KR102236962B1 - All-In-One Hybrid Transformer to be Installed at Construction Site - Google Patents

Abstract

According to the present invention, a transformer, which is an integrated hybrid transformer for installation on a construction site capable of performing transformation by using three primary coils and three secondary coils sharing cores with the three primary coils respectively, includes: first, second and third high-voltage bushing terminals receiving a three-phase high voltage of 22900V and 60Hz; fourth, fifth and sixth high-voltage bushing terminals outputting a three-phase high voltage of 3300 or 6600V and 60Hz; three low-voltage bushing terminals for supplying three-phase power to electric equipment for 380V 60Hz; and a neutral line bushing terminal. Each of the three primary coils has one end connected in common and has the other end individually connected with the first, second and third high-voltage bushing terminals. Each of the three secondary coils has one end connected in common with the neutral line bushing terminal and has the other end individually connected with the three low-voltage bushing terminals. The fourth, fifth and sixth high-voltage bushing terminals outputting a three-phase high voltage of 3300 or 6600V and 60Hz are individually connected to a middle spot of the primary coils.

Description

All-In-One Hybrid Transformer to be Installed at Construction Site}

The present invention relates to a transformer that converts the high voltage of the supplied commercial AC power to a lower low voltage, and specifically relates to a transformer capable of outputting a plurality of voltages, and further, at a frequency different from the frequency of the supplied commercial AC power. It relates to a transformer that can be installed and operated at a construction site using the designed electric equipment.

In construction sites such as tunnel construction sites, the use of construction electric equipment is increasing. Since construction electric equipment usually uses low voltage such as 380V or 220V, construction sites such as 380V or 220V from high pressure such as 22900V supplied by KEPCO A transformer that converts to low voltage is usually installed and operated near the entrance of the tunnel.

However, if the length of the tunnel to be built is long enough to reach several kilometers, it is also necessary to use 380V or 220V electric equipment at a location greater than a certain distance from the tunnel entrance (about 600m or more deep in the tunnel from the tunnel entrance). do. In this situation, transmission at a low voltage of 380V or 220V from the tunnel entrance is difficult to use because the voltage loss is too large. In this case, it is converted to an intermediate voltage such as 6600V and transmitted to the inside of the tunnel for a certain distance. At the branch, a low voltage transformer that converts 6600V voltage to low voltage is installed and operated.

Therefore, when the length of the tunnel is long, it is necessary to install and operate two types of transformers at the entrance of the tunnel. A transformer that converts 22900V directly to low voltage for electric equipment to be used within a short distance from the tunnel entrance, and a tunnel. All of the transformers that convert from 22900V to 6600V are needed to transmit deeper power.

Meanwhile, in North and Central American countries including Korea, power supply systems supply AC with a frequency of 60 Hz, while power supply systems in Europe, China and some Southeast Asia supply AC with a frequency of 50 Hz.

Accordingly, construction power equipment supplied to Europe, China and some Southeast Asia is designed and manufactured assuming a 50Hz power supply. We hope that 50Hz construction equipment will be introduced and used or used in countries that adopt 60Hz like Korea.

However, most of the users do not know or overlook the problem due to the frequency mismatch, and even though the design frequency does not match, they use the electric power equipment for construction in the same way as in the situation where the frequency matches.

Although the problems and problems of the prior art have been described above, recognition of these problems and problems is not obvious to those of ordinary skill in the art.

It is an object of the present invention to provide an integrated hybrid transformer for installation on a construction site that can solve the problem of having to have a transformer for converting power to be supplied to a low-voltage electric equipment and a transformer for power transmission in duplicate.

In addition, another object of the present invention is to provide an integrated hybrid transformer for installation on a construction site that can be used together with a 50Hz electric equipment and a 60Hz electric equipment and operated more efficiently under a 60Hz power supply system.

