JP2563294Y2 - Zero-phase current / voltage detection unit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zero-phase current / voltage detection unit capable of detecting a zero-phase component of a current flowing through a three-phase power line in a distribution line and detecting a zero-phase voltage. It is.

[0002]

2. Description of the Related Art As a conventional zero-phase current detecting unit, an annular iron core is provided so as to surround a bushing penetrating a three-phase lead conductor supported by a switch case, and a secondary winding wound around the iron core is provided. An optical voltage sensor is connected to the winding, and the secondary-side detection current output from the optical voltage sensor is converted into a voltage via a secondary burden resistor, a zero-phase current is detected, and a three-phase electric line is detected. Can be monitored.

[0003]

However, the above-mentioned conventional zero-phase current detection unit requires a secondary winding on a ring-shaped iron core mounted around a three-phase bushing, which is cumbersome to manufacture and high in cost. In addition, there is a problem that the work of mounting the detection unit around the three-phase conductor is very troublesome.

An object of the present invention is to solve the above-mentioned problems in the prior art, to omit the winding of the current transformer, to simplify the structure and to reduce the cost, and to reduce the cost around the three-phase conductor. The annular iron core assembly can be easily attached,
Furthermore the mounting of the magnetic field sensor head can be easily performed, it is to provide a zero-phase current and voltage <br/> detection unit that can be detected a zero-phase voltage.

[0005]

[0006]

Devised this SUMMARY OF THE INVENTION In order to achieve the above Symbol object, switches one three-phase conductor outer periphery of which is supported through an insulator to the ground of the case or the like of the loop An annular iron core assembly formed of an annular iron core wound in a manner described above and an insulating jacket formed on an outer periphery thereof; a mounting bracket for mounting the annular iron core assembly to the grounding object; and a mounting member provided on the mounting bracket. A magnetic field sensor head which is supported by the support member and which is interposed in a notch space formed in a part of the annular iron core assembly.
And an outer electrode plate on an outer peripheral surface and an inner peripheral surface of the annular iron core assembly.
And the inner electrode plate and the outer electrode plate and the inner electrode
Electric field sensor provided near the plate and the magnetic field sensor head
The head and head are connected by a lead wire .

[0007]

[0008]

[Action] Since devised This notch space in a part of the annular iron core assembly is provided, the magnetic field sensor head through the support member to the mounting bracket for supporting the ground material an annular iron core assembly body Thus, the magnetic field sensor head can be directly mounted so as to apply a magnetic field, and the mounting operation of the magnetic field sensor head into the cutout space can be performed simultaneously with the mounting of the circular iron core assembly.

Furthermore, devised This voltage difference caused by the capacitance between the outer electrode plate and the inner electrode plate side by the zero-phase voltage of the three-phase conductors, the voltage difference supplied to the voltage sensor head via a lead wire Is done. Therefore, the zero-phase voltage of the three-phase conductor is detected.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. Bushing insulator tubes 2A to 2C are supported in parallel on one side surface of the switch case 1 as a grounded object. Three-phase through conductors 3A to 3C are supported in the insulator tube. In addition, the insulator tube 2 is provided on the side of the case 1.
Support bolts 4 at a total of four places so as to be located between A and 2C
Is fixed. The support bolt 4 is inserted into the bolt insertion holes 5a and 6a provided in the pair of left and right mounting brackets 5 and 6, and the support bolt 4 is attached to the side surface of the case 1 by nuts 7 screwed to the bolts. Have been.
Then, the annular iron core assembly 8 is pressed and held at a predetermined position on the side surface of the case 1 by the holding portions 5b and 6b formed by bending the both end portions of the mounting brackets 5 and 6.

The ring-shaped iron core assembly 8 is formed by a ring-shaped iron core 9 located at the center and an insulating jacket 10 made of resin molded over the entire outer periphery of the iron core 9. A cut-out space 9a is provided in a part of the annular iron core 9, and a current / voltage detection unit 15 described later is provided in the space.
Can be accommodated.

An outer annular electrode plate 11 and an inner annular electrode plate 12 are wound around the outer peripheral surface and the inner peripheral surface of the insulating outer cover 10, and when the outer cover 10 is formed by molding, one of the outer cover 10 is formed. Parts formed in the electrode plates 11 and 12
The two electrode plates 11 and 12 are locked at predetermined positions of the outer casing 10 by entering into 12a.

Both ends of a support plate 13 serving as a support member extending in the horizontal direction are fastened and fixed to holding portions 5b and 6b located at lower ends of the mounting members 5 and 6, respectively. The detection unit 15 inserted into the cutout space 9a is attached to an outer surface of the support plate 13. The unit 15 is fixed to the support plate 13 by screws 17.
Is attached by a presser 16 which is fastened and fixed.

The detecting unit 15 includes a magnetic field sensor head 18 for detecting a magnetic field induced by the annular iron core 9 in a cutout space 9a of the annular iron core 9, and the magnetic sensor head 18 disposed on the sensor head. An electric field sensor head 19 for detecting a potential difference between the outer and inner annular electrode plates 11 and 12 is provided. An optical fiber signal line 20 is connected to the magnetic field sensor head 18 and an optical fiber signal line 21 is connected to the electric field sensor head 19 via connectors 22 and 23, respectively, and connected to a signal control device (not shown).

