JP2014093378A - Electric power transformer and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric power transformer that is reduced in size and weight and excellent in saving energy and stability by reducing magnetic leakage flux from a coil and by improving a magnetic flux bonding via a core, and to provide a manufacturing method therefor.SOLUTION: An electric power transformer 1 comprises a core 2, a primary coil 3 wound around the core 2, and a secondary coil 4 wound around the core 2. A line path forming the primary coil 3 connected to a power source 5 is a conductive wire, and a line path forming a secondary coil 4 connected to a load 6 is a conductive wire. A pair of line paths, which is a combination of the line path forming the primary coil 3 and the line path forming the secondary coil 4, are wound around the core 2 in a single layer or a plurality of layers, thereby forming a coil. Additionally, the primary coil 3 and the secondary coil 4 are arranged so that their currents are opposite to each other. In the case where the coil ratio of the primary coil 3 and the secondary coil 4 is 1:1, the transformer operates as an electric power balancer.

Description

  The present invention relates to a power transformer and a method for manufacturing the same. More specifically, the present invention relates to a power transformer applicable to a power transformer and a power balancer, and a method for manufacturing the power transformer.

  Conventional power transformers and power balancers generally have a configuration in which a primary side coil assembly and a secondary side coil assembly are individually provided on a leg portion (magnetic body) of a core (see Patent Document 1). The power balancer can be regarded as a special power transformer having a turns ratio of 1: 1.

  FIG. 11 is a schematic diagram illustrating an example of a conventional power transformer 100. As shown in FIG. 11, in a conventional power transformer 100, a coil 103 serving as a primary winding and a coil 104 serving as a secondary winding are individually wound around a core 102.

  Some conventional power transformers 100 and power balancers have a configuration in which the secondary coil assembly is placed outside the primary coil assembly in the positional relationship between the primary coil assembly and the secondary coil assembly. However, this is merely for convenience of arrangement and does not consider the electromagnetic relationship between the primary winding 103 and the secondary winding 104.

Below, the function of the electric power balancer which eliminates the problem of a single-phase three-wire type distribution line is demonstrated.
As a distribution line, the single-phase three-wire system is superior to other systems in terms of the reduction in the amount of wires, that is, the economical efficiency of the amount of copper wire used. Furthermore, compared to the single-phase two-wire system, in the case of a balanced load, both the voltage drop and the power loss are 1/4. In addition, the distance between external lines is 200 V, which increases the distribution voltage, and can cope with an increase in power demand. Therefore, the use of a single-phase three-wire transformer makes the single-phase three-wire system a standard power distribution system for low piezoelectric lamp loads. However, there are the following problems.

The first problem is the case where the terminal voltages of the loads on both sides cause a very imbalance and sometimes cause fatal damage. For example, if all of the load lights and electrical devices are cut off or broken, it will be a serious loss.
FIG. 12 is a circuit diagram when the neutral wire 120c of the single-phase three-wire distribution line 120 is cut. As shown in FIG. 12, the single-phase three-wire distribution line 120 is connected to a single-phase three-wire transformer 122. The primary winding 123 of the single-phase three-wire transformer 122 is connected to an AC power source 124. In the single-phase three-wire distribution line 120, the voltage line 120a is connected to the voltage terminal 125a of the secondary winding 125 of the single-phase three-wire transformer 122, and the voltage line 120b is a single-phase three-wire transformer. The neutral wire 120c is connected to the neutral terminal 125c of the secondary winding 125 of the single-phase three-wire transformer 122.

  A first load 127 is connected to the voltage line 120a and the neutral line 120c, and a single phase of, for example, 105V is applied. Similarly, the second load 128 is connected to the voltage line 120b and the neutral line 120c, and a single phase of, for example, 105V is applied. The voltage line 120a is also called an A outer line, and the voltage line 120b is also called a B outer line.

In FIG. 12, it is assumed that the neutral wire 120c is disconnected when there are ten 100W lamps as the first load 127 between the ANs and two 100W lamps as the second load 128 between the BNs. Since the load resistance between AN = 100/10 = 10 [Ω] and the load resistance between BN = 100/2 = 50 [Ω], the neutral line current I _N = 0 because the neutral line 120c is disconnected. Thus, since the current flows through the unbalanced loads on both sides in series and I _A = I _B = I, I = 210 / (10 + 50) = 3.5 [A]. Therefore, the load voltage between the ANs = 3.5 × 10 = 35 [V] and the load voltage between the BNs = 3.5 × 50 = 175 [V], which is extremely imbalanced.

