JP2598404Y2 - Abnormality monitoring device for gas insulated switchgear - Google Patents

Description

[Detailed description of the invention]

[0001]

[Industrial application] The present invention relates to a gas insulated switchgear.
The present invention relates to an abnormality monitoring device for a gas insulated switchgear that monitors the presence or absence of a normal state.

[0002]

2. Description of the Related Art When partial discharge occurs due to insulation deterioration in a gas insulated switchgear , it is necessary to immediately detect this and take measures such as replacement of parts. Gas insulated switchgear
If a ground fault or short circuit accident occurs inside the device, it is necessary to locate the place where the accident occurred. Therefore, Oite the gas insulated switchgear, various phenomena occurring therein when an abnormality occurs (partial discharge occurs, the temperature rise, such as generation of arc light) by detecting the presence or absence of abnormality of the apparatus There is provided an abnormality monitoring device for monitoring

[0003] This type of abnormality monitoring device is a gas insulated switchgear.
A sensor unit for abnormality monitoring attached to location, it has a receiving portion for receiving a detection signal obtained from the sensor unit, the gas absolute by performing the processing of the detection signal at the receiver
The presence or absence of an abnormality in the edge opening / closing device is detected.

FIG. 2 shows an example of a conventional abnormality monitoring device in which a partial discharge generated inside a gas insulated switchgear is detected. In FIG. 2 , reference numeral 1 denotes an antenna 1a for detecting an electromagnetic wave generated by the partial discharge. Sensor part, 2
A receiving unit comprising: an amplifier 2a for amplifying a detection signal detected by the sensor unit; and a signal processing unit for processing the detection signal amplified by the amplifier to determine the presence or absence of partial discharge.
Reference numeral 3 denotes a signal transmission circuit that transmits the output of the sensor unit 1 to the reception unit 2. The signal transmission circuit 3 includes a coaxial cable 3a having one end of a center conductor connected to the antenna 1a, and a coaxial cable 3a.
a, and a voltage suppression element (surge absorbing element) 4 connected between the center conductor and the shield conductor of the coaxial cables 3a and 3b. The other end of 3b is connected to the input terminal of amplifier 2a.

The signal processing section 2b comprises, for example, a comparator for comparing the output of the amplifier 2a with a reference signal. When the detection signal amplified by the amplifier 2a is larger than the reference signal, the occurrence of partial discharge is detected. Is output.

[0006] voltage suppression element 4 is for example a gas-filled arrester, zinc arrester oxide, consist voltage suppression element such as utilizing the forward characteristics of the diode, the surge voltage Vs, as shown in FIG. 3 at both ends is applied When this is done, the internal impedance drops, and the voltage across it drops to a predetermined suppression voltage Vo.

As the detecting means constituting the sensor unit 1 for monitoring an abnormality, an ultrasonic sensor, a vibration sensor or the like is used in addition to the above-mentioned antenna.

[0008]

In a monitoring device for monitoring an abnormality of a gas insulated switchgear , an excessive energy level such as a switching surge or a lightning surge is included in detection signals of various sensors for monitoring abnormality. Unnecessary signals having the following are mixed, and this unnecessary signal causes erroneous detection. Therefore, a voltage suppression element 4 is provided in the signal transmission circuit 3 so that the level of the unnecessary signal is limited to the suppression voltage Vo or less.

In the abnormality monitoring device for a gas insulated switchgear, in order to accurately detect the presence / absence of an abnormality, the suppression voltage Vo is controlled according to the configuration of the sensor section, the configuration of the receiving section, or the content of the abnormality to be monitored. It is necessary to set the size to an appropriate value. For example, if the detection output of the sensor unit is compared with a predetermined threshold to detect the occurrence of an abnormality when the detection output exceeds the threshold, if the suppression voltage is set too low, the normal detection is performed. The signal is also suppressed and abnormality detection cannot be performed. If the suppression voltage is set too high, there is a possibility that the protection of the receiving unit cannot be properly achieved.

However, in the conventional abnormality monitoring device, since the suppression voltage is determined by the suppression voltage inherent to the voltage suppression element, there is a problem that the suppression voltage cannot be finely adjusted.

[0011] Conventional gas-insulated switchgear apparatus shown in FIG. 2
The abnormality monitoring device for gas was unable to insulate the sensor unit from the receiving unit.
When the sensor section is placed close to the voltage section, the sensor
This is dangerous because a high voltage may be applied to the receiving unit from the unit.

As shown in FIG. 4 , the coaxial cable 3a
Insert a capacitor C between the coaxial cable 3 and
Although there is a type in which DC is insulated between a and 3b, such a configuration cannot prevent a surge from passing through the signal transmission circuit.

An object of the present invention is to provide a gas insulated switchgear capable of adjusting a suppression voltage for an unnecessary signal such as a surge and insulating between a sensor unit and a receiving unit . An object of the present invention is to provide an abnormality monitoring device.

