharge pulses and external noise based on the correlation of their generation times. Discrimination from noise may be incomplete and what should be external noise may be determined to be internal discharge pulse. In other words, all induced noise and external ultrasonic noise that enter when the gate pulse is open are determined to be internal discharges. It is important to prevent malfunctions by detecting the presence or absence of a detection delay time difference, and the structure is such that the time difference between two ultrasonic waves is determined by a time counter and calculations by a microcomputer. However, this device requires an arithmetic circuit to calculate the measurement results of this counter circuit in addition to a counter circuit that counts the entire delay time of the ultrasonic pulse that operates simultaneously with the detection of an electric pulse. The means for detecting the time difference requires a complicated circuit, and there is a comparison/judgment section, etc., which is expected to use a microcomputer, which has the drawback of increasing the price of the fruiting device. In addition, the use of complex circuits and microcomputers not only poses difficulties in terms of maintenance, but also restricts the installation location, making it particularly unsuitable for normal installations such as substations and outdoor switchboards. There are drawbacks to substations, such as malfunction of circuits caused by switching surges generated by substations, and it is extremely difficult to take measures to prevent this.Also, inside outdoor panels, noise and temperature from the power supply that operates the equipment become a problem. This is because the rise, etc. requires more care than with a normal pulse circuit metal biasing device. If the device is installed in a monitoring shed, etc., the detection part and the judgment part are quite far apart, so optical cables must be used to transmit signals between them to prevent noise, which can significantly increase installation costs. There are also drawbacks.

SUMMARY OF THE INVENTION An object of the present invention is to provide an internal partial discharge monitoring device for high-voltage stationary electric appliances that eliminates the above-mentioned conventional drawbacks, has high discrimination accuracy, has fewer restrictions on installation locations, is easy to handle, and is inexpensive.

According to the present invention, the above object is to provide a pulse control circuit powered by electric pulses detected by an internal discharge electric detector provided in a bushing or the like of a high-voltage stationary electric appliance, and to provide a pulse control circuit that is powered by an electric pulse detected by an internal discharge electric detector provided in a bushing or the like of a high-voltage stationary electric appliance, and a A monitoring device comprising an ultrasonic detection circuit provided in each of a plurality of acoustic detectors mounted at different positions and detecting the internal discharge as an ultrasonic pulse, wherein the ultrasonic detection circuit is controlled by the pulse control circuit. A discriminating circuit including a pulse generation circuit and a logic circuit is provided, and the electric hartz is determined by detecting the correlation of the generation time with the ultrasonic pulse to determine whether the electric hartz is due to internal discharge or other causes. reach it.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows one example of this, and in the figure, 1 is a high-voltage stationary electric appliance such as an oil-immersed transformer or a sealed switchgear, and a high-voltage bushing 2 of the stationary electric appliance 1 is connected to a power transmission line 3.

When a partial discharge occurs in the stationary electric appliance 1, a current pulse flows through the bushing 2, and the PD tap 4 of the bushing 2
An electrical pulse appears on a detector (not shown) connected to. This electrical pulse to be detected is input to the partial discharge measuring device 5 via the cable 21a, where it is amplified and waveform-shaped and transmitted to the pulse control circuit 8 via the cable 21b. When the pulse control circuit 8 detects the input signal from the cable 21b, it immediately controls the first and second pulse generation circuits 10a, 10b, 10C; 12 for a certain period of time tm.
The cables 31a, 31b, and 31c transmit a control signal that makes the cables 31a, 31b, and 31c standby for operation only during the period ax.

31d i, the first pulse generating circuit 10
a to 10c and the second pulse generating circuit 12 are on standby. At this time, the first and second pulse generation circuits 10a to 10c and the output circuit 26a of the 12
, 26b, 26c: 25b u each off
, off, off and on.

On the other hand, on the tank wall of the stationary electric appliance 1, there are a plurality of acoustic detectors 6a such as ultrasonic microphones at different positions.
, 6b, and 6c are attached, and each of the detectors 6a to 67 detects the ultrasonic pulse caused by the occurrence of partial discharge with a delay of propagation time ta, tb, and tc relative to the electric pulse, and detects the ultrasonic pulse through the cables 22a, 22b+22c, respectively. and pulse amplification/shaping circuits 7a and 7b.

It is input to 7C. The pulse amplification/shaping circuits 73 to 7C are configured to output the detected ultrasonic pulses as rectangular waves of pulse mid/2 through cables 23a, 23b, and 23c. Here, tmax is stationary 1@, vessel 1
The propagation time of the ultrasonic pulse is determined by the structure of the tank and the mounting position of the detectors 63 to 6c.

