JPS61203819A - Reactor faul detector - 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 Field of Industrial Application This invention relates to a reactor failure detection device for detecting a coil short circuit such as a layer short circuit (interlayer short circuit) of a reactor such as a shunt reactor.

Conventional technology A conventional reactor failure detection device for detecting a coil short circuit in a shunt reactor detects each phase of a shunt reactor 1, which is formed by star-connecting coils la, lb, and lc of each phase, as shown in FIG. Coils la, lb.

By detecting the line current flowing into the IC with current transformers 2A, 2B, and 2C, and applying the secondary outputs of current transformers 2A, 2B, and 2C to overcurrent relays 3A, 3B, and 3G, the line current of each phase can be adjusted. Overcurrent relays 3A, 3B, 3
At the same time, the generation of gas in oil due to arc discharge when the coil is short-circuited is detected by a puffuhol relay 4 and a pressure relief alarm relay 5. 6 is a circuit breaker.

Problems to be Solved by the Invention The above-mentioned conventional reactor failure detection device fails to detect overcurrent relays 3A and 3B due to an increase in line current due to a coil short circuit.
, 3C is operating, but if the number of shorted turns is small, the increase in current is extremely small, so overcurrent relays 3A, 3
It could not be detected in B and 3C. In general, overcurrent relay!
! 3A, 3B.

The number of short circuit turns that Suzua C can detect is about 1% of the total number of turns, and for example, in 66KV class shunt reactor 1, it is 10 to
This corresponds to 15 turns, and a minute short circuit such as a one-turn short circuit could not be detected.

In addition, the number of short circuit turns that could be detected by the Buchfuhror relay 4 and the pressure relief alarm relay 5 was equal to or lower than the detection sensitivity of the current carrying relays 3A to 3C, and a minute short circuit could not be detected.

For this reason, the short circuit in the coil of the shunt reactor 1 could not be detected (in the initial stage) while it was still a minute short circuit, and it was not possible to prevent the failure from expanding.

Means for Solving the Problems This invention provides a reactor in which a coil is wound around an iron core having a plurality of gaps, and when the coil is locally short-circuited, the magnetic flux distribution in the vicinity of the gaps near the short-circuit location changes significantly. This was done based on that.

The reactor failure detection device of the present invention is a reactor failure detection device for detecting a coil short circuit in a reactor formed by winding a coil around an iron core having a plurality of voids, the reactor failure detection device detecting a coil short circuit in a reactor formed by winding a coil around an iron core having a plurality of voids. a plurality of magnetic field sensors installed inside a distributed portion; a plurality of differential circuits that calculate an output difference between two of the plurality of magnetic field sensors for each different combination of the plurality of magnetic field sensors; The configuration includes a plurality of comparison circuits that compare the outputs of the differential circuits with respective reference values.

Function: This reactor failure detection device has the above-mentioned configuration.
A plurality of magnetic field sensors detect the magnetic field in the air gap of the iron core, and a plurality of differential circuits detect the output difference of 211 of the plurality of magnetic field sensors for each different combination of the plurality of magnetic field sensors. A plurality of comparison circuits each compare the output of the coil with a reference value, and based on the comparison results of each comparison circuit, it is possible to detect the presence or absence of a coil short circuit and the location where it has occurred.

This reactor failure detection device has a magnetic field sensor installed in the air gap where the magnetic flux changes significantly due to a coil short circuit, so it can detect coil short circuits with high sensitivity and discover reactor failures early. can do. Further, since the magnetic field sensor is installed in the air gap, the magnetic field sensor can be easily attached and the structure of the reactor itself does not become complicated.

Additionally, the output difference between two of the magnetic field sensors is determined for each different combination of the magnetic field sensors using multiple differential circuits, and the outputs of the multiple differential circuits are compared with reference values using multiple comparison circuits. Therefore, it is possible to know whether there is a coil short circuit and where the coil short circuit occurs based on the comparison results of multiple comparison circuits.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 4. In FIG. 1, the shunt reactor has three core legs 12A, 12B each having a plurality of voids 11Al, 11B, and IIC.

