JPH04127623U - composite transformer - Google Patents

Abstract

(57) [Summary] [Purpose] To miniaturize the tap switching mechanism of a composite transformer and to enable tap switching to be performed easily and in a short time. [Structure] The winding of a first unit transformer Cu and the winding of a second unit transformer Cv are housed in a common tank and are V-connected. One end of the winding of the first unit transformer Cu is connected to the line terminal U, and a tap is drawn from the other end of the winding. Second
Connect one end of the winding of the unit transformer Cv to the line terminal W,
The tap is drawn out from the other end of the winding. The taps of the winding of the first unit transformer and the taps of the winding of the second unit transformer are connected to a common tap switching mechanism, and any pair of taps of the same voltage of both unit transformers are connected to each other. Commonly connected to line terminal V.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a composite transformer consisting of two single-phase transformer bodies. Ru.

0002

[Conventional technology]

In power distribution lines, V-connection is generally used as a phase connection when stepping down voltage from high voltage to low voltage. line is used. In this case, conventionally two independent single-phase transformers are used to The transformer was V-wired externally.

0003 However, in recent years, two single-phase transformers (hereinafter referred to as unit transformers) have been connected to a common A transformer that is housed in a tank and has both single-phase transformer bodies V-connected in the tank (hereinafter referred to as multiple transformer) It is called a coupling transformer. ) has come into use.

0004 Composite transformers provide more power than regular transformers for the same distribution grid power. Since the number of machines to be installed can be reduced to half, construction and maintenance costs can be significantly reduced. Moreover, since the appearance is simple, it is preferable in terms of the urban environment. Therefore, in urban areas Pole-mounted transformers are being replaced by composite transformers.

[0005] Also, in ground-mounted transformers, which have become widely used in urban areas in recent years, complex Transformers are now being used.

[0006] In conventional tapped composite transformers, the taps used in ordinary single-phase transformers are Two sets of similar top switching mechanisms were provided.

[0007] FIG. 7 is an inter-winding connection diagram of a conventional composite transformer (the number of taps is 6), Taps tu1 to tu6 are provided at the center of the winding Cu1 of the first unit transformer; Taps tv1 to tv6 are provided at the center of the winding Cv1 of the unit transformer.

[0008] In this specification, "winding" refers to the winding on the side where the tap is provided (usually (primary winding).

[0009] Taps tu1 to tu6 of the first unit transformer and tap tv1 of the second unit transformer. The taps tv6 and tv6 are connected to separate tap switching mechanisms (not shown).

0010 Therefore, when performing tap switching, the tap switching of the first unit transformer is The installation work and the tap switching work of the second unit transformer were performed separately.

[0011] In the example of FIG. 7, taps tu3 and tu4 are connected, and taps tv3 and tv4 are connected. is the highest tap when it is connected, taps tu1 and tu6 are connected, and the tap The state where tv1 and tv6 are connected is the lowest tap. Also, the highest tap voltage and The difference between the low tap voltage and the low tap voltage is the total tap-to-tap voltage.

0012

[Problem that the idea aims to solve]

In conventional composite transformers, a tap switching mechanism is provided for each unit transformer. Therefore, a large amount of material and installation space is required, and tap switching work is also time-consuming. There was a problem that it took a while.

[0013] In addition, in conventional composite transformers, the taps of two unit transformers are combined into one set of taps. Although it is possible to attach them all at once to the switching mechanism, there are the following problems.

[0014] In other words, the maximum voltage applied between taps of the same unit transformer is the above-mentioned total tap voltage. However, the voltage between the windings (voltage between line terminals) is approximately 1/1 between the taps of different unit transformers. 2 voltage is applied.

[0015] Since the value of 1/2 of the voltage between line terminals is several times larger than the value of the voltage between all taps, the difference is The insulation distance between the taps of a unit transformer is equal to the insulation distance between the taps of the same unit transformer. The tap switching mechanism would also need to be much larger.

[0016] Also, since a switching piece must be provided for each unit transformer, tap switching work is difficult. , it requires almost the same number of steps as providing a tap switching mechanism for each unit transformer. .

