Single-phase transformer

Abstract

To provide a single-phase transformer that can achieve both energy savings and improved workability while suppressing an increase in size. [Solution] The single-phase transformer 1 of the embodiment includes a starting coil terminal 31, an intermediate coil terminal 32, and a ending coil terminal 33 that are drawn out in a state that is offset vertically in the same direction, a starting phase connecting conductor 41, an intermediate phase connecting conductor 42, and an ending phase connecting conductor 43 that electrically connect each coil terminal 3, and a starting external terminal 51, an intermediate external terminal 52, and an ending external terminal 53 that are electrically connected to each coil terminal 3. The connection position (H2) between the intermediate coil terminal 32 and the intermediate phase connecting conductor 42 in the vertical direction is set lower than the connection position (H1) between the starting coil terminal 31 and the starting phase connecting conductor 41 and the connection position (H3) between the ending coil terminal 33 and the ending phase connecting conductor 43.

Description

Technical Field

[0004] , , ,

[0006] , ,

[0005] , , , , ,

[0001] The present disclosure relates to a single-phase transformer.

Background Art

[0002] Conventionally, there is a single-phase transformer in which a coil body having a low-voltage coil and a high-voltage coil arranged concentrically is arranged adjacent to each other, and a coil terminal is drawn out from the low-voltage coil (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Such a conventional single-phase transformer has a problem in achieving both energy saving and improvement in workability. That is, in order to achieve energy saving, it is conceivable to shorten the coil terminals drawn from the coil to suppress losses. However, in that case, the working space for fixing the coil terminals becomes small or the connection positions overlap, resulting in deterioration of workability.

[0005] On the other hand, in order to improve workability, for example, it is conceivable to shift the connection positions with each coil terminal in the vertical direction. However, in that case, the coil terminals become long and the losses deteriorate. Further, in order to compensate for the deteriorated losses, it is necessary to increase the size of the transformer, and in that case, new problems such as strict dimensional limitations during transportation and installation occur.

[0006] Therefore, a single-phase transformer is provided that can achieve both energy saving and improvement in workability while suppressing an increase in size.

Means for Solving the Problems

[0007] The single-phase transformer according to this embodiment has a low-voltage coil and a high-voltage coil arranged concentrically, and comprises a plurality of adjacent coil bodies, a starting coil terminal, an intermediate coil terminal and a ending coil terminal drawn out from the upper end of the low-voltage coil in the same direction, offset vertically, and includes a starting phase connecting conductor that electrically connects the starting coil terminals of each coil body, an intermediate phase connecting conductor that electrically connects the intermediate coil terminals, and an ending phase connecting conductor that electrically connects the ending coil terminals, and includes a starting external terminal that is electrically connected to the starting coil terminal, an intermediate external terminal that is electrically connected to the intermediate coil terminal, and an ending external terminal that is electrically connected to the ending coil terminal, wherein the connection position between the intermediate coil terminal and the intermediate phase connecting conductor is set lower than the connection position between the starting coil terminal and the starting phase connecting conductor, and the connection position between the ending coil terminal and the ending phase connecting conductor. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram showing an example of the configuration of a single-phase transformer according to an embodiment. [Figure 2] A schematic diagram showing the structure of the coil body and the structure of the main parts. [Figure 3] A diagram schematically showing the connection configuration in a side view. [Figure 4] A schematic diagram showing the connection configuration in a plan view. [Figure 5] A schematic diagram showing an example of the configuration of external terminals. [Figure 6] Diagram illustrating the factors causing losses at coil terminals. [Modes for carrying out the invention]

[0009] The embodiments will now be described with reference to the drawings. As shown in the perspective view in Figure 1, the single-phase transformer 1 according to this embodiment includes two adjacent coil bodies 2, coil terminals 3 drawn out from each coil body 2, inter-phase connecting conductors 4 connecting the coil terminals 3 of each coil body 2, external terminals 5 to which external wiring (not shown) is connected, an iron core 6 formed in an annular shape with legs inserted into the inner circumference of each coil body 2, an upper support fitting 7 that supports the iron core 6 from above, and a lower support fitting 8 that supports the iron core 6 from below.