  As is clear from this result, the terminal voltage of the second load 128 becomes higher, that is, the one with less load. The greater the load imbalance between the two sides, the greater the difference in voltage distribution and the greater the risk. For this reason, the 3-wire neutral wire 120c must not be provided with any circuit breaker or device for opening a circuit such as a fuse. The disconnection of the neutral wire 120c is an extreme accident example. However, even if the neutral wire 120c is not disconnected, if there is an imbalance in the load on both sides, a considerable difference appears in the voltage distribution on both sides. Is in the single-phase three-wire system. In reality, in any case, a load imbalance may occur in time, which is an unavoidable problem.

The next problem is when a short circuit occurs between the neutral wire 120c and the A outer wire 120a or the B outer wire 120b.
FIG. 13 is a circuit diagram when a short circuit occurs between the neutral wire 120c of the single-phase three-wire distribution line 120 and the B outer wire 120b. When a short circuit occurs between the neutral wire 120c and the B outer wire 120b, the voltage generated between the healthy A outer wire 120a and the neutral wire 120c is obtained using FIG.
The resistance of the A outer line 120a and the B outer line 120b from the terminal of the single-phase three-wire transformer 122 to the failure point is r _l , and the resistance between N′P of the neutral line 120c is r _n . The voltage V _A of the A outer line 120a is V _A = V + r _n I _S , and the voltage V _B of the B outer line 120b is V _B = V−r _n I _S = r _p I _S , where r _p is the resistance at the failure point. It becomes. When r _p is 0, I _S is I _S = V / (r _n + r _e ) from the previous equation. Therefore, the voltage V _A of the A outer line 120a is V _A = V [1 + r / (rn + re)].

Thus, when a line of the same thickness to A line wire 120a and B outside line 120b and the neutral line _{120c (r n = r e)} , the voltage of A external 120a and B outside line 120b is a single-phase three-wire type transformer 1.5 times the terminal voltage of the capacitor 122 and 1.7 times when the neutral wire 120c has a conductor with a half cross-sectional area of the outer wires 120a and 120b.

Next, the most common problem in the single-phase three-wire distribution line will be described with reference to FIG.
FIG. 14 is a circuit diagram when a first load 127 and a second load 128 having different currents flowing through the single-phase three-wire distribution path 120 are connected. The first load 127 and the second load 128 are, for example, electric lamps. The primary voltage of the single-phase three-wire transformer 122 is 3150V, the secondary voltages are 210V and 105V, and the resistance per low-voltage side wire is 0.05Ω. As a lamp load, when a current of 80A is flowing through the A external line 120a, 20A through the neutral line 120c, and 100A through the B external line 120b, the voltage between the load points AN, NB and AB is obtained. However, the primary voltage is not changed, and the impedance of the single-phase three-wire transformer 122 and the reactance of the low-voltage distribution line are ignored.

Since the power factors of the loads 127 and 128 on both sides are the same, if the voltage between the required AN is expressed as Van and the voltage between NB is expressed as Vnb, in the upper half circuit, 105 = (0.05 × 80) + Van From (0.05 × 20), Van = 102 [V].
In the lower half circuit, Vnb = 99 [V] from 105 = (0.05 × 20) + Vnb + (0.05 × 100).
Therefore, the voltage between AB is Vab = Van + Vnb = 201 [V]. Thus, it can be seen that in the single-phase three-wire distribution path 120, it is very common that the voltage at the load end varies depending on the load.

A power balancer 130 (also referred to as a pressure balancer) that can eliminate the above-described drawbacks of the single-phase three-wire distribution line 120 will be described.
FIG. 15 is a schematic diagram showing the configuration of a conventional power balancer 130, and FIG. 16 is a circuit diagram when the conventional power balancer 130 is connected to the single-phase three-wire distribution line 120.
As shown in FIG. 15, the conventional power balancer 130 includes a core 132, a primary winding 133 and a secondary winding 134 wound around the core 132, similar to the power transformer 100 of FIG. 11. Has been. The primary winding 133 and the secondary winding 134 are individually wound. One end of the primary winding 133 becomes an a terminal 130a of the power balancer. One end 134a of the secondary winding 134 serves as a b terminal 130b of the power balancer. The other end of the primary winding 133 and the other end of the secondary winding 134 are connected to serve as the n terminal 130c of the power balancer. In the power balancer 130, the winding ratio between the primary winding 133 and the secondary winding 134 is 1: 1. That is, the power balancer 130 corresponds to a special transformer having a turn ratio in the power transformer 100 of FIG.