It is the maximum delay time for the electric pulse, and im is set as the minimum delay time. From this, the delay time ta by the detectors 68 to 6C.

tb, tc is td<ta, tb, tc tma
It will be within the range of x. Now cable 23a~
23c, the outputs of the pulse amplification/shaping circuits 73-7C are on standby for the first pulse generation circuits 10a-10c.
When the output is inputted to , this output changes from off to on, and the first logic circuit 13 connected to the output side of the first pulse generation circuit 102 to IOC via cables 26a, 26b, and 26c When the input state is on or off, it turns off when the state reaches the specified number of circuits or more.
The signal is changed from Oo to output to cable 27. That is, the ultrasonic pulse is output only when ta, tb, tc and tmax are reached.

On the other hand, the cable 24 is connected to the pulse amplification and shaping circuits 73 to 7C.
A, 24b, 24c are connected to the second logic circuit 11, and this second logic circuit 11u'' determines whether or not the ultrasonic pulses input from the pulse amplification/shaping circuits 73 to 7C overlap (ultrasonic waves). This function determines whether or not the signals occur simultaneously, and the output is turned off only when input at the same time.
The above-mentioned second noise generating circuit 12 connected to the second logic circuit 11 through the cable 25a changes from on to off when this input signal becomes on. and is output to the cable 25b. In the case of internal partial discharge, acoustic detectors 6a+6b are used to ensure that the propagation time difference between detected ultrasonic pulses is greater than a specified value.
, 6c, the second logic circuit 1
The inputs of 1 are never input at the same time, and the outputs 1j,
As a result, the output of cable 25b is on with the mother being off.
It will remain as .

This can be seen by looking at the output states of the first logic circuit 13 and the second pulse generation circuit 12, which are linked to the signal of the pulse control circuit 8 that operates in conjunction with the detection of the electric pulse of partial discharge. It is possible to determine whether the cause is an internal partial discharge or something else, and this is because the outputs of the first logic circuit 13 and the second pulse generation circuit 12 due to the electric pulse detected by the partial discharge measuring device 5 are both o
The logic circuit 14 outputs an output only when n, on, and it can be determined that there is an internal partial discharge, and all other states can be determined to be caused by external noise or the like. That is, the pulse control circuit 8 and the first pulse generation circuit 108
~In the IOC and the first logic circuit 13, the propagation time of the detected ultrasonic wave/curse is ta, tb, tc<tm
If only determining whether the ax is constant or not, it will be determined that there is an internal partial discharge even in response to signals input at the same time, such as induced noise, so the second logic controlled by the pulse control circuit 8 The circuit 11 and the second Noculus generating circuit 12 determine whether or not ultrasonic pulses occur simultaneously to prevent malfunctions.

Further, a cable 21d for a command signal to operate the recorder 18 when there is an input signal is connected to the pulse control i8, and the recording mycelium 18 is connected to the partial discharge measuring device 5 via the cable 21C. The output signal of the pulse peak value holding circuit 9 connected to It is designed to record whether it is noise or the like. Note that the logic circuit 14 is connected to the respective output sides of the first logic circuit 13 and the second pulse generation circuit 12 via cables z7 and 25b, and the respective cables 27.2
If the states of the input signals from 5b are both on, this means an internal partial discharge as described above, so the output becomes on and is sent to the recorder 18 via the cable 28a.

It is also input to the logic circuit 16 via the cable 28b. In addition, the logic circuit 16 has a level detection circuit 15 to which the output of the Norculus wave high value holding circuit 9 is connected via a cable 21e, and only when the input signal thereof is equal to or higher than a set value, the output is turned on and the cable 21f is connected. input via The logic circuit 16 outputs only when the input from the level detection circuit 15, that is, the magnitude of the partial discharge is greater than a set value, and when the input from the logic circuit 14, that is, it is determined that it is an internal discharge. Reference numeral 17 provided in the logic circuit 16 is this output terminal, which is connected to a device for stopping the operation of the electric appliance 1 or issuing various other alarms in response to this signal.

Next, different embodiments of the present invention will be described based on the drawings. In each figure, the same reference numerals are given to the same parts as those in the embodiment shown in FIG. First, the difference between the embodiment shown in the second factor and the embodiment shown in FIG. A third pulse generating circuit 40 is provided in place of the second pulse generating circuit 12 in order to delay the operation of the cable 31 for a certain period of time.
Cables 31b, 31c,
31d.