[0017] The purpose of this invention is to make the tap switching mechanism itself compact and to Not only does it take up less space, it also allows tap switching to be done easily and quickly. The objective is to provide a composite transformer that can

[0018]

[Means to solve the problem]

The present invention connects the windings of the first unit transformer and the windings of the second unit transformer to a common tank. This relates to a composite transformer that is housed in a V-wired V-connected transformer. The tap drawer and tap switching mechanism shall have the following configuration.

[0019] One end of the winding of the first unit transformer is connected to the line terminal U, and the other end of the winding is connected to the line terminal U. Make a withdrawal.

[0020] One end of the winding of the second unit transformer is connected to the line terminal W, and the other end of the winding is connected to the line terminal W. Make a withdrawal.

[0021] The tap of the winding of the first unit transformer and the tap of the winding of the second unit transformer are common. is connected to the tap switching mechanism of the One pair is commonly connected to the line terminal V.

[0022] For example, the tap switching mechanism described above may include the tap terminal connected to the tapped tap and the tap terminal connected to the tap connected to the Switch the tap terminal connected to the tap to the common terminal connected to the line terminal V. It is possible to use a structure in which the connection is made by the following. In that case, the first unit transformer and the tap terminal connected to the tap drawn from the winding of the second unit transformer. A tap terminal connected to a tap drawn out from a line is, for example, a tap terminal connected to a tap drawn out from a line. When the tap terminals are lined up and connected to taps of the same voltage, Place it in the position. Also, the first unit transformer and the second unit transformer are identical. Place the common terminal connected to the line terminal V between the tap terminals of one voltage, and The tap terminal and the corresponding common terminal are connected by a switching piece.

[0023] In addition, a tap terminal drawn out from the winding of the first unit transformer and a second unit transformer Connect the tap terminal connected to the tap pulled out from the winding to the line terminal V. The first unit transformer and the second unit transformer are arranged on the same circumference with the common terminal as the center. Connect the tap terminals of the unit transformers with the same voltage to the common terminal using a switching piece. It's okay.

[0024] Furthermore, the tap connected to the tap drawn out from the winding of the first unit transformer is connected to connected to the tap terminal connected to the tap terminal connected to the winding of the second unit transformer. tap terminals with different radii using the common terminal connected to the line terminal V. The first unit transformer and the second unit transformer are arranged in a fan shape on the circumference, and the voltage transformers of the first unit transformer and the second unit transformer are It is also possible to connect the top terminal to the common terminal by means of a switching piece.

[0025]

[Effect]

As mentioned above, connect one end of each of the windings of the two unit transformers to the three-phase line terminal. Connect to the other two terminals (U, W), pull out the tap from the other end of each winding, Connect any pair of taps with the same voltage to connect the remaining 3-phase line terminal (V ), one tap switching mechanism can connect the taps of two unit transformers. can be switched at the same time. And the voltage between the taps of the two unit transformers The voltage will not exceed the voltage across all taps.

[0026] Therefore, tap switching can be done easily and in a short time. The switching mechanism can be made smaller.

[0027]

【Example】

Embodiments of the present invention will be described below with reference to the drawings.

[0028] The number of taps for a composite transformer is arbitrary, but here we use the standard number of taps, 5 taps. Let's take the case of a drop-off as an example.

[0029] FIG. 1 is an inter-winding connection diagram of a composite transformer according to the present invention, in which the first unit transformer The winding Cu of the second unit transformer and the winding Cv of the second unit transformer are V-connected.

[0030] One end 1u of the winding Cu of the first unit transformer is connected to the line terminal U, and the winding Cu Taps tu1, tu2, ..., tu5 are pulled out from a portion near the other end. tap t u1, tu2,..., tu5 are arranged in order in the direction away from one end of the winding Cu. Coup tu5 is the other end of the winding Cu.

[0031] One end 1v of the winding Cv of the second unit transformer is connected to the line terminal W; Taps tv1, tv2,..., tv5 are pulled out from the portion near the end. These taps The windings tv1, tv2, ..., tv5 are also arranged in order in the direction away from one end of the winding Cv, Tap tv5 is the other end of winding Cv.