  As shown in FIG. 16, the power balancer 130 is connected to the end of the single-phase three-wire distribution line 120 farthest from the AC power supply 124 side. The a terminal of the power balancer 130 is connected to the A external line 120a of the single-phase three-wire distribution line, and the n terminal of the power balancer 130 is connected to the neutral terminal 120c of the single-phase three-wire distribution line 120. The b terminal of the balancer 130 is connected to the B outer line 120 b of the single-phase three-wire distribution path 120. The power balancer 130 is preferably disposed at the end of the single-phase three-wire distribution line 120.

  According to the conventional power balancer 130, when the current flowing through the A external line 120a is smaller than the current flowing through the B external line 120b, the compensation current io flows into the terminals a and b, and the current flowing through the A external line 120a When it is larger than the current flowing through 120b, the compensation current io flows out from the terminals a and b. Providing the power balancer 130 is inductively coupled through the power balancer 130 so that the circuits on both sides are always at the same voltage, so even if there is an imbalance in the load on both sides, the neutral 120c Even if the power breaks, the voltages on both sides are always balanced and act to act on the load. This is because the power balancer 130 allows the compensation current to flow so that the voltages on both sides of the single-phase three-wire distribution line 120 are balanced.

Next, the effect of the conventional power balancer 130 will be described.
In order to show the effect of the power balancer 130, when the power balancer 130 is installed, it is calculated what kind of effect is produced in the voltages on both sides.
FIG. 17 is a circuit diagram illustrating the effect of the power balancer 130 of the present invention.
In order to simplify the calculation, the voltage drop caused by the power balancer 130 is ignored. The power balancer 130 is a pressure receiver having a transformation ratio of 1: 1, and generates and circulates a compensation current io in the circuit as shown in FIG. 17, so that the voltage at the end is balanced. It will work. Since the current of the A outer line 120a = 80 + io, the current of the neutral line 120c = 20-2io, and the current of the B outer line 120b = 100−io, 105 = 0.05 × (80 + io) + V1-0 in the upper half circuit. .05 × (20−2io), in the lower half circuit, 105 = 0.05 × (20−2io) + V2 + 0.05 × (100−io). Therefore, V1 and V2 are V1 = 102−0.15io and V2 = 99 + 0.15io.

Here, because of the nature of the power balancer 130 as a transformer, V1 = V2 = V, so the compensation current at this time is io = 10 [A]. As described above, when the power balancer 130 is not provided, the current on the side with a large voltage drop is reduced, the current on the side with a small voltage drop is increased, and the voltage drop at the neutral line 120c is further reduced to zero. .
Further, it can be seen that half of the current of the neutral wire 120c when there is no power balancer 130 flows as the current of the power balancer 130. That is, in this example, the current of the A outer line 120a = the current of the B outer line 120b = 90 [A], V1 = V2 = 100.5 [V], and the current of the neutral line 120c = 0 [A]. .

(When the neutral wire is disconnected)
In the circuit of FIG. 12, the problem when the neutral wire 120c is disconnected will be examined as to what the result will be when the power balancer 130 is installed. Since a current of 8.4 [A] flows through the neutral wire 120c when there is no power balancer 130 before disconnection, when the power balancer 130 is installed, the circulating current generated by the power balancer 130 Is 8.4 / 2 = 4.2 [A]. The A outer line 120a is 6.3 [A], the B outer line 120b is also 6.3 [A], and no current flows through the neutral line 120c. Therefore, even if the neutral wire 120c is disconnected, there is no difference between the voltages on both sides.

  As described above, as long as the power balancer 130 is provided in the single-phase three-wire distribution path 120, the voltage on both sides of the single-phase three-wire distribution path 120 does not differ even if the neutral line 120c is disconnected. . By installing the power balancer 130 in the single-phase three-wire distribution path 20, the conventional drawbacks that existed in the single-phase three-wire distribution path 120 are eliminated.

