JPH0436017Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a transformer built-in switch, and in particular to a transformer that integrates a switch and a transformer and has a cut-off function by self-detection of overcurrent. This invention relates to a transformer built-in switch that is more compact.

[Conventional technology]

Conventional distribution transformers are designed to step down the voltage from a high voltage of 6.6KV to a low voltage of 100/200V.For example, a cut-out switch equipped with a fuse is used for overload protection. Built-in.

[Problem that the invention attempts to solve]

However, in crowded areas such as cities,
Due to demand, a large number of distribution transformers are required, and increasing the capacity also increases the size and makes surrounding poles very complex, which makes maintenance work, equipment management, insulation coordination, and aesthetics difficult. Undesirable.
In addition, if a cut-out switch with a fuse is installed, if the fuse blows, it will take time to replace it, and furthermore, in three-phase operation, the fuse will blow out, resulting in an open-phase operation. , which has the disadvantage of damaging the equipment itself.

[Means and actions for solving problems]

The present invention was developed in view of the above, and in order to suppress the increase in the size of the transformer itself and prevent phase loss due to fuse blowout, the present invention is based on a tripping system that automatically detects overcurrent and releases all phases at once. The present invention provides a transformer-integrated switch in which a switch equipped with a mechanism is integrated with a transformer.

Hereinafter, the transformer built-in switch according to the present invention will be described in detail with reference to the accompanying drawings. [Embodiment] FIG. 1 shows an embodiment of a transformer built-in switch according to the present invention. This transformer built-in switch 1 is composed of a transformer 2 and a switch 3. Switch 3
As shown in FIG. 2A, a rotating interlocking shaft 4 is provided inside the
Rotary insulators 5a, 5b, and 5c are connected at 120° intervals, and movable contacts 6a, 6b, and 6c are fixed to their tips.
Further, an operating link 7 is connected to the upper part of the interlocking shaft 4, and an opening latch 8 is rotatably connected to the operating link 7. A release latch 9 is rotatably connected to the release latch 8 at a point a, and the other end of the release latch 9 is rotatably connected to a latch fixing part 10 fixed to the side wall of the switch 3. At point a, the trip solenoid 12 is fixed to the switch 3 so that the trip plunger 11 projects in the direction of arrow b. Further, a trip spring 13 is fixed to the switch 3 and has a biasing force in the direction c for moving the operation link in the direction of the arrow c. Furthermore, three high-pressure outlet cables 14 are connected to the bushing 1.
5 through the wall of the switch 3, and the movable contact
6a, 6b, and 6c, and are connected to power supply side fixed contacts 16a, 16b, and 16c, which form opening/closing contacts, respectively. In addition, each bushing 15 includes a current transformer (CT) 16d,
16e and 16f are provided, and a fixed contact on the power supply side is also provided.
Load side fixed contact 17a, corresponding to 16a, 16b, 16c.
17b, 17c are provided, and are connected to terminals 18a, 18b, 18c (each phase is insulated with insulating oil of the transformer) protruding for connection to the primary side of the transformer 2. On the other hand, a pressure relief valve 19 is provided at the top of the switch 3, and an operation handle 21 having a handle shaft 20 is provided at the side thereof. The handle shaft 20 is connected to the interlocking shaft 4 via a gear mechanism (not shown), and by rotating the operating handle 21, the movable contacts 6a, 6b,
6c is moved in both directions of engagement and release. The inside of the switch 3 is filled with an insulating gas (for example, sulfur hexafluoride gas (SF ₆ ), etc.) to improve insulation performance. The step-down voltage is outputted from the transformer 2 via a low voltage bushing 22 to a low voltage cable 23 in the direction of each load. Low voltage cable 2
3 is connected to the main body of the transformer 2 by a fixing member 24, and the transformer 2 has a built-in lightning arrester 25 (for example, zinc oxide (ZnO), etc.) as a countermeasure against abnormal voltage caused by lightning surges, etc. to protect transformer 2. The switch 3 is connected to the upper part 26 of the transformer 2 with a bolt 27 or the like.

In the above configuration, the operation is explained as follows.
A current transformer that responds when an overcurrent flows to the high voltage outlet 14
The outputs of 16d, 16e, and 16f also increase accordingly, and the trip solenoid 12 is actuated based on the increased output. As a result, the trip plunger 11 protrudes in the direction b. Initially, the trip mechanism, which was in the state shown in FIG. The operating link 7, which has been fixed, is moved in the direction of the arrow c, and along with this movement, the interlocking shaft 4 to which the operating link 7 is fixed is moved in the direction of the arrow d. As a result, as shown in FIG. 2B, the movable contacts 6a, 6b, 6c rotate, respectively, and disconnect the power supply side fixed terminals 16a, 16b, 16c from the load side fixed terminals 17a, 17b, 17c. Therefore, the current of each phase is cut off all at once. On the other hand, in order to return to the original closed state, the interlocking shaft 4 may be manually rotated using the operation handle 21 to bring the trip mechanism into the state shown in FIG. 2A. In this embodiment, the movable contacts 6a, 6b, and 6c in the switch 3 move horizontally in circles, so the vertical space can be kept to a minimum, and the gasification makes it more compact. It can be done. Therefore, as shown in FIG.
The switch 3 can be placed using 1a.

[Effect of idea]

As explained above, according to the transformer built-in switch of the present invention, overcurrent is detected in each phase and all three phases are released at once, thereby ensuring that open phase movement caused by fuse blowout is prevented. In addition, a movable contact that rotates in a horizontal plane is inserted into the gap between the fixed contacts on the power supply side and the load side, which are provided on the bushings that extend in the horizontal and vertical directions, so that the three phases can be released at once. It is possible to reduce the size and simplify the shape while reliably realizing the above.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the structure of the transformer built-in switch according to the present invention, and Fig. 2 A and B are the structure of the transformer built-in switch according to the present invention.
Explanatory diagram showing the opening/closing operation of the switch of the embodiment, Explanation of symbols, 1...Transformer built-in switch, 2
... Transformer, 3 ... Switch, 4 ... Interlocking shaft, 5a, 5b ... Rotary insulator, 6a, 6b, 6c ... Movable contact, 7 ... Operation link, 8, 9 ... Opening latch, 10 ... Latch fixing part, 11 ... Trip plunger, 12 ... Trip solenoid,
13... Trip spring, 16a, 16b, 16c...
...Power supply side fixed contact, 16d, 16e, 16f...Current transformer,
17a, 17b, 17c...Load side fixed contact, 18a, 18b,
18c...terminal, 21...operation handle.

Claims (1)

[Claims for Utility Model Registration] In a switch that is located on the top of a transformer, is integrated with the transformer, and is connected to the primary winding of the transformer, the switch horizontally penetrates the side wall and is spaced at equal intervals. A fixed contact on the power side of each phase provided at the tip of the bushing of each phase located with load-side fixed contacts of each phase connected to the primary winding, and tips of insulators of each phase fixed at equal angles to a rotating interlocking shaft provided perpendicular to the center. A movable contact for each phase that is provided and enters the gap by rotation to close the fixed contacts on the power supply side and load side of each phase, and overcurrent detection for each phase provided in the bushing of each phase. means, and when the overcurrent detection means for each phase detects that an overcurrent has flowed in at least one phase, the interlocking shaft is rotated to simultaneously rotate the movable contacts of the respective phases, thereby detecting the overcurrent of each phase. A transformer built-in switch characterized by being equipped with a drive means for releasing the closing of fixed contacts on the power supply side and the load side.