Power Converters and Transformers

Abstract

To provide a power conversion device and a transformer capable of improving dielectric strength and suppressing a temperature rise while suppressing an increase in size.SOLUTION: A power conversion device 100 includes a transformer 2 including: a core 20 having a leg 21 forming a magnetic path; and a winding 10 wound around the leg 21 of the core 20. The winding 10 has a winding 11 on the primary side and a winding 12 on the secondary side. The winding 11 is sealed together with a part of core 20 by a resin member 50 while being wound around the leg 21 of the core 20. Moreover, the winding 12 is exposed while being wound around the leg 21 of the core 20.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a power conversion device and a transformer. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a transformer including a first coil serving as a primary winding and a second coil serving as a secondary winding is known (see, for example, Patent Document 1).

[0003] The transformer described in Patent Document 1 includes a core that forms a magnetic path for the coil. A first coil, which is a primary winding, and a second coil, which is a secondary winding, are arranged to be wound around the core. In the transformer described in Patent Document 1, the first coil, the second coil, and the core are all assembled in a case and sealed with insulating resin to improve dielectric strength. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-19120 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the transformer described in Patent Document 1, the first coil (primary winding), the second coil (secondary winding), and the core are all enclosed (sealed) with insulating resin (resin member) to improve dielectric strength, which reduces the cooling performance of the entire transformer. As a result, when applying a high voltage to the windings sealed with the resin member, it is necessary to enlarge the windings and the core to suppress the rise in temperature. Therefore, when increasing the withstand voltage (applying a high voltage), there is a problem that the transformer becomes larger in size in order to improve the dielectric strength and suppress the rise in temperature.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power conversion device and a transformer that are capable of improving dielectric strength and suppressing temperature rise while preventing an increase in size. [Means for solving the problem]

[0007] In order to achieve the above object, a power conversion device according to a first aspect of the present invention comprises a power conversion unit that converts input DC power into AC power, and a transformer that transforms the AC power from the power conversion unit, the transformer including a core having legs that form a magnetic path, and a winding wound around the legs of the core, the winding having a high-voltage side winding which is either a primary winding on the primary side or a secondary winding on the secondary side, and a low-voltage side winding which is the other of the primary winding and secondary winding, the high-voltage side winding is sealed together with a part of the core by a resin member while wound around the legs of the core, and the low-voltage side winding is exposed while wound around the legs of the core.

[0008] In the power converter according to the first aspect of the present invention, as described above, the high-voltage side winding is sealed with a resin member together with a part of the core while being wound around the leg of the core. This allows the high-voltage side winding and a part of the core to be sealed with a resin member having a small dielectric constant (high insulating performance), so that the dielectric strength of the high-voltage side winding can be improved compared to when the high-voltage side winding is exposed. Also, as described above, the low-voltage side winding is exposed while being wound around the leg of the core. This allows heat to be released from the exposed low-voltage side winding and the part of the core around which the low-voltage side winding is wound. Therefore, the temperature rise of the transformer can be suppressed compared to when both the high-voltage side winding and the low-voltage side winding are sealed with a resin member together with the entire core. As a result, it is not necessary to increase the size of the winding and the core in order to suppress the temperature rise, so that the dielectric strength can be improved and the temperature rise can be suppressed while suppressing the size increase.

[0009] In the power conversion device according to the first aspect, the transformer preferably further includes a high-voltage winding casing that houses a high-voltage winding of the winding, and the high-voltage winding is sealed together with a part of the core by a resin material filled inside the high-voltage winding casing while it is housed in the high-voltage winding casing. With this configuration, it is possible to fill the inside of the high-voltage winding casing with a resin material while the high-voltage winding wound around the leg of the core is housed in the high-voltage winding casing together with the core. Therefore, the high-voltage winding can be easily sealed together with a part of the core by the resin material.

[0010] In the power converter according to the first aspect, preferably, the power converter further includes a bobbin for holding a winding in order to wind the winding around the leg of the core, and the high-voltage side winding is sealed with a resin member together with the bobbin and a part of the core while being held by the bobbin and wound around the leg of the core. With this configuration, the winding can be easily arranged so as to be wound around the core by holding the winding with the bobbin. In addition, since the high-voltage side winding is sealed with a resin member together with the bobbin and a part of the core, the high-voltage side winding, the bobbin, and the core can be sealed together. Therefore, for example, it is possible to suppress a decrease in dielectric strength due to the presence of an air layer between the core and the bobbin. As a result, the bobbin allows the winding to be easily arranged so as to be wound around the core, and a high voltage resistance can be achieved by suppressing a decrease in insulation.

[0011] In the power converter according to the first aspect, preferably, the high-voltage side winding and the low-voltage side winding are wound around the legs of the core in a state where they are separated from each other in the direction in which the legs extend, the high-voltage side winding is wound around one side of the legs and sealed with a resin member together with a part of the core, and the low-voltage side winding is exposed in a state where it is wound around the other side of the legs. With this configuration, since the high-voltage side winding is wound around one side of the legs, by sealing only one side of the legs with a resin member, the high-voltage side winding can be more easily sealed while exposing the low-voltage side winding wound around the other side. Therefore, the workload for sealing the high-voltage side winding while exposing the low-voltage side winding can be further reduced.

[0012] In the power converter according to the first aspect, the high-voltage side winding preferably has a first high-voltage side winding and a second high-voltage side winding that are divided into two and wound around the legs of the core, the low-voltage side winding is wound around the legs so as to be sandwiched between the first high-voltage side winding and the second high-voltage side winding in the direction in which the legs of the core extend, and the first high-voltage side winding and the second high-voltage side winding are each sealed with a resin member together with a part of the core in a state in which they are wound around the legs so as to sandwich the low-voltage side winding. With this configuration, the low-voltage side winding is wound so as to be sandwiched between the first high-voltage side winding and the second high-voltage side winding, so that the magnetic coupling between the windings on the high-voltage side and the low-voltage side can be improved. Therefore, the leakage inductance from the windings can be reduced, and the electrical loss caused by the leakage inductance can be reduced.