[0010] Hereinafter, the orientation in which the coil bodies 2 are arranged will be referred to as the left-right direction, the front-back direction with the side from which the coil terminals 3 are drawn out being the front, and the direction perpendicular to the left-right and front-back directions will be referred to as the up-down direction. The view of the single-phase transformer 1 from the left or right side will be referred to as the side view, and the view from above will be referred to as the top view. In this embodiment, molded coils are assumed for the coil bodies 2, but other types of coils may be used.

[0011] As shown in Figure 2(a), the coil body 2 has a structure in which a low-voltage coil 21 and a high-voltage coil 22 are arranged concentrically, and multiple coil terminals 3 are drawn out from the low-voltage coil 21 located on the inner circumference side. Specifically, from each low-voltage coil 21, a starting coil terminal 31 connected to the beginning of the winding of the conductor, an intermediate coil terminal 32 connected to the middle, and a ending coil terminal 33 connected to the end of the winding are drawn out.

[0012] Each coil terminal 3 is drawn out from the upper end of the low-voltage coil 21 in the same direction in the circumferential direction, with each terminal offset vertically from the others. At this time, as shown in the side view in Figure 3, although there are differences in length, each coil terminal 3 is basically formed in a bent shape that is inclined outward and upward from the upper end of the low-voltage coil 21, with its tip extending upward. In this embodiment, the intermediate coil terminal 32 has a parallel connection structure in which two coil terminals, the first coil terminal 32a and the second coil terminal 32b, overlap.

[0013] Furthermore, the coil terminals 3 of each coil body 2 are electrically connected by inter-phase connecting conductors 4. Specifically, as shown in Figure 2(b), the starting coil terminals 31 are electrically connected by an inter-phase connecting conductor 41, the intermediate coil terminals 32 are electrically connected by an intermediate inter-phase connecting conductor 42, and the ending coil terminals 33 are electrically connected by an ending inter-phase connecting conductor 43.

[0014] Furthermore, each coil terminal 3 is electrically connected to an external terminal 5. Specifically, the starting coil terminal 31 is directly and electrically connected to the starting external terminal 51, which is fixed by bolt fastening. The intermediate coil terminals 32 are indirectly and electrically connected to each other by the intermediate interphase connecting conductor 42 being fixed by bolt fastening, and the intermediate external terminal 52 being fixed to the intermediate interphase connecting conductor 42. The ending coil terminals 33 are directly and electrically connected to each other by the ending external terminal 53 being fixed by bolt fastening.

[0015] At this time, the initial phase-connecting conductor 41 is bolted to the intermediate external terminal 52 via an insulating member 11a, as shown in a plan view in Figure 4, and the final phase-connecting conductor 43 is bolted to the intermediate external terminal 52 via an insulating member 11b. Therefore, the intermediate external terminal 52 is provided with a hole 12a for fixing it between itself and the intermediate phase-connecting conductor 42, a hole 12b for fixing it between itself and the initial phase-connecting conductor 41, a hole 12c for fixing it between itself and the final phase-connecting conductor 43, a hole 12d for fixing the intermediate external terminal 52, and holes 12e, 12f, 12g, and 12h for connecting external wiring.

[0016] On the other hand, the winding start external terminal 51 and the winding end external terminal 53 are formed in the same shape in this embodiment, and as shown in Figure 5(b), they are provided with a hole 13a for connecting to the winding start coil terminal 31 or the winding end coil terminal 33, a hole 13b for fixing it between itself and the intermediate interphase connecting conductor 42, and holes 13c, 13d, 13e, and 13f for connecting external wiring.

[0017] Further, as shown in FIG. 1, the single-phase transformer 1 includes an upper support member 14 provided on the upper surface of the upper support fitting 7. The upper support member 14 is formed in a shape in which three arm portions extend forward, and the start winding external terminal 51, the intermediate external terminal 52, and the end winding external terminal 53 are respectively connected to the tips of the respective arm portions. Therefore, the upper support member 14 positions each external terminal 5 in the vertical and front-rear directions. However, the upper support member 14 is not directly connected to each coil terminal 3.

