CN115394539A

CN115394539A - Power conversion device and transformer

Info

Publication number: CN115394539A
Application number: CN202210343181.2A
Authority: CN
Inventors: 藤田悟; 长野刚
Original assignee: Fuji Electric Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2021-05-24
Filing date: 2022-03-31
Publication date: 2022-11-25
Also published as: JP2022179963A

Abstract

The invention provides a power conversion device and a transformer. The power conversion device is provided with a transformer, and the transformer comprises: a core having a leg portion forming a magnetic path; and a winding wound around the leg portion of the core. The winding has a high voltage side winding and a low voltage side winding. The high-voltage side winding is sealed with a resin member together with a part of the core in a state of being wound around the leg portion of the core. In addition, the low-voltage side winding is exposed in a state of being wound around the leg portion of the core.

Description

Power conversion device and transformer

Technical Field

The present invention relates to a power conversion device and a transformer.

Background

Conventionally, a transformer including a 1 st coil as a primary winding and a 2 nd coil as a secondary winding is known. Such a transformer is disclosed in, for example, japanese patent laid-open No. 2007-19120.

The transformer described in japanese patent application laid-open No. 2007-19120 includes a core that forms a magnetic path of a coil. The 1 st coil as a primary winding and the 2 nd coil as a secondary winding are disposed so as to be wound around the core. In the transformer described in japanese patent application laid-open No. 2007-19120, the 1 st coil, the 2 nd coil, and the core are entirely encapsulated with an insulating resin in a state of being housed in a case in order to improve the insulating strength.

However, in the transformer described in the above-mentioned japanese patent application laid-open No. 2007-19120, in order to improve the insulation strength, the entire three of the 1 st coil (primary winding) and the 2 nd coil (secondary winding) and the core are sealed (sealed) with an insulating resin (resin member), and therefore, the cooling performance of the entire transformer is lowered. Therefore, when a high voltage is applied to the coil sealed by the resin member, the coil and the core need to be increased in size in order to suppress a temperature increase. Therefore, when the voltage resistance is increased (high voltage is applied), there is a problem that the transformer is increased in size in order to increase the insulation strength and suppress the temperature rise.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power conversion device and a transformer capable of improving insulation strength, suppressing increase in size, and suppressing temperature increase.

Means for solving the problems

In order to achieve the above object, according to claim 1 of the present invention, there is provided a power conversion device including: a power conversion unit that converts input direct-current power into alternating-current power; and a transformer that transforms the ac power from the power conversion unit, the transformer including: a core having a leg portion forming a magnetic path; and a winding wound around a leg portion of the core, the winding having a high-voltage side winding as any one of a primary winding on a primary side and a secondary winding on a secondary side, and a low-voltage side winding as the other of the primary winding and the secondary winding, the high-voltage side winding being sealed with a resin member together with a part of the core in a state of being wound around the leg portion of the core, the low-voltage side winding being exposed in a state of being wound around the leg portion of the core.

In the power conversion device according to claim 1 of the present invention, as described above, the high-voltage side winding is sealed with the resin member together with a part of the core in a state of being wound around the leg portion of the core. Thus, the high-voltage side winding and a part of the core can be sealed by the resin member having a small dielectric constant (high insulating performance), and therefore, the insulating strength of the high-voltage side winding can be improved as compared with a case where the high-voltage side winding is exposed. As described above, the low-voltage side winding is exposed in a state of being wound around the leg portion of the core. This allows heat to be released from the exposed low-voltage side winding and the part of the core wound by the low-voltage side winding. Therefore, compared to the case where both the high-voltage side winding and the low-voltage side winding are sealed with the resin member along with the entire core, the temperature rise of the transformer can be suppressed. As a result, it is not necessary to increase the size of the winding and the core in order to suppress the temperature rise, and therefore, the insulation strength can be improved, and the temperature rise can be suppressed while suppressing the size increase.

In the power conversion device according to claim 1, the transformer preferably further includes a high-voltage side winding case that houses a high-voltage side winding of the winding, and the high-voltage side winding is sealed with a resin member that fills the inside of the high-voltage side winding case together with a part of the core in a state of being housed in the high-voltage side winding case. With this configuration, the resin material can be filled into the high-voltage side winding case in a state where the high-voltage side winding wound around the leg portion of the core is housed in the high-voltage side winding case together with the core. Therefore, the high-voltage side winding can be easily sealed together with a part of the core by the resin member.