[0013] In this case, the transformer preferably further includes a high-voltage winding housing for housing a high-voltage winding of the winding, the high-voltage winding housing having a first housing for housing a first high-voltage winding from one side of the leg and a second housing for housing a second high-voltage winding from the other side of the leg so as to face the first housing, the first high-voltage winding being sealed together with a part of the core by a resin material filled inside the first housing when housed in the first housing, and the second high-voltage winding being sealed together with a part of the core by a resin material filled inside the second housing when housed in the second housing. With this configuration, the first high-voltage winding can be easily sealed together with a part of the core by filling the first housing with a resin material when housed together with the core in the first housing. Also, the second high-voltage winding can be easily sealed together with a part of the core by filling the second housing with a resin material when housed together with the core in the second housing. Therefore, even when one low-voltage side winding is sandwiched between two high-voltage side windings, each of the two high-voltage side windings can be easily sealed.

[0014] In the power conversion device according to the first aspect, preferably, the high-voltage side winding has a partial high-voltage side winding divided into a plurality of parts, and the low-voltage side winding has a partial low-voltage side winding divided into a plurality of parts, the partial high-voltage side windings and the partial low-voltage side windings are wound alternately around the legs of the core in the direction in which the legs extend, and each of the partial high-voltage side windings is sealed together with a part of the core with a resin member in a state in which it is wound alternately with the partial low-voltage side windings. With this configuration, since the partial high-voltage side windings are arranged alternately with the partial low-voltage side windings, it is possible to further improve the magnetic coupling between the windings on the high-voltage side and the low-voltage side compared to a case in which one low-voltage side winding is sandwiched between two high-voltage side windings. Therefore, it is possible to further reduce leakage inductance from the windings, and therefore it is possible to further reduce electrical loss caused by leakage inductance. Also, since the high-voltage side winding and the low-voltage side winding are each divided into a plurality of parts, it is possible to disperse heat generated from the windings. Therefore, the temperature rise caused by heat generation from the windings can be further suppressed.

[0015] In this case, preferably, the transformer further includes a high-voltage winding housing for housing a high-voltage side winding of the winding, the high-voltage winding housing having a plurality of partial housings for housing each of the plurality of partial high-voltage side windings, each of the plurality of partial high-voltage side windings being sealed together with a portion of the core by a resin material filled inside each of the plurality of partial housings while housed in each of the plurality of partial housings. With this configuration, each of the plurality of partial high-voltage side windings can be easily sealed together with a portion of the core by filling the interior of each of the plurality of partial housings with a resin material while each of the plurality of partial high-voltage side windings is housed in each of the plurality of partial housings together with the core. Therefore, even when the plurality of partial high-voltage side windings are arranged alternately with the plurality of partial low-voltage side windings, each of the plurality of partial high-voltage side windings can be easily sealed.

[0016] The power conversion device according to the first aspect preferably further includes a blower fan for cooling the low-voltage side winding of the transformer. With this configuration, the low-voltage side winding and the portion of the leg of the core around which the low-voltage side winding is wound can be effectively cooled by blowing cooling air from the blower fan to the exposed low-voltage side winding. As a result, an increase in temperature of the entire transformer can be effectively suppressed.

[0017] A transformer according to a second aspect of the present invention comprises a core having legs that form a magnetic path, and a winding wound around the legs of the core, the winding having a high-voltage side winding which is either a primary winding on the primary side or a secondary winding on the secondary side, and a low-voltage side winding which is the other of the primary winding or the secondary winding, the high-voltage side winding being sealed together with a part of the core by a resin member while being wound around the legs of the core, and the low-voltage side winding being exposed while being wound around the legs of the core.

[0018] In the transformer according to the second aspect of the present invention, as described above, the high-voltage side winding is sealed with a resin member together with a part of the core while being wound around the leg of the core. This allows the high-voltage side winding and a part of the core to be sealed with a resin member having a small dielectric constant (high insulating performance), so that the dielectric strength of the high-voltage side winding can be improved compared to when the high-voltage side winding is exposed. Also, as described above, the low-voltage side winding is exposed while being wound around the leg of the core. This allows heat to be released from the exposed low-voltage side winding and the part of the core around which the low-voltage side winding is wound. Therefore, the temperature rise of the transformer can be suppressed compared to when both the high-voltage side winding and the low-voltage side winding are sealed with a resin member together with the entire core. As a result, it is not necessary to increase the size of the winding and the core in order to suppress the temperature rise, so that it is possible to provide a transformer that can improve the dielectric strength and suppress the temperature rise while suppressing the size increase. Effect of the Invention

[0019] According to the present invention, as described above, it is possible to provide a power conversion device and a transformer that can improve the dielectric strength and suppress an increase in temperature while suppressing an increase in size. [Brief description of the drawings]

[0020] [Figure 1] 1 is a diagram showing an overall configuration of a power conversion device according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view illustrating the configuration of a transformer according to the first embodiment. [Diagram 3] 1 is an exploded schematic view of a transformer according to a first embodiment. FIG. [Figure 4] 3 is a cross-sectional view taken along line 110-110 in FIG. 2. [Diagram 5] FIG. 2 is a diagram for explaining filling of a resin material according to the first embodiment. [Figure 6] FIG. 11 is a diagram showing an overall configuration of a power conversion device according to a second embodiment. [Figure 7] FIG. 11 is a diagram for explaining the configuration of a transformer according to a second embodiment. [Figure 8] 10A to 10C are diagrams illustrating a method of assembling the transformer according to the second embodiment. [Figure 9] FIG. 11 is a diagram showing an overall configuration of a power conversion device according to a third embodiment. [Figure 10] FIG. 11 is a diagram for explaining the configuration of a transformer according to a third embodiment. [Figure 11] 13A to 13C are diagrams illustrating a method of assembling the transformer according to the third embodiment. [Figure 12] FIG. 13 is a diagram showing a transformer according to a modification of the first to third embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] [First embodiment] The configuration of a power conversion device 100 according to a first embodiment will be described with reference to Fig. 1 to Fig. 5. The power conversion device 100 includes a DC-DC converter that converts the voltage of input DC power and outputs the DC power with the converted voltage. The power conversion device 100 is used in, for example, a solar PCS (power conditioner system) that converts DC power from a power source 101 such as a solar cell.