[0018] Next, the operation and effects of the above-described configuration will be described. As described above, if the coil terminals 3 are shortened to suppress losses, the workability may deteriorate. Further, if the heights of the connection positions of the coil terminals 3 are made different or shifted in the front-rear direction to improve workability, the coil terminals 3 may become longer, resulting in deterioration of losses or an increase in size. Thus, in the conventional configuration, it has been difficult to achieve both energy saving and improvement of workability, and there has been a risk of an increase in size.

[0019] Therefore, in the present embodiment, while suppressing an increase in size, energy saving and improvement of workability are achieved as follows. Specifically, as shown in FIG. 3, in the single-phase transformer 1, the connection position (H2) between the intermediate coil terminal 32 and the intermediate phase-to-phase connection conductor 42 is lower than the connection position (H1) between the start winding coil terminal 31 and the start winding phase-to-phase connection conductor 41, and the connection position (H3) between the end winding coil terminal 33 and the end winding phase-to-phase connection conductor 43. In the present embodiment, the connection position (H1) and the connection position (H3) are set at the same position in the vertical direction.

[0020] Further, since the intermediate connection position (H2) is lower than the start connection position (H1) and the end connection position (H3), the length of the conductive portion drawn from the low-voltage coil 21 of the intermediate coil terminal 32 is shorter than the lengths of the conductive portions of the start winding coil terminal 31 and the end winding coil terminal 33. In the case of the present embodiment, the intermediate coil terminal 32 has the shortest length of the conductive portion.

[0021] Now, when the connection positions in the left - right direction are the same as shown in FIG. 4, as shown in FIG. 3, the minimum distance between the intermediate - side member and the start - winding - side member is defined as the start - winding insulation distance (L1). In the case of this embodiment, the start - winding insulation distance (L1) is the distance from the end of the bolt 10b that connects the intermediate coil terminal 32 and the intermediate phase - to - phase connection conductor 42 to the lower end of the start - winding external terminal 51. Note that the start - winding insulation distance (L1) may be at a different location depending on the structure.

[0022] This start - winding insulation distance (L1) is the distance necessary to ensure the insulation between the intermediate - side member and the start - winding - side member. In FIG. 3, since the intermediate external terminal 52 is located deeper (in the direction away from the viewer in the figure) than the bolt 10b, as shown in FIG. 5, even when the connection points of each coil terminal 3 are positioned on the virtual line (CL) and at the same position in the left - right direction, the start - winding insulation distance (L1) is the minimum distance.

[0023] In this case, as described above, by positioning the intermediate connection position (H2) below the start - winding connection position (H1), it is possible to suppress the increase in the size of the single - phase transformer 1 in the front - rear direction. That is, when the intermediate connection position (H2) and the start - winding connection position (H1) are at the same position in the up - down direction, it is necessary to arrange the end of the bolt 10b at a position further away from the rear end of the bolt 10a connecting the start - winding external terminal 51 by the start - winding insulation distance (L1). And in such a case, since the depth in the front - rear direction becomes long, the single - phase transformer 1 becomes larger.

[0024] In contrast, by shifting the intermediate connection position (H2) and the winding start connection position (H1) in the vertical direction, the required winding start insulation distance (L1) can be secured while shortening the depth in the front-to-back direction. Furthermore, a large working space (S1) can be secured between the winding start external terminal 51 and the winding end external terminal 53. In this embodiment, the intermediate connection position (H2) is arranged from the rear (left side in the figure) in the order of intermediate coil terminal 32, intermediate interphase connecting conductor 42, and washer 15, and fastened with bolt 10b. However, for example, the arrangement order can be different or the bolt 10b can be fastened in the reverse direction. In that case, the position of the minimum distance may change depending on the arrangement order. Similarly, the position of the minimum distance may also change for the winding start connection position (H1) and the winding end connection position (H3) depending on the arrangement order and fastening method.

[0025] On the other hand, the minimum distance between the intermediate member and the end-of-winding member is defined as the end-of-winding insulation distance (L2). In this embodiment, the end-of-winding insulation distance (L2) is the distance from the head of the bolt 10b to the end-of-winding coil terminal 33. This end-of-winding insulation distance (L2) is the distance necessary to ensure insulation between the intermediate member and the end-of-winding member. In this case as well, by shifting the intermediate connection position (H2) and the end-of-winding connection position (H3) in the vertical direction, it is possible to ensure the necessary end-of-winding insulation distance (L2) while suppressing an increase in size in the front-to-back direction. Note that the end-of-winding insulation distance (L2) may be in a different location depending on the structure.

