JP2008058140A - Tool for inspecting pt and ct of transformer installed on road - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool for inspecting a PT and CT of a transformer installed on a road capable of significantly simplifying preparing work and ending work in inspecting the PT and CT. <P>SOLUTION: A power transformer installed on road includes a fuse holder 15 composed of a fuse folding body 15a folding a power fuse 12 and a fuse support body 15b, and PT 18, CT 19 for measuring an amount of power at the primary side of the power transformer 13 set in fulled up insulation oil. Enabling to achieve inspecting of PT and CT for the transformer in pulled-off state of a fuse support body from the fuse folding body, an electrode connection part 1b is formed at the one end of a rod type conductive member 1a so as to sliding contact with a load-side fixed electrode 15b2 and a voltage applying part 1c applying an inspection voltage is formed at the other end, and the structure is formed optionally attachable/detachable to the fuse folding body. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention comprises a three-phase switch, a three-phase power fuse and a power transformer filled with insulating oil, and is housed in an outer box, and the fuse holder for housing the power fuse is a power transformer. The present invention relates to a PT / CT inspection instrument for a road-mounted transformer device which is attached in a state where a transformer case is penetrated and is provided with PT and CT for measuring the amount of electric power in insulating oil.

  As shown in Patent Document 1, a road-mounted transformer device generally includes a transformer, a power fuse composed of three phases, a switch device composed of three phases, and the like, and is housed in an outer box. The switchgear and the power fuse are sequentially connected from the power source side to the primary side (high voltage side) of the power transformer.

  A power fuse is usually connected to the power supply side of the power transformer in order to protect the transformer from a short circuit current due to an overload current or a short circuit accident on the load side. The power fuse is housed and held in a power fuse holder attached in a state of penetrating the upper part of the side surface of the transformer case.

  On the other hand, a watt hour meter may be provided in a road-mounted transformer device. In addition, the amount of power may be measured on the primary side of the power transformer. A schematic configuration diagram of the road-mounted transformer device in which the measurement of the electric energy is applied to the road-mounted transformer device as described above is shown in FIG. 3, and an electric circuit diagram of the road-mounted transformer device is shown in FIG. It is shown in FIG. Each figure shows only one phase.

As shown in the figure, a three-phase switch 11, a power fuse 12, and a power transformer 13 are provided and housed in an outer box 14. The power transformer 13 is transformed by a transformer body (not shown). The three-phase switch 11 is configured by accommodating a switch body (not shown) in the switch case 11a, and the switch case 11a is attached to the side surface of the transformer case 13a. Yes. The transformer case 13a is filled with mineral oil or the like as the insulating oil 13b, and the switch case 11a is filled with SF ₆ gas or the like as the insulating gas. The three-phase switch 11 is provided with a power supply side bushing 11b and a load side bushing 11c.

  The power fuse 12 is housed in a fuse holder 15, and the fuse holder 15 includes a fuse housing body 15 a and a fuse gripping body 15 b as shown in FIGS. 5A and 5B, and the fuse gripping body 15 b is a fuse. It is attached to the storage body 15a so as to be freely inserted and removed. The fuse housing body 15a includes an insulating cylindrical member 15a1 having a bottom, a power supply side fixed electrode 15a2, and a load side fixed electrode 15a3. The power fuse 12 is completely stored along the longitudinal direction of the cylindrical member 15a1. A ring-shaped power supply side fixed electrode 15a2 is attached to the inner peripheral surface at a position facing the power supply side electrode 12a of the power fuse 12 in the state. Further, the load side electrode 12b of the power fuse 12 is slidably contacted at a position facing the load side electrode 12b of the power fuse 12 in a state where the power fuse 12 is completely accommodated along the longitudinal direction of the cylindrical member 15a1. For this purpose, a load side fixed electrode 15a3 formed in a tulip shape is attached. The power fuse housing body 15a is attached by being screwed to the transformer case 13a by a pressing plate 16 provided with a hole through which the opening side of the cylindrical member 15a1 passes through the upper side of the transformer case 13a. It has been.

