JP2004259945A - Transformer, and receiving and transforming facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent increase of cost and installation area of a secondary side unit and a casing storing the secondary side unit with an increase of capacity of a transformer. <P>SOLUTION: In a receiving and transforming facility, a primary side winding wire 13 and a tertiary side winding wire 14 in the transformer 1A are delta-connected. Delta connection is divided into three so that respective phases of a secondary side winding wire 15 become three single phase transformers. Single phase three line connection is obtained where neutral lines are installed for the respective phases. The cost and the installation areas of the receiving and transforming facility are reduced by branching current of a secondary side into three phases. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transformer and a power receiving and transforming facility that receives high-voltage or extra-high voltage at a primary side of the transformer, converts the voltage into a working voltage at a secondary side, and supplies power to a customer via a low-voltage switch.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a transformer is used in a power receiving room provided in a high-rise building or a large apartment to convert a supply voltage to a low voltage. It has a feature of a two-bank configuration in consideration of, for example, a large capacity load, a large capacity of the transformer, and minimizing the influence of a power failure.
[0003]
It receives power at high or extra high voltage and is connected to a low voltage switch via a transformer. A fuse is stored on the load side of the low-voltage switch, and power is directly supplied to the load from the fuse.
[0004]
The transformer is a system in which single-phase transformers of different capacities are V-connected, and the capacity of one of the two transformers is larger than the capacity of the other transformer. For a single-phase 100V load, use a large-capacity transformer, and when using a three-phase 200V load, use the other small-capacity transformer together for V connection, Power. In a large-capacity transformer corresponding to a single-phase 100 V load, the secondary side of the transformer has a large current. Therefore, a low-voltage switch that can carry a large current is selected.
[0005]
Since the eddy current is generated in the housing that houses the low-voltage switch due to leakage magnetic flux generated from the conductor due to the large current, the area near the conductor where the large current flows is surrounded by a busbar box made of stainless steel. I have. The low-voltage housing on the secondary side of the transformer houses the power receiving and feeder devices in separate housings.
[0006]
However, in the above-described conventional technology, the current on the secondary side of the transformer is large, and the cost of the low-voltage switch on the secondary side increases due to the increase in the current on the secondary side accompanying the increase in the capacity of the transformer. In addition, the use of a stainless steel material for the structural material near the conductor through which a large current flows and the low-pressure housing increases the material and processing cost of the low-pressure housing.
[0007]
Furthermore, the size of the transformer casing increases due to the fact that the low-voltage power receiving and feeder devices are housed in separate casings and the insulation distance between the two single-phase transformers is ensured. There is a problem that the installation area when the low-voltage housing is combined in the power receiving room increases. As a power receiving and transforming facility using a transformer, Patent Document 1 can be cited.
[0008]
[Patent Document 1]
JP-A-55-160905 (abstract)
[0009]
[Problems to be solved by the invention]
Therefore, in order to reduce the cost and installation area of power receiving and transforming equipment such as transformers and low-voltage enclosures, simplification of secondary equipment, cost, installation area, and measures against leakage magnetic flux due to secondary current of the transformer are required. It is conceivable to reduce the number of stainless steel members and the number of transformers.
[0010]
However, in any case, it is difficult to solve the above problem unless the current on the secondary side of the transformer is reduced.
[0011]
An object of the present invention is to provide a power receiving and transforming facility with reduced cost and installation area.
[0012]
[Means for Solving the Problems]
In order to solve the above problem, the substation equipment of the present invention divides each phase of the secondary winding, divides the delta connection into three so that each phase supplies power to a low-voltage load, and splits each phase into three phases. It is characterized by a single-phase three-wire connection in which a neutral wire is provided for each, and the energization value is reduced by the amount divided into each phase, thereby reducing the cost and installation area of the substation equipment.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the transformer and the power receiving and transforming equipment shown in FIGS. 1 and 2 are diagrams showing an equivalent circuit of a transformer and a system of power receiving and transforming equipment.