[0023] As shown in Fig. 1, the power conversion device 100 according to the first embodiment includes an inverter unit 1, a transformer 2, a converter unit 3, and a blower fan 4. The power conversion device 100 may also include a smoothing circuit. The inverter unit 1 is an example of a "power conversion unit" in the claims.

[0024] The inverter unit 1 converts DC power input from a power source 101 into AC power. The inverter unit 1 includes an inverter circuit having switching elements such as IGBTs (insulated gate bipolar transistors) or MOSFETs (metal-oxide-semiconductor field-effect transistors). The inverter unit 1 converts the input DC power into AC power by switching operations of the switching elements based on a control signal (gate signal) from a control unit (not shown). The inverter unit 1 then outputs the converted AC power to a transformer 2.

[0025] The transformer 2 transforms the AC power from the inverter unit 1. Then, the transformer 2 outputs the transformed AC power to the converter unit 3. The transformer 2 is a high-frequency transformer that transforms high-frequency AC power. The details of the transformer 2 will be described later.

[0026] The converter unit 3 converts the AC power from the transformer 2 into DC power. The converter unit 3 includes, for example, a rectifier circuit (diode bridge circuit) having diodes. The converter unit 3 outputs the converted DC power. Note that in the rectifier circuit of the converter unit 3, a switching element such as an IGBT or a MOSFET may be used instead of a diode.

[0027] The blower fan 4 cools the transformer 2. Specifically, the blower fan 4 is configured to blow cooling air for cooling the windings 12 (see FIG. 2) of the transformer 2.

[0028] (Transformer configuration) As shown in FIG. 2, the transformer 2 according to the first embodiment includes a winding 10, a core 20, a bobbin 30, and a housing 40.

[0029] As shown in FIG. 3, the winding 10 includes a winding 11 and a winding 12. The winding 11 is a winding (coil) on the primary side of the transformer 2. The winding 12 is a winding (coil) on the secondary side of the transformer 2. In the transformer 2, the winding 11 is on the high voltage side, and the winding 12 is on the low voltage side. That is, the transformer 2 steps down the voltage of the input AC voltage. The winding 11 and the winding 12 are, for example, enameled wire or Litz wire. The winding 11 is an example of the "primary winding" and the "high voltage side winding" in the claims. The winding 12 is an example of the "secondary winding" and the "low voltage side winding" in the claims.

[0030] The core 20 includes a pair of core members 20a and 20b. The pair of core members 20a and 20b includes an EE-shaped ferrite core. The core 20 has legs 21 (see FIG. 4) that form a magnetic path by a current flowing through the winding 10 when the pair of core members 20a and 20b are combined. That is, when the core members 20a and 20b are combined, one rectangular prism-shaped leg 21 is formed. The winding 10 (windings 11 and 12) is arranged so as to be wound around the rectangular prism-shaped leg 21. In the transformer 2, a magnetic field is generated in the legs 21 (core 20) by a current flowing through the primary winding 11. Then, an induced electromotive force is generated in the secondary winding 12 by the magnetic field generated in the legs 21, and a current flows through the winding 12.

[0031] Core 20 is an annular core in which a magnetic circuit (magnetic path) is formed by leg 21 around which winding 10 is wound and outer leg parts arranged outside winding 10 on each of the Y1 direction side and the Y2 direction side of leg 21. Here, the term "annular core" is used not only to mean a completely closed state, but also to include a concept in which a pair of core members 20a and 20b are arranged with a gap between them.

[0032] As shown in FIG. 3, the bobbin 30 has members 31, 32, and 33. The bobbin 30 has a spool-like shape by combining the members 31 to 33. In the first embodiment, the bobbin 30 holds the winding 10 (the winding 11 and the winding 12) in order to wind the winding 10 around the leg portion 21 of the core 20. That is, the winding 10 is arranged so as to be wound around the leg portion 21 of the core 20 while being held by the bobbin 30. The bobbin 30 is made of a resin material having a low dielectric constant and high insulating properties. The bobbin 30 is made of a thermoplastic resin such as an olefin resin, for example.

[0033] As shown in FIG. 4, in the first embodiment, the winding 11 and the winding 12 are wound around the legs 21 of the core 20 in a state in which they are separated from each other in the direction in which the legs 21 extend (Z direction). Specifically, the winding 11 is wound around one side (Z2 direction side) of the legs 21. The winding 12 is wound around the other side (Z1 direction side) of the legs 21. That is, the winding 11 is wound around the legs 21 on the core member 20b side in a state in which it is held by a member 33 on the lower side (Z2 direction side) of the bobbin 30. The winding 12 is wound around the legs 21 on the core member 20a side in a state in which it is held by a member 32 on the upper side (Z1 direction side) of the bobbin 30. The transformer 2 is a split-winding transformer in which the primary winding 11 and the secondary winding 12 are each separated. An end of the winding 11 is led out in the X1 direction (see FIG. 2), and an end of the winding 12 is led out in the X2 direction (see FIG. 2).

[0034] The housing 40 houses the winding 11. Specifically, the housing 40 houses the winding 11 and the lower half (half on the core member 20b side) of the core 20 and the bobbin 30 including a part of the leg 21 around which the winding 11 is wound. That is, the housing 40 houses the lower half (Z2 direction side) of the transformer 2 therein. Moreover, the winding 12 and the upper side (Z1 direction side) of the transformer 2 are not housed in the housing 40 and are exposed.

[0035] In the first embodiment, the winding 11 is wound around one side (Z2 direction side) of the leg 21 while being held by the bobbin 30, and is sealed together with the bobbin 30 and a part of the core 20 (core member 20b) by the resin member 50. The winding 12 is exposed while being wound around the other side (Z1 direction side) of the leg 21 of the core 20. Specifically, in the first embodiment, the winding 11 is housed in the housing 40 and is sealed together with the bobbin 30 and the core member 20b that is a part of the core 20 by the resin member 50 filled inside the housing 40.