  The power fuse gripping body 15b includes an insulating joint member 15b1, an electrode gripping member 15b2, a movable side electrode 15b3, and a lid member 15b4. In this state, an electrode gripping member 15b2 formed so as to grip the power supply side electrode 12a of the power fuse 12 by screwing is attached, and the other end is for closing the opening of the power fuse housing body 15a. A lid member 15b4 is attached. The electrode gripping member 15b2 is formed such that a toroidal coil-shaped power supply side movable electrode 15b3 that is brought into conduction with the power supply side electrode 12a of the power fuse 12 and is slidably contacted with the inner periphery of the power supply side fixed electrode 15a2 is wound around the outer periphery. ing.

  A cable 17 with a connector is connected to the power supply side bushing 11b of the three-phase switch 11, the load side bushing 11c of the three phase switch 11 is connected to the power supply side fixed electrode 15a2, and the load side fixed electrode 15a3 and the power transformer. The primary coil 13c of the vessel 13 is connected. In the insulating oil 13b filled in the transformer case 13a, an instrument transformer (hereinafter referred to as PT) 18 and an instrument current transformer (hereinafter referred to as CT) 19 for measuring the electric energy are provided, and The PT 18 is connected so that the voltage across the primary coil 13 c of the power transformer 13 is output, and the CT 19 is provided so that the primary current of the power transformer 13 is output.

  In order to take out the outputs of PT 18 and CT 19 to the outside, as shown in FIG. 4, PT and CT through terminals 20 and 21 are provided in the transformer case 13a. It is connected.

  PT18 and CT19 increase the withstand voltage of PT and CT if the voltage on the primary side of power transformer 13 increases, and if PT and CT are used in the air, the dimensions will increase and the demand for compactness will increase. Therefore, PT and CT are reduced in size in the oil specification and installed in the insulating oil 13b filled in the transformer case 13a.

  If PT18 and CT19 are provided in the oil of the transformer case 13a, deterioration due to heat is promoted and PT and CT may break down. Therefore, it is necessary to periodically inspect them.

When inspecting, after turning off the power supply to the road-mounted transformer device by setting the upper system switch of the road-mounted transformer device to the “off” state, removing the lead-in cable 17 with connector and power The cable (not shown) connected to the secondary side bushing of the transformer for transformer 13 is disconnected, a specified inspection voltage is applied from the power supply side bushing 11b of the three-phase switch 11, and the PT transformation ratio is applied to the secondary side of PT18. Check if the voltage corresponding to is output. Further, it is confirmed whether or not the current corresponding to the current transformation ratio of CT is output to the secondary side of CT19.
JP-A-9-282985 (FIG. 1)

  However, in the conventional inspection, it is necessary to attach and detach the cable connected to the power supply side bushing 11 b of the three-phase switch 11 and the cable connected to the secondary side bushing of the power transformer 13. Therefore, there is a problem that the preparation work and the completion work of the inspection become complicated. In addition, since the power fuse 12 is connected to the inspection circuit, there is a problem that the resistance of the power fuse is included, and the secondary side output of the PT 18 includes a measurement error. There is a problem that measurement errors are included in the secondary output.

  An object of the present invention is to provide a PT / CT inspection instrument for a road-mounted transformer device that greatly simplifies preparation work and termination work when inspecting PT and CT.

  The first invention includes a three-phase switch, a three-phase power fuse, and a power transformer filled with insulating oil, and is housed in an outer box. The three-phase switch and the power fuse are In the state where the fuse storage body of the fuse holder consisting of the fuse storage body and the fuse gripping body, which are sequentially connected from the power supply side to the primary side of the power transformer, penetrates the transformer case of the power transformer. The fuse housing body is provided with a power-side fixed electrode and a load-side fixed electrode so as to be mounted and slidably contacted with the power-side electrode and the load-side electrode of the power fuse, respectively. It is formed so as to hold the side electrode, and is attached to the fuse housing body so that it can be inserted and removed freely. The load side bushing of the switch and the power supply side fixed electrode provided in the fuse housing body are connected, the load side fixed electrode and the primary side (high voltage side) of the power transformer are connected, and Is equipped with an instrument transformer (PT) and an instrument current transformer (CT) for measuring the electric energy, and the instrument transformer is connected so that the primary voltage of the power transformer is output. An instrumental current transformer is intended for PT / CT inspection equipment for road-mounted transformer devices provided so that the primary current of a power transformer is output. An electrode that is made of a conductive rod-shaped member and is in sliding contact with the load-side fixed electrode at one end formed on the rod-shaped member so that the inspection of the flutes can be performed with the fuse gripping body removed from the fuse housing body. A connection is formed and an inspection voltage is applied to the other end Sea urchin with a voltage applying unit is formed, in which so as to be formed so as to be detachably attached to the fuse housing body.