[0014]
The transformer 1A will be described with reference to FIG. The primary winding 13 and the tertiary winding 14 of the transformer 1A are delta-connected. The tertiary winding 14 forms a three-phase transformer. As a three-phase load from the three-phase transformer, power is supplied to, for example, an elevator, a pump, lighting of a building, and the like.
[0015]
Each phase U, V, and W of the secondary winding 15 is divided into three delta connections so as to form three single-phase transformers, and is a single-phase three-wire connection in which a neutral wire is provided for each phase. . The secondary windings of the three single-phase transformers 1A are U-phase, V-phase, and W-phase secondary windings 15U, 15V, and 15W. In other words, the delta connection is divided into three so that each phase of the secondary winding forms a single-phase transformer that supplies power from each phase to the load, and a single-phase three-wire in which a neutral wire is provided for each phase It is connected. In this connection, for example, between the U-phase secondary winding 15U and the V-phase secondary winding 15V is electrically insulated.
[0016]
As shown in FIG. 2, the transformer 1A has two banks of transformers 1A,
1B is arranged. Since the transformer 1B has the same structure as the transformer 1A, the transformer 1A will be described below as a representative similarly to the above.
[0017]
Since the transformers 1A and 1B have a two-bank configuration, the transformer 1A and the transformer 1B are arranged on the right and left sides. From the terminals of the secondary winding 15 of the transformer 1A, three low-voltage housings having both functions of low-voltage power receiving and feeder are arranged.
[0018]
The three low-voltage housings correspond to the U-phase, V-phase, and W-phase secondary windings 15U, 15V, and 15W of the transformer 1A, and the U-phase low-voltage housing 4A and the V-phase low-voltage housing from the left. 5A, arranged as a W-phase low-pressure housing 6A. A low-voltage switch 7 is housed in these low-voltage housings. Since the U-phase low-pressure housing 4A, the V-phase low-pressure housing 5A, and the W-phase low-pressure housing 6A are all of the same structure, the W-phase low-pressure housing 6A will be described as a representative, but the details will be described later.
[0019]
The communication housing 8 is arranged in the middle between the W-phase low-pressure housing 6A and the U-phase low-pressure housing 4B. The communication housing 8 is used to operate one of the two banks operating in parallel during normal operation, for example, when the transformer 1A is stopped and inspected, the other operating transformer 1B is operated. In this case, three communication switches 9 necessary for supplying power to the load on the transformer 1A that is scheduled to be stopped from the power supply are housed. Details of the communication housing 8 will be described later.
[0020]
When the transformer 1A is stopped and inspected, all the three switching switches 9 are turned on, and the transformer 1B is stopped from the other transformer 1B instead of the transformer 1A of the bank to be stopped. Power to the load of the existing transformer 1A. During normal operation, all three switches 9 are shut off, both banks are disconnected, and two banks are operated in parallel.
[0021]
An electric wire 10 connected to the tertiary winding 14 of the transformer 1A is connected to a tertiary switch 12 in the communication housing 9 and supplies power to a three-phase load requiring three-phase 200V.
[0022]
The electrical connection relationship between the transformer 1A and the low-voltage switch 7, the communication switch 9, and the tertiary switch 12 will be described with reference to FIG.
[0023]
FIG. 3 illustrates the communication housing 8 and the inside of the low-pressure housing on the right side. The configuration in the left low-pressure housing is the same as that in the right low-pressure housing, and a description thereof will be omitted. Since the configurations inside the three low-voltage housings are the same, the W-phase low-voltage housing 6A will be described, and the electrical connection relationship between the other V-phase low-voltage housing 5A and the W-phase low-voltage housing 4A will be described. Will not be described.
[0024]
The main circuit conductor 16 is connected to the W-phase secondary windings 15W1 and 15W3 of the transformer 1A. The W-phase neutral main circuit conductor 16N is connected to the W-phase secondary winding 15W2. The main circuit conductor 16 and the neutral main circuit conductor 16N are connected to the communication main circuit conductors 18 and 18N in the W-phase low-voltage housing 6A.
[0025]
Two main circuit conductors 16 from the W-phase secondary windings 15W1 and 15W3 are connected to the low-voltage switch 7 and the current transformer 17 and also to the communication main circuit conductor 18. The neutral main circuit conductor 16N is connected to one neutral communication main circuit conductor 18N. The neutral connection main circuit conductor 18N is also connected to the V-phase and U-phase secondary windings 15V and 15U, and serves as a common line.