[0026] Furthermore, the intermediate connection position (H2) is located within the inclined range (R1) of the starting coil terminal 31 in the vertical direction. Therefore, at the intermediate connection position (H2), it is possible to have a wider space between the intermediate coil terminal 32 and the starting coil terminal 31. This suppresses an increase in size in the front-to-back direction and ensures sufficient insulation distance. In addition, it is possible to secure working space (S2) for inserting and fastening the bolt 10b.

[0027] Furthermore, the intermediate connection point (H2) is located within the range (R2) of the portion extending above the end coil terminal 33 in the vertical direction. This allows for a wider space between the intermediate coil terminal 32 and the end coil terminal 33 at the intermediate connection point (H2), ensuring sufficient working space (S3) for inserting and fastening the bolt 10b.

[0028] As shown in Figure 4, the initial phase-connecting conductor 41 and the final phase-connecting conductor 43 are fixed to the intermediate external terminal 52 by bolt fastening via insulating members 11a and 11b. This ensures that a predetermined distance is maintained between the initial phase-connecting conductor 41 and the intermediate phase-connecting conductor 42, and between the intermediate phase-connecting conductor 42 and the final phase-connecting conductor 43 by insulating members 11a and 11b.

[0029] Accordingly, a predetermined distance is ensured between the starting coil terminals 31 connected to both ends of the starting phase connecting conductor 41, the intermediate coil terminals 32 connected to both ends of the intermediate phase connecting conductor 42, and the ending coil terminals 33 connected to both ends of the ending phase connecting conductor 43. This allows each coil terminal 3 to be positioned in the front-to-back direction without the need to provide a separate member to directly fix the position of each coil terminal 3. Furthermore, since there is no need to provide or fix a separate member, deterioration in workability is suppressed.

[0030] Furthermore, the above configuration in the single-phase transformer 1 can suppress the deterioration of losses. Specifically, if the coil conductor 61 is cut during winding, coil terminals 3 will be provided on both the coil conductor 61 that was wound up to the point of cut and the coil conductor 61 wound from the point of cut onward.

[0031] In this embodiment, as shown in Figure 6(a) as a model diagram illustrating the connection configuration between the coil terminal 3 and the conductor, the first coil terminal 32a and the second coil terminal 32b are connected to the cut point of the coil conductor 61, which is midway between the winding start and winding end. The first coil terminal 32a and the second coil terminal 32b are then pulled out and electrically connected at an external connection point (P2). The connection point (P2) is the connection position between the intermediate coil terminal 32 and the intermediate interphase connecting conductor 42. The connection point (P2) is also the connection position between the winding start coil terminal 31 and the winding start interphase connecting conductor 41, and the connection point (P3) is the connection position between the winding end coil terminal 33 and the winding end interphase connecting conductor 43.

[0032] Now, as shown in the current path diagram, if current flows from connection point (P1) to connection point (P3) as indicated by the dashed arrow (F1), current will also flow through the intermediate coil terminal 32 of the connection structure that brings the first coil terminal 32a and the second coil terminal 32b outside the coil and connects them externally, resulting in a loss. In this case, it is thought that the loss can be suppressed by making the intermediate coil terminal 32 as short as possible.

[0033] Therefore, in this embodiment, the length of the intermediate coil terminal 32 among the coil terminals 3 is minimized. This reduces losses, and since the current path passing through the first coil terminal 32a and the second coil terminal 32b is shortened, losses can be further reduced more effectively in a configuration that includes both the first coil terminal 32a and the second coil terminal 32b.

[0034] Furthermore, as shown in Figure 6(b), when the coil terminals 3 are connected by welding or the like without cutting the coil conductor 62, one intermediate coil terminal 132 is provided. In the case of such a single-phase transformer 101, as shown in the current path diagram, even if current flows from the connection point (P21), which is the end of the starting coil terminal 131, to the connection point (P3), which is the end of the ending coil terminal 133, as indicated by the dashed arrow (F2), no current flows through the connection point (P12) of the intermediate coil terminal 132.