At the upper end of the electric field sensor head 19, a pair of input terminals 24, 25 is provided so as to protrude therefrom.
An output terminal 25 is formed by cutting and raising the outer and inner annular electrode plates 11 and 12 via lead wires 26 and 27.
8 and 29 are connected by screws 30. A capacitor 31 for capacitance correction is connected between the two lead wires 26 and 27. Further, the output terminal 29 is grounded to the mounting bracket 6 by a ground wire 32.

To mount the annular iron core assembly 8 around the three-phase through conductors 3A to 3C, the annular iron core assembly 8 is inserted from the front of the insulator tubes 2A to 2C, and then the annular iron core assembly 8 is inserted. The case 1
Touch the side of the After that, by attaching the two mounting brackets 5 and 6 to the side surface of the case 1 using the support bolts 4, the outer side surfaces of the annular iron core assembly 8 are pressed by the holding portions 5 b and 6 b of the two mounting brackets 5 and 6. Then, the mounting of the assembly 8 is completed.

At this time, as described above, the detection unit 15 is provided so that the magnetic field sensor head 18 is positioned in the cutout space 9a of the annular iron core 9 via the support plate 13 with respect to the two mounting brackets 5, 6. Therefore, the detection unit 15 can be positioned and fixed at the same time when the annular iron core assembly 8 is attached.

The operation of the zero-phase current / voltage detection unit configured as described above will be described. Now, when an operating current flows through the three-phase through conductors 3A to 3C, a magnetic field is induced in the annular iron core 9. This magnetic field acts on the magnetic field sensor head 18 of the detection unit 15 housed in the cutout space 9a. As a result, the magnetic field induced by the three-phase through conductors 3A to 3C is detected, and the detection signal is transmitted to the optical fiber signal line 20. To the signal controller.

Further, a shared voltage is generated between the outer electrode plate 11 and the inner electrode plate 12 located on the inner and outer surfaces of the insulating jacket 10 by the electrostatic induction action between the two electrode plates 11 and 12, and a three-phase zero voltage is generated. The phase voltage is detected by the electric field sensor head 19, and the detection signal is supplied to the signal control device through the optical fiber signal line 21.

In the embodiment of the present invention, the annular iron core assembly 8 can be easily mounted by being inserted around the three-phase conductors 3A to 3C from the front.
Further, in the embodiment of the present invention, since the secondary winding is not required for the annular iron core, the structure can be simplified and the cost of the device can be reduced.

Further, in the embodiment of the present invention, the detection unit 15 is attached via the support plate 13 to the mounting brackets 5 and 6 for supporting the annular iron core assembly 8 to the case 1, and at the same time, the unit is connected to the above-mentioned unit. The mounting work can be easily performed by positioning in the notch space 9a.

[0022]

This invention is limited to the above embodiment.
Instead, it can be embodied as follows. ( 1 ) The mounting brackets 5, 6 and the support plate 13 are integrally formed. ( 2 ) The magnetic field sensor head 18 and the electric field sensor head 1
As shown in FIG. 5, the capacitor 9 and the capacitance correcting capacitor 31 are housed in a case 33 and provided on the support plate 13. In the figure, the upper box-34 and the lower box-35 is adhered and fixed at the butt portion 36, also small on the side wall bore 34
a, 34b and 35a are provided to insert optical fiber signal lines and lead wires.

[0024]

As described in detail [devised effects above, devised This makes it possible to reduce the cost by simplifying the structure by omitting the secondary winding of the annular iron core, still three-phase cables are live An annular iron core assembly can be easily attached around the conductor,
Further can be mounted to position the magnetic field sensor head at the same time, there is an effect that can be detected a zero-phase voltage.

[0025]

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment embodying a zero-phase current / voltage detection unit of the present invention.

FIG. 2 is a bottom view of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 1 from which the bushing insulator tube is omitted.

FIG. 4 is a perspective view of a mounting bracket and a support plate.

FIG. 5 is a perspective view showing a main part of another embodiment.

[Explanation of symbols]

1 Switch case as grounding object, 2A-2C bushing insulator tube, 3A-3C through conductor, 4 support bolt, 5,
6 Mounting bracket, 5b, 6b Holder, 7 Nut, 8
Annular iron core assembly, 9 Annular iron core, 9a Notched space, 10
Insulation jacket, 11 outer annular electrode plate, 12 inner annular electrode plate, 13 support plate as support member, 15 current / voltage detection unit, 18 magnetic field sensor head, 19 electric field sensor head.

Continuation of front page (56) References JP-A-55-78514 (JP, A) JP-A-3-277979 (JP, A) JP-A-1-274070 (JP, A) JP-A-3-206971 (JP) , A) JP-A-1-270679 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] An annular core wound around a three-phase conductor supported by a grounded object such as a switch case via an insulator with a single loop, and an insulating jacket formed on the outer periphery thereof. An annular iron core assembly comprising: a mounting member for mounting the annular iron core assembly to the grounded object; a support member provided on the mounting metal member; and a part of the annular iron core assembly. A magnetic field sensor head interposed in the formed notch space, and an outer periphery of the annular iron core assembly.
Wind the outer electrode plate and the inner electrode plate around the
With outer and inner electrode plates and the magnetic field sensor head
Connect a nearby electric field sensor head with a lead wire.
Zero-phase current and voltage detecting unit, characterized in that connection was.