[0036] That is, the winding 11 housed inside the housing 40 and the lower half (Z2 direction side) of the core 20 and the bobbin 30 including a part of the leg 21 around which the winding 11 is wound are hermetically sealed with the resin member 50. On the other hand, the winding 12 and the upper half (Z1 direction side) of the core 20 are exposed without being sealed with the resin member 50. The exposed upper side (Z1 direction side) of the transformer 2 is configured to be cooled by the blower fan 4.

[0037] The housing 40 and the resin member 50 are formed of the same resin material as the bobbin 30. That is, the thermal expansion coefficients of the bobbin 30, the housing 40, and the resin member 50 are approximately equal to each other. Therefore, the resin member 50 is configured to be capable of suppressing voids (molding defects) caused by cracks due to thermal expansion when the resin material for forming the resin member 50 is hardened.

[0038] (Method of Assembling the Transformer According to the First Embodiment) Next, a method of assembling (manufacturing) the transformer 2 according to the first embodiment will be described with reference to FIGS.

[0039] As shown in FIG. 3, first, the winding 10 (winding 11 and winding 12) is held by the bobbin 30. Specifically, the winding 11 is held by member 33 of the bobbin 30. Then, the winding 12 is held by member 32 of the bobbin 30. Then, the winding 10, the core 20, and the bobbin 30 are combined. Specifically, while holding the winding 10, members 31-33 of the bobbin 30 are combined with the pair of core members 20a and 20b of the core 20. Then, the winding 10, the core 20, and the bobbin 30 are fixed in their combined state by tape or the like.

[0040] 5, the combined winding 10, core 20, and bobbin 30 are housed in housing 40. Specifically, a portion of winding 10, winding 11, is housed inside housing 40, with a portion of winding 12 of winding 10 exposed. In addition, an end of winding 11 is drawn out to the outside of housing 40.

[0041] Then, after the hole in the housing 40 through which the winding 11 is drawn out is blocked, the inside of the housing 40 is filled with a resin material. That is, the winding 11 housed in the housing 40, a part of the core 20 (the part of the core member 20b), and the bobbin 30 (the lower half of the bobbin 30) are sealed with the resin material. When filling with the resin material, a vacuum may be drawn to prevent the occurrence of molding defects such as voids. That is, the resin material may be filled inside the housing 40 in a vacuum atmosphere.

[0042] [Effects of the first embodiment] In the first embodiment, the following effects can be obtained.

[0043] In the first embodiment, as described above, the winding 11 (high-voltage side winding) is sealed together with a part of the core 20 by the resin member 50 while being wound around the leg 21 of the core 20. This allows the winding 11 and a part of the core 20 to be sealed by the resin member 50 having a small dielectric constant (high insulating performance), so that the dielectric strength of the winding 11 can be improved compared to when the winding 11 is exposed. Also, as described above, the winding 12 (low-voltage side winding) is exposed while being wound around the leg 21 of the core 20. This allows heat to be released from the exposed winding 12 and the part of the core 20 around which the winding 12 is wound. Therefore, the temperature rise of the transformer 2 can be suppressed compared to when both the winding 11 and the winding 12 are sealed together with the entire core 20 by the resin member 50. As a result, it is not necessary to increase the size of the winding 10 (winding 11 and winding 12) and the core 20 in order to suppress the temperature rise, so that the dielectric strength can be improved and the temperature rise can be suppressed while suppressing the size increase.

[0044] In the first embodiment, as described above, the transformer 2 further includes a housing 40 (housing for high-voltage side winding) that houses the winding 11 (high-voltage side winding) of the winding 10, and the winding 11 is sealed together with a part of the core 20 by the resin member 50 filled inside the housing 40 while being housed in the housing 40. This allows the inside of the housing 40 to be filled with a resin material while the winding 11 wound around the leg portion 21 of the core 20 is housed in the housing 40 together with the core 20. Therefore, the winding 11 can be easily sealed together with a part of the core 20 by the resin member 50.

[0045] In the first embodiment, as described above, the bobbin 30 for holding the winding 10 is further provided in order to wind the winding 10 around the leg 21 of the core 20, and the winding 11 (high-voltage side winding) is sealed with the resin member 50 together with the bobbin 30 and a part of the core 20 in a state where it is wound around the leg 21 of the core 20 while being held by the bobbin 30. In this way, by holding the winding 10 with the bobbin 30, the winding 10 can be easily arranged so as to be wound around the core 20. In addition, since the winding 11 is sealed with the resin member 50 together with the bobbin 30 and a part of the core 20, the winding 11, the bobbin 30, and the core 20 can be sealed together. Therefore, for example, it is possible to suppress a decrease in dielectric strength due to the presence of an air layer between the core 20 and the bobbin 30. As a result, the bobbin 30 allows the winding 10 to be easily arranged so as to be wound around the core 20, and a high voltage resistance can be achieved by suppressing a decrease in insulation.

[0046] In the first embodiment, as described above, the winding 11 (high voltage side winding) and the winding 12 (low voltage side winding) are wound around the legs 21 of the core 20 in a state where they are separated from each other in the direction in which the legs 21 extend (Z direction), and the winding 11 is sealed with the resin member 50 together with a part of the core 20 in a state where it is wound close to one side (Z2 direction side) of the legs 21, and the winding 12 is exposed in a state where it is wound close to the other side (Z1 direction side) of the legs 21. As a result, since the winding 11 is wound close to one side of the legs 21, by sealing only one side of the legs 21 with the resin member 50, the winding 11 can be sealed more easily while exposing the winding 12 wound close to the other side. Therefore, the workload for sealing the winding 11 while exposing the winding 12 can be further reduced.

[0047] As described above, the first embodiment further includes a blower fan 4 that cools the winding 12 (low-voltage side winding) of the transformer 2. As a result, by blowing cooling air from the blower fan 4 to the exposed winding 12, the winding 12 and the portions of the legs 21 of the core 20 around which the winding 12 is wound can be effectively cooled. As a result, an increase in the temperature of the entire transformer 2 can be effectively suppressed.

[0048] [Second embodiment] Next, the configuration of a power conversion device 200 according to a second embodiment will be described with reference to Fig. 6 to Fig. 8. In the second embodiment, a secondary winding 212 is wound so as to be sandwiched between two divided primary windings 211a and 211b. Note that the same components as those in the first embodiment are given the same reference numerals and will not be described.