The pulse generating circuit 40 receives the control signal from the pulse control circuit 8 from this input for a certain period of time t-40a to 40.
It was output to c, and it was published in Byakutan I crush 4h-4 edition-ba 1suke 44
The 4 pulse generation circuits 40a to 40c have a time of 1 maX −
It can be opened at 1 am and kept on standby.

tc is input to the pulse amplification/shaping circuits 7a to 7c with a delay, and the pulse amplification/shaping circuits 73 to 7c input the pulse with a width tf (if(ts&)) to the cable 23.
a to 23c, pulse generation circuits 40a to 40c
It will be output to . Here tjth and t ma
x is the structure of the tank of electric appliance 1 and the detectors 63 to 6 as described above.
These are the minimum and maximum delay times of the ultrasonic pulse propagation determined by the mounting position of c, and the delay times ta, tb, tc of the ultrasonic pulses detected by the detectors 63 to 6c.
are all 1m ta, tb, tc<t max
There is a relationship between

As a result, if there is an input from the pulse amplification/shaping circuits 7a to 7c during the operation standby period by the pulse generation circuit 40, the pulse generation circuits 40a to 40c output the input to the first logic circuit 13. Logic circuit 1
3, the number of input channels N (in this example, N=3) is set in advance to 7 (n When the generated electric pulse is an internal partial discharge of the electric appliance 1, a pulse is outputted to the output of the logic circuit 13.Then, the cables 21a, 22a to 22c
When electromagnetic induction noise of a certain level or more is induced in this system due to a surge in the signal line, etc., output pulses are generated almost simultaneously in the pulse control circuit 8 and the pulse amplification/shaping circuits 73 to 7C. Become.

However, it is the pulse generation circuit 40 that generates the pulse signal 1 = 16'A; Seven russian generation 0 circuits-
1=04 Since a delay time t- is taken before the pulse generation circuits 40a to 40c reach their operating time, the pulses generated in the pulse amplification/shaping circuits 73 to 7C due to this delay are generated in the pulse generation circuits 40a to 40c. It will disappear before the operation of 40c and will not be output from the logic circuit 13. Also.

Even if an external electric pulse that has entered through the power transmission line 3 is detected by the partial discharge measuring device 5, no ultrasonic pulse is generated within the electric appliance 1 at this time.

Therefore, since there is no input to the pulse amplification/shaping circuits 73 to 7 seconds, the pulse generation circuits 40a to 40cti pulses are not generated, and the logic circuit 13 has no output. Furthermore, in this embodiment, if a solid object collides with the electric appliance 1, there is no electric pulse to be detected, so the pulse control circuit 8
There is no operation, and therefore there is no output from the logic circuit 13.

The operations of the pulse control circuit 8, the pulse peak value holding circuit 9 controlled thereby, and the recorder 18 and alarm circuit operated by the output of the logic circuit 13 are the same as in the embodiment shown in FIG. do.

Next, differences between the embodiment shown in FIG. 3 and the embodiment shown in FIG. 1 and the embodiment shown in FIG. 2 will be explained. In FIG. 3, in the embodiment shown in FIG. 2, a pulse generation circuit 40 was used as a means for removing external noise such as Fi electromagnetic induction, but 1. In this embodiment, a similar function is performed by detecting the output signal of the logic circuit 13, and for this purpose, cables 27a, 27b are connected between the logic circuits 13 and 14 corresponding to the embodiment of FIG. The determination section is constituted by the pulse generating circuit 41 which is controlled via the cable 34a from the pulse control circuit 8 in the fifth pulse generating circuits 41 and 42 connected via the fifth pulse generating circuit 27c. If the electric pulse detected by this is caused by electromagnetic induction, the output pulse almost simultaneously with the operation standby signal sent from the pulse control circuit 8 to the pulse generation circuit 41, which is the determination section, will be output to the first logic circuit. 13 to the pulse generation circuit 41. Therefore, if the operation time of the fifth pulse generating circuit 41 is set so that it operates after a delay time t- after the input signal from the pulse control circuit 8 is received.

All input signals within this time width can be determined as noise based on electromagnetic induction, and these are not output from the logic circuit 14.

Furthermore, the embodiment shown in FIG. 4 will be compared with the embodiments shown in FIGS. 1 to 3, and the differences between the embodiment will be explained.