[0032] When taps tu1 to tu5 of the winding of the first unit transformer are collectively referred to as the first tap, The tap group tu is used to collectively refer to the taps tv1 to tv5 of the winding of the second unit transformer. In this case, it will be called the second tap group tv.

[0033] Also, the voltage difference between the same voltages in the first tap group tu and the second tap group tv The paired taps will be referred to as corresponding taps.

[0034] For example, the pair of taps tu1 and tv1 are corresponding taps, and generally the taps tun and tvn is the corresponding tap. The corresponding taps tu1 and tv1 are the lowest taps, and the corresponding taps are Taps tu5 and tv5 are the highest taps. The voltage of the highest tap and the voltage of the lowest tap The difference is the total tap-to-tap voltage. In the first tap group tu and the second tap group tv Any corresponding tabs are commonly connected and connected to the line terminal V.

[0035] FIG. 2 is a voltage vector diagram at the connection between the windings in FIG. (b) shows the voltage vector when the tap is selected, and (b) shows the voltage vector when the tap is selected. Shows the voltage vector when selected.

[0036] 3 and 4 show a tap switching mechanism 10 in an embodiment of the present invention, FIG. 3 is a partially sectional plan view of the same tap switching mechanism. Also, Figure 4 is similar to Figure 3. It is a side view of the same tap switching mechanism seen from the lower side to the upper side. first tap group tu and the second tap group tv are connected to one tap switching mechanism 10.

[0037] The first tap group tu is connected to the first tap terminal group Tu. That is, Taps tu1 to tu5 of the winding of the first unit transformer are respectively corresponding tap ends. Connected to children Tu1 to Tu5.

[0038] The second tap group tv is connected to the second tap terminal group Tv. That is, Taps tv1 to tv5 of the winding of the second unit transformer are respectively corresponding tap ends. Connected to child Tv1 to Tv5.

[0039] The tap terminals Tu1 to Tu5 are arranged in a straight line and attached to the insulating plate 20. The tap terminals Tv1 to Tv5 are arranged in a straight line parallel to the tap terminals Tu1 to Tu5. and are attached to the same insulating plate 20.

[0040] Between tap terminals Tu1 and Tv1, ..., between tap terminals Tu5 and Tv5, A common terminal T0 is attached.

[0041] As shown in Figure 3, the tap terminals are arranged along parallel straight lines. The switching mechanism will be referred to as a linear tap switching mechanism.

[0042] The five common terminals T0 are commonly connected by the connecting plate 30, and are connected to one end of the connecting plate 30. A hole 30a is provided. This hole 30a is a lead connected to the line terminal V. This is for attaching a cable (not shown in Figure 3).

[0043] 40 is a switching piece, which connects the tap terminal of any corresponding tap to the common terminal T0. It is a rectangular plate-shaped conductor. The switching piece 40 is provided with three cut grooves 40a. The cut grooves 40a are opened on the same long side of the switching piece 40. . Using these three cut grooves 40a, the switching piece 40 is connected to the first tap terminal group. Tu, the second tap terminal group Tv and the common terminal T0. In other words, switching Fit the common terminal T0 into the cut groove 40a in the center of the piece 40, and then The first tap terminal group Tu and the second tap terminal group Tv are fitted into the groove portion 40a. Ru. This one switching piece 40 switches the winding Cu of the first unit transformer and the second unit transformer. Connect any corresponding taps of the transformer winding Cv to form a V connection between both windings.

[0044] In the example shown in Fig. 3, the tap tu3 of the winding Cu of the first unit transformer and the tap tu3 of the winding Cu of the first unit transformer The tap tv3 of the winding Cv of the transformer is selected, and the tap terminals Tu3, Tv3 and the common terminal T0 is connected by a switching piece 40. Switch from this state to another tap In this case, loosen the nuts on the tap terminal and common terminal that tighten the switching piece 40. After that, remove the switching piece 40 from the bolt part of the tap terminal and the common terminal, and remove the switching piece 40 from the bolt part of the tap terminal and the common terminal. Just connect it again to the tap terminal of and the common terminal T0.

[0045] In FIG. 3, the portion above the break line a-a is the top surface of the switching piece 40 (in FIG. The cross-section is shown along the front side of the paper (the front side is the upper side).