In the power conversion device according to claim 1, it is preferable that the power conversion device further includes a bobbin that holds the winding so that the winding is wound around the leg portion of the core, and the high-voltage side winding is sealed together with the bobbin and a part of the core by a resin member in a state of being held by the bobbin and wound around the leg portion of the core. With this configuration, the coil can be easily arranged to be wound around the core by holding the coil by the bobbin. In addition, since the high-voltage side winding is sealed by the resin member together with the bobbin and the part of the core, the high-voltage side winding, the bobbin, and the core can be sealed integrally. Therefore, for example, it is possible to suppress a decrease in the insulation strength due to the presence of the air layer between the core and the bobbin. As a result, the winding can be easily arranged around the core by the bobbin, and the high withstand voltage can be achieved by suppressing the decrease in insulation.

In the power converter according to claim 1, preferably, the high-voltage side winding and the low-voltage side winding are wound around the leg portion in a state of being separated from each other in an extending direction of the leg portion of the core, the high-voltage side winding is sealed with a resin member together with a part of the core in a state of being wound around one side of the leg portion, and the low-voltage side winding is exposed in a state of being wound around the other side of the leg portion. With this configuration, since the high-voltage side winding is wound closer to one side of the leg portion, the high-voltage side winding can be more easily sealed while exposing the low-voltage side winding wound closer to the other side by sealing only one side of the leg portion with the resin member. Therefore, the low-voltage side winding can be exposed while the work load for sealing the high-voltage side winding is further reduced.

In the power conversion device according to claim 1, it is preferable that the high-voltage side winding includes a 1 st high-voltage side winding and a 2 nd high-voltage side winding that are divided into two and wound around the leg portion of the core, the low-voltage side winding is wound around the leg portion so as to be sandwiched between the 1 st high-voltage side winding and the 2 nd high-voltage side winding in the extending direction of the leg portion of the core, and the 1 st high-voltage side winding and the 2 nd high-voltage side winding are sealed with a resin member together with a part of the core in a state of being wound around the leg portion so as to sandwich the low-voltage side winding. With this configuration, the high-voltage side winding and the low-voltage side winding are wound so as to sandwich the low-voltage side winding between the 1 st high-voltage side winding and the 2 nd high-voltage side winding, and therefore the magnetic coupling between the high-voltage side winding and the low-voltage side winding can be improved. Therefore, leakage inductance (leakage inductance) from the winding can be reduced, and thus electrical loss due to the leakage inductance can be reduced.

In this case, it is preferable that the transformer further includes a high-voltage side winding case that houses a high-voltage side winding of the winding, the high-voltage side winding case includes a 1 st case that houses a 1 st high-voltage side winding from one side of the leg portion and a 2 nd case that houses a 2 nd high-voltage side winding from the other side of the leg portion so as to face the 1 st case, the 1 st high-voltage side winding is sealed with a resin member that fills the inside of the 1 st case together with a part of the core in a state of being housed in the 1 st case, and the 2 nd high-voltage side winding is sealed with a resin member that fills the inside of the 2 nd case together with a part of the core in a state of being housed in the 2 nd case. With this configuration, the 1 st high-voltage side winding and the core can be easily sealed together at a part thereof by filling the resin material into the 1 st case in a state where the 1 st high-voltage side winding is housed in the 1 st case together with the core. Further, by filling the resin material into the 2 nd case in a state where the 2 nd high-voltage side winding is housed in the 2 nd case together with the core, the 2 nd high-voltage side winding can be easily sealed together with a part of the core. Therefore, even in the case where 1 low-voltage side winding is arranged to be sandwiched by two high-voltage side windings, each of the two high-voltage side windings can be easily sealed.