First, the acoustic detectors 63 to 63 are similar to those in the three embodiments described above.
Each of the ultrasonic detection circuits connected to 6b is provided with a gate, and the incoming ultrasonic pulses are regulated by this gate. Note that the ultrasonic detection circuit includes the aforementioned detectors 6a to 6c and connects them to cables 223 to 6c.
Pulse amplification circuits 43a, 43b, 43c via 22c
A cable 44 is connected to these amplifier circuits 43a to 43c.
The aforementioned gates 45a, 45b, 45c connected via a+44bT44c and the cable 46 provided on the output side of these gates 45a to 45c.
a, 46b.

The n1 cables 46a to 46c are connected to the sixth pulse generating circuits 47a, 47b, and 47c. Further, the gates 45a to 45c are connected to a pulse control circuit 8 and a sixth pulse generation circuit 47a to 47c.
and control cables 36a, 36b, 36c, respectively.
: Connected via 39a, 39b, 39c.

Each of the gates 45a to 45c is opened immediately when an electric pulse is input to the pulse control circuit 8, and in this open state, the pulse generating circuits 47a to 45c are opened immediately. Detector 6 on 47c
From the electric pulse from 3 to 6c, the propagation time t a −t
When an ultrasonic pulse delayed by c is input 2'L, the pulse width t according to the detection time of the pulse generation circuits 473 to 47c
It is designed to be closed simultaneously with the generation of the rectangular wave pulse w. As a result, only one pulse is input to the pulse generation circuits 47a to 47c, and ultrasonic pulses are not detected redundantly. The pulse generation circuits 47a to 47c are connected to cables 48a, 48b,
48c to the first '['TL circuits 49a, 49b,
49c is connected, 'I'TL circuits 49a to 49
A first AND circuit 51 is connected to c through cables 50a, 50b, and 50c, and a TTL circuit 49
When the rectangular wave pulses from the pulse generation circuits 47a to 47c are input, the outputs of a to 49c immediately become L (Low).
The state changes from the state to the H (1-1ight) state, and when the AND circuit 51 receives a certain number of inputs, its output also changes from the state to the H state. On the other hand, a sampling gate 52 connected to the pulse control circuit 8 via the control cable 37 is connected to the output side of the AND circuit 51 via a cable 53a, and the output state of the AND circuit 51 is determined by the pulse control circuit. 8, the gate 52 is activated twice with delay times t and t after the electric pulse due to internal partial discharge is detected.
2 connected to it via cable 53b.
The signal is input to the decimal counting circuit 54 and its state is checked. In other words, the delay time is 1° and t! If the output of the AND circuit 51 is in the H state or in the L state both times, the output of the binary counting circuit 54 is in the L state, and the output of the AND circuit 51 is delayed for a time t,
If it is not tv, the output of the binary counting circuit 54 is in the H state, and the ultrasonic pulse detected when the output state of the binary counting circuit 54 is in the L state, ! The Qi pulse is an external noise, and the ultrasonic pulse detected when in the H state, the electric pulse is likely to be an internal partial discharge.8 And the ultrasonic pulse Detection of simultaneity is performed by the sixth pulse generation circuits 47a to 4.
7c via cables 55a, 55b, and 55c.

What is the detection of concomitant ultrasonic pulses here?

Generally, when a partial discharge occurs inside an electric appliance, as is well known, an ultrasonic pulse is generated along with the electric pulse that occurs at the same time as the partial discharge occurs, and a 1% ultrasonic pulse is generated at the same time as the generation (there is a propagation delay in the electric circuit, but the speed of light is 1%). However, the ultrasonic pulse propagates inside the appliance from the ultrasonic source and takes time to reach the detection point on the appliance tank wall. And this delay time is td
For example, td is determined by the size of the electric appliance tank, the installation location of the detector, and the geometrical position of the partial discharge point, etc., since the ultrasonic propagation speed in oil is 1200 to 1800 mlsec in oil-filled electric appliances. 0 things
．． In many cases, the delay time is about 1 m sec to 5 m sec, and this delayed ultrasonic pulse is not detected within the aforementioned delay time 17 after the electric pulse is generated, but is detected within 11, that is, tl (t d < tz This is to detect whether or not the relationship between ultrasonic waves is maintained, and to detect whether or not the ultrasonic pulses from each detector are detected at the same time. It is something to do.

If the ultrasonic pulses overlap, for example, the second AND circuit 56
If induced noise or the like enters 44c at the same time, it will be detected at the same time with the pulse width tw of the rectangular wave pulses of the sixth pulse generation circuits 47a to 47c, and the output of the second AND circuit 56 will be generated by overlapping the respective rectangular wave pulses. It goes from L state to H state for the time it lasts.