In addition, another object of the present invention is to reduce the installation cost and iron loss of the transformer by reducing the 2 transformers to 1 unit or even the 3 transformers to 1 unit, and to reduce the power loss by increasing the effect and efficiency of reducing incidental costs. It is to provide an integrated hybrid transformer for installation on construction sites that has the effect of significantly lowering and reducing power bills.

A transformer according to an aspect of the present invention is an integrated hybrid transformer for installation on a construction site that transforms using three primary coils and three secondary coils that share the three primary coils and the core, respectively, and is 22900V and 60Hz. The first, second, and third high-voltage bushing terminals that receive the high-voltage input of the three phases, the fourth, fifth, and sixth high-voltage bushing terminals that output the high-voltage of the three phases of 3300V or 6600V and 60Hz, and the electric equipment for 380V 60Hz provide three-phase power. It has three low-voltage bushing terminals for supply and a neutral wire bushing terminal, and each of the three primary coils has one end connected in common and the other end connected to the first, second, and third high-voltage bushing terminals, respectively, and the Each of the three secondary coils has one end connected in common to the neutral wire bushing terminal and the other end connected to the three low-voltage bushing terminals, respectively, and the fourth and fifth outputs of the three-phase high voltage of 3300V or 6600V and 60Hz as described above. And 6, the high-voltage bushing terminal is characterized in that each is connected to the intermediate point of the primary coil.

A transformer according to an aspect of the present invention is an integrated hybrid transformer for installation on a construction site that transforms using three primary coils and three secondary coils that share the three primary coils and the core, respectively, and is 22900V and 60Hz. Three-phase power is supplied with the 1st, 2nd, 3rd high voltage bushing terminals that receive the high voltage of the three phases, the 4th, 5th, and 6th high voltage bushing terminals that output the high voltage of the three phases of 3300V or 6600V and 60Hz, and the electric equipment for 380V 50Hz. It has 1st, 2nd, 3rd low voltage bushing terminals for supply, 4th, 5th, 6th low voltage bushing terminals for supplying 3-phase power with electric equipment for 380V 60Hz, and neutral bushing terminals. Each of the coils has one end connected in common and the other end connected to the first, second, and third high voltage bushing terminals, respectively, and the 4th, 5th, and 6th high voltage bushing terminals that output the three-phase high voltage of 3300V or 6600V and 60Hz as described above. Is connected to the middle point of the primary coil, and each of the three secondary coils has one end connected in common to the neutral wire bushing terminal and the other end connected to the first, second, and third low voltage bushing terminals, respectively, The fourth, fifth, and sixth low-voltage bushing terminals are characterized in that they are respectively connected to an intermediate point of the secondary coil.

In the integrated hybrid transformer for installation on the construction site, the turns ratio between the number of turns from one end to the middle point and the number of turns from one end to the other end in each of the primary coils may be selected to be 6.94 times or 3.47 times. .

The integrated hybrid transformer for installation at the construction site may be for installation at the entrance of the tunnel construction site.

In the integrated hybrid transformer for installation on the construction site, the primary coil, the secondary coil and the core are accommodated, and an enclosure (55) providing a space to fill the transformer oil and covering the upper surface of the enclosure (55) A top cover 54 is provided, wherein the first, second, and third high-pressure bushing terminals, the first, second, and third low-pressure bushing terminals, and the fourth, fifth, and sixth low-pressure bushing terminals, and the neutral wire bushing terminal are provided on the top surface. It is installed on the cover 54, and the fourth, fifth, and sixth high pressure bushing terminals are installed on the enclosure 55 and may protrude to the side.

In the integrated hybrid transformer for installation on the construction site, a high-voltage bushing terminal cover 56 that is detachably coupled to the enclosure 55 and covers the fourth, fifth, and sixth high-voltage bushing terminals. It may further include.

In the integrated hybrid transformer for installation on the construction site, the number of windings from one end to the other end of the secondary coil is 380V so that a torque of 90% to 120% is output compared to when the 380V 50Hz electric equipment is used in a 50Hz 380V power source. Compared to the transformer for a 60Hz electric motor, it can be increased to 1.0392 times to 1.2 times the number of windings.