[0035] Therefore, although there is no effect on reducing losses at the intermediate coil terminal 132, by using the same configuration and arrangement as the single-phase transformer 1, the starting coil terminal 131, intermediate coil terminal 132, and ending coil terminal 133 can be shortened, thereby suppressing losses and improving workability and preventing an increase in size.

[0036] According to the single-phase transformer 1 described above, the following effects can be obtained. The single-phase transformer 1 of this embodiment has a low-voltage coil 21 and a high-voltage coil 22 arranged concentrically, a plurality of adjacent coil bodies 2, a starting coil terminal 31, an intermediate coil terminal 32, and a ending coil terminal 33 that are drawn out from the upper end of the low-voltage coil 21 in the same direction, offset vertically, and an inter-phase connecting conductor 41 that electrically connects the starting coil terminals 31 of each coil body 2, an inter-phase connecting conductor 42 that electrically connects the intermediate coil terminals 32, and an inter-phase connecting conductor 42 that electrically connects the ending coil terminals 33. The coil comprises a winding end phase connecting conductor 43 that is electrically connected, a winding start external terminal 51 electrically connected to the winding start coil terminal 31, an intermediate external terminal 52 electrically connected to the intermediate coil terminal 32, and a winding end external terminal 53 electrically connected to the winding end coil terminal 33. The connection position (H2) between the intermediate coil terminal 32 and the intermediate phase connecting conductor 42 is set lower than the connection position (H1) between the winding start coil terminal 31 and the winding start phase connecting conductor 41 and the connection position (H3) between the winding end coil terminal 33 and the winding end phase connecting conductor 43.

[0037] By shifting the connection position vertically in this way, the deterioration of workability is suppressed even if the conductive portion of the coil terminal 3 is shortened. Furthermore, because the deterioration of workability is suppressed, there is no need to make the height of the connection position of the coil terminals 3 different or to enlarge the front-to-back direction for the sake of workability, and the deterioration of losses and the increase in size are also suppressed. In addition, a large working space (S1) can be secured between the winding start external terminal 51 and the winding end external terminal 53, making it easy to perform tasks such as inserting and fastening bolts.

[0038] Therefore, it is possible to achieve both energy conservation and improved work efficiency while suppressing the increase in size. In addition, because the size can be suppressed, the possibility of violating dimensional restrictions during delivery or installation is reduced, and work efficiency outside of manufacturing can be improved.

[0039] Furthermore, in the single-phase transformer 1, the intermediate coil terminal 32 has a structure in which two terminals are drawn out from the low-voltage coil 21 in a stacked manner. As described above, when the intermediate coil terminal 32 has a structure in which the first coil terminal 32a and the second coil terminal 32b are stacked and connected externally, the current flows back and forth between the first coil terminal 32a and the second coil terminal 32b, resulting in large losses. Therefore, by making the conductive portion of the coil terminal 3 shorter as described above, and by minimizing the length of the intermediate coil terminal 32 as in this embodiment, the effect of reducing losses can be further enhanced when using an intermediate coil terminal 32 in which multiple terminals are drawn out from the middle of the coil and connected externally.

[0040] Furthermore, in the single-phase transformer 1, the intermediate external terminal 52 also serves as a fixing member for fixing the initial phase-connecting conductor 41 and the final phase-connecting conductor 43. The initial phase-connecting conductor 41 and the final phase-connecting conductor 43 are fixed to the intermediate external terminal 52 via insulating members 11a and 11b by bolt fastening. This allows each phase-connecting conductor 4 to be fixed without the need for individual members, and improves workability by allowing for easy bolt fastening.

[0041] Furthermore, in the single-phase transformer 1, the starting coil terminal 31 is formed in a bent shape that slopes outward and upward from the upper end of the low-voltage coil 21, with the tip extending upward. The connection position between the intermediate coil terminal 32 and the intermediate interphase connecting conductor 42 is located within the range where the starting coil terminal 31 is sloped in the vertical direction. As a result, when connecting the intermediate coil terminal 32 and the intermediate interphase connecting conductor 42, the space between the intermediate coil terminal 32 and the starting coil terminal 31 is widened, and a working space (S2) can be secured there, making it easier to position and fasten bolts without increasing the length of the intermediate coil terminal 32.