  In the conventional power transformer 100 and power balancer 130, coils in which the primary windings 103 and 133 and the secondary windings 104 and 134 are individually wound are used. Magnetic flux leakage in such a single-wound coil has a strong feature that changes depending on its arrangement and current value.

Japanese Patent Laid-Open No. 10-201097

  As for the magnetic flux leakage in the single coil used in the conventional power transformer 100 and power balancer 130, the larger the number of windings, the lower the magnetic flux coupling and the higher the leakage magnetic flux. The number of windings is, for example, the number of stacked primary windings 103 or the number of stages in the coil assembly for electric power. This is an essential problem that cannot be avoided when used in the conventional power transformer 100 or the power balancer 130.

  The present inventors have reviewed the concept of coil assembly used in conventional power transformers from the basics, so that the amount of leakage magnetic flux is small and the coupling ratio is improved in the interaction between the magnetic flux in the magnetic path and the coil. A single line or multiple layers of a pair of lines that are a combination of a line that forms a primary winding connected to a power source and a line that forms a secondary winding connected to a load is wound around the core by a single layer or multiple layers. And the directions of the current in the primary winding and the secondary winding are reversed. According to the configuration of this power transformer, the magnetic flux leakage from the coil is reduced, the magnetic flux coupling through the core is improved, and the magnetic flux in the magnetic path is much less than the conventional power transformer. We have come up with a power transformer that is responsive to changes, that is, has good coupling.

  SUMMARY OF THE INVENTION A first object of the present invention is to provide a power transformer that is excellent in energy saving and stability while being small and light by reducing magnetic flux leakage from a coil and improving magnetic flux coupling through a core. The second object is to provide a manufacturing method thereof.

  In order to achieve the first object, a power transformer of the present invention includes a core, a primary winding wound around the core, and a secondary winding wound around the core, and is connected to a power source. The line forming the primary winding is made of a conductive wire, the line forming the secondary winding connected to the load is made of a conductive wire, and the line forming the primary winding and the line forming the secondary winding A coil is formed by winding a pair of lines in a single layer or multiple layers around the core, and the direction of current in the primary and secondary windings is reversed. It is arranged.

In the above configuration, preferably, the winding ratio of the primary winding and the secondary winding is 1: 1, and the device operates as a power balancer.
The pair of lines is preferably composed of a single layer or a plurality of layers. In a power transformer or a power balancer, preferably, a pair of lines is wound around a core by a bifilar.
The end portion of the core is preferably provided with a leakage magnetic flux absorbing portion.
The gap between the end of the core and the coil is preferably provided with a magnetic material for absorbing leakage magnetic flux.

  In order to achieve the second object, a method for manufacturing a power transformer of the present invention includes a step of producing a pair of lines composed of a primary winding and a secondary winding, and winding a pair of lines around a core. And a step of fixing a pair of wound lines to a core.

  According to the power transformer of the present invention, a pair line is formed by the primary winding line and the secondary winding line, and the current direction in the primary winding line and the secondary winding line is opposite, Due to the inductive action, the magnetic flux leakage from the coil is reduced, the magnetic flux coupling through the core is improved, and a power transformer with a coil that is excellent in energy saving and stability while being small and light is obtained.

  In a power transformer in which the turns ratio of the primary winding and the secondary winding is 1: 1, the arrangement of the pair lines includes a line that forms the primary winding and a line that forms the secondary winding. A power balancer can be easily obtained with a simple configuration that is alternately arranged. Since the paste-like magnetic material for absorbing leakage magnetic flux is provided in the gap between the end of the core and the coil, the influence on the external region is sufficiently suppressed.

  According to the method for manufacturing a power transformer of the present invention, it is possible to manufacture a power transformer excellent in energy saving and stability while being small and light at low cost.