In the integrated hybrid transformer for installation on the construction site as described above, a turn ratio between the number of turns from the one end to the middle point and the number of turns from the one end to the other end in each of the secondary coils may be selected to be 1.1569 times.

The integrated hybrid transformer for construction site installation according to the present invention has the advantage of not having to have dual transformers for converting power to be supplied to low-voltage electric equipment and a transformer for power transmission, and 50Hz electric equipment and 60Hz under a 60Hz power supply system. There is an advantage of not having to have a double transformer even at a construction site where electric equipment can be operated together.

In addition, the integrated hybrid transformer for installation on a construction site according to the present invention has the advantage of being able to significantly reduce the construction cost and installation and relocation costs of the transformer and the accompanying power reception equipment at the construction site using 50Hz electric equipment.

In addition, the integrated hybrid transformer for installation on a construction site according to the present invention can reduce the spare capacity that must be secured for the same level of contrast at a construction site where 50 Hz electric equipment is used together, and power loss due to iron loss of the transformer itself is reduced. It is drastically reduced and has the advantage of saving electricity bills.

In addition, the integrated hybrid transformer for construction site installation according to the present invention includes all three transformers: a transformer for outputting an intermediate voltage of 3300V or 6600V, a transformer for driving 380V 50Hz electric equipment, and a transformer for driving 380V 60Hz electric equipment. Since it can be implemented as a single transformer, compared to the case of operating three transformers, the convenience of installation, removal and relocation, simplification of auxiliary devices, increase in operating efficiency, and reduction in power bills are further doubled.

In addition, the integrated hybrid transformer for installation on a construction site according to the present invention reduces installation costs and transformer iron loss by reducing two transformers to one unit, or even three transformers to one unit, thereby reducing incidental cost and efficiency. By increasing it, there is an effect of significantly lowering power loss and reducing power bills.

1 is a view showing the appearance of an integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention.
2 is a view showing the internal configuration of an integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention.
3 is a diagram showing a circuit configuration of an integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention.
4 is a view showing a state in which a high-voltage bushing terminal cover is coupled in an integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention.

With reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar names and reference numerals are used for similar parts throughout the specification.

1 is a view showing the appearance of an integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention, Figure 2 is a view showing the internal configuration of the integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention 3 is a diagram showing a circuit configuration of an integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention, and FIG. 4 is a high-voltage bushing terminal cover in the integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention. It is a diagram showing a combined state.

The integrated hybrid transformer for installation at a construction site according to an embodiment of the present invention is to be installed at the same place as the entrance of a tunnel construction site, and both the transformation to the intermediate voltage to be transmitted and the low voltage to drive the electric equipment are all in the same transformer. It is a transformer that can perform and can simultaneously cope with the same electric equipment with electric equipment with different designed frequencies. Specifically, it is a situation in which both 50Hz electric equipment and 60Hz electric equipment are driven by receiving commercial AC power of 60Hz. It relates to a transformer to respond to.

The integrated hybrid transformer for installation on a construction site according to an embodiment of the present invention includes a primary coil (31,32,33), a secondary coil (41,42,43), and the 1st, 2nd, 3rd high voltage bushing terminals (11,12). ,13) (The bushing terminal is also simply referred to as'bushing'), the 4th, 5th, 6th high voltage bushing terminals (14,15,16), the 1st, 2nd, 3rd low voltage bushing terminals (21, 22, 23), 4, 5, 6 low pressure bushing terminal (24, 25, 26), radiator (51), core (52), high or low pressure lead (53), top cover (54), enclosure (55) and high voltage bushing terminal cover (56) and the like.

