KR102199763B1 - Transformer To be Installed at Construction Site Coping with Electric Motion Equipment With Different Frequency - Google Patents

Abstract

The present invention relates to a transformer for construction site installation which can respond to electric facilities with different frequencies, wherein the transformer for construction site installation uses three primary coils and three secondary coils each sharing a core with the three primary coils to receive a high voltage of three phases of 60 Hz and output a low pressure of three phases of 60 Hz, and provides first, second, and third low-pressure bushing terminals for supplying three-phase power to electric facilities for 380V 50Hz, and fourth, fifth, and sixth low-voltage bushing terminals for supplying three-phase electric power to electric facilities for 380V 60Hz, and, medium wire low pressure bushing terminal, and each of the three secondary coils, one end is commonly connected to the neutral low-voltage bushing terminal and the other end is connected to the first, second, and third low-voltage bushing terminals, respectively, and the fourth, fifth, and sixth low-pressure bushing terminals are respectively connected to midpoints of the secondary coil.

Description

Transformer to be installed at construction site coping with electric motion equipment with different frequency

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

In countries in North America and Central America including Korea, power supply systems supply AC with a frequency of 60 Hz, but 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. Due to various reasons such as price advantage, distribution of used goods, and movement between countries at construction sites, this is often the case. We hope that 50Hz construction equipment will be introduced and used or used in countries that adopt 60Hz, such as Korea.

However, most of the users do not know or overlook the problem of frequency mismatch, and even though the frequency does not match, they are using the electric 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 a transformer that enables a 50Hz power supply system to be used more efficiently under a 60Hz power supply system.

In addition, another object of the present invention is to provide a transformer that can be operated more efficiently while using a 50Hz electric equipment and a 60Hz electric equipment together under a 60Hz power supply system.

The present invention is a transformer for installation on a construction site that can cope with electric equipment with different frequencies, and includes three primary coils, the three primary coils and the core in order to receive a high voltage of 60 Hz and output a low voltage of three phases of 60 Hz. In the construction site installation transformer that transforms using three secondary coils that share each of the first, second, and third low voltage bushing terminals for supplying three-phase power to 380V 50Hz electric equipment, and a neutral low voltage bushing terminal. And, each of the three secondary coils, one end is commonly connected to the neutral low-voltage bushing terminal, and the other end is connected to the first, second, and third low-voltage bushing terminals, respectively, and the 380V 50Hz electric equipment is 50Hz 380V It is characterized in that the number of windings from one end to the other end is increased to 1.0392 to 1.2 times compared to a transformer for a 380V 60Hz electric motor to output 90% to 120% of torque compared to when used in a power source. .

In addition, the present invention is a transformer for installation on a construction site that can cope with electric equipment with different frequencies, in order to receive a high voltage of three phases of 60 Hz and output a low voltage of three phases of 60 Hz, three primary coils, and the three primary coils. In a construction site installation transformer that transforms using three secondary coils that share a core and a core, the first, second, and third low-voltage bushing terminals for supplying three-phase power to electric equipment for 380V 50Hz, and for 380V 60Hz. It has 4th, 5th and 6th low voltage bushing terminals for supplying three-phase power to electric equipment, and a neutral low voltage bushing terminal, and each of the three secondary coils has one end commonly connected to the neutral low voltage bushing terminal. The other end is connected to the first, second, and third low-voltage bushing terminals, respectively, and the fourth, fifth, and sixth low-voltage bushing terminals are connected to an intermediate point of the secondary coil, respectively.

In the construction site installation transformer capable of responding to electric equipment having different frequencies, the intermediate point is between the number of windings from the one end to the intermediate point and the number of windings from the one end to the other end of each of the secondary coils. Can be chosen so that the turns ratio of is 1.1569 times.

In a construction site installation transformer capable of corresponding to electric equipment having different frequencies, the number of windings from the one end to the middle point is selected so that 380V is output to the 4th, 5th, 6th low voltage bushing terminals, and the number of windings from the one end to the middle point is selected. The number of windings from one end to the other end is increased to 1.0392 to 1.2 times compared to a transformer for a 380V 60Hz motor so as to output 90% to 120% of torque compared to when electric equipment is used in a 50Hz 380V power source. Can be.

