JP2002209314A - Power-receiving and transforming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power-receiving and transforming device which enables a test of a transformer single body safely without removing an incoming cable in the case of a periodic test of a transformer or installing a grounding apparatus on the transformer side of a primary breaker or a switch. SOLUTION: A grounding position is set in a tap of a primary winding tap switch of the transformer, and a key for storing open circuit positions of the primary breaker and a secondary breaker of the transformer or the switch is installed at the grounding position for operating a mechanism of the tap switch, so that the grounding apparatus for an insulation resistance test is not necessary to be installed in a compact breaker or the switch. When the tap of the tap switch of the transformer primary winding is located on the grounding position, accidents such as a short-circuit and ground fault can be prevented by installing a key for storing the state of an open circuit of the primary breaker and the secondary breaker of the transformer or the switch and by assembling an interlock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power receiving and transforming apparatus in which an enclosed transformer and an enclosed primary circuit breaker or switch are integrally formed.

[0002]

2. Description of the Related Art Various tests must be periodically performed on a power receiving and transforming apparatus to confirm its performance. A typical test is an insulation resistance test. By the way, in the conventional power receiving and transformation equipment provided with a transformer and a primary circuit breaker or a switch, the transformer and the primary circuit breaker panel or the switch panel of the transformer are connected by a communication bus or a cable, so that a partition is provided. Since the charged portion was exposed by removing the board, various tests were possible from the exposed portion.

In addition, the sealing of circuit breakers and switches has been reduced in size by the development of insulation technology and technology for simplifying mechanisms. A conventional example of such a compact transformer unit will be described with reference to FIG.

[0004] As shown in the figure, a sealed switchgear 9 is provided on the primary side of a transformer 6 via a bushing 5, and the sealed switchgear 9 is connected to the power receiving cable head 1.
Connected to the power receiving cable. In the enclosed switchgear 9, the disconnecting switch 2, the circuit breaker 3, and the current transformer 4 are connected in series between the power receiving cable head 1 and the bushing 5, and both ends connected in series are the grounding device 7 and the ground. It is grounded via a bushing 8.

[0005] As described above, the sealing of circuit breakers and switches has been made compact by the development of insulation technology and technology for simplifying the mechanism, and can be integrated with a transformer. The functions are limited to the original functions, that is, cutoff and disconnection, and the provision of a test device is not usually considered because it is a hindrance to compactness. Therefore, at the time of the insulation test of hermetically sealed equipment, a method has been adopted in which the power receiving cable is removed and the test is performed from that part, or a grounding device is provided on the transformer side of the switch and the grounding terminal is used.

[0006]

Further, in the case of a power receiving and transforming device composed of a closed type device, it is difficult to even partially expose the charged portion during the test because the charged portion is sealed with a mold or gas. It has a simple structure.

SUMMARY OF THE INVENTION The present invention has been made in order to cope with the above situation, and has as its object to remove a power receiving cable during a periodic test of a transformer or to provide a grounding device on a transformer side of a primary circuit breaker or a switch. It is another object of the present invention to provide a power receiving and transforming apparatus that can safely and safely test a transformer alone.

[0008]

To achieve the above object, a first aspect of the present invention is to provide a grounding position in a tap of a primary winding tap changer of a transformer, and a ground position operation mechanism of the tap changer. A key storing the open circuit positions of the primary circuit breaker and the secondary circuit breaker or the switch of the transformer.

According to claim 1, the object of the insulation resistance test is a primary circuit (primary winding) of a transformer, and the transformer has a tap changer for adjusting a transformer ratio. By adding a grounding position to the tap of the transformer tap changer, it is not necessary to provide a grounding device for an insulation resistance test in a compact circuit breaker or switch. When the tap of the tap changer of the primary winding of the transformer is set to the ground position, the primary circuit breaker and the secondary circuit breaker or the switch of the transformer memorize the open circuit state (exit in the open circuit state).
Equipped with a key, so-called key lock system, and an interlock to prevent accidents such as short circuit and ground fault.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a tap changer of a transformer with a ground tap according to a first embodiment of the present invention. FIG. 1 (a) shows a normal conduction state, and FIG. 1 (b) shows an insulation test. It is a figure which shows the conduction | electrical_connection state of.

As shown in the figure, a sliding contact 13 of a tap changer of a transformer with a ground tap according to the present embodiment is connected to a power receiving cable via a bushing 5 provided in a closed container main body (not shown). The tap side of the sliding contact 13 is
The highest tap contact 11 to the intermediate tap contact 11n to the lowest tap contact 12 of the transformer primary winding 10 according to a desired voltage
To move. The shape of the sliding contact 13 is configured to have a width between adjacent taps or between the lowest tap contact 12 and the ground tap contact 14. Further, the separation between the voltage taps is set to a width exceeding 1/2 of the width of the sliding contact 13 in order to secure insulation between the taps. The grounding position tap 14 is grounded via a grounding bushing 8 penetrating inside and outside the sealer.

Since the present embodiment is configured as described above, during the insulation resistance test of the primary winding of the transformer, as shown in FIG.
By moving to touch the grounding position tap 14,
An insulation resistance test can be performed from an external ground terminal.

FIG. 2 is a configuration diagram of a sliding interlock of a tap changer of a transformer with a ground tap according to a second embodiment of the present invention. As shown in the figure, an interlock for moving a ground tap changer of a transformer with a ground tap according to the present embodiment to a ground position is shown. That is, when moving from the lowest tap contact 12 to the ground tap contact 14, the key 17 (generally called a key lock device) storing the open positions of the primary and secondary circuit breakers or switches of the transformer and the interlock pin 16 are used. The operation of the sliding mechanism 15 is restricted. Note that the key 17 is structured to be pulled out at a position other than the ground tap.

Since the present embodiment is configured as described above, when operating the primary and secondary circuit breakers or switches of the transformer, the key must be inserted into the circuit breakers or switches. Needless to say.

[0015]

As described above, according to the power receiving and transforming apparatus of the present invention, the insulation resistance test of the primary circuit of the transformer is performed by using the tap of the transformer to remove the power receiving cable and to provide the grounding device. It has an excellent effect that it can be easily done at the same time, leading to improved maintainability and cost reduction.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a tap changer of a transformer with a ground tap according to a first embodiment of the present invention, wherein FIG. 1A shows a normal conduction state, and FIG. 1B shows an insulation test; FIG. 6 is a diagram showing a conduction state at the time.

FIG. 2 is a configuration diagram of a sliding interlock of a tap changer of a transformer with a ground tap according to a second embodiment of the present invention.

FIG. 3 is a power receiving and transforming apparatus in which a conventional sealed transformer and a sealed primary circuit breaker or switch are integrally structured.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power receiving cable head, 2 ... Disconnector, 3 ... Circuit breaker, 4
... current transformer, 5 ... bushing, 6 ... transformer, 7 ... grounding device, 8 ... grounding bushing, 9 ... hermetic switchgear, 1
0 ... Transformer primary winding, 11 ... Highest tap contact, 11n ...
Middle tap contact, 12: Lowest tap contact, 13: Sliding contact, 14: Ground tap contact, 15: Tap sliding mechanism, 1
6 ... interlock pin, 17 ... key.

Claims (1)

[Claims] 1. A grounding position is provided at a tap of a primary winding tap changer of a transformer, and an opening position of a primary breaker and a secondary breaker or a switch of the transformer is provided at a grounding position operation mechanism of the tap changer. A power receiving and transforming device, characterized in that a key storing therein is provided.