The primary coil, secondary coil, lead and core are hermetically protected by the enclosure 55 and the top cover 54, and provide a space to fill the transformer oil therein. The radiator 51 has microcavities communicating with the space composed of the enclosure 55 and the top cover 54, and a large surface area surrounding the microcavities, and heat generated from coils and cores through transformer oil is externally Helps to release into.

The transformer of one embodiment receives three-phase AC high voltage at 60 Hz and outputs three primary coils 31, 32, 33 and three secondary coils 41 for outputting a three-phase AC low voltage at 60 Hz, like a conventional transformer. ,42,43), each of the three primary coils (31,32,33) has one end connected in common and the other end is supplied with high-voltage, for example, 22,900V AC power, and mutually It is connected to Y (Y) and may be switched by further providing a tap changer for fine adjustment in some cases. In addition, each of the three primary coils (31, 32, 33) is connected to the 4th, 5th, 6th high voltage bushing terminals (14, 15, 16) at an intermediate point between its one end and the other end, respectively, and 3300V or It outputs an intermediate voltage of 6600V (preferably an intermediate voltage of 6600V).

The three secondary coils 41, 42, 43 share these three primary coils and the core 52, respectively. That is, a part of the core 52 is located inside concentric with the primary coil 31 and the secondary coil 41, and another part of the core 52 is the primary coil 32 and the secondary coil 42 It is located on the inner side of the and concentric, and another part of the core 52 is configured in a manner that is located inside the primary coil 33 and the secondary coil 43 and concentrically.

The top cover 54 includes 1st, 2nd, 3rd high pressure bushing terminals (11,12,13), 1st, 2, 3, 4, 5, 6 low pressure bushing terminals (21, 22, 23, 24, 25, 26). ) And a neutral wire bushing terminal 20 are formed.

On one side of the enclosure 55, the 4th, 5th, 6th high voltage bushing terminals 14, 15, 16 are installed and protrude to the side, and the 1st, 2nd, 3rd high voltage bushing terminals 11, 12, 13 and The 4th, 5th, and 6th high voltage bushing terminals 14, 15, 16 are installed on different surfaces (top and side) of the transformer, respectively, and their longitudinal directions are extended at an angle of 90 degrees to each other, resulting in a problem of insufficient installation space. And prevent possible electrical shorts with each other.

In addition, by providing a high-pressure bushing terminal cover 56 that is detachably coupled to the enclosure 55 using bolts (B) and nuts (N) for the 4th, 5th, and 6th high-voltage bushing terminals (see Fig. 4). ), If transmission of medium voltage (6600V or 3300V) is not necessary depending on the situation of the construction site, safety measures can be reinforced by covering the 4th, 5th, 6th high voltage bushing terminals. In addition, it is possible to prevent damage to the 4th, 5th, and 6th high voltage bushing terminals in the process of moving and installing the transformer.

Each of the three Y-connected primary coils has one end connected in common, but one end connected in common is electrically open, and the other end is connected to the first, second, and third high voltage bushing terminals 11, 12, 13, respectively. The 1st, 2nd, 3rd high voltage bushing terminals (11,12,13) receive 22,900V of commercial power and the other ends of the primary coils (31,32,33) Y-connected to each other through each lead (not shown). Each is connected by.

The 4th, 5th, 6th high voltage bushing terminals 14, 15, 16 are for outputting intermediate voltages to be transmitted, and are bushing terminals for outputting a three-phase high voltage of 3300V or 6600V and 60Hz. The 4th, 5th, 6th high voltage bushing terminals 14, 15, 16, which output a three-phase high voltage of 3300V or 6600V and 60Hz, are respectively connected to the midpoint of the primary coil through corresponding leads.

In each of the primary coils, the turns ratio between the number of turns from one end to the middle point and the number of turns from one end to the other end is selected to be 6.94 times or 3.47 times.