The transformer for installation at a construction site according to the present invention has the advantage of being able to very efficiently operate 50Hz power equipment that can be used often at construction sites where electric equipment based on AC induction motors, such as tunnel construction sites, is frequently used. have.

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

In addition, the transformer for installation at 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 50Hz electric equipment is used together, and power loss due to iron loss of the transformer itself is greatly reduced. And there is an advantage in that the electricity bill is reduced.

1 is a view showing the appearance of a transformer for installation on a construction site according to a first embodiment of the present invention.
2 is a view showing the internal configuration of a transformer for installation on a construction site according to the first embodiment of the present invention.
3 is a diagram showing a circuit configuration of a transformer for installation on a construction site according to the first embodiment of the present invention.
4 is a view showing the appearance of a transformer for installation on a construction site according to a second embodiment of the present invention.
5 is a view showing the internal configuration of a transformer for installation on a construction site according to a second embodiment of the present invention.
6 is a diagram showing a circuit configuration of a transformer for installation on a construction site according to a second embodiment of the present invention.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may 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 exterior of a construction site installation transformer according to the first embodiment of the present invention, Figure 2 is a view showing the internal configuration of the construction site installation transformer according to the first embodiment of the present invention. 3 is a diagram showing the circuit configuration of a transformer for installation on a construction site according to the first embodiment of the present invention.

The transformer for installation on a construction site according to the first embodiment of the present invention is capable of coping with electric equipment having different frequencies, and is specifically intended to respond to a situation for driving a 50 Hz electric device by receiving commercial AC power of 60 Hz.

The transformer for installation on a construction site according to the first embodiment of the present invention includes the primary coil (31,32,33), the secondary coil (41,42,43), the first, second, and third high voltage bushing terminals (11,12, 13) and the 1st, 2nd, 3rd low pressure bushing terminals 21, 22, 23, radiator 51, core 52, high or low pressure lead 53, cover 54 and enclosure 55, etc. It consists of including.

The primary coil, the secondary coil and the core 52 are hermetically protected by the enclosure 55 and the cover 54, and provide a space to fill the transformer oil therein. The radiator 51 has microcavities communicating with the inner space composed of the enclosure 55 and the cover 54 and a large surface area surrounding the microcavities, and heat generated from coils and cores through transformer oil is transferred to the outside. Help to release

The transformer of the first embodiment receives three-phase AC high voltage at 60 Hz and outputs three primary coils 31, 32 and 33 and three secondary coils ( 41,42,43) are used to transform, and the three primary coils (31,32,33) are supplied with high voltage, for example, AC power of 22,900V, and are delta (∇) connected to each other. According to this, it may be switched by further providing a tap changer for fine adjustment. 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.

On the upper surface of the cover 54, 1st, 2nd and 3rd high-pressure bushing terminals (11,12,13), 1st, 2nd, and 3rd low-pressure bushing terminals (21,22,23) and low-voltage bushing terminals (20) are formed. However, the bushing terminal is also commonly referred to as'bushing'.

The first, second, and third high voltage bushing terminals 11,12,13 receive, for example, 22,900V of commercial power, and the primary coils 31,32,33 connected to each other delta through each lead (not shown). It is connected to the bonding point of ).

The 1st, 2nd and 3rd low-voltage bushing terminals (21, 22, 23) and the neutral low-voltage bushing terminal (20) are terminals for supplying three-phase power to electric equipment, and the electric equipment may specifically be electric equipment for 380V 50Hz. have. The three secondary coils (41, 42, 44) are Y-connected to each other, and each of the three secondary coils (41, 42, 44) is common to the neutral low-voltage bushing terminal (20) through one end of the lead. It is connected and the other end is connected to the first, second, and third low-voltage bushing terminals 21, 22, and 23, respectively, through a lead.

Since the transformer is supplied with 60Hz power, the 1st, 2nd, and 3rd low-voltage bushing terminals 21, 22, and 23 naturally supply 60Hz low-voltage power, but in order to effectively drive 50Hz electric equipment, according to the first embodiment of the present invention. The resulting transformer is deformed.