[0026]
The two communication main circuit conductors 18N and one neutral communication main circuit conductor 18N are a U-phase low-voltage housing 4A, a V-phase low-voltage housing 5A, a W-phase low-voltage housing 6A, and a communication housing. 8, and extends orthogonally, that is, in the horizontal direction with respect to the main circuit conductor 16 and the neutral main circuit conductor 16N.
[0027]
As shown in FIG. 4, two main U-phase, V-phase and W-phase secondary windings and a neutral secondary winding are provided in a bus box 19 as shown in FIG. Seven conductors corresponding to the wires are accommodated. The seven conductors are the communication main circuit conductors 18 (U1, U3), (V1, V3), (W1, W3), and the neutral communication main circuit conductor 18N.
[0028]
The busbar box 19 is made of a stainless member. That is, a stainless member is used where a large current flows. The main circuit conductor 16 and the connecting main circuit conductor 18 are formed of strip-shaped conductor bars. The communication switch 9 is connected to the communication main circuit conductor 18. Five fuses 20 are connected to the fuse line 20A connected to the communication main circuit conductor 18. Each fuse 20 is connected to a low-voltage load L. The fusing of the fuse 20 prevents the fault current generated in the load L from spreading to the power system side.
[0029]
Next, the details of the transformer housing 1, the W-phase low-voltage housing 6A, and the communication housing 8 will be described with reference to FIGS. FIGS. 5A and 6 are sectional views taken along lines AA and BB of FIG.
[0030]
A three-phase three-legged iron core 1Z is arranged in the transformer housing 1 of FIG. As shown in FIG. 5B, a tertiary winding 14 is disposed on the iron core leg 1Z, and a secondary winding 15 is disposed on the outer peripheral side of the tertiary winding 14. The primary winding 13 is arranged on the outer peripheral side. The primary winding 13, the secondary winding 15, and the tertiary winding 14 use a molded coil obtained by molding a coil with an insulating member.
[0031]
The connection of the transformer 1A is a delta connection between the primary winding 13 and the tertiary winding 14 of the transformer 1A. The secondary winding 15 is apparently a single three-phase transformer, but functionally, the secondary side is a single-phase three-wire system in which the delta connection is divided into three and a neutral line is provided for each phase. Because of the connection, the single-phase transformer is equivalent to three transformers. Since all three single-phase transformers have the same configuration, they are composed of U-phase, V-phase, and W-phase secondary windings 15U, 15V, and 15W. The W-phase secondary winding 15W will be described as a representative. I do.
[0032]
The secondary terminals 15W1 and 15W3 and the secondary neutral terminal 15W2, which are the lead wires of the W-phase secondary winding 15W, are bent so as to have a margin of dimensions when connected to the low-voltage housing 6A. The conductor 22 is used. Therefore, when the primary terminal 13A is brought in the opposite direction to take out space for the flexible conductor 22 and the secondary terminals 15W1 and 15W3 and the secondary neutral terminal 15W2, the transformer 1A is stored by that amount. The dimensions of the casing 1 increase. Therefore, the primary terminal 13A is pulled out in the same drawing direction as the secondary terminals 15W1 and 15W3 and the secondary neutral terminal 15W2, that is, in the low-voltage switch 7 side, thereby reducing the space of the transformer housing 1.
[0033]
Note that in FIG. 3, the drawing directions of the primary terminal 13A and the secondary terminal 15 do not always match those of FIG. 5A, but FIG. 3 is a diagram created for easy understanding of the connection destination of each terminal. Therefore, it does not always coincide with FIG.
[0034]
In order to generate a single-phase 100V voltage from the secondary terminals 15W1, 15W3 and the secondary neutral terminal 15W2 drawn out to the W-phase secondary winding 15W, one of the three secondary terminals is It is a secondary neutral terminal 15W2. The secondary current of the transformer 1A is the same as that of three single-phase transformers when viewed from the secondary side of the transformer 1A. Therefore, the secondary current per single-phase transformer is different from the conventional one. This is 1/3 of the case where the capacity transformer is V-connected. The tertiary terminal 14A corresponds to a three-phase 200V load.