[0046] According to the above embodiment, one tap switching mechanism is used to connect two units with one switching piece. Since the taps of unit transformers can be switched at the same time, the location of the tap switching mechanism is reduced. In addition to requiring less material and space, tap changeover is easy and quick. I can. Also, consider the distance between the tap terminals of compatible taps and the taps with different voltages. Since the distance between the tap terminals is different, the switching piece 40 can be connected to the tap terminals with different voltages. Cannot connect. Therefore, a compatible tap will always be selected, and two Reliably eliminates work errors such as connecting taps with different voltages to unit transformers. can do.

[0047] Note that instead of providing the cut groove 40a, a hole (similar to the hole 30a of the connecting plate) is provided. ) may be provided, but in terms of tap switching workability, a cut groove is more suitable. . However, from the perspective of preventing the switching piece from falling off, it is better to use a hole rather than a cut groove. stomach. From this point of view, we aim to improve the workability of tap switching and prevent the switching piece from falling off. Therefore, only the central part of the switching piece that is connected to the common terminal Make the holes to fit together, and make the parts on both sides where the tap terminals fit in opposite directions. It can also be an open cut groove. In this case, the common terminal T0 and both After loosening the nut on the tap terminal on the side, insert the switching piece on either side centering on the common terminal. Remove the switching piece from the tap terminals on both sides by rotating it in the direction Remove only the nut of the terminal and remove the switching piece.

[0048] The unit transformer in this example uses an end tap method (tap is pulled from one end of the winding). In particular, in the case of inner iron type transformers, the windings of both legs of the iron core are connected in parallel. Connecting.

[0049] FIG. 5 is a plan view showing a tap switching mechanism used in another embodiment of the present invention. child In the tap switching mechanism 11, the tap is connected to the tap of the winding Cu of the first unit transformer. to the tapped terminals Tu1 to Tu5 and the tap of the winding Cv of the second unit transformer. The connected tap terminals Tv1 to Tv5 are arranged on the circumference with the common terminal T0 as the center. has been done. Then, each corresponding tap is placed at a point symmetrical position with respect to the common terminal T0. has been done.

[0050] As shown in Figure 5, the tap switching mechanism is arranged in a circular manner with tap terminals arranged on the circumference. We will call this the type tap switching mechanism.

[0051] In FIG. 6, 21 is an insulating plate, 31 is a connecting plate, and 31a is connected to the line terminal V. This is a hole for attaching a lead wire (not shown in FIG. 5). 41 is This switching piece has three cut grooves 41a, and this switching piece is shown in FIGS. 3 and 4. This is similar to that used in the linearly arranged tap switching mechanism 10.

[0052] The cut groove 41a in the center of the switching piece 41 is a part connected to the common terminal T0. The notch grooves 41a at both ends of the switching piece 41 are connected to the first tap terminal group Tu and the second tap terminal group Tu. This is the part connected to the tap terminal group Tv.

[0053] In FIG. 5, taps tu3 and tv3 are selected, and the tap terminals Tu3 and T are connected by the switching piece 41. v3 is connected to the common terminal T0.

[0054] In addition, as a configuration that combines tap switching workability and prevention of the switching piece from falling off, the switching piece is Only the part connected to the common terminal T0 in the center is a hole, and the tap terminals on both sides The portions connected to the grooves can also be cut grooves that open in opposite directions. .

[0055] In the circularly arranged tap switching mechanism 11, there is only one tap terminal T0. , because the connecting plate is also shorter, the conductor location is shorter than in the case of the linearly arranged tap switching mechanism 10. Only a small amount is required. Also, since only one common terminal T0 is required, the lead wire It is also possible to omit the connecting plate 31 by connecting directly to the common terminal T0. Ru. In this case as well, the switching piece cannot connect between tap terminals with different voltages. This prevents tap switching mistakes when selecting taps with different voltages for two unit transformers. be able to.