  In the second invention, in addition to the first invention, a support member is provided between the electrode connecting portion and the voltage applying portion through the rod-shaped member, and the electrode connecting portion is fitted into the load side fixed electrode. In this state, the support member is formed to be supported by the opening of the fuse housing body.

  According to a third invention, in addition to the first or second invention, there is provided a three-phase switch for inspection assistance that enables opening of the load side fixed electrode and the primary side of the power transformer from the outside of the transformer case. It is intended to be provided.

  As described above, according to the first invention, when PT and CT are inspected, it is not necessary to detach the cable with connector, so that the inspection preparation work and the end work can be greatly simplified. . In addition, since the inspection voltage is applied from the primary side of the power transformer without interposing the resistance component of the power fuse, the secondary side outputs of PT and CT can be accurately measured.

  According to the second invention, since the rod-like member is fixed when the PT / CT inspection instrument is mounted on the fuse housing body 15a, the inspection work can be performed stably.

  According to the third invention, when PT and CT are inspected, it is not necessary to detach the cable connected to the secondary side bushing of the power transformer. Can be simplified.

  FIG. 1 is a schematic configuration diagram showing an embodiment of a PT / CT inspection instrument for a road-mounted transformer device according to the present invention, and FIG. 2 is a PT / CT test for a road-mounted transformer device according to the present invention. It is a figure which shows the state which has applied the instrument to the road installation type transformer apparatus. As shown in FIG. 1, the PT / CT inspection instrument 1 has a conductive rod-shaped member 1a, a conductive electrode connecting portion 1b formed at one end of the rod-shaped member 1a, and an inspection voltage applied to the other end. The voltage applying portion 1c formed as described above, the cylindrical insulating member 1d provided so as to cover the rod-like member 1a between the electrode connecting portion 1b and the voltage applying portion 1c, and the electrode penetrating the rod-like member 1a For example, it includes a disk-shaped support member 1e provided between the connection portion 1b and the voltage application portion 1c.

The electrode connection portion 1b is appropriately attached to the rod-shaped member 1a, is formed in the same shape as the load side electrode 12b of the power fuse 12, the voltage application portion 1c is formed in a screw terminal shape, and the support member 1e is formed of the electrode connection portion 1b. It is formed so as to be fixed and supported in the opening of the fuse housing body 15a in a state of being completely fitted to the load side fixed electrode 12b. The insulating member 1d is made of an organic material such as FRP, and the support member 1e is made of an organic material such as EPDM.

  When inspecting PT18 and CT19, the upper system switch of the road-mounted transformer device is set to the “off” state to stop the power supply to the road-mounted transformer device, or the three-phase switch 2, the load-side fixed electrode 15a3 of the fuse housing body 15a and the primary side of the power transformer 13 can be opened from the outside of the transformer case 13a as shown in FIG. In such a manner, the inspection auxiliary three-phase switch 23 provided in the transformer case 13a is turned off, the fuse gripping body 15b is pulled out of the fuse housing body 15a, and the PT / CT inspection instrument 1 is housed in the fuse. The electrode connecting portion 1b is pushed into the main body 15a so as to be completely fitted into the load side fixed electrode 15a3. In this state, a specified inspection voltage is applied from the voltage application unit 1c, and the watt hour meter 22 is removed from the through terminals 20 and 21 to determine whether a voltage corresponding to the transformation ratio of PT is output to the secondary side of PT18. Measurement is performed by connecting a voltmeter to the through terminal 20. In addition, the watt hour meter 22 is removed from the through terminals 20 and 21 and the ammeter is connected to the through terminal 21 to check whether the current corresponding to the current transformation ratio of CT is output to the secondary side of the CT 19. And measure.

  Thus, when inspecting PT18 and CT19, it is not necessary to remove the cable connected to the secondary cable bushing of the lead-in cable 17 with the connector and the power transformer 13, and the resistance of the power fuse is reduced. The inspection voltage can be applied from the primary side of the power transformer 13 without interposition. Furthermore, the inspection work can be performed stably.