12C are connected with two upper and lower joints #C13A and 13B to form a gapped core 14, and three cores 1! j12A.

12B and 12C have coils 15A and 15B for each phase.

15C, an iron core 14 with a gap and a coil 15A.

15B and 15C are housed in a container 16, and
The inside is filled with an insulating medium such as oil. And coil 1
One end of 5A, 15B, 15C is commonly connected, and the other end is bushing 17A, 17B.

It is pulled out of the container via 17C. Each of the core legs i2A, 12B, and 12C is constructed by stacking a plurality of core units each composed of, for example, a radial core via a gap spacer made of an insulating material such as ceramic. Note that a plurality of gap spacers are arranged side by side between two core units.

The reactor failure detection device attached to the shunt reactor includes the core legs 15A, 15B, 15C (7) cavity 11
Magnetic field sensors 18A to 1 are installed in A, IIB, and IIC, respectively.
81 is installed, and the lead wires 20 of the magnetic field sensors 18A to 181 are led out of the container 16 via the bushing 19 and guided to the determination device 21.

In this case, the magnetic field sensors 18A to 181 each
One fit each is installed in A, IIB, and IIC,
It is not necessary to install the iron core legs 15A, 15B in all the cavities 11A, 11B, and IIC.

An appropriate number of sensors may be distributed in the length direction of the coil 15c, that is, the number of sensors can be selected depending on the change in the magnetic flux distribution when the coil is short-circuited. In addition, magnetic field sensor 18A~
181 is an induction coil.

Various types of magneto-optical field sensors and Hall elements can be used.In the case of induction coils, it is structurally simple to wrap them around a gap spacer, and in the case of magneto-optical sensors and Hall elements using the Faraday effect, It is preferable to arrange it between gap spacers. Note that if a magneto-optical field sensor is used, it will be connected to the determination device 21 with an optical fiber.

As shown in FIG. 2 for one phase, this determination device 21 includes a differential amplifier 22 that takes the difference between the output of the magnetic field sensor 18B and the output of the magnetic field sensor 18A, and the output of the magnetic field sensor 18B and the output of the magnetic field sensor 18C. A differential amplifier 23 that takes the difference between the two, a comparison circuit 24.25 that compares the output of the differential amplifier W22.23 with a reference value, an OR circuit 26 and a NAND circuit that performs a logical operation on the output of the comparison circuit 24.25. circuit 2
7 to 29.

This reactor failure detection device includes, for example, the magnetic field sensor 18
A, 18B, and 18C, the magnetic field H18A of each gap 11A located at the top, middle, and bottom of the iron core leg 2^,
HIBB, I (detects tea, magnetic field sensor 18A
, 18B, and 18C (Fig. 3(A).

By adding (B) and (C)) to the differential amplifier 22.23 and performing calculations, the magnetic fields H1llll^ and HIeB are obtained.

The difference between Htac H1fl B H18^-HHI
I'm looking for B-HI8C. And this magnetic field difference H1
8B H18A.

)(teB-1 (differential amplifier 22.23 according to tea
The output (Fig. 3 (D), (E)) of
with positive and negative reference values VRI, VRL', VR2°V
R2' is compared, and the outputs of the comparison circuits 24 and 25 (FIG. 3 (F), (G)') are input to the OR circuit 26 and NAND circuits 27-29. 30 to 33 are output terminals, respectively.

Therefore, the outputs of the coils 18C with no short circuit occurring in the coils 15A are approximately the same value, and the mutual output differences, that is, the outputs of the differential amplifiers 22 and 23, are the reference values v, 1, respectively.
+ Within the range of VR1' and reference values VR2, VR2'
The outputs of the comparison circuits 24 and 25 are both within the range of , and the outputs of the OR circuit 26 and the NAND circuits 27 to 29 are as shown in FIG. 3(H).