[0056] FIG. 6 is a plan view showing a tap switching mechanism according to still another embodiment of the present invention. Ta In the tap switching mechanism 12, a tap is connected to the tap of the winding Cu of the first unit transformer. connected to the tap terminals Tu1 to Tu5 and the tap of the winding Cv of the second unit transformer. The tap terminals Tv1 to Tv5 are located on the circumference with different radii around the common terminal T0. They are arranged in a fan shape. And corresponding taps with equal voltage are common They are arranged in a radial direction of a circle centered on the terminal T0. Therefore, common terminal T 0 and each corresponding tap are arranged in a straight line.

[0057] As shown in FIG. 6, the first tap terminal group Tu (Tu1 to Tu5) and the second tap terminal group A configuration in which terminal groups Tv (Tv1 to Tv5) are arranged on concentric circles with different radii. The tap switching mechanism will be referred to as a fan-shaped tap switching mechanism.

[0058] In FIG. 6, 22 is an insulating plate, 32 is a connecting plate, and 32a is connected to the line terminal V. This is a hole for attaching a lead wire (not shown in FIG. 6). 42 42a is a cut groove of the switching piece 42, and the switching piece is arranged in a straight line. It is similar to that used in the type tap switching mechanism 10.

[0059] The cut groove portion 42a on one end side of the switching piece 42 is a portion connected to the common terminal T0. The notch grooves 42a at the center and other ends of the switching piece 42 are respectively connected to second taps. It is a portion coupled to the tap terminals of the terminal group Tv and the first tap terminal group Tu. .

[0060] In FIG. 6, the tap terminals tu3 and tv3 are selected and the tap terminals are switched by the switching piece 42. A state in which Tu3 and Tv3 are connected to the common terminal T0 is shown. In addition, tap switching One end of the switching piece is designed to improve workability and prevent the switching piece from falling off. Only the part connected to the common terminal T0 of is made a hole, and connected to other tap terminals. The portions can also be cut grooves that open on the same side.

[0061] In the fan-shaped tap switching mechanism 12, only one common terminal T0 is required. In addition, since the connecting plate can be extremely short, it can be made shorter than in the case of the circularly arranged tap switching mechanism 11. Moreover, the amount of conductor required can be further reduced.

[0062] Also, since only one tap terminal T0 is required, the lead wire can be directly connected to the common terminal. It is also possible to omit the connecting plate 32 by connecting it to T0. In addition, the common end Since the child T0 is located on one end side of the insulating plate 22, even if the connecting plate 32 is omitted, the lead Attaching the wire to the common terminal is easy.

[0063] Even when the structure shown in Fig. 6 is adopted, the switching piece 42 connects the tap terminals with different voltages. Therefore, mistakes in tap switching can be prevented.

[0064] As mentioned above, there are three types of tap switching mechanisms (linear tap switching mechanism, circular In both the arranged tap switching mechanism and fan-shaped arranged tap switching mechanism, the switching piece is The structure was designed to be tightened with nuts, but some parts of the switching piece are now tightened with bolts. You may.

[0065] For example, the portion where the switching piece is fastened to the common terminal may have a bolt fastening structure. Immediately The common terminal has a structure in which a screw hole is provided in the conductor, and the cut groove (or Switching is possible by aligning the hole (hole) with this screw hole and screwing the bolt into the screw hole. The pieces may be connected to a common terminal.

[0066] In addition, when configured in this way, the connecting plate must also function as a common terminal. Can be done. That is, the connecting plate is placed on the mounting side of the switching piece (the upper surface side of the insulating plate), and A screw hole is provided at the position corresponding to the common terminal of the connection plate, and the switching piece is bolted using the screw hole. The structure can be tightened. Especially in the case of linearly arranged tap change mechanisms. By adopting a structure in which the common terminal is a screw hole as described above, the required materials can be saved. The configuration can be simplified.

[0067] In the embodiments described above, all tap switching mechanisms are tap switching panels. However, the present invention is not limited to these embodiments, but can also be used as a tap switching mechanism. A top switch may also be used.

[0068] When the tap change mechanism is a tap changer, the tap change panel of the above embodiment is used. The tap terminal and common terminal in the tap changer are connected to the fixed contact in the tap changer, respectively. The switching piece corresponds to a movable contact.