[0035]
Next, the internal structure of the W-phase low-pressure housing 6A will be described with reference to the right side view of FIG. From the secondary side of the transformer 1A, the secondary terminals 15W1, 15W3 and the secondary neutral terminal 15W2 are drawn out and connected to the main circuit conductors 16 and 16N. These three conductors are used for the W-phase low voltage. It enters the housing 6A.
[0036]
After passing through the current transformer 17, the main circuit conductor 16 is connected to the low-voltage switch 7. The remaining one secondary neutral terminal 15W2 does not pass through the current transformer 17, and is connected to the low-voltage switch 7. Thereafter, the main circuit conductors 16 and 16N are connected to the communication main circuit conductors 18 and 18N required for connection to another bank, and the five main circuits are connected from the communication main circuit conductor 18 via the fuse wires 20A. Connected to fuse 20. Each of the fuses 20 is connected to a single-phase 100V load L.
[0037]
That is, in the U-phase low-voltage housing 4A, the V-phase low-voltage housing 5A, and the W-phase low-voltage housing 6A, a single-phase 100V load L can be obtained for five trunk lines. The U-phase low-pressure housing 4A, the V-phase low-pressure housing 5A, and the W-phase low-pressure housing 6A constitute one bank. Therefore, it is possible to obtain a single-phase 100 V load L of 15 trunks in one bank and 30 trunks in two banks. Because of the two-bank configuration, the bank of the transformer 1B has exactly the same configuration as the bank of the transformer 1A.
[0038]
The communication main circuit conductor 18 and the neutral communication main circuit conductor 18N are provided in the U-phase, V-phase, and W-phase low-voltage housings 4A, 5A, and 6A, respectively, with at least two buses and one neutral bus. Busbars are placed. In addition, the main circuit conductor 18 for communication and the main circuit conductor 18N for neutral communication are connected to the main circuit conductor 18 for communication in the low-voltage housings 4B, 5B, 6B for the U, V, and W phases of the other bank. Connected to the main circuit conductor 18N. Therefore, the V-phase bus and the U-phase bus are arranged in the W-phase low-voltage housing 6A, and a total of six buses and one neutral bus are arranged.
[0039]
The communication housing 8 will be described with reference to FIGS. FIG. 6 is a side view of the communication housing 8.
[0040]
The communication housing 8 houses the communication circuit breaker 9 and also draws out the tertiary terminal 14A from the tertiary winding 14 of the transformer 1A. The tertiary terminal 14A is connected to the electric wire 10. The electric wire 10 and the tertiary terminal 14A are drawn out from the opposite sides of the secondary terminals 15W1, 15W3 and the secondary neutral terminal 15W2. The electric wire 10 enters the communication housing 8 from inside the transformer housing 1 so as not to cross the secondary terminals 15W1 and 15W3. The electric wire 10 in the communication case 8 is connected to the tertiary switch 12.
[0041]
At the end of the tertiary switch 12, there is an interlocked switch 23 having one switch and two switches. For example, when there is a voltage in both banks, one of the switches in the interlocked switch 23 is turned on, and the other switch is turned off.
[0042]
In addition, when the transformer connected to the switch being turned off stops and the voltage is lost, the switch being turned on is turned off and the other circuit breaker is turned off. It becomes. Thereafter, it is connected to a three-phase 200 V load via a three-phase 200 V load switch 24. In addition, the power supply for operation and the power supply for controlling the extra high side are supplied.
[0043]
As described above, in this embodiment, the secondary winding 15 is divided into three delta connections so that three single-phase transformers are provided, and a single-phase three-wire connection in which a neutral wire is provided for each phase. I have. As a result, the secondary current of each phase of the secondary windings 15U, 15V, and 15W of the three single-phase transformers can be reduced by the divided current as compared with the conventional case.