It is a figure which shows the structure of the electric power transformer which concerns on the 1st Embodiment of this invention, (a) is a front view, (b) is sectional drawing which follows the II line | wire of (a). It is a schematic diagram which shows the winding method of the coil used for the primary winding and secondary winding of the electric power transformer of this invention. It is a front view which shows the modification of a power transformer. It is a figure which shows the structure of the balancer for electric power which concerns on the 2nd Embodiment of this invention, (a) is a front view, (b) is sectional drawing which follows the II-II line of (a). It is front sectional explanatory drawing which shows the 1st modification of the balancer for electric power. It is front sectional explanatory drawing which shows the 2nd modification of the balancer for electric power. It is a circuit diagram which shows the application example 1 of the balancer for electric power. It is a circuit diagram which shows the application example 2 of the balancer for electric power. It is a circuit diagram which shows the application example 3 of the balancer for electric power. It is a flowchart which shows the process of the manufacturing method of the electric power transformer of this invention. It is a schematic diagram which shows an example of the conventional electric power transformer. It is a circuit diagram at the time of the cutting | disconnection of the neutral line of a single phase 3 wire type distribution line way having arisen. It is a circuit diagram at the time of the short circuit with the neutral line and B outside line of a single phase 3 wire type distribution line way having arisen. It is a circuit diagram at the time of connecting the 1st load and the 2nd load from which the current which flows into a single phase 3 line type distribution line differs. It is a schematic diagram which shows the structure of the conventional power balancer. It is the circuit diagram which connected the conventional power balancer to the single-phase three-wire type distribution line. It is a circuit diagram explaining the effect of the power balancer of this invention.

Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.
(Power transformer)
The power transformer 1 according to the first embodiment of the present invention will be described.
1A and 1B are diagrams showing a configuration of a power transformer 1 according to a first embodiment of the present invention, in which FIG. 1A is a front view, and FIG. 1B is a cross-sectional view taken along line I-I in FIG. is there.
As shown in FIG. 1A, the power transformer 1 includes a core 2, and a primary winding 3 and a secondary winding 4 that are wound around the core 2. The primary winding 3 is connected to an AC power source described later, and the line forming the primary winding 3 is a conductive wire. A line forming a secondary winding 4 connected to a load described later is composed of a conducting wire. A pair of lines formed by pairing a line forming the primary winding 3 and a line forming the secondary winding 4 is wound in a single layer or multiple layers around the core 2 to form a coil, and The pair of lines are arranged so that the directions of the currents in the lines of the primary winding 3 and the secondary winding 4 are reversed. The pair of lines is also called a pair line.

  As shown in FIG. 1B, the power transformer 1 includes a line layer forming the primary winding 3 and a line layer forming the secondary winding 4 on the leg 2 a of the core 2. Two layers are laminated to form a layer. That is, in the power transformer 1, the arrangement of the pair lines with respect to the core 2 is layered by a line layer that forms the primary winding 3 and a line layer that forms the secondary winding 4.

FIG. 2 is a schematic diagram showing a winding method of coils used in the primary winding 3 and the secondary winding 4 of the power transformer of the present invention.
As shown in FIG. 2, the power transformer 1 includes a pair of lines including a primary winding 3 connected to a power source 5 and a secondary winding 4 connected to a load 6. One end of the primary winding 3 is connected to one end of the power source 5, and the other end of the primary winding 3 is connected to the other end of the power source 5. Similarly, one end of the secondary winding 4 is connected to one end of the load 6, and the other end of the secondary winding 4 is connected to the other end of the load 6.

  The primary winding 3 connected to the power source 5 is formed of a coil composed of one or a plurality of conductive wires. Similarly, the secondary winding 4 connected to the load 6 is formed of a coil composed of one or a plurality of conductive wires. For example, a copper wire coated with an insulating material can be used as the conductive wire used for the primary winding 3 and the secondary winding 4. Examples of the copper wire with insulation coating include enameled copper wire and polyamide-imide copper wire.

  The coil of the primary winding 3 and the coil of the secondary winding 4 are paired. And it sets so that the direction of the electric current in each primary winding 3 and secondary winding 4 which comprises a pair line may become reverse direction.

In the power transformer 1, inside the loop conductor on the power source 5 side constituted by the primary winding 3 connected to the power source 5, on the load 6 side constituted by the secondary winding 4 connected to the load 6. A loop conductor is arranged to form a pair line.
In this pair line, the direction of current flow is opposite to the direction of the primary winding 3 in the line (IS) and the direction of the secondary winding 4 in the line (IL) as shown in the figure. Therefore, when a current flows through the loop conductor on the power supply 5 side, an electromotive force is generated in the loop conductor on the load 6 side in order to cancel the magnetic field caused thereby, and a reverse current flows in the loop conductor on the load 6 side. The direct inductive action between the primary winding 3 and the secondary winding 4 can be regarded as a power transformer action in a broad sense. Thereby, the radio noise generated from the loop conductor on the power source 5 side is canceled.