In the power converter according to claim 1, it is preferable that the high-voltage side winding includes a plurality of divided partial high-voltage side windings, the low-voltage side winding includes a plurality of divided partial low-voltage side windings, the plurality of partial high-voltage side windings and the plurality of partial low-voltage side windings are alternately wound around the leg portion in the extending direction of the leg portion of the core, and each of the plurality of partial high-voltage side windings is sealed with the resin member together with a part of the core in a state where each of the plurality of partial high-voltage side windings is alternately wound around the leg portion of the core. With this configuration, since the plurality of partial high-voltage side windings are arranged so as to be alternately arranged with the plurality of partial low-voltage side windings, the magnetic coupling between the high-voltage side winding and the low-voltage side winding can be further improved as compared with the case where 1 low-voltage side winding is arranged so as to be sandwiched by two high-voltage side windings. Therefore, leakage inductance (leakage inductance) from the winding can be further reduced, and thus electrical loss due to the leakage inductance can be further reduced. Further, since the high-voltage side winding and the low-voltage side winding are each divided into a plurality of sections, heat generated from the windings can be dispersed. Therefore, the temperature rise due to heat generation from the winding can be further suppressed.

In this case, it is preferable that the transformer further includes a high-voltage side winding case that houses the high-voltage side winding of the winding, the high-voltage side winding case has a plurality of partial cases that house respective partial high-voltage side windings of the plurality of partial high-voltage side windings, and the respective partial high-voltage side windings of the plurality of partial high-voltage side windings are sealed with a resin member that fills the insides of the respective partial cases of the plurality of partial cases together with the part of the core in a state of being housed in the respective partial cases of the plurality of partial cases. With this configuration, the resin material is filled into the respective partial cases of the plurality of partial cases in a state where the respective partial high-voltage side windings of the plurality of partial high-voltage side windings are housed in the respective partial cases together with the core, whereby the respective partial high-voltage side windings of the plurality of partial high-voltage side windings can be easily sealed together with the part of the core. Therefore, even in the case where the plurality of partial high-voltage side windings are arranged so as to be alternately arranged with the plurality of partial low-voltage side windings, it is possible to easily seal each of the plurality of partial high-voltage side windings.

In the power conversion device according to claim 1, it is preferable that the power conversion device further includes a blower that cools a low-voltage side winding of the transformer. With this configuration, the low-voltage side winding and the portion of the leg portion of the core around which the low-voltage side winding is wound can be efficiently cooled by sending cooling air from the blower to the exposed low-voltage side winding. Therefore, the temperature rise of the entire transformer can be effectively suppressed.

The 2 nd aspect of the present invention provides a transformer, wherein the transformer includes: a core having a leg portion forming a magnetic path; and a winding wound around a leg portion of the core, the winding having a high-voltage side winding as any one of a primary winding and a secondary winding of a primary side and a low-voltage side winding as the other of the primary winding and the secondary winding, the high-voltage side winding being sealed with a resin member together with a part of the core in a state of being wound around the leg portion of the core, the low-voltage side winding being exposed in a state of being wound around the leg portion of the core.

In the transformer according to claim 2 of the present invention, as described above, the high-voltage side winding is sealed with the resin member together with a part of the core in a state of being wound around the leg portion of the core. Thus, the high-voltage side winding and a part of the core can be sealed by the resin member having a small dielectric constant (high insulating performance), and therefore, the insulating strength of the high-voltage side winding can be improved as compared with a case where the high-voltage side winding is exposed. As described above, the low-voltage side winding is exposed in a state of being wound around the leg portion of the core. This allows heat to be released from the exposed low-voltage side winding and the part of the core wound by the low-voltage side winding. Therefore, compared to the case where both the high-voltage side winding and the low-voltage side winding are sealed with the resin member along with the entire core, the temperature rise of the transformer can be suppressed. As a result, it is not necessary to increase the size of the winding and the core in order to suppress the temperature rise, and therefore it is possible to provide a transformer capable of improving the insulation strength, suppressing the increase in size, and suppressing the temperature rise.

Drawings

Fig. 1 is a diagram showing an overall configuration of a power converter according to embodiment 1.

Fig. 2 is a perspective view for explaining the structure of the transformer according to embodiment 1.

Fig. 3 is an exploded view of the transformer according to embodiment 1.

Fig. 4 is a sectional view taken along line 110-110 of fig. 2.