[0044]
That is, in the prior art, a current of about 5000 amps on the secondary side was flowing through the main circuit conductor 16 and the connecting main circuit conductor 18. On the other hand, in the embodiment of the present invention, the current on the secondary side is divided into three phases by dividing the delta connection, so that a current of about 1600 amperes per phase that flows through the secondary winding 15 per phase is: It flows evenly through the main circuit conductor 16 and the connecting main circuit conductor 18.
[0045]
As a result, the eddy current and the normal current flowing through the main circuit conductor 16 and the connecting main circuit conductor 18 and the like in the embodiment of the present invention are reduced to about 1/3 as compared with the prior art, and the bus box 19 and the main circuit conductor 16 are reduced. The main circuit conductor for communication 18 and the like can be reduced to about 1/3, and the transformer, the transformer housing, and the low-voltage housing can be reduced.
[0046]
For example, assuming that the installation area of the conventional power receiving and transforming equipment is about 10, the installation area of the power receiving and transforming equipment of the present invention can be reduced to about 6 to 7. Further, the stainless steel materials used for the low-pressure housings 4A, 5A, 6A and the busbar box 19 can be reduced. Therefore, according to the transformer and the power receiving and transforming equipment of the present invention, the installation area and the cost can be reduced.
[0047]
Further, since the energization values of the main circuit conductor 16, the communication main circuit conductor 18 and the like are reduced, the low-voltage housings 4A, 5A, and 6A are separated into three so as to face each of the secondary conductors of the transformer. Can now be placed. In other words, when a short circuit fault occurs in each low-voltage housing, the fault current is small compared to the prior art, and there is little adverse effect on other low-voltage housings. Can be separated into bodies.
[0048]
As a result, the wiring of the U-phase, V-phase, and W-phase secondary windings 15U, 15V, and 15W can be easily understood from the low-voltage housing, and the transformer and the low-voltage housings 4A and 5A can be easily understood. , 6A can be prevented from being erroneously connected.
[0049]
Further, by pulling out the tertiary terminal 14A from the side opposite to the secondary terminals 15W1, 15W3 and the secondary neutral terminal 15W2, the pull-out operation is facilitated. For example, when the tertiary terminal 14A is drawn from the direction perpendicular to the secondary terminals 15U1 and 15U3, the tertiary terminal 14A is drawn from between the W-phase secondary winding 15W and the V-phase secondary winding 15V of the transformer. Sex worsens. Further, there is a disadvantage that an insulation distance is required.
[0050]
Furthermore, since the primary terminal 13 and the secondary terminals 15U1 and 15U3 are drawn out in the same direction, the transformer housing 1 can be reduced, and workability is further improved.
[0051]
Further, a case where the above-described embodiment is used as two lines and two banks will be described.
[0052]
That is, the primary winding 13 and the tertiary winding 14 are delta-connected with the two banks as transformers 1A and 1B, respectively, and the secondary winding 15 becomes three single-phase transformers 15U, 15V and 15W. The delta connection is divided into three parts, and a single-phase three-wire connection is provided in which a neutral line is provided for each phase. The low-voltage switch 7 is connected to the secondary windings 15W1 and 15W3 of the W-phase transformer 15 to perform low-voltage switching. The transformer 7 is connected to one side (transformer 1A side) and the other side (transformer 1B side) of the communication switch 9 so that when one transformer 1A is out of power, The switch 7 is opened and the communication switch 9 is closed to supply the electric power from the operating transformer 1B on the other side to the load L on the transformer 1A that is out of power.
[0053]
In the above-described embodiment, the low-voltage switch and the low-voltage housing have been described. However, it is needless to say that a normal switch and a non-low-voltage switch and housing can also be used.
[0054]
【The invention's effect】
As described above, according to the power receiving and transforming equipment of the present invention, it is possible to reduce the installation area and cost of the transformer and the power receiving and transforming equipment.
[Brief description of the drawings]
FIG. 1 is an equivalent circuit diagram of a transformer shown as an embodiment of the present invention.
FIG. 2 is a schematic plan view showing an arrangement of substation equipment using the transformer of FIG.