The 1st, 2nd, 3rd, 4th, 5th, 6th low voltage bushing terminals (21, 22, 23, 24, 25, 26) and neutral bushing terminals (20) are terminals for supplying 3-phase power to electric equipment. The equipment may specifically be a power equipment for 380V 50Hz and a power equipment for 380V 60Hz. 1st, 2nd and 3rd low voltage bushing terminals for supplying 3-phase power with 380V 50Hz electric equipment, 4th, 5th, 6th low-voltage bushing terminals for supplying 3-phase power with 380V 60Hz electric equipment, and neutral wire bushings Equipped with a terminal.

The three secondary coils (41, 42, 44) are Y-connected to each other, and each of the three secondary coils (41, 42, 44) is connected in common to the neutral wire bushing terminal (20) via one end of the lead. And the other end is connected to the first, second, and third low-voltage bushing terminals 21, 22, and 23, respectively, through a lead.

In addition, the fourth, fifth, and sixth low-voltage bushing terminals 24, 25, 26 are connected to the intermediate points of the above-described one end and the other end of the secondary coil through corresponding leads, respectively.

According to an embodiment of the present invention, an integrated hybrid transformer is configured to implement a transformer function for converting power to be supplied to a low-voltage electric equipment and a transformer function for power transmission in the same transformer. The integrated hybrid transformer according to an embodiment of the present invention can simultaneously use an intermediate voltage (3300V or 6600V) output and a low voltage output.

On the other hand, in the 60Hz power supply system, in order to use both 50Hz power equipment and 60Hz power equipment (simultaneously), it is characterized by adopting a transformer with a modified secondary coil and an added bushing terminal, which is an electric equipment for 380V 50Hz. The total number of windings of the three secondary coils (41, 42, 44) is selected so that the torque becomes similar or within a certain range compared to when used in 50Hz 380V power supply. It has additional bushing terminals 24, 25, 26 connected to the midpoint.

Since the transformer is supplied with 60Hz power, it supplies low-voltage power of 60Hz to the low-voltage bushing terminal, but the bushing terminals (21, 22, 23) for effectively driving 50Hz electric equipment and the bushing terminal for effectively driving 60Hz electric equipment (24, 25, 26) are all provided at once, and in particular, the secondary coils 41, 42, and 43 are shared by both.

According to an embodiment of the present invention, in order to use both (simultaneously) 50Hz power equipment and 60Hz power equipment in a 60Hz power supply system, a transformer with a secondary coil modified and a bushing terminal is used. However, the total number of windings of the three secondary coils (41, 42, 44) is selected so that the torque becomes similar or within a certain range compared to when the electric equipment for 380V 50Hz is used in the 50Hz 380V power supply. Additional bushing terminals (24, 25, 26) connected to the middle point of the secondary coil are provided for the equipment.

The number of turns from one end to the middle point is selected so that 380V is output to the 4th, 5th and 6th low-voltage bushing terminals, and 90% to 120% of torque is output compared to when the 380V 50Hz electric equipment is used in 50Hz 380V power supply. The number of turns from one end to the other end of the secondary coil is increased to 1.0392 to 1.2 times the number of turns compared to a transformer for a 380V 60Hz motor. For example, it may be preferred to increase the number of turns by 1.1569 times. Accordingly, the above-described intermediate point may be selected so that the number of turns from one end to the middle point and the number of turns from one end to the other in each of the secondary coils is 1.0392 times to 1.2 times the number of turns, and is preferred. It can also be chosen to be 1.1569 times.

In the construction site of a long tunnel, both a transformer that converts 22900V directly to low voltage for electric equipment to be used within a short distance, and a transformer that converts 22900V to 3300V or 6600V for transmission to a long distance such as deep in the tunnel. It was necessary, but in the integrated hybrid transformer according to an embodiment of the present invention, it is necessary to install only a single transformer by providing an additional high-voltage bushing terminal connected to the midpoint of the primary coil and pulling out the intermediate voltage of 3300V or 6600V together. There is an advantage.

In addition, by having a structure in which the intermediate voltage of 3300V or 6600V is extracted from the middle point of the primary coil, the voltage fluctuation rate is small because the copper loss is reduced and the transformation efficiency is good and the impedance is small.