[0049] (Configuration of power conversion device according to second embodiment) As shown in Fig. 6, the power conversion device 200 according to the second embodiment includes an inverter unit 1, a transformer 202, a converter unit 3, and a blower fan 4. Similarly to the first embodiment, the power conversion device 200 includes a DC-DC converter that converts the voltage of input DC power and outputs the DC power with the converted voltage. Similarly to the transformer 2 according to the first embodiment, the transformer 202 transforms the AC power from the inverter unit 1. Then, the transformer 202 outputs the transformed AC power to the converter unit 3.

[0050] 7, in the second embodiment, transformer 202 includes winding 210, core 220, bobbin 230, housing 240a, and housing 240b. Housing 240a is an example of the "high-voltage side winding housing" and the "first housing" in the claims. Housing 240b is an example of the "high-voltage side winding housing" and the "second housing" in the claims.

[0051] In the second embodiment, the winding 210 includes a winding 211a, a winding 211b, and a winding 212. The windings 211a and 211b are windings (coils) on the primary side of the transformer 202. The winding 212 is a winding (coil) on the secondary side of the transformer 202. In the transformer 202, the windings 211a and 211b are on the high-voltage side, and the winding 212 is on the low-voltage side. The winding 211a is an example of a "primary winding," a "high-voltage side winding," and a "first high-voltage side winding" in the claims. The winding 211b is an example of a "primary winding," a "high-voltage side winding," and a "second high-voltage side winding" in the claims. The winding 212 is an example of a "secondary winding" and a "low-voltage side winding" in the claims.

[0052] The core 220 is an EE-type ferrite core formed by combining a pair of E-shaped core members 220a and 220b, similar to the first embodiment. The core 220 has legs 221 that form a magnetic path by a current flowing through the winding 210, similar to the core 20 of the first embodiment, when the pair of core members 220a and 220b are combined. The windings 211a, 211b and the winding 212 are arranged so as to be wound around the leg 221 having a rectangular prism shape. Note that in FIG. 7, the outer legs arranged on the outer side of the winding 210 of the core 220 are not shown.

[0053] The bobbin 230 holds the winding 210 (windings 211a, 211b, and 212) in order to wind the winding 210 around the legs 221 of the core 220, similar to the bobbin 30 of the first embodiment.

[0054] In the second embodiment, the winding 211a and the winding 211b are divided into two and wound around the leg 221 of the core 220. The winding 212 is wound around the leg 221 so as to be sandwiched between the winding 211a and the winding 211b in the direction in which the leg 221 of the core 220 extends (Z direction). Specifically, the winding 211a is wound around the leg 221 on the upper side (Z1 direction side) of the bobbin 230 while being held by the bobbin 230. The winding 211b is wound around the leg 221 on the lower side (Z2 direction side) of the bobbin 230 while being held by the bobbin 230. The winding 212 is wound around the leg 221 at the center in the Z direction while being held by the bobbin 230.

[0055] In the second embodiment, the housing 240a houses the winding 211a from one side (Z1 direction side) of the leg 221. The housing 240b houses the winding 211b from the other side (Z2 direction side) of the leg 221 so as to face the housing 240a. Specifically, the housing 240a houses the winding 211a and a portion of the core 220 and the bobbin 230 including a portion of the leg 221 around which the winding 211a is wound. The housing 240b houses the winding 211b and a portion of the core 220 and the bobbin 230 including a portion of the leg 221 around which the winding 211b is wound.

[0056] In the second embodiment, the windings 211a and 211b are each sealed with a part of the core 220 by a resin member 250 in a state where they are wound around the leg portions 221 so as to sandwich the winding 212. Specifically, the winding 211a is sealed with a part of the core 220 by the resin member 250 filled in the inside of the housing 240a in a state where it is housed in the housing 240a. The winding 211b is sealed with a part of the core 220 by the resin member 250 filled in the inside of the housing 240b in a state where it is housed in the housing 240b.

[0057] That is, the winding 211a, the part of the bobbin 230 that holds the winding 211a, and a part (the part on the Z1 direction side) of the core 220 around which the winding 211a is wound are disposed inside the housing 240a and are sealed together with the resin member 250. The winding 211b, the part of the bobbin 230 that holds the winding 211b, and a part (the part on the Z2 direction side) of the core 220 around which the winding 211b is wound are sealed together with the resin member 250 in a state where they are disposed inside the housing 240b. The winding 212 is not housed in the housings 240a and 240b and is exposed. That is, the winding 212 is not sealed by the resin member 250 and is exposed.

[0058] Other configurations of the second embodiment are similar to those of the first embodiment.

[0059] (Method of Assembling a Transformer According to the Second Embodiment) Next, a method of assembling (manufacturing) the transformer 202 according to the second embodiment will be described with reference to FIG.

[0060] As shown in FIG. 8, in the second embodiment, first, the winding 211a and the winding 211b, which are the primary coils, are arranged so as to be wound around the core 220 together with the bobbin 230. For example, the winding 211b on the lower side (Z2 direction side) is housed in the housing 240b together with a part of the bobbin 230 and the core member 220b. Then, the housing 240b in a state in which the winding 211b, the bobbin 230, and the core member 220b are housed therein is filled with a resin material. The winding 211a is also housed in the housing 240a together with the bobbin 230 and the core member 220a, similar to the winding 211b. Then, the housing 240a in a state in which the winding 211a, the part of the bobbin 230, and the core member 220a are housed therein is filled with a resin material.

[0061] Then, the primary windings 211a and 211b are each sealed with a resin member 250, and then the two primary windings 211a and 211b are assembled so that the secondary winding 212 is sandwiched between them.

[0062] [Effects of the second embodiment] In the second embodiment, the following effects can be obtained.