According to the first embodiment of the present invention, a transformer with a secondary coil is used in order to use a 50Hz electric equipment in a 60Hz power supply system, when the electric equipment for 380V 50Hz is used in a 50Hz 380V power supply. Compared with, the number of turns of the three secondary coils 41, 42, 44 is selected so that the torque becomes similar or within a certain range.

According to the torque characteristics of an induction motor, the torque is inversely proportional to the frequency of the power supply and is proportional to the square of the voltage. Since the frequency of the supply power has been increased from 50Hz to 60Hz, the frequency increases by 1.2 times, the voltage increases by 1.0954 times for the same torque, and the number of windings of the secondary coil of the transformer increases by 1.0954 times. As a 380V 50Hz electric equipment, the secondary coil of the transformer is 1.0392 times higher than that of a normal 380V 60Hz electric equipment transformer in order to achieve a similar torque, for example, 90% to 120% torque compared to the torque at the 380V 50Hz power supply. It should be increased to 1.2 times the number of turns. It is preferred that the number of turns is increased to 1.1569 times in consideration of the commonly used voltage.

FIG. 4 is a view showing the appearance of a transformer for installation on a construction site according to a second embodiment of the present invention, and FIG. 5 is a view showing an internal configuration of a transformer for installation on a construction site according to a second embodiment of the present invention. 6 is a diagram showing the circuit configuration of a transformer for installation on a construction site according to a second embodiment of the present invention.

Compared to the construction site installation transformer according to the first embodiment of the present invention, the same reference numerals may be used for components having the same or similar functions.

The transformer for installation on the construction site according to the second embodiment of the present invention is capable of simultaneously responding to electric equipment with different designed frequencies and the same electric equipment.Specifically, the electric equipment for 50Hz and electric equipment of 60Hz by receiving commercial AC power of 60Hz It is to respond to the situation that drives all of them.

The transformer for installation on a construction site according to the second embodiment of the present invention includes a primary coil (31, 32, 33), a secondary coil (41, 42, 43), the first, second, and third high voltage bushing terminals (11, 12, 13), 1st, 2nd, 3rd low pressure bushing terminals (21, 22, 23), 4th, 5, 6 low pressure bushing terminals (24, 25, 26), radiator 51, core 52, high or low pressure It is configured to include a lid 53, a cover 54, an enclosure 55, and the like.

The primary coil, the secondary coil and the core 52 are hermetically protected by the enclosure 55 and the 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 cover 54 and a large surface area surrounding the microcavities, and dissipates heat generated from coils and cores to the outside through transformer oil. Help to do.

The transformer of the second embodiment receives three-phase AC high voltage at 60 Hz and outputs three primary coils 31, 32, 33 and three secondary coils ( 41,42,43) are used to transform, and the three primary coils (31,32,33) are supplied with high voltage, for example, AC power of 22,900V, and are delta (∇) connected to each other. According to this, it may be switched by further providing a tap changer for fine adjustment. 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.

On the upper surface of the cover 54, the 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 low-voltage bushing terminal 20 are formed.

The first, second, and third high voltage bushing terminals 11,12,13 receive, for example, 22,900V of commercial power, and the primary coils 31,32,33 connected to each other delta through each lead (not shown). It is connected to the bonding point of ).

The 1st, 2nd, 3rd, 4th, 5th, 6th low voltage bushing terminals (21, 22, 23, 24, 25, 26) and neutral low voltage bushing terminals (20) are terminals for supplying 3-phase power to electric equipment. The electric equipment may specifically be electric equipment for 380V 50Hz and electric 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 Equipped with a bushing 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 common to the neutral low-voltage bushing terminal (20) through one end of the lead. It is connected 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, respectively, through corresponding leads.

Since the transformer is supplied with 60Hz power, it supplies low-voltage power of 60Hz to the low-voltage bushing terminal, but the bushing terminal (21, 22, 23) for effectively driving 50Hz electric equipment and the bushing terminal (for effectively driving 60Hz electric equipment) Although all of the 24, 25, and 26 are provided at once, the secondary coils 41, 42, and 43 have one characteristic in that they share.