On the other hand, if there is a 380V 50Hz power equipment, the 380V 60Hz power equipment transformer cannot properly drive the 380V 50Hz equipment.Therefore, in addition to the 380V 60Hz power equipment low voltage transformer, a 380V 50Hz low voltage transformer for power equipment must be additionally configured. did. That is, two transformers and accompanying ASS, lightning arrester, MOF, and circuit breaker must be provided respectively, and thus two banks of power receiving facilities must be provided and constructed. In order to use up to 50Hz electric equipment, there is a problem that it takes nearly twice as much power reception equipment including a transformer. In addition, there is a double hassle in that such a power receiving facility must be installed and removed at the beginning and end of construction and transferred to the next site.

On the other hand, when the integrated hybrid transformer for installation on the construction site according to an embodiment of the present invention is employed, the transformer and the accompanying ASS, arrester, MOF, and circuit breaker need only be constructed with only 1 bank, so the required equipment is greatly reduced and installation, There is an advantage that works such as demolition and relocation can be drastically reduced.

Furthermore, if the capacity required by the entire electric powertrain that can be driven at the construction site is, for example, a 1000KVA transformer, including the margin, if a transformer for driving 380V 50Hz power equipment is separately configured, it is a product for power equipment for 60Hz. 1 A method of dividing the required capacity by 1/2 as it is, as if preparing the second transformer for 50Hz power equipment at 500KVA, or by dividing the required capacity by 1/2, or by dividing a ratio by dividing it by 1/3 and 2/3. You can't do it with your back. Due to uncertainty, the sum of the margins when dividing into the 1st and 2nd transformers should be increased more than with 1 transformer. Compared to the additional configuration of a transformer for driving 380V 50Hz electric equipment due to uncertainty, etc., the use of the integrated hybrid transformer of the present invention has the advantage of having the same level of margin even with a smaller capacity.

And, when the transformer transfers power from the primary side to the secondary side, a transformer loss, which is a self-loss of power generated inside the transformer, occurs. The transformer loss includes no-load loss and load loss. There are, and in particular, iron loss, which is a no-load loss, is a problem. Compared to constructing two transformers for driving 380V 50Hz electric equipment, constructing one transformer using the integrated hybrid transformer of the present invention increases the efficiency of use of the transformer capacity, so power loss due to iron loss of the transformer itself is greatly reduced. There is an advantage. Briefly, for example, when two transformers were built, there was a power loss of about 20 kW per unit time, but in the case of using the transformer of an embodiment as a single transformer, it was reduced to about 16 kW, saving about 4 kW of power, and thus the number of months There is an effect of saving a million won of electricity bills.

Further, according to an embodiment of the present invention, all of the three transformers of a transformer for outputting an intermediate voltage of 3300V or 6600V, a transformer for driving 380V 50Hz power equipment, and a transformer for driving 380V 60Hz power equipment are single Since it can be implemented as a transformer, compared to the case of operating three transformers, the convenience of installation, removal and relocation, simplification of auxiliary devices, increase in operating efficiency, and reduction in power bills are further doubled.

11, 12, 13, 14, 15, 16: high pressure bushing terminal
21, 22, 23, 24, 25, 26: Low pressure bushing terminal
31, 32, 33: primary coil 41, 42, 43: secondary coil
51: radiator 52: core
53: lead 54: top cover
55: enclosure 56: high pressure bushing terminal cover

Claims (8)