[0063] In the second embodiment, as described above, the power conversion device 200 has the winding 211a (first high voltage side winding) and the winding 211b (second high voltage side winding) divided into two and wound around the leg 221 of the core 220, and the winding 212 (low voltage side winding) is wound around the leg 221 so as to be sandwiched between the winding 211a and the winding 211b in the direction in which the leg 221 of the core 220 extends (Z direction), and the winding 211a and the winding 211b are each sealed with the resin member 250 together with a part of the core 220 in a state in which the winding 212 is sandwiched between the winding 211a and the winding 211b. As a result, since the winding 212 is wound so as to be sandwiched between the winding 211a and the winding 211b, it is possible to improve the magnetic coupling between the windings on the high voltage side and the low voltage side. Therefore, the leakage inductance from the winding 210 can be reduced, and the electrical loss caused by the leakage inductance can be reduced.

[0064] Furthermore, in the second embodiment, as described above, transformer 202 has housing 240a (first housing) that houses winding 211a (first high-voltage side winding) from one side (Z1 direction side) of leg 221, and housing 240b (second housing) that houses winding 211b (second high-voltage side winding) from the other side (Z2 direction side) of leg 221 so as to face housing 240a. Winding 211a is sealed together with a part of core 220 by resin member 250 filled inside housing 240a when housed in housing 240a, and winding 211b is sealed together with a part of core 220 by resin member 250 filled inside housing 240b when housed in housing 240b. As a result, by filling a resin material inside housing 240a with winding 211a together with core 220 in housing 240a, winding 211a can be easily sealed together with a part of core 220. Also, by filling a resin material inside housing 240b with winding 211b together with core 220 in housing 240b, winding 211b can be easily sealed together with a part of core 220. Therefore, even when one winding 212 (low-voltage side winding) is sandwiched between two windings 211a and 211b, each of the two windings 211a and 211b can be easily sealed.

[0065] Other effects of the second embodiment are similar to those of the first embodiment.

[0066] [Third embodiment] Next, the configuration of a power conversion device 300 according to the third embodiment will be described with reference to Fig. 9 to Fig. 11. In the third embodiment, a plurality of primary side windings 311a to 311c and a plurality of secondary side windings 312a to 312c are arranged alternately in the extending direction of legs 321 of a core 320. Note that the same components as those in the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0067] (Configuration of power conversion device according to third embodiment) As shown in Fig. 9, the power conversion device 300 according to the third embodiment includes an inverter unit 1, a transformer 302, a converter unit 3, and a blower fan 4. Similarly to the first embodiment, the power conversion device 300 includes a DC-DC converter that converts the voltage of input DC power and outputs the DC power with the converted voltage. Similarly to the transformer 2 according to the first embodiment, the transformer 302 transforms the AC power from the inverter unit 1. Then, the transformer 302 outputs the transformed AC power to the converter unit 3.

[0068] 10, in the third embodiment, transformer 302 includes winding 310, core 320, bobbins 330a, 330b, and 330c, and housings 340a, 340b, and 340c. Housings 340a to 340c are examples of the "high voltage side winding housing" and "multiple partial housings" in the claims.

[0069] In the third embodiment, the winding 310 includes windings 311a, 311b, and 311c which are a plurality of divided primary windings (coils) of the transformer 302. The winding 310 also includes windings 312a, 312b, and 312c which are a plurality of divided secondary windings (coils) of the transformer 302. In the transformer 302, the primary windings 311a to 311c are the high voltage side, and the secondary windings 312a to 312c are the low voltage side. The windings 311a to 311c are an example of the "primary winding", "high voltage side winding", and "multiple partial high voltage side windings" in the claims. The windings 312a to 312c are an example of the "secondary winding", "low voltage side winding", and "multiple partial low voltage side windings" in the claims.

[0070] The core 320 is an EI type ferrite core formed by combining an E-shaped core member 320a and an I-shaped core member 320b. Like the core 20 of the first embodiment, the core 320 has legs 321 that form a magnetic path by a current flowing through the winding 310 when the two core members 320a and 320b are combined. The windings 311a to 311c and the windings 312a to 312c are arranged so as to be wound around the leg 321 in the shape of a rectangular prism. Note that, in FIG. 10, the outer legs arranged on the outer side of the winding 310 of the core 320 are not shown.

[0071] The bobbins 330a to 330c, like the bobbin 30 of the first embodiment, hold the winding 310 in order to wind the winding 310 around the leg portion 321 of the core 320. Specifically, the bobbin 330a holds the winding 311a and the winding 311b. The bobbin 330b holds the winding 311b and the winding 312b. And the bobbin 330c holds the winding 311c and the winding 312c.

[0072] In the third embodiment, the multiple windings 311a-311c and the multiple windings 312a-312c are wound alternately around the leg portion 321 in the extending direction (Z direction) of the leg portion 321 of the core 320. Specifically, from the Z2 direction side of the leg portion 321, the winding 311a, the winding 312a, the winding 311b, the winding 312b, the winding 311c, and the winding 312c are arranged in this order along the extending direction of the leg portion 321 (Z direction).

[0073] In the third embodiment, the housings 340a to 340c house the plurality of windings 311a to 311c. Specifically, the housing 340a houses the winding 311a, a portion of the bobbin 330a, and a portion of the core 320 (core member 320a). Similarly, the housing 340b houses the winding 311b, a portion of the bobbin 330b, and a portion of the core 320 (core member 320a). The housing 340c houses the winding 311c, a portion of the bobbin 330c, and a portion of the core 320 (core member 320a). The length (thickness) of the housing 340a in the Z direction is greater than the lengths (thicknesses) of the housings 340b and 340c in the Z direction.

[0074] In the third embodiment, each of the windings 311a-311c is wound alternately with the windings 312a-312c around the leg portions 321 of the core 320, and is sealed together with a part of the core 320 by a resin member 350 (see FIG. 11). Specifically, each of the windings 311a-311c is housed in each of the casings 340a-340c, and is sealed together with a part of the core 320 by the resin member 350 filled in each of the casings 340a-340c.

[0075] That is, the winding 311a, the portion of the bobbin 330a that holds the winding 311a, and the portion of the core 320 around which the winding 311a is wound are disposed inside the housing 340a and are integrally sealed by the resin member 350. Similarly, the winding 311b, the portion of the bobbin 330b that holds the winding 311b, and the portion of the core 320 around which the winding 311b is wound are disposed inside the housing 340b and are integrally sealed by the resin member 350. Then, the winding 311c, the portion of the bobbin 330c that holds the winding 311c, and the portion of the core 320 around which the winding 311c is wound are disposed inside the housing 340c and are integrally sealed by the resin member 350.