All L as shown in (1), (J), and (K)
becomes.

Also, above the coil 15A (near the magnetic field sensor 18A)
When a short circuit occurs in the magnetic field H1ll! l and magnetic field) 1t
ec is almost the same as the magnetic field sensor 18B.

Although the output of magnetic field sensor 18c is approximately the same value, magnetic field H18A greatly increases magnetic field HIIIB and magnetic field H18C, and the output of magnetic field sensor 18A and magnetic field sensor 18B.

The output of the differential amplifier 1s22 is significantly different from the output of the 18C, and the output of the differential amplifier 1s22 is outside the range between the reference values v, 1 * vR1', and the output of the differential amplifier 23 is within the range between the reference values VR2 and VR2'. The outputs of circuits 24 and 25 are respectively H.
, L, and the output of the OR circuit 26 becomes H.

The outputs of NAND circuits 27 to 29 are H and L, respectively.

L and Ru.

Further, when a short circuit occurs in the middle part of the coil A (near the magnetic field sensor 18B), the magnetic field HIliilA and the magnetic field HIl? C
are almost the same, but the magnetic field HIEIB is the magnetic field H1fl
A.

Significantly different from H18C, therefore, the magnetic field sensor 18
The output of B and the output of magnetic field sensors 18A and 18G will greatly increase, and the output of differential amplifier 622゜23 will be outside the range between reference values VRI and VR1', and the reference value V.
It is out of the range between R2 and VR2', and the comparison circuit 24.25
The outputs of the OR circuit 26 become H and the outputs of the NAND circuits 27 to 29 become H and L, respectively.

Also, below the coil 15A (near the magnetic field sensor 18C)
When a short circuit occurs in the magnetic field H18A and magnetic field 1 (tsB
is almost the same, but the magnetic field) 1tsc is the magnetic field HI8A
, HIBB, and therefore the outputs of the magnetic field sensors 18A and 18B are almost the same, but the output of the magnetic field sensor 18C and the magnetic field sensors 18A and 18B are
The output of the differential amplifier 22 is significantly different from the reference value VRt.

However, the output of the differential amplifier 23 is outside the range between the reference values VR2 and VR2', and the comparator circuit 2
The output of 4.25 becomes H, the output of the OR circuit 26 becomes H, and the outputs of the NAND circuits 27 to 29 become L.
, becomes H.

Then, when the OR circuit 26 becomes H, the coil 15
Since a short circuit has occurred at A, a signal is applied from the terminal 30 to activate a protection device such as a circuit breaker or an i-information device inserted into the main circuit of the shunt reactor.

In addition, when the NAND circuits 27, 28, and 29 each become H, a short circuit occurs in the coils at the top, middle, and bottom, so a signal is sent from the terminals 31, 32, and 33 to the display a (not shown). By supplying the power and lighting it, you can find out where the short circuit has occurred.

In addition, Ike's magnetic field sensors 18D~18! The same applies to

41st! I shows the magnetic flux distribution near the core leg 12A when the shunt reactor is normal (no short circuit) and when a coil short circuit occurs. Note that each distribution diagram shows a half cross section of the core leg and coil for one phase.

FIG. 4(A) shows the magnetic flux distribution in a normal state without a short circuit in the coil. Figure 4 (B) shows 1 in the part A of the coil 15A.
Fig. 4 (C) shows the magnetic flux distribution when a one-turn coil short circuit occurs in part B, and Fig. 4 (CD) shows the magnetic flux distribution in part C. This shows the magnetic flux distribution when a one-turn coil short circuit occurs, and the fourth
Figure (E) shows the magnetic flux distribution when a one-turn coil short circuit occurs in the part D, and Figure 4 (F) shows the magnetic flux distribution when a one-turn coil short circuit occurs in the part E. FIG. 4(G) shows the magnetic flux distribution when a one-turn coil short-circuit occurs at part F.