  In the power transformer 1 using the core 2 shown in FIG. 1, in addition to the direct inductive action between the primary winding 3 and the secondary winding 4 described in FIG. An electromotive force is also generated in the secondary winding 4 due to the indirect induction effect by the magnetic flux in the core 2 generated. That is, in the power transformer 1, the core 2 is used as a magnetic path, and the magnetic flux in the magnetic path is also used for the action of the power transformer. Therefore, leakage magnetic flux and noise are extremely reduced, and the efficiency is higher than that of the conventional single-phase power transformer 100, and the magnetic flux value in the core 2 is also reduced. Accordingly, a core having a smaller cross-sectional area can be used, and the weight can be reduced. Thereby, the power transformer 1 can be manufactured at low cost.

  In the power transformer 1 shown in FIG. 1, the transformation ratio can be adjusted by appropriately adjusting the composition of the pair line, such as 1: 2 to 10 such as the winding ratio of the primary winding 3 and the secondary winding 4, The paired lines may be appropriately laminated such as two layers.

(Modification of power transformer)
FIG. 3 is a front view showing Modification Example 10 of the power transformer.
As shown in FIG. 3, the power transformer 10 has a configuration in which a leakage flux absorbing magnetic body 8 is further provided in the power transformer 1 shown in FIG. In the power transformer 10, the primary winding 3 and the secondary winding 4 are wound around the core 2, and leakage magnetic flux absorbing magnetic bodies 8 are disposed at four locations in the illustrated case. .

  The leakage flux absorbing magnetic body 8 includes a leakage flux absorbing magnetic body 8a provided at one end of the upper left winding of the core 2 and a leakage flux absorbing magnetic body provided in the center of the lower left winding of the core 2. 88 b, a leakage flux absorbing magnetic body 8 c provided at the winding center portion on the lower right side of the core 2, and a leakage flux absorbing magnetic body 8 d provided at the winding end portion on the upper right side of the core 2. The magnetic substance 8 for absorbing magnetic flux leakage can be formed by applying a material made of a magnetic substance in a paste form and then drying it.

  In the power transformer 100 using the conventional single coil, the magnetic flux leakage changes depending on the arrangement and the current value. In the power transformer 10 of the present invention, the pair line can be constituted by, for example, a bifilar winding coil. As a result, the magnetic flux is always canceled between two adjacent primary windings 3 and secondary windings 4. For this reason, in the power transformers 1 and 10 of the present invention, the magnetic flux leakage is basically hardly affected by the current value, and the absolute amount of the leakage magnetic flux is a single unit used in the conventional power transformer 100. Very small compared to a wound coil.

  Furthermore, in the power transformer 10 of the present invention, since the paste-like magnetic body 8 for absorbing the leakage magnetic flux is provided in the gap between the end of the core 2 and the coil, the influence on the external region is almost negligible. Can be suppressed.

(Power balancer)
Next, a power balancer 20 according to a second embodiment of the present invention will be described.
4A and 4B are diagrams showing a configuration of a power balancer 20 according to the second embodiment of the present invention, in which FIG. 4A is a front view, and FIG. 4B is a cross-sectional view taken along line II-II in FIG. is there.
As shown in FIG. 4A, the power balancer 20 includes a core 22, and a primary winding 3 and a secondary winding 4 that are wound around the core 22. 1 is the same as the power transformer 1 of FIG. 1 except that the winding ratio of the primary winding 3 and the secondary winding 4 is 1: 1. The primary winding 3 and the secondary winding 4 can be wound by a so-called bifilar winding, which is wound around the core 22 by using a so-called parallel two-wire cable having an insulation coating with the same thickness.

  In the power balancer 20 of the present invention, the winding ratio of the primary winding 3 and the secondary winding 4 is 1: 1, and the arrangement of the pair line with respect to the core 22 is the line that forms the primary winding 3. The lines forming the secondary winding 4 are alternately arranged.