[0014]

The present invention provides a gas insulated switchgear.
The present invention relates to an abnormality monitoring device for a gas insulated switchgear provided with a sensor unit for monitoring abnormality arranged in a container of the device and a receiving unit for detecting the presence or absence of an abnormality in the gas insulated switchgear from a detection signal of the sensor unit. Things.

In the present invention , a first insulating transformer whose primary side is connected to the sensor unit, and a second insulating transformer which is cascaded to the first insulating transformer and whose secondary coil is connected to the receiving unit. And a voltage suppression element connected in parallel to the secondary coil of the first insulating transformer and the primary coil of the second insulating transformer .

[0016] The electric pressure suppression element consists of arrester
Then , when a voltage equal to or higher than a predetermined level is applied to both ends, the internal impedance is reduced and the voltage at both ends is reduced to a predetermined suppression voltage .

[0017]

As described above, by inserting an insulating transformer between the sensor unit and the receiving unit and inserting voltage suppressing elements at both ends of the coil of the insulating transformer, the winding ratio of the transformer is adjusted. Since the suppression voltage for unnecessary signals such as surges can be adjusted arbitrarily, the magnitude of the suppression voltage can be delicately adjusted according to the configuration of the sensor unit and reception unit, or the nature of the abnormality to be detected. Can,
Abnormality monitoring of the gas insulated switchgear can be accurately performed.

As described above, the sensor unit and the receiving unit
A first isolation transformer and a second isolation transformer cascaded between
Gas-insulated open / close when two transformers with lance are inserted
Sensor and receiver located close to the high voltage section of the device
Can be double insulated from the
Protection can be ensured.

Further, as described above, the first insulating transformer and the second insulating transformer are cascade-connected, and are connected in parallel with the secondary coil of the first insulating transformer and the primary coil of the second insulating transformer. When so as to connect the voltage suppression element,
By appropriately setting the turns ratio of the first insulating transformer and the second insulating transformer, the primary
Matching between the circuit on the sensor side and the sensor side
Between the secondary side of the second insulating transformer and the circuit on the receiving side.
Impedance matching between the two
Since it is, Sen without affecting the transmission of the signal
A voltage suppression element can be inserted into a transmission circuit for transmitting a signal from the receiving unit to the receiving unit .

[0020]

1 shows an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a sensor unit having an antenna 1a for detecting an electromagnetic wave generated when a partial discharge occurs in a gas insulated switchgear ; Reference numeral 2 denotes a receiving unit having an amplifier 2a and a signal processing unit 2b. Reference numeral 3 denotes a signal transmission circuit that connects between the sensor unit 1 and the receiving unit 2.

The signal transmission circuit 3 includes a coaxial cable 3a having one end connected to the antenna 1a, and an amplifier 2a of the receiver 2.
And a voltage suppression circuit 5 inserted between the other end of the coaxial cable 3a and the other end of the coaxial cable 3b.

The voltage suppressing circuit 5 includes a first insulating transformer 6 having one end and the other end of the primary coil 6p connected to the antenna 1a and the ground terminal of the sensor unit 1 through the center conductor and the shield conductor of the coaxial cable 3a, respectively. A second insulating transformer 7 connected in cascade to the first insulating transformer 6 by connecting the primary coil 7p in parallel with the secondary coil 6s of the first insulating transformer 6, and a secondary of the first insulating transformer 6 The voltage control element 4 is connected in parallel to the coil 6s and the primary coil 7p of the second insulating transformer. As the voltage suppressing element 4, a gas-filled arrester, a zinc oxide (ZnO) type arrester, or a voltage suppressing element utilizing the nonlinearity of a forward characteristic of a diode (a plurality of diodes are connected in series or in series / parallel) ) Can be used.

In the monitoring apparatus shown in FIG. 1, the antenna 1a of the sensor unit 1 is mounted in a container of the gas insulated switchgear, and when a partial discharge occurs in the gas insulated switchgear, the partial discharge is generated. Receive the resulting electromagnetic waves. The signal received by the antenna 1a is provided to the receiving unit 2 through the signal transmission circuit 3, and is amplified by the amplifier 2a and then input to the signal processing unit 2b. The signal processing unit 2b includes, for example, a comparator that compares the output signal of the amplifier 2a with a reference signal that provides a threshold value, and determines that partial discharge has occurred when the level of the output signal of the amplifier 2a is equal to or higher than the level of the reference signal. Then, a predetermined alarm signal is generated.

When a more complicated signal processing is performed in the receiving unit, a computer may be used for the signal processing unit.

In the above embodiment, the number of turns of the primary coil and the secondary coil of the first insulating transformer 6 is n 1
, N2, and the numbers of turns of the primary coil and the secondary coil of the second insulating transformer 7 are n2 'and n3, respectively.
If the relationship of n1: n2 = n3: n2 'is established, the input impedance and the output impedance of the cascade connection circuit (voltage suppression circuit 5) of the first insulating transformer 6 and the second insulating transformer 7 are determined. Can be the same. By changing the turns ratios n1 / n2 and n2 '/ n3, the actual protection voltage viewed from the output side can be set freely. For example, when the operating voltage (suppression voltage) is V
2 is used as the voltage suppression element 4, the suppression voltage V1 viewed from the input side of the voltage suppression circuit 5 is
V1 = (n1 / n2) V2, and the suppression voltage V3 viewed from the output side is V3 = (n3 / n2 ') V2. As an example, if V2 = 200 [v] and n1 / n2 = 1/10, the suppression voltage V1 viewed from the input side is 20 [v].