[0042] Furthermore, in the single-phase transformer 1, the end coil terminal 33 is formed in a bent shape that slopes outward and upward from the upper end of the low-voltage coil 21, with the tip extending upward. The connection position between the intermediate coil terminal 32 and the intermediate inter-phase connecting conductor 42 is located within the range of the portion extending upward from the end coil terminal 33 in the vertical direction. As a result, when connecting the intermediate coil terminal 32 and the intermediate inter-phase connecting conductor 42, the space between the intermediate coil terminal 32 and the end coil terminal 33 is widened, and insulation distance and working space (S3) can be secured there, making connection work easy and also suppressing an increase in the dimensions of the front and rear.

[0043] In the embodiment, a single-phase transformer 1 is exemplified by an intermediate coil terminal 32 having a first coil terminal 32a and a second coil terminal 32b. However, as shown in Figure 6(b), even in a single-phase transformer 101 having one intermediate coil terminal 132 that does not have a structure for connecting multiple terminals externally, the same configuration as the single-phase transformer 1 of the embodiment can be used to achieve energy saving and improved workability while suppressing an increase in size, thus obtaining the various effects described above.

[0044] In this embodiment, the coil terminal 3 is shown as being formed from a bent plate-shaped member, but cylindrical or rectangular bar-type members can also be used.

[0045] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0046] In the drawing, 1 and 101 represent single-phase transformers, 2 represents a coil body, 11a and 11b represent insulating members, 21 represents a low-voltage coil, 22 represents a high-voltage coil, 31 and 131 represent the starting coil terminals, 32 and 132 represent intermediate coil terminals, 32a represents the first coil terminal, 32b represents the second coil terminal, 33 and 133 represent the ending coil terminals, 41 represents the starting phase-to-phase connecting conductor, 42 represents the intermediate phase-to-phase connecting conductor, 43 represents the ending phase-to-phase connecting conductor, 51 represents the starting external terminal, 52 represents the intermediate external terminal, and 53 represents the ending external terminal.

Claims

1. It has low-voltage coils and high-voltage coils arranged concentrically, and multiple coil bodies arranged adjacent to each other, The winding start coil terminal, intermediate coil terminal, and winding end coil terminal are drawn out from the upper end of the low-voltage coil in the same direction, offset vertically. Each of the coil bodies comprises a starting phase connecting conductor that electrically connects the starting coil terminals, an intermediate phase connecting conductor that electrically connects the intermediate coil terminals, and a ending phase connecting conductor that electrically connects the ending coil terminals, It comprises a starting external terminal electrically connected to the starting coil terminal, an intermediate external terminal electrically connected to the intermediate coil terminal, and a ending external terminal electrically connected to the ending coil terminal. A single-phase transformer in which the connection position between the intermediate coil terminal and the intermediate inter-phase connecting conductor is set lower than the connection position between the starting coil terminal and the starting inter-phase connecting conductor and the connection position between the ending coil terminal and the ending inter-phase connecting conductor.

2. The single-phase transformer according to claim 1, wherein the intermediate coil terminals are drawn out in two stacks from the low-voltage coil.

3. The aforementioned intermediate external terminal also serves as a fixing member for fixing the initial phase connecting conductor and the final phase connecting conductor. The single-phase transformer according to claim 1 or 2, wherein the initial phase-connecting conductor and the final phase-connecting conductor are fixed to the intermediate external terminal via an insulating member by bolt fastening.

4. The winding start coil terminal is formed in a bent shape that slopes outward and upward from the upper end of the low-voltage coil, with the tip extending upward. The single-phase transformer according to claim 1 or 2, wherein the connection position between the intermediate coil terminal and the intermediate interphase connecting conductor is located within the range in which the winding start coil terminal is inclined in the vertical direction.

5. The winding end coil terminal is formed in a bent shape that slopes outward and upward from the upper end of the low-voltage coil, with the tip extending upward. The single-phase transformer according to claim 1 or 2, wherein the connection position between the intermediate coil terminal and the intermediate interphase connecting conductor is located within the range of the portion extending above the winding end coil terminal in the vertical direction.

Images