FIG. 3 is a system circuit diagram illustrating a system of the power receiving and transforming equipment of FIG. 2;
FIG. 4 is a sectional view of the bus box taken along the line CC of FIG. 3;
5 (A) and 5 (B) are a cross-sectional view taken along line AA of FIG. 2 and a cross-sectional view showing an iron core and windings of the transformer of FIG. 5 (A).
FIG. 6 is a sectional view taken along line BB of FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Transformer housing, 1A, 1B ... Transformer, 1Z ... Iron core, 4A, 5A, 6A ... Low pressure housing, 4B, 5B, 6B ... Low pressure housing, 7 ... Low voltage switch, 8 ... Communication housing, 9 Communication switch, 10 Wire, 12 Tertiary switch, 13 Primary winding, 13A Primary terminal, 14 Tertiary winding, 14A Tertiary terminal, 15 Secondary Winding, 15U, 15V, 15W ... U, V, W phase secondary winding, 15W1, 15W3 ... secondary terminal, 15W2 ... secondary neutral terminal, 16 ... main circuit conductor, 16N ... neutral Main circuit conductor, 17: Current transformer, 18: Main circuit conductor for connection, 18N: Main circuit conductor for neutral connection, 19: Busbar box, 20: Fuse.

Claims (7)

In a transformer for supplying power of a primary winding of a transformer to a secondary winding and a tertiary winding, the primary winding and the tertiary winding of the transformer are delta-connected, and the secondary winding is Wherein each phase is divided into three delta connections so that each phase forms a single-phase transformer, and a single-phase three-wire connection is provided in which a neutral line is provided for each phase. The power of the primary winding of the transformer is supplied to the secondary winding and the tertiary winding, and the power from the secondary winding is supplied to a plurality of switches. In a power receiving and supplying facility for supplying power to a three-phase load, the primary winding and the tertiary winding of the transformer are delta-connected, and each phase of the secondary winding is a single-phase transformer. The delta connection is divided into three so as to form a single-phase three-wire connection in which a neutral wire is provided for each phase, and the switch is connected to each phase of the secondary winding. Substation equipment. The power of the primary winding of the transformer is supplied to the secondary winding and the tertiary winding, and the power from the secondary winding is supplied to a plurality of switches. In a power receiving and supplying facility for supplying power to a three-phase load, the primary winding and the tertiary winding of the transformer are delta-connected, and each phase of the secondary winding is a single-phase transformer. The delta connection is divided into three so as to form a single-phase three-wire connection in which a neutral line is provided for each phase, the switch is connected to each phase of the secondary winding, and the transformer and the Power receiving and transforming equipment, wherein the switch facing each phase of the secondary winding is housed in a housing. The power of the primary winding of the transformer is supplied to the secondary winding and the tertiary winding, and the power from the secondary winding is supplied to a plurality of switches. In a power receiving and supplying facility for supplying power to a three-phase load, the primary winding and the tertiary winding of the transformer are delta-connected, and each phase of the secondary winding is a single-phase transformer. The delta connection is divided into three to form a single-phase three-wire connection in which a neutral wire is provided for each phase, the switch is connected to each phase of the secondary winding, and the secondary winding is A power receiving and transforming facility, wherein a wire is drawn out to the switch as a secondary-side lead-out terminal, and a tertiary-side lead-out terminal is drawn out from the tertiary-side winding opposite to the secondary-side lead-out terminal. As a transformer, the primary winding and the tertiary winding are delta-connected, and each phase of the secondary winding is divided into three delta connections so that each phase forms a single-phase transformer. A single-phase three-wire connection with a power line is provided, a switch is connected to each phase of the secondary winding, and the switch is connected to one side and the other side of the communication switch. When a power failure occurs in the transformer, the switch on the power failure side is opened, and the communication switch is closed to open the switch on the power failure side and the power supply from the operating transformer on the other side is interrupted. Substation equipment characterized by supplying to the load side. The power receiving and transforming equipment according to any one of claims 2 to 5, wherein the current of the secondary winding is equally divided into each phase. The receptacle according to any one of claims 2 to 5, wherein a primary-side extraction terminal of the primary winding and a secondary-side extraction terminal of the secondary winding are extracted toward the switch. Substation equipment.

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