Since the gas-filled arrester has a small capacitance between the electrodes, it can also be used in circuits that handle signals of several hundred MHz or more. However, the operating voltage is several tens of volts or more.
Although it cannot be set to 00 mV, if it is connected to a circuit via a transformer as described above, it is possible to obtain a suppression voltage of several hundred mV by adjusting the turns ratio of the transformer. Further, since the first insulation transformer 6 and the second insulation transformer 7 are insulated from each other between the primary and secondary sides, the provision of the voltage suppression circuit 5 described above allows the sensor unit 1 and the reception unit 2 to be connected to each other. It is possible to insulate between them, and it is possible to prevent a high voltage from being applied to the receiving unit 2 when the sensor unit is arranged near the high voltage unit .

In the above embodiment , since the capacitance between the windings can be reduced by devising the windings of the transformer, it is possible to reduce the common mode noise between the available powers.

In the above description, an abnormality monitoring device for detecting an abnormality of the gas insulated switchgear by detecting a partial discharge has been described as an example. However, other abnormalities such as an abnormality of the pressure in the container of the gas insulated switchgear. It is needless to say that the present invention can also be applied to the case of detecting.

[0029]

[Effects of the Invention] As described above, according to the present invention , gas exhaustion
The sensor and the receiver arranged in the container of the rim opening and closing device
Insert first and second isolation transformers cascaded between
And the secondary coil of the first insulation transformer and the second insulation
Since the voltage suppression element is connected in parallel to the primary coil of the transformer, the suppression voltage for unnecessary signals such as surge can be arbitrarily adjusted by adjusting the turns ratio of the transformer. The magnitude of the suppression voltage can be finely adjusted according to the configuration of the unit or the content of the abnormality to be detected, so that the abnormality monitoring of the electric device can be performed accurately.

Further, according to the present invention, the sensor unit and the receiving unit
Insert two isolation transformers cascaded between
Double insulation between sensor and receiver
In the high voltage section inside the container of the gas insulated switchgear
The insulation between the sensor unit and the receiving unit in the robust, high voltage can be reliably prevented from being applied to the receiving unit.

Further, according to the present invention, the first insulating transformer and the second insulating transformer are cascade-connected, so that the secondary coil of the first insulating transformer and the primary coil of the second insulating transformer are connected. since so as to connect the voltage suppression element in parallel, by setting the turns ratio of the first insulation transformer and a second isolation transformer to appropriately, the first insulating transformer
Adjust the impedance between the primary side and the sensor side circuit.
And the secondary side of the second insulating transformer and the circuit on the receiving side
And impedance matching between
The signal transmission circuit between the sensor and the receiver.
It is possible to prevent a mismatched portion of the dance from occurring. I
Therefore, the transmission of signals from the sensor to the receiver has no effect.
Insert a voltage suppression element into the signal transmission circuit without affecting
To protect the receiving unit.

Also, in the present invention, the first and second absolute
The edge transformer is cascaded and the secondary of the first isolation transformer is
Parallel to the coil and the primary coil of the second insulating transformer.
Since the voltage suppression element is connected to the column, the transformer
The suppression voltage can be compared by appropriately adjusting the turns ratio of
Using a highly arrestor as a voltage suppression element,
Can get the low suppression voltage needed to protect
You.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a conventional monitoring device.

FIG. 3 is a voltage waveform diagram for explaining an operation of the voltage suppressing element.

FIG. 4 is an explanatory diagram showing a configuration of a signal transmission circuit employed in a conventional monitoring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sensor part 2 Receiving part 3 Signal transmission circuit 4 Voltage suppression element 5 Voltage suppression circuit 6 First insulation transformer 6p Primary coil 6s Secondary coil 7 Second insulation transformer 7p Primary coil 7s Secondary coil

Continuation of front page (58) Fields investigated (Int.Cl. ⁶ , DB name) H02H 9/00-9/08 G01R 31/00 H02B 13/06

Claims (1)

(57) [Scope of request for utility model registration] 1. A sensor unit for <br/> abnormality monitoring disposed in the container of a gas insulated switchgear, gas from the detection signal of the sensor unit
In the abnormality monitoring device for a gas insulated switchgear that includes a receiver for detecting the presence or absence of abnormality of the scan-insulated switchgear, a first insulating transformer primary side is connected to the sensor unit, the first insulating transformer And a secondary coil connected in cascade to the receiver and connected in parallel to the secondary coil of the first insulating transformer and the primary coil of the second insulating transformer. A voltage suppressing element , wherein the voltage suppressing element comprises an arrester.
A gas insulated switchgear for abnormality monitoring device, characterized in that are.