Fig. 5 is a diagram for explaining filling of the resin material according to embodiment 1.

Fig. 6 is a diagram showing the overall configuration of the power converter according to embodiment 2.

Fig. 7 is a diagram for explaining the structure of the transformer according to embodiment 2.

Fig. 8 is a diagram for explaining an assembly method of the transformer according to embodiment 2.

Fig. 9 is a diagram showing the overall configuration of the power converter according to embodiment 3.

Fig. 10 is a diagram for explaining the structure of the transformer according to embodiment 3.

Fig. 11 is a diagram for explaining an assembly method of the transformer according to embodiment 3.

Fig. 12 is a diagram showing a transformer according to a modification of embodiments 1 to 3.

Detailed Description

Hereinafter, embodiments embodying the present invention will be described based on the drawings.

[ embodiment 1 ]

The configuration of a power conversion device 100 according to embodiment 1 will be described with reference to fig. 1 to 5. The power conversion device 100 includes a DCDC converter that converts a voltage of input dc power and outputs the dc power having the converted voltage. The power conversion device 100 is used for a solar PCS (power conditioning system) that converts dc power from a power supply 101 such as a solar cell.

As shown in fig. 1, a power converter 100 according to embodiment 1 includes an inverter unit 1, a transformer 2, a converter unit 3, and a blower 4. The power conversion apparatus 100 may be provided with a smoothing circuit or the like. The inverter unit 1 is an example of a "power conversion unit" in the claims.

The converter unit 1 converts dc power input from the power supply 101 into ac power. The converter unit 1 includes an inverter circuit having a switching element such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (metal-oxide-semiconductor field-effect Transistor). The converter unit 1 converts input dc power into ac power by switching operations of switching elements in accordance with a control signal (gate signal) from a control unit (not shown). Then, the converter unit 1 outputs the converted ac power to the transformer 2.

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 for transforming high-frequency ac power. The details of the transformer 2 will be described later.

The converter unit 3 converts ac power from the transformer 2 into dc power. The converter section 3 includes a rectifier circuit (diode bridge circuit) having, for example, a diode. The converter unit 3 outputs the converted dc power. In the rectifier circuit of the converter unit 3, switching elements such as IGBTs and MOSFETs may be used instead of diodes.

The blower 4 cools the transformer 2. Specifically, the blower 4 is configured to send cooling air for cooling the winding 12 (see fig. 2) of the transformer 2.

(Structure of Transformer)

As shown in fig. 2, the transformer 2 of embodiment 1 includes a winding 10, a core 20, a bobbin 30, and a case 40.

As shown in fig. 3, the winding 10 includes a winding 11 and a winding 12. The winding 11 is a winding (coil) of 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. In other words, the transformer 2 steps down the voltage of the input ac voltage. The

windings

11 and 12 are, for example, enameled wires or litz wires. Further, the winding 11 is an example of the "primary winding" and the "high-voltage side winding" in the claims. In addition, the winding 12 is an example of "secondary winding" and "low-voltage side winding" in the claims.

The core 20 includes a pair of

core members

20a, 20b. The pair of

core members

20a, 20b includes an EE-shaped ferrite core. The core 20 has a leg portion 21 (see fig. 4) that forms a magnetic path by a current flowing through the winding 10 in a state where the pair of

core members

20a and 20b are combined. That is, in a state where the core member 20a and the core member 20b are combined, 1 quadrangular-prism-shaped leg portion 21 is formed. The winding 10 (the winding 11 and the winding 12) is arranged to be wound around the quadrangular prism-shaped leg portion 21. In the transformer 2, a magnetic field is generated in the leg portion 21 (core 20) due to the current flowing in the winding 11 on the primary side. Then, an induced electromotive force is generated in the secondary-side winding 12 due to the magnetic field generated in the leg portion 21, and a current flows in the winding 12.

The core 20 is an annular core in which a magnetic circuit (magnetic circuit) is formed by a leg portion 21 and an outer leg portion, the leg portion 21 being wound around the winding 10, the outer leg portion being disposed outside the winding 10 on the Y1 direction side and the Y2 direction side of the leg portion 21, respectively. Here, the "annular core" is described as a concept including not only a completely closed state but also a case where the pair of

core members

20a and 20b are disposed with a gap therebetween.