The output of the second 'J' TL circuit 58 connected to the second AND circuit 56 via the cable 57a changes from the FiH state to the L
The situation will change. If the ultrasonic pulses associated with internal partial discharges are detected, it is unlikely that they will be detected at the same time depending on the mounting position of the detectors 63 to 6c or the partial discharge occurrence position, and there will be a time difference between the ultrasonic pulses. Due to the deviation, the output of the second AND circuit 56 remains in the L state, and the output of the second TTL circuit 58 remains in the H state.

That is, when the output of the binary counting circuit 54 is in the H state, the ultrasonic pulse lags behind the electric pulse by a time t.

and t, and the second TTL
When the output of the circuit 58 is in the H state, it means that there is no simultaneity of the ultrasonic pulses.

Only in such a state, the cables 53c and 5 are connected to the output sides of the binary counting circuit 54 and the second TTL circuit 58.
The output of the third AND circuit 59 connected through 7b changes from the L state to the H state, and when the output state of the third AND circuit 59 is in the H state, there is internal partial discharge, and when it is in the L state, there is no other discharge. A comprehensive judgment is made regarding the noise caused by The signal cable 38 from the pulse control circuit 8 connected to the recorder 18 connected to the output side of the third AND circuit 59 via the cable 28a is connected to the output side of the third AND circuit 59 via the cable 28a. , for data recording commands issued later. Control cable 30 for pulse control circuit 8
The cable 21 is connected to the partial discharge measuring device 5 controlled by a.
The operation of the circuit from the level detection circuit 15 connected to the pulse wave height value holding circuit 9 via the cable 21e to the alarm output terminal 17 via the logic circuit 16 is as described above. Since it is the same as the example, the description will be omitted.

In this embodiment, as described above, the pulse control circuit 8
Since all circuits are automatically reset to the initial state after an elapsed time t4 after the electric pulse is detected by ! a pulse control circuit 8 which generates a signal to open the gates 45a to 45c of the ultrasonic detection circuit when an ultrasonic pulse is detected;
The sixth pulse generation circuits 47a to 47c, which issue signals for closing 45a to 45c, enable detection of only one ultrasonic pulse. In addition, the second AND circuit 56 is connected to the second T
The TL circuit 58 detects the simultaneity of the ultrasonic pulses,
and the first AND by the signal from the pulse control circuit 8.
By sampling the output state of the circuit 51 twice with a delay time t and -Bt1, the ultrasonic pulse reaches t.

A binary counting circuit 5 that determines whether or not it is detected within ~t.
4, and further includes a third AND circuit 59 which receives the respective outputs of the binary counting circuit 54 and the second TTL circuit 58. This makes it possible to determine whether the noise is

Note that FIGS. 5 and 6 are time charts during the operation of the main circuits in this embodiment, respectively. FIG. 5 shows the case where a partial discharge occurs in the electric appliance 1, and FIG. This shows cases caused by noise other than discharge, and as both correspond to the above, explanations are omitted, but
By checking the output state of the PA at 13:00 of the output signal 28a of the third AND circuit 59, if it is in the H state, it is an internal partial discharge, and if it is in the L state, it is due to other causes such as external noise. It can be determined that

As described above, according to the present invention, n is a pulse generating circuit that determines the correlation between electric pulses and ultrasonic pulses, that is, whether a detected electric pulse is due to internal discharge or other noise. Since it is composed only of circuits and logic circuits, the structure is simple, easy to handle, and inexpensive. This also means that installation costs are low because devices with restrictions in the installation environment, such as minicomputers and microcomputers, are not used, and it is also possible to make judgments based on both incidental and simultaneity when detecting ultrasonic pulses. Because of this, it has high discrimination accuracy. Therefore, it makes a significant contribution to improving cost and reliability in preventive maintenance of high-voltage stationary electrical appliances.