  In the power balancer 20 of the present invention, since the paired line is composed of a bifilar winding coil, the magnetic flux is always canceled between two adjacent windings. Therefore, basically, the influence of the current value is extremely small, and the absolute amount of the leakage magnetic flux is extremely small as compared with the power balancer 130 using the conventional single coil. Further, similarly to the power transformer 1, by providing the magnetic flux absorbing portion 8, the leakage magnetic flux from the bifilar winding coil is absorbed by the magnetic flux absorbing portion, so that the influence on the external region can be suppressed to a negligible level.

  Thereby, in the power balancer 20 of the present invention, as with the conventional power balancer 130, it is possible to prevent the neutral line from being cut, short-circuited, and load imbalance in the single-phase three-wire distribution line. Instability of the magnetic balancer 130 that has reduced the efficiency of the power balancer 130 and fluctuations in the capacity of the power balancer 130 due to changes in the absolute amount of leakage magnetic flux can be stabilized regardless of changes in load current. It is possible to obtain the stability of the power distribution system as well as energy saving.

(First variation of power balancer)
FIG. 5 is an explanatory front sectional view showing a first modification of the power balancer 30.
As shown in FIG. 5, the power balancer 30 has a configuration in which the shape of the core 22 of the power balancer 20 shown in FIG. 3 is changed, and the primary winding 3 and the secondary winding are formed on the cut core 32. 4 is wound by bifilar winding. The cut core 32 includes a winding forming part 32a and a leakage magnetic flux absorbing part 32b connected to both ends of the winding forming part 32. The cut core 32 has, for example, a rod shape, and the size of the leakage magnetic flux absorbing portion 32b is larger than the outer shape of the winding. That is, the diameter of the end portion of the cut core 32 is increased to a position corresponding to the thickness of the wound coil. The shape of the winding forming part of the cut core 32 can be a cylinder, an elliptical cylinder, a prism, or the like. When the shape of the winding forming portion of the cut core 32 is a cylinder, the cross-sectional shape of the cut core 32 is a substantially I-shape.

  In bifilar winding, a parallel two-wire cable may be wound around the cut core 32. The number of windings may be multilayered according to the specifications of the power balancer 30, and in FIG. 5, the winding has three layers.

  In the power balancer 30 of the present invention, since the pair line is composed of a bifilar winding coil, the magnetic flux is always canceled between two adjacent windings. Therefore, basically, the influence of the current value is extremely small, and the absolute amount of leakage magnetic flux is extremely small as compared with the power balancer 130 of the conventional single coil. Further, by providing the leakage flux absorbing portion 32b on the end side of the cut core 32, the leakage flux from the bifilar winding coil is absorbed by the flux absorbing portion 32b, so that the influence on the external region is suppressed to a level that can be ignored. it can.

  This stabilizes the imbalance of the magnetic coupling, which has reduced the efficiency of the conventional power balancer 130, and fluctuations in the capacity of the power balancer due to changes in the absolute amount of leakage magnetic flux regardless of changes in load current. System stability as well as energy savings.

(Second modification of power balancer)
FIG. 6 is an explanatory front sectional view showing a second modification of the power balancer 35.
As shown in FIG. 6, the power balancer 35 has a configuration in which a leakage flux absorbing magnetic body 38 is further provided in the power balancer 30 shown in FIG. 5. In the power balancer 35, the windings 32 a of the cut core 32 are wound by bifilar winding with the primary winding 3 and the secondary winding 4, and both ends of the winding portion 32 a of the cut core 32. Is provided with a magnetic substance 38 for leakage magnetic flux absorption. The magnetic substance 38 for absorbing magnetic flux leakage can be formed by applying a paste-like material made of a magnetic substance and then drying it.

  In the power balancer 35 of the present invention, since the paste-like magnetic body 38 for absorbing leakage magnetic flux is provided in the gap between both ends of the winding portion 32a of the core 32 and the coil, the influence on the external region is also affected. It can be suppressed to a level that can be almost ignored.

