JPS61203818A - 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 the Invention This invention relates to a reactor failure detection device for detecting a coil short circuit such as a layer seat (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.

The line current flowing into the IC is detected by current transformers 2A, 2B, and 2C, and the secondary outputs of current transformers 2A, 2B, and 2C are applied to overcurrent relays, 1i3A, 3B, and 3C. Overcurrent relay 1) 3A, 3
B and 3C, and the Puchhol relay 4 and pressure release alarm relay 5 detect the generation of gas in the oil due to arc discharge when the coil is short-circuited. 6 is a circuit breaker.

Problems to be Solved by the Invention The above-mentioned conventional reactor failure detection device fails due to an increase in line current due to a coil short circuit.
, 3C is operating, but short circuit: f If the number of learns is small, the increase in current is extremely small, so -
, could not be detected by overcurrent relays 3A, 3B, and 3C. Generally, overcurrent relays 3A, 3B.

The number of short circuit turns that 3C can detect is about 1% of the total number of turns, and for example, in a 66KV class shunt reactor, it is 10 to 1.
This corresponds to 5 turns, and a minute short circuit such as a 1-turn short circuit could not be detected.

Furthermore, the number of short circuit turns that could be detected by the Puchholz relay 4 and the pressure release alarm relay 5 was equal to or lower than the detection sensitivity of the overcurrent 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 are installed inside a distributed part, and the outputs of the plurality of magnetic field sensors are each compared with the magnetic field sensor output during normal operation of the reactor, and when the difference exceeds a predetermined value, a short circuit detection signal is generated. This configuration includes a determining section that generates the generated information.

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 the outputs of the magnetic field sensors are applied to a determination device, and the determination device compares the current output of the magnetic field sensors with the magnetic field sensor output when the reactor is normal. When the difference exceeds a predetermined value, the determination device outputs a short circuit detection signal.

Because magnetic field sensors are installed in the reactor, coil short circuits can be detected with high sensitivity, allowing early detection of reactor failures. 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.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 and 2. In FIG. 1, the shunt reactor has three core legs 12A, 12B each having a plurality of voids 1)A, IIB, 1)(').

12C is connected with two upper and lower yokes 13A and 13B to form a gapped core 14, and three core legs 12A.

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 container s16
The inside is filled with an insulating medium such as oil. And coil 1
One end of 5A, 15B, and 15C is commonly connected, and the other end is a bushing 17A.

It is drawn out of the container 16 via 17B and 17G. Each of the core legs 12A, 12B, and 12C is constructed by stacking a plurality of core units each composed of, for example, a radial core via a gear 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 above shunt reactor is the iron core 1! j15A, 15B, 15C voids 1)
Magnetic field sensors 18A to 1 are installed in A, IIB, and IIC, respectively.
81 is installed, and the lead wire 20 of this magnetic field sensor 18A-181 is drawn 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 are connected to each gap 1).
One each is installed in A, IIB, and IIG, but it is not necessary to install one in all voids 1) A, IIB, and IIC, and iron cores 1) 1) 5A, 15B.

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

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

This reactor failure detection device includes, for example, the magnetic field sensor 18
A, 18B, 18C detect the magnetic field of the air gap 1) A', and these magnetic field sensors 18A, 18B.

18C is compared with the magnetic field sensor output when the shunt reactor is normal in the determination device 21, and when the difference exceeds a certain value, it is considered that a coil short circuit has occurred, and the determination device 21
Another magnetic field sensor 1 that outputs a coil short-circuit detection signal from, for example, opens a circuit breaker provided in the main circuit of a shunt reactor.
The same applies to 8D to 181.

FIG. 2 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. 2(A) shows the magnetic flux distribution in a normal state without a short circuit in the coil. Figure 2 (B) shows the coil 15A at part A.
Fig. 2 (C) shows the magnetic flux distribution when a one-turn coil short circuit occurs at part B, and Fig. 2 (D) shows the magnetic flux distribution when a one-turn coil short circuit occurs at part B. shows the magnetic flux distribution when a one-turn coil short circuit occurs, and the second
Figure (E) shows the magnetic flux distribution when a one-turn coil short circuit occurs in the part D, and Figure 2 (F) shows the magnetic flux distribution when a one-turn coil short circuit occurs in the part E. FIG. 2(G) shows the magnetic flux distribution when a one-turn coil short circuit occurs in the portion F. As is clear from each figure, the magnetic flux density near the parts A to F where the coil short circuit has occurred is lower than in the normal state, and the magnetic flux density is higher in other parts. This magnetic flux change is detected by the magnetic field sensor 18A and the determination device 21. In this way, in this embodiment, for example, the magnetic field sensors 18A to 18G are arranged in each of the gaps IIA in the iron core leg 12A, and the outputs of the magnetic field sensors 18A to 18C are The determination device 21 compares the output of the magnetic field sensors 18A-18c under normal conditions with the determination device 21, and when the difference in output is greater than a certain value, the determination device 21 outputs a short circuit detection signal. can be detected. In addition, since the magnetic field sensors 18A to 18C are installed in the air gap 1)A where the magnetic flux changes greatly due to a coil short circuit, it is possible to detect a coil short circuit with high sensitivity. Even minute short circuits can be adequately detected, and as a result, failures in the shunt reactor can be discovered at an early stage. In addition, a magnetic field sensor 1 is inserted into the air gap 1).
By placing 8A to 18C, magnetic field sensor 18A
The structure for installation of ~18C is simple. Note that the void portion 18A~.

Since the magnetic flux change is larger near the outer periphery of the gap 18C, the sensitivity can be further increased by installing the magnetic field sensors 18A to 18C near the outer periphery of the gap 1)A.

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.

[Brief explanation of drawings]

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 diagram showing the magnetic flux distribution in normal conditions and when the coil is short-circuited, and FIG. 3 is a diagram showing a conventional reactor failure detection device. FIG. 2 is a schematic diagram showing the configuration. 1)A~1)C...Gap part, 12A-120...Iron core part, 14...Iron core with gap, 15A-150...Coil, 18A-18C...Magnetic field sensor, 21...・Judgment device Figure 3

Claims (2)

[Claims] (1) A reactor failure detection device that detects a coil short circuit in a reactor formed by winding a coil around an iron core having a plurality of voids, the inside of all or a distributed part of the plurality of voids of the core. a plurality of magnetic field sensors installed in the reactor, and a determination unit that compares the outputs of the plurality of magnetic field sensors with the magnetic field sensor outputs of the reactor during normal operation, and generates a short circuit detection signal when the difference exceeds a predetermined value. Equipped with a reactor failure detection device. (2) The reactor failure detection device according to claim (1), wherein the magnetic field sensor is a coil and is wound around a gap spacer that forms the air gap.