  In the above embodiment, PT 18 and CT 19 are separately configured, but may be integrated PCT. Further, the rod-shaped member 1a is covered with the insulating member 1d formed in a cylindrical shape, but may be integrally covered with an insulating member made of a resin material. Furthermore, the insulating member 1d may not be provided according to the primary voltage of the transformer, or the thickness thereof may be changed. Furthermore, although the electrode connection part 1b was formed in the same shape as the load side electrode 12b of the electric power fuse 12, it is not limited to this.

It is a schematic block diagram which shows one Embodiment of the instrument for PT / CT inspection of the road installation type transformer apparatus which concerns on this invention. It is a figure which shows the state which has applied the PT / CT test | inspection instrument of the road-mounted transformer apparatus which concerns on this invention to the road-mounted transformer apparatus. It is a schematic block diagram of the conventional road installation type transformer apparatus which measured the electric energy. FIG. 4 is an electric circuit diagram of the on-road transformer device shown in FIG. 3. (A) is a longitudinal cross-sectional view which shows the fuse storage main body which comprises a power fuse holder, (B) is a side view which shows the power fuse holding main body which comprises a power fuse holder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Bar-shaped member 1b Electrode connection part 1c Voltage application part 1e Support member 11 Three-phase switch 12 Power fuse 13 Power transformer 14 Outer box 22 Switch case 11 Three-phase switch 11b Power supply side bushing 11c Load side bushing 12 Power fuse 12a Power supply side electrode 12b Load side electrode 13 Power transformer 13a Transformer case 13b Insulating oil 14 Outer box 15 Fuse holder 15a Fuse gripping body 15a2 Power supply side fixed electrode 15b2 Load side fixed electrode 15b Fuse gripping body 17 Connector lead-in cable 18 Instrument transformer (PT)
19 Current Transformer for Instrument (CT)
23 Three-phase switch for inspection assistance

Claims (3)

A three-phase switch, a power fuse composed of three phases, and a power transformer filled with insulating oil are housed in an outer box,
The three-phase switch and the power fuse are sequentially connected from the power source side to the primary side of the power transformer,
The fuse storage body of the fuse holder consisting of a fuse storage body and a fuse gripping body for storing the power fuse is attached in a state of passing through the transformer case of the power transformer,
The fuse housing body is provided with a power supply side fixed electrode and a load side fixed electrode so as to be in sliding contact with the power supply side electrode and the load side electrode of the power fuse, respectively.
The fuse gripping body is formed so as to grip the power supply side electrode of the power fuse, and is attached to the fuse storage body so as to be freely inserted and removed.
A pull-in cable with a connector is connected to the power supply side bushing of the switch,
A load side bushing of the switch and a power supply side fixed electrode provided in the fuse housing body are connected,
The load side fixed electrode and the primary side (high voltage side) of the power transformer are connected,
The insulating oil is provided with a meter transformer (PT) and a meter current transformer (CT) for measuring the amount of power, and the meter transformer is a primary voltage of the power transformer. Is connected to output
The instrument current transformer is a PT / CT inspection instrument for a road-mounted transformer device provided so that a primary current of the power transformer is output,
In order to perform inspection of the instrument transformer and the instrument current transformer in a state where the fuse gripping body is removed from the fuse housing body, the instrument transformer is formed of a conductive rod-like member, and the one end formed on the rod-like member is An electrode connecting portion is formed so as to be in sliding contact with the load side fixed electrode, a voltage applying portion is formed so that an inspection voltage is applied to the other end, and the fuse housing body is detachable. A formed PT / CT inspection instrument for a road-mounted transformer device. A support member is provided between the electrode connection portion and the voltage application portion through the rod-shaped member,
The road-mounted transformer device according to claim 1, wherein the support member is formed to be supported by an opening of the fuse housing body in a state where the electrode connection portion is fitted into the load-side fixed electrode. PT / CT testing equipment. The on-road installation type according to claim 1 or 2, further comprising an inspection auxiliary three-phase switch that enables opening of the load-side fixed electrode and the primary side of the power transformer from the outside of the transformer case. PT / CT inspection equipment for transformer devices.

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