[0076] Other configurations of the third embodiment are similar to those of the first embodiment.

[0077] (Method of Assembling a Transformer According to the Third Embodiment) Next, a method of assembling (manufacturing) the transformer 302 according to the third embodiment will be described with reference to FIG.

[0078] 11, in the third embodiment, first, the windings 311a and 312a held by the bobbin 330a are arranged so as to be wound around the legs 321 of the core 320 (core member 320a). Then, the windings 311a and a part of the core 320 (core member 320a) are housed in the housing 340a.

[0079] Then, the housing 340a, which contains the winding 311a, the bobbin 330a, and the core member 320a, is filled with a resin material.

[0080] Next, the windings 311b and 312b held by the bobbin 330b are arranged to be wound around the legs 321 of the core 320 (core member 320a) so as to overlap the windings 311a and 312a. Here, the windings 311b and a part of the core 320 are arranged to be housed in the housing 340b. Then, the housing 340b with the windings 311b, the bobbin 330b, and the core member 320a housed therein is filled with a resin material.

[0081] Then, the winding 311c and the winding 312c held by the bobbin 330c are arranged to be wound around the leg 321 of the core 320 (core member 320a) so as to overlap the winding 311b and the winding 312b. As with the winding 311b, the winding 311c and a part of the core 320 are arranged to be housed in the housing 340c. Then, the housing 340c in which the winding 311c, the bobbin 330c, and the core member 320a are housed is filled with a resin material. Then, by combining the I-shaped core member 320b, the core member 320a and the core member 320b form a magnetic path of the core 320.

[0082] [Effects of the third embodiment] In the third embodiment, the following effects can be obtained.

[0083] In the third embodiment, as described above, the transformer 302 has a plurality of divided windings 311a-311c (partial high voltage side windings) and a plurality of divided windings 312a-312c (partial low voltage side windings), the plurality of windings 311a-311c and the plurality of windings 312a-312c are wound around the leg 321 of the core 320 alternately in the direction in which the leg 321 extends, and each of the plurality of windings 311a-311c and the plurality of windings 312a-312c are wound around the leg 321 of the core 320 alternately and sealed together with a part of the core 320 by the resin member 350. As a result, the plurality of windings 311a-311c are arranged alternately with the plurality of windings 312a-312c, and therefore the magnetic coupling between the windings on the high voltage side and the low voltage side can be improved compared to the case in which one winding is sandwiched between two windings. Therefore, leakage inductance from winding 310 can be further reduced, and electrical loss due to leakage inductance can be further reduced. Also, since windings 311a-311c and windings 312a-312c are each divided into a plurality of pieces, heat generated from winding 310 can be dispersed. Therefore, temperature rise due to heat generated from winding 310 can be further suppressed.

[0084] Moreover, in the third embodiment, the transformer 302 has a plurality of housings 340a-340c (partial housings) that house the plurality of windings 311a-311c, and each of the plurality of windings 311a-311c is sealed together with a part of the core 320 by a resin member 350 filled inside each of the plurality of housings 340a-340c while being housed in each of the plurality of housings 340a-340c. This makes it possible to easily seal each of the plurality of windings 311a-311c together with a part of the core 320 by filling the inside of each of the plurality of housings 340a-340c with a resin material while each of the plurality of windings 311a-311c is housed in each of the plurality of housings 340a-340c together with the core 320. Therefore, even when the plurality of windings 311a to 311c are arranged alternately with the plurality of windings 312a to 312c, each of the plurality of windings 311a to 311c can be easily sealed.

[0085] Other effects of the third embodiment are similar to those of the first and second embodiments.

[0086] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and further includes all modifications (variations) within the meaning and scope of the claims.

[0087] For example, in the above first to third embodiments, the core 20 (220, 320) is formed by a pair of core members 20a and 20b (220a and 220b, 320a and 320b), but the present invention is not limited to this. In the present invention, the number of cores is not limited to a pair, and three or more cores may be connected together, as in the modified transformers 402 and 502 shown in FIG.

[0088] In the first and second embodiments, the core 20 (220) has an EE shape, and in the third embodiment, the core 320 has an EI shape, but the present invention is not limited to this. For example, the core may have an EER shape, a PQ shape, a UU shape, or a UI shape.

[0089] In the above first to third embodiments, the high-voltage side windings 11 (211a and 211b, 311a to 311c) are housed in the housing 40 (240a and 240b, 340a to 340c) and sealed together with a part of the core 20 (220, 320) by the resin member 50 (250, 350) filled inside the housing 40 (240a and 240b, 340a to 340c), but the present invention is not limited to this. For example, the transformer may not be provided with a housing, and the windings 11 (211a and 211b, 311a to 311c) and a part of the core 20 (220, 320) may be sealed together with the resin member 50 (250, 350).

[0090] In the above first to third embodiments, an example is shown in which the bobbin 30 (230, 330a to 330c) is provided to hold the winding 10 (210, 320) in order to wind the winding 10 (210, 320) around the leg 21 (221, 321) of the core 20 (220, 320), but the present invention is not limited to this. For example, the windings may be insulated from each other or from the winding to the core by a plate-shaped insulating member instead of a bobbin. In that case, the high-voltage side winding, the insulating member, and a part of the core may be integrally sealed with a resin material.

[0091] In the above second embodiment, the windings 211a and 211b (high voltage side windings) are wound around the legs 221 so as to sandwich the winding 212 (low voltage side winding) and are sealed together with a part of the core 220 by the resin member 250, but the present invention is not limited to this. For example, two split low voltage side windings may be arranged to sandwich one high voltage side winding.

[0092] In the third embodiment, the primary windings 311a-311c and the secondary windings 312a-312c are each divided into three, but the present invention is not limited to this. For example, the primary windings and the secondary windings may be divided into four or more. The number of divisions on the primary side and the number of divisions on the secondary side may be different.