In the integrated hybrid transformer for installation on a construction site that transforms using three primary coils and three secondary coils that share the three primary coils and the core, respectively,
With the 1st, 2nd and 3rd high voltage bushing terminals that receive the high voltage of 3 phases of 22900V and 60Hz, the 4th, 5th and 6th high voltage bushing terminals that output the high voltage of 3 phases of 3300V or 6600V and 60Hz, and the electric equipment for 380V 60Hz. It has 3 low-voltage bushing terminals for supplying 3-phase power, and neutral bushing terminals.
Each of the three primary coils has one end connected in common and the other end connected to the first, second, and third high voltage bushing terminals, respectively,
Each of the three secondary coils has one end connected in common to the neutral wire bushing terminal and the other end connected to the three low-voltage bushing terminals, respectively,
The 4th, 5th, and 6th high voltage bushing terminals that output the three-phase high voltage of 3300V or 6600V and 60Hz are respectively connected to the intermediate points of the primary coil,
In each of the primary coils, a turns ratio between the number of turns from one end to the middle point and the number of turns from one end to the other end is selected to be 6.94 times or 3.47 times,
All-in-one hybrid transformer for construction site installation. In the integrated hybrid transformer for installation on a construction site that transforms using three primary coils and three secondary coils that share the three primary coils and the core, respectively,
With the 1st, 2nd and 3rd high voltage bushing terminals that receive the high voltage of the 3 phases of 22900V and 60Hz, the 4th, 5, and 6th high voltage bushing terminals that output the high voltage of the 3 phases of 3300V or 6600V and 60Hz, and the electric equipment for 380V 50Hz. It is equipped with 1st, 2nd, 3rd low voltage bushing terminals for supplying 3-phase power, 4th, 5th, 6th low-voltage bushing terminals for supplying 3-phase power with electric equipment for 380V 60Hz, and neutral bushing terminals.
Each of the three primary coils has one end connected in common and the other end connected to the first, second, and third high voltage bushing terminals, respectively,
The 4th, 5th, and 6th high voltage bushing terminals that output the three-phase high voltage of 3300V or 6600V and 60Hz are connected to the intermediate points of the primary coil, respectively,
Each of the three secondary coils has one end connected in common to the neutral wire bushing terminal and the other end connected to the first, second, and third low-voltage bushing terminals, respectively,
The fourth, fifth, and sixth low-voltage bushing terminals are characterized in that they are respectively connected to an intermediate point of the secondary coil,
All-in-one hybrid transformer for construction site installation. The method according to claim 2,
In each of the primary coils, a turns ratio between the number of turns from one end to the middle point and the number of turns from one end to the other end is selected to be 6.94 times or 3.47 times,
All-in-one hybrid transformer for construction site installation. The method according to claim 1 or 2,
Characterized in that to be installed at the entrance of the tunnel construction site,
All-in-one hybrid transformer for construction site installation. The method according to claim 2,
The primary coil, the secondary coil, and the core are provided with an enclosure 55 providing a space to fill the transformer oil in a state in which the core is accommodated, and a top cover 54 covering an upper surface of the enclosure 55,
The first, second, and third high-pressure bushing terminals, the first, second, and third low-pressure bushing terminals, the fourth, fifth, and sixth low-pressure bushing terminals, and the neutral wire bushing terminal are installed on the top cover 54, and the The 4th, 5th, 6th high pressure bushing terminals are installed on the enclosure 55 and protrude to the side,
All-in-one hybrid transformer for construction site installation. The method of claim 5,
A high-pressure bushing terminal cover 56 that is detachably coupled to the enclosure 55 and covers the fourth, fifth, and sixth high-pressure bushing terminals; further comprising,
All-in-one hybrid transformer for construction site installation. The method according to claim 2,
The number of turns from one end to the other end of the secondary coil is 1.0392 times higher than that of a transformer for a 380V 60Hz motor so that the 380V 50Hz electric equipment outputs 90% to 120% of torque compared to when the 380V 50Hz power supply is used. An integrated hybrid transformer for installation on a construction site, characterized in that it increases to 1.2 times the number of windings. The method according to claim 2,
In each of the secondary coils, an integrated hybrid transformer for installation on a construction site, characterized in that the winding ratio between the number of turns from the one end to the intermediate point and the number of turns from the one end to the other end is 1.1569 times.

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