[0069]

[Effect of the idea]

As described above, according to the present invention, end taps can be drawn out from the windings of two unit transformers. The taps can be pulled out using the system, and the taps can be changed using a single tap switching mechanism. Therefore, there is an advantage that tap switching can be performed easily and in a short time.

[0070] In addition, in this invention, the voltage between the tap terminals in the tap switching mechanism is The advantage is that the tap switching mechanism can be made compact because the voltage between taps will not be exceeded. There is.

[0071] In particular, according to the inventions described in claims 2 to 4, the switching pieces are configured to have different voltages. It cannot be connected to pressure taps, which prevents mistakes that could lead to mismatched taps. It has the advantage of being eliminated.

[Brief explanation of drawings]

FIG. 1 is an inter-winding connection diagram of an embodiment of the present invention.

2(a) and (b) are voltage vector diagrams when the inter-winding connection of FIG. 1 is adopted; FIG.

FIG. 3 is a partially sectional plan view of the tap switching mechanism used in the embodiment of the present invention.

FIG. 4 is a side view of the tap switching mechanism used in the embodiment of the present invention.

FIG. 5 is a plan view of a tap switching mechanism used in another embodiment of the present invention.

FIG. 6 is a plan view of a tap switching mechanism used in yet another embodiment of the present invention.

FIG. 7 is an inter-winding connection diagram of a conventional composite transformer.

[Explanation of symbols]

Cu...Winding of the first unit transformer, Cv...Winding of the second unit transformer, U, V, W...Line terminals, tu1 to tu5...Tap in the winding of the first unit transformer, tu ...First tap group, tv1 to tv5...Taps in the winding of the second unit transformer, tv...Second tap group, Tu1 to Tu5...Tap terminals in the winding of the first unit transformer, Tu... 1st tap terminal group, Tv1 to Tv5...Tap terminal in the winding of the second unit transformer, Tv...2nd tap terminal group, T0...Common terminal, 10, 11, 12...Tap switching mechanism, 20, 21,
22... Insulating plate, 30, 31, 32... Connection plate, 40, 4
1, 42...Switching piece.

Claims (4)

[Scope of utility model registration request] 1. A composite transformer in which a winding of a first unit transformer and a winding of a second unit transformer are housed in a common tank and are V-connected, wherein the first unit transformer One end of the winding of the second unit transformer is connected to the line terminal U, and a tap is pulled out from the other end of the winding, and one end of the winding of the second unit transformer is connected to the line terminal W, and the winding is connected to the line terminal U. A tap is pulled out from the other end of the wire, the tap of the winding of the first unit transformer and the tap of the winding of the second unit transformer are connected to a common tap switching mechanism, and the tap of the winding of the first unit transformer is connected to a common tap switching mechanism, A composite transformer characterized in that any pair of taps of the same voltage in the winding of the unit transformer and the winding of the second unit transformer are connected together and commonly connected to a line terminal V. Claim 2: The tap terminal connected to the tap drawn out from the winding of the first unit transformer is parallel to the tap terminal connected to the tap drawn out from the winding of the second unit transformer. The first unit transformer and the second unit transformer are arranged along a straight line and with tap terminals connected to taps of the same voltage located at corresponding positions. A common terminal connected to the line terminal V is arranged between tap terminals of the same voltage, and a switching connection piece is provided for connecting the tap terminals of the same voltage and the corresponding common terminals. A composite transformer according to claim 1. 3. A tap terminal drawn out from the winding of the first unit transformer and a tap terminal connected to the tap drawn out from the winding of the second unit transformer are connected to the line terminal V. arranged on the same circumference with the common terminal as the center,
2. The composite transformer according to claim 1, further comprising a switching connection piece that connects tap terminals of the same voltage of the first unit transformer and the second unit transformer to the common terminal. 4. The tap terminal connected to the tap drawn out from the winding of the first unit transformer and the tap terminal connected to the tap drawn out from the winding of the second unit transformer are The first unit transformer and the second unit transformer are arranged in a sector shape on the circumference of different radii with the common terminal connected to the line terminal V as the pivot, and the tap terminals of the same voltage of the first unit transformer and the second unit transformer are connected to the common terminal. 2. The composite transformer according to claim 1, further comprising a switching connection piece for connection.