[Brief explanation of the drawing]

1 to 4 show block connections of different embodiments of the internal partial discharge monitoring device for high-voltage stationary electrical appliances according to the present invention, and FIGS. 5 and 6 show main parts of the embodiment of FIG. 4. In the operation time chart, FIG. 5 shows the time when internal discharge is detected, and FIG. 6 shows the time when noise etc. below the internal discharge is detected. 1... High voltage stationary electrical equipment, 2... Bushing, 4...
- Electrical detector, 6a, 6b, 6c... Acoustic detector, 8... Pulse control circuit, 10 a + 10 b
+10 c: 12: 40 a +40b, 4
0c: 41; 47a, 47b, 47cm...Pulse generation circuit, 11.13...Logic circuit, 45a, 45b, 4
5c:52...Gate circuit, 49a, 49b, 49
c: 58-...TTL circuit, 51.56...AND
Circuit, 54...Binary counting circuit. 1 flash f2 3 mouth? 4 diagrams J 圀 Ii, z , t, 314 'It'A 圀

Claims (1)

[Scope of Claims] 1) A pulse control circuit that operates and outputs electric pulses detected by an internal discharge electric detector provided in a bushing or the like of a high-voltage stationary electric appliance, and a container wall or the like of the electric appliance, respectively. In a monitoring device comprising an ultrasonic detection circuit provided in each of a plurality of acoustic detectors installed at different positions and detecting the internal number t as an ultrasonic pulse, reverse control by the pulse control circuit is provided. and a discrimination circuit comprising a pulse generation circuit and a logic circuit, and is configured to discriminate whether the electric pulse is caused by internal discharge or another cause based on the correlation of the generation time with the ultrasonic pulse. An internal partial discharge monitoring device for high-voltage stationary electrical appliances, which is characterized by: 2. The device according to claim 1, wherein the pulse generating circuit and the logic circuit of the discriminating circuit are put on standby for a certain period of time by the output of the pulse control circuit, and the ultrasonic pulse is activated during the waiting period. A first ultrasonic detection circuit provided corresponding to each of the ultrasonic detection circuits that outputs an output if there is an input of
a first logic circuit that outputs only when all of the outputs of the first pulse generation circuit are in the standby period; and an ultrasonic detection circuit provided on the output side of the ultrasonic detection circuit; a second logic circuit that detects and outputs simultaneous occurrence of ultrasonic pulse outputs from the circuit; The interior of a high-voltage stationary electrical appliance characterized by comprising: a second pulse generating circuit that is put on standby for a certain period of time by the output of the pulse control circuit and outputs only when there is an output from the second logic circuit. Partial discharge monitoring device. 3) In the item described in claim 1. a third pulse generating circuit that outputs the pulse generating circuit and the logic circuit of the discriminating circuit for a certain period of time with an input from the pulse control circuit; a fourth pulse generation circuit provided corresponding to each of the ultrasonic detection circuits that is placed on standby during output for the certain period of time and outputs the ultrasonic pulse if inputted during the standby period; and a fifth logic circuit that outputs only when all of the outputs of the pulse generating circuit No. 4 are in the standby period. 4) % In the item described in claim 1, Ai
The pulse generation circuit and logic circuit of the discrimination circuit written in J are
A first pulse generation circuit provided corresponding to each of the ultrasonic detection circuits that is kept on standby for a certain period of time by the output of the pulse control circuit J, and outputs the ultrasonic pulse manually during the standby period. and. a first logic circuit that outputs only when all of the outputs of the first pulse generation circuit are in the standby period; and an input from the pulse control circuit that regulates the output of the first logic circuit; The fifth output is output for a certain period of time with a certain time delay due to
1. An internal partial discharge monitoring device for high-voltage stationary electric appliances, characterized by comprising a pulse generation circuit. 5) % Allowance In the thing described in claim 1, MiJ
A gate circuit that is opened in response to the electric pulse input of the pulse generation circuit provided in each of the ultrasonic detection circuits, and the pulse generation circuit and the logic circuit of the discrimination circuit are connected to each other of the ultrasonic detection circuit. a sixth pulse generating circuit provided in each of the gate circuits and immediately closing the gate circuit when the ultrasonic pulse is inputted through the gate circuit; a first TTL circuit whose output state changes when the respective outputs of the pulse generation circuits are input; and a first AN whose output state changes when a certain number of inputs from the first TTL circuit are received.
A sixth circuit comprising a binary counting circuit provided via a sampling gate circuit controlled by the D circuit and the pulse control circuit and checking the input from the first AND circuit.
a logic circuit, a second AND circuit provided on the output side of each of the sixth pulse generating circuits and detecting simultaneous occurrence of ultrasonic pulse outputs from the sixth pulse generating circuits, and the second AND circuit. A device for monitoring the number of internal parts of a high-voltage stationary electric appliance, characterized in that the AND circuit comprises a seventh logic circuit including a second rTL circuit whose output state changes only when the simultaneous occurrence is detected.