According to a second 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 windings 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 to output 90% to 120% of torque compared to when the electric equipment for 380V 50Hz 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. It may also be preferred to increase the number of turns to 1.1569 times. Accordingly, the above-described intermediate point may be selected such 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 selected to be 1.1569 times.

The transformer according to the present invention has the advantage of being able to very efficiently use 50Hz power equipment, which can often be used, in a construction site where electric equipment based on an AC induction motor is frequently used, such as a tunnel construction site.

On the other hand, when using the transformer for installation on the construction site according to the first embodiment to drive the 380V 50Hz electric equipment, a conventional transformer should also be provided for the electric equipment for 380V 60Hz. That is, since two transformers and accompanying ASS, lightning arrester, MOF, and circuit breaker must be provided, respectively, two banks of power receiving facilities must be provided. 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 the construction and transferred to the next site.

On the other hand, if the transformer for installation on the construction site according to the second embodiment is employed, the transformer and accompanying ASS, arrester, MOF, and circuit breaker need only be built with only one bank, so the required equipment is greatly reduced and installation, demolition and relocation, etc. There is an advantage that the work of the work can be greatly reduced.

Furthermore, if the capacity required by the entire transmission device that can be driven at the construction site is, for example, a 1000KVA transformer, including the margin, if the transformer for installation at the construction site according to the first embodiment is adopted, the electric equipment for 60Hz is used. As if the first transformer for 50Hz is 500KVA and the second transformer for 50Hz is prepared as 500KVA, the required capacity is divided by 1/2 as it is, or by setting the ratio by dividing it by 1/3 and 2/3. You can't do it in the way you do. 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 construction site installation transformer according to the first embodiment due to uncertainty, etc., the transformer according to the second embodiment has an 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 is, in particular, a no-load loss, which is a problem. Compared to building two transformers using the transformer of the first embodiment, building one transformer using the transformer of the second embodiment increases the efficiency of use of the capacity of the transformer, so power loss due to core 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 the second embodiment as a single transformer, it was reduced to about 16 kW and power was saved by about 4 kW. There is an effect of saving millions of won in electricity bills.

11, 12, 13: 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: cover

Claims (4)

A transformer for installation at a construction site that transforms using three primary coils and three secondary coils that share the three primary coils and the core to output the low voltage of the three phases at 60 Hz by receiving the high voltage of the three phases at 60 Hz. In,
It is equipped with 1st, 2nd, 3rd low-voltage bushing terminals for supplying 3-phase power with electric equipment for 380V 50Hz, and low-voltage bushing terminals for neutral wires.
Each of the three secondary coils has one end connected in common to the neutral low-voltage bushing terminal and the other end connected to the first, second, and third low-voltage bushing terminals, respectively,
The number of turns from one end to the other end is 1.0392 to 1.2 times higher than that of a transformer for a 380V 60Hz motor so that the 380V 50Hz electric equipment outputs a torque of 90% to 120% compared to when the 380V 50Hz power supply is used. A transformer for installation on a construction site capable of responding to electric equipment with different frequencies, characterized in that the number of windings is increased. A transformer for installation at a construction site that transforms using three primary coils and three secondary coils that share the three primary coils and the core to output the low voltage of the three phases at 60 Hz by receiving the high voltage of the three phases at 60 Hz. In,
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 Equipped with a bushing terminal,
Each of the three secondary coils has one end connected in common to the neutral low-voltage 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 respectively connected to an intermediate point of the secondary coil. A transformer for installation on a construction site capable of responding to electric equipment having different frequencies. The method according to claim 2,
The middle point is,
A construction site capable of responding to electric equipment with different frequencies, 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 of each of the secondary coils is selected to be 1.1569 times Installation transformer. The method according to claim 2,
The number of turns from the one end to the middle point is selected so that 380V is output to the 4th, 5th, 6th low voltage bushing terminals,
The number of turns from one end to the other end is 1.0392 to 1.2 times higher than that of a transformer for a 380V 60Hz motor so that the 380V 50Hz electric equipment outputs a torque of 90% to 120% compared to when the 380V 50Hz power supply is used. A transformer for installation on a construction site capable of responding to electric equipment with different frequencies, characterized in that the number of windings is increased.

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