[0093] In addition, in the above first to third embodiments, an example is shown in which a blower fan 4 is provided to cool the windings 12 (212, 312a to 312c), but the present invention is not limited to this. For example, water-cooling may be used instead of air-cooling by the blower fan 4. Also, heat dissipation members such as fins may be provided on exposed portions of the core 20 (220, 320).

[0094] In the above first to third embodiments, the primary winding 11 (211a and 211b, 311a to 311c) is on the high voltage side and the secondary winding 12 (212, 312a to 312c) is on the low voltage side, but the present invention is not limited to this. For example, the primary side may be configured to be low voltage and the secondary side to be high voltage. In that case, the secondary winding, which is on the high voltage side, is sealed with a resin member together with a part of the core, and the primary winding, which is on the low voltage side, is exposed.

[0095] In the above first to third embodiments, the winding 10 (210, 310) is a circular enameled wire or Litz wire, but the present invention is not limited to this. For example, the winding 10 (210, 310) may be a flat (edgewise) winding such as a rectangular wire or a flat wire. The transformer 2 (202, 302) may be a planar transformer in which the winding 10 (210, 310) is formed by a printed circuit board. [Explanation of symbols]

[0096] 1. Inverter section (power conversion section) 2, 202, 302, 402, 502 transformers 4 Blower fan 10, 210, 310 windings 11 Windings (primary winding, high voltage winding) 12, 212 windings (secondary winding, low voltage side winding) 20, 220, 320 cores 21, 221, 321 Legs 30, 230, 330a, 330b, 330c bobbins 40 Housing (Housing for high voltage side winding) 50, 250, 350 Resin material 100, 200, 300 Power Converter 211a Winding (primary winding, high voltage side winding, first high voltage side winding) 211b Windings (primary winding, high voltage side winding, second high voltage side winding) 240a Housing (Housing for high voltage side winding, first housing) 240b Housing (Housing for high voltage side winding, second housing) 311a, 311b, 311c Windings (primary winding, high voltage side winding, partial high voltage side winding) 312a, 312b, 312c Windings (Secondary Winding, Low-Voltage Side Winding, Partial Low-Voltage Side Winding) 340a, 340b, 340c Housing (high voltage side winding housing, partial housing)

Claims

1. a power conversion unit that converts input DC power into AC power; a transformer that transforms AC power from the power conversion unit, The transformer includes a core having legs that form a magnetic path, and a winding wound around the legs of the core, the windings include a high-voltage side winding which is one of a primary winding on a primary side and a secondary winding on a secondary side, and a low-voltage side winding which is the other of the primary winding and the secondary winding; the high-voltage side winding is wound around the leg of the core and sealed together with a part of the core by a resin member, A power conversion device, wherein the low-voltage side winding is exposed while being wound around the legs of the core.

2. The transformer further includes a high-voltage side winding housing that houses the high-voltage side winding of the winding, 2. The power conversion device according to claim 1, wherein the high-voltage side winding is housed in the high-voltage side winding casing and sealed together with a portion of the core by the resin material filled inside the high-voltage side winding casing.

3. a bobbin for holding the winding for winding the winding around the legs of the core; 3. The power conversion device according to claim 1, wherein the high-voltage side winding is held by the bobbin and wound around the leg of the core, and is sealed together with the bobbin and a portion of the core by the resin member.

4. the high-voltage side winding and the low-voltage side winding are wound around the legs of the core in a state separated from each other in a direction in which the legs extend, the high-voltage side winding is wound toward one side of the leg portion and sealed together with a part of the core by the resin member, 4. The power conversion device according to claim 1, wherein the low-voltage side winding is exposed in a state where it is wound around the other side of the leg.

5. the high voltage side winding includes a first high voltage side winding and a second high voltage side winding that are divided into two and wound around the legs of the core, the low-voltage side winding is wound around the legs of the core so as to be sandwiched between the first high-voltage side winding and the second high-voltage side winding in the extending direction of the legs, A power conversion device as described in any one of claims 1 to 3, wherein the first high-voltage side winding and the second high-voltage side winding are each wound around the leg portions so as to sandwich the low-voltage side winding, and are sealed together with a portion of the core by the resin member.

6. The transformer further includes a high-voltage side winding housing that houses the high-voltage side winding of the winding, the high voltage side winding casing includes a first casing that houses the first high voltage side winding from one side of the leg portion, and a second casing that houses the second high voltage side winding from the other side of the leg portion so as to face the first casing, the first high voltage side winding is housed in the first housing and is sealed together with a part of the core by the resin member filled inside the first housing, The power conversion device according to claim 5 , wherein the second high voltage side winding is sealed together with a portion of the core by the resin material filled inside the second housing when housed in the second housing.

7. The high voltage side winding has a plurality of divided high voltage side winding portions, The low-voltage side winding has a plurality of divided low-voltage side winding sections, the plurality of partial high voltage side windings and the plurality of partial low voltage side windings are wound around the legs of the core alternately in a direction in which the legs extend, A power conversion device as described in any one of claims 1 to 3, wherein each of the multiple partial high-voltage side windings is wound alternately with the multiple partial low-voltage side windings around the leg of the core and is sealed together with a portion of the core by the resin material.

8. The transformer further includes a high-voltage side winding housing that houses the high-voltage side winding of the winding, the high voltage side winding casing includes a plurality of partial casings each accommodating one of the plurality of partial high voltage side windings, 8. The power conversion device according to claim 7, wherein each of the plurality of partial high voltage side windings is housed in each of the plurality of partial housings and sealed together with a portion of the core by the resin material filled inside each of the plurality of partial housings.

9. The power conversion device according to any one of claims 1 to 8, further comprising a blower fan that cools the low-voltage side winding of the transformer.

10. a core having legs that form a magnetic path; a winding wound around the leg of the core, the windings include a high-voltage side winding which is one of a primary winding on a primary side and a secondary winding on a secondary side, and a low-voltage side winding which is the other of the primary winding and the secondary winding; the high-voltage side winding is wound around the leg of the core and sealed together with a part of the core by a resin member, A transformer, wherein the low-voltage side winding is exposed while being wound around the legs of the core.

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