Next, an application example of the power balancer 20 according to the second embodiment will be described.
FIGS. 7 to 9 are circuit diagrams showing application examples of such a power balancer 20, FIG. 7 shows application example 1, FIG. 8 shows application example 2, and FIG. 9 shows application example 3. .
In the application example 1 shown in FIG. 11, the power balancer 20 is connected to the end of the single-phase three-wire distribution line 50, and one load 53 among the loads 51 to 53 to which the AC power supplies 54 and 55 are connected. The circuit is the same as that of FIG. 16 except that it is connected to the R terminal and the T terminal. The power balancer 20 may be power balancers 30 and 35. The same applies to the following examples.

  Application Example 2 shown in FIG. 8 is the same circuit as FIG. 7 except that the neutral wire terminal of the single-phase three-wire distribution line 50 is floating.

  The application example 3 shown in FIG. 9 is the same circuit as that in FIG. 7 except that the power balancer 20 is directly connected to an AC power source.

(Manufacturing method of power transformer)
Next, a method for manufacturing the power transformer of the present invention will be described.
FIG. 10 is a flowchart showing the steps of the method for manufacturing the power transformer 1 of the present invention.
First, in step ST1, a pair wire of the primary winding 3 and the secondary winding 4 is produced.
In step ST2, a pair of wires consisting of the primary winding 3 and the secondary winding 4 is wound around the core 2 or the winding frame.

In step ST3, the pair wire is fixed to the core 2 or the winding frame. An adhesive can be used for fixing the core 2 or the winding frame of the pair wires.
In step ST <b> 4, the leakage flux absorbing magnetic body 8 is formed between the end portions of the primary winding 3 and the secondary winding 4 and the core 2. This step may be omitted.

  Next, in step ST5, the ends of the primary winding 3 and the secondary winding 4 are connected to the terminals of the power transformer 1. This step may be omitted when the conducting wires at the ends of the primary winding 3 and the secondary winding 4 are directly connected to the power source 5 or the load 6.

(Method for manufacturing power balancer)
Next, a method for manufacturing the power balancers 20, 30, and 35 of the present invention will be described.
The power balancers 20, 30, and 35 of the present invention include the primary winding 3 and the secondary winding 4 in step ST <b> 1 for producing a paired wire of the primary winding 3 and the secondary winding 4 shown in FIG. 10. Can be manufactured in the same manner except that the pair wire is manufactured so that the winding ratio is 1.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these are also included in the scope of the present invention. In the above description, in order to explain the basic principle of the present invention in detail, a single-phase power transformer is used as an example of its use. Furthermore, the present invention can be appropriately used for coil assembly of various conventional power transformers, including power balancers.

DESCRIPTION OF SYMBOLS 1,10: Power transformer 2: Core 3: Primary winding 4: Secondary winding 5: Power supply 6: Load 8, 38: Magnetic substance 20, 30, 35 for leakage magnetic flux absorption: Power balancer 22: Core 22a: Leg part 32 of core: Cut core 32a: Winding forming part 32a
32b: Leakage magnetic flux absorber 32b
50: Single-phase three-wire distribution line 51-53: Loads 54, 55: AC power supply

Claims (7)

A core, a primary winding wound around the core, and a secondary winding wound around the core;
With
The line that forms the primary winding connected to the power supply consists of a conductor,
The line forming the secondary winding connected to the load consists of a conducting wire,
A pair of lines formed by pairing a line forming the primary winding and a line forming the secondary winding is wound in a single layer or multiple layers around the core to form a coil, and A power transformer, wherein the currents in the primary winding and the secondary winding are arranged in opposite directions.   2. The power transformer according to claim 1, wherein a winding ratio of the primary winding to the secondary winding is 1: 1 and operates as a power balancer.   The power transformer according to claim 1, wherein the pair of lines includes a single layer or a plurality of layers.   The power transformer according to any one of claims 1 to 3, wherein in the power transformer or the power balancer, the pair of lines are bifilar wound around the core.   The power transformer according to any one of claims 1 to 4, wherein an end portion of the core includes a leakage magnetic flux absorption portion.   The power transformer according to any one of claims 1 to 5, wherein a magnetic material for absorbing leakage magnetic flux is provided in a gap between an end of the core and the coil. A method for manufacturing a power transformer according to any one of claims 1 to 6,
Producing a pair of lines composed of a primary winding and a secondary winding;
Winding the pair of lines around a core;
Fixing the pair of wound lines to the core;
The manufacturing method of the transformer for electric power characterized by including.