In the normal state shown in Figure 3 (A), the magnetic flux densities in the upper, middle, and lower air gaps are almost equal (balanced), but when a coil short circuit occurs, the air gaps in the vicinity For example, if the coil 15A is short-circuited at position C or F, the air gap magnetic flux density in the middle part and the upper and lower air gap magnetic flux densities will be unbalanced, and the upper and lower air gap magnetic flux densities will be balanced. It turns out. Further, if the coil 15A is short-circuited at position A or D, the upper air gap magnetic flux density and the middle and lower air gap magnetic flux densities will be unbalanced, and the middle and lower air gap magnetic flux densities will be balanced.

Therefore, when a coil short circuit occurs, the magnetic field sensor 18A
, 18B, and 18C, and by comparing this with a reference value, it is possible to detect that there is a short circuit. The location of the short circuit can be determined.

Note that, as is clear from each figure, the magnetic flux density near the portion A-F where the coil short circuit has occurred is reduced compared to the normal state, and the magnetic flux density is increased in other portions.

In this embodiment, for example, each cavity 11A in the core leg 12A
Magnetic field sensors 18A to 18C are arranged inside:' 171
m! IIl & ”/+I Q Q I Q A ff
1jJJ+m4 Since the output difference between the toyfm field sensors 18B and 18C is determined and compared with each reference value, it is possible to detect whether or not a coil short circuit has occurred and where it has occurred based on the comparison result. In addition, since the magnetic field sensors 18A to 18C are installed in the air gap 11A where the magnetic flux changes greatly due to a coil short circuit, it is possible to detect a coil short circuit with high sensitivity. can also be sufficiently detected, and as a result, failures in the shunt reactor can be detected at an early stage.

Furthermore, by installing the magnetic field sensors 18A to 18C within the gap 11A, the structure for installing the magnetic field sensors 18A N18c is simple. In addition, the void portions 18A to 18
Since the magnetic flux change is larger near the outer periphery of C, the sensitivity can be further increased by installing the magnetic field sensors 18A to 18C near the outer periphery of the gap 11A.

Effects of the Invention The reactor failure detection device of this invention uses a magnetic field sensor,
Because the magnetic field sensor is installed within the gap where the magnetic flux changes significantly due to a coil short circuit, it is possible to detect coil short circuits with high sensitivity, and reactor failures can be detected early. Further, since the magnetic field sensor is installed in the air gap, the magnetic field sensor can be easily attached and the structure of the reactor itself does not become complicated.

In addition, two magnetic field sensors are combined, the output difference between them is determined, and the determined output difference is compared with a reference value, so the comparison results not only detect the presence or absence of a coil short circuit, but also the location of its occurrence. can.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the configuration of a reactor failure detection device according to an embodiment of the present invention, Fig. 2 is a detailed block diagram of its main parts, Fig. 3 is a time chart of each part, and Fig. 4 is a FIG. 5 is a diagram showing the magnetic flux distribution during normal operation and when the coil is short-circuited, and is a schematic diagram showing the configuration of a conventional reactor failure detection device. 11A to IIC... Gap portion, 12A to 12C... Iron core portion, 14... Iron core with gap, 15A to 15C... Coil, 18A to 18C... Magnetic field sensor, 21... Judgment device, 22.23...Differential tank m device (differential circuit), 2
4. -Figure 1Figure 5Figure 2

Claims (1)

[Claims] A reactor failure detection device for detecting a coil short circuit in a reactor formed by winding a coil around an iron core having a plurality of voids, the device being installed inside all or a portion of the plurality of voids in the core. a plurality of magnetic field sensors; a plurality of differential circuits for determining an output difference between two of the plurality of magnetic field sensors for each different combination of the plurality of magnetic field sensors; and an output of the plurality of differential circuits, each based on the output of the plurality of differential circuits; A reactor failure detection device comprising a plurality of comparison circuits for comparing values.