As shown in fig. 3, the bobbin 30 has

members

31, 32, 33. The bobbin 30 has a winding shape by combining the members 31 to 33. In embodiment 1, the bobbin 30 holds the winding 10 so that the winding 10 (the winding 11 and the winding 12) is wound around the leg 21 of the core 20. That is, the winding 10 is wound around the leg 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 insulation properties. The bobbin 30 is formed of a thermoplastic resin such as an olefin resin, for example.

As shown in fig. 4, in embodiment 1, the winding 11 and the winding 12 are wound around the leg portion 21 of the core 20 in a state of being separated from each other in the extending direction (Z direction) of the leg portion 21. Specifically, the winding 11 is wound toward one side (Z2 direction side) of the leg portion 21. The coil 12 is wound so as to be closer to the other side (Z1 direction side) of the leg portion 21. That is, the coil 11 is wound around the leg portion 21 on the core member 20b side in a state of being partially held by the member 33 on the lower side (Z2 direction side) of the bobbin 30. The coil 12 is wound around the leg 21 on the core member 20a side in a state of being partially held by the member 32 on the upper side (Z1 direction side) of the bobbin 30. The transformer 2 is a split-winding transformer in which a primary winding 11 and a secondary winding 12 are split. The end of the coil 11 is drawn out in the X1 direction (see fig. 2). The end of the winding 12 is drawn out in the X2 direction (see fig. 2).

The case 40 houses the winding 11. Specifically, the case 40 houses: the winding 11, the lower half (the core member 20b side half) of the core 20 and the bobbin 30 including the part of the leg portion 21 wound by the winding 11. That is, the case 40 internally houses a lower half (Z2 direction side) of the transformer 2. The upper side (Z1 direction side) of the winding 12 and the transformer 2 is not housed in the case 40, but is exposed.

In embodiment 1, the coil 11 is held by the bobbin 30 and wound around the leg 21 on one side (the Z2 direction side), and is sealed with the resin member 50 together with a part of the bobbin 30 and a part of the core 20 (the core member 20 b). The winding 12 is exposed in a state of being wound close to the other side (Z1 direction side) of the leg portion 21 of the core 20. Specifically, in embodiment 1, the coil 11 is sealed by the resin member 50 filled in the case 40 together with the bobbin 30 and the core member 20b which is a part of the core 20 in a state of being housed in the case 40.

That is, the coil 11 housed inside the case 40, and the lower half (Z2 direction side) of the core 20 and the bobbin 30 including the part of the leg portion 21 wound around the coil 11 are hermetically sealed by the resin member 50. On the other hand, the upper side (Z1 direction side) half of the winding 12 and the core 20 is not sealed by the resin member 50, but is exposed. The exposed upper side (Z1 direction side) of the transformer 2 is configured to be cooled by the blower 4.

In addition, the case 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 case 40, and the resin member 50 are substantially equal to each other. Therefore, the resin member 50 is configured to be able to suppress voids (molding defects) caused by cracks due to thermal expansion when the resin material for forming the resin member 50 is cured.

(method of assembling transformer in embodiment 1)

Next, an assembling method (manufacturing method) of the transformer 2 according to embodiment 1 will be described with reference to fig. 3 and 5.

As shown in fig. 3, first, the winding 10 (the winding 11 and the winding 12) is held by the bobbin 30. Specifically, the winding 11 is held by the member 33 of the bobbin 30. The winding 12 is then retained to the member 32 of the bobbin 30. Then, the winding 10, the core 20 and the bobbin 30 are combined. Specifically, the members 31 to 33 of the bobbin 30 and the pair of

core members

20a and 20b of the core 20 are combined while holding the winding 10. The coil 10, the core 20, and the bobbin 30 are fixed by a tape or the like in a combined state.

Then, as shown in fig. 5, the combined winding 10, core 20, and bobbin 30 are housed in a case 40. Specifically, in a state where the winding 12 of the winding 10 is partially exposed, the winding 11 of the winding 10 is partially housed inside the case 40. The end of the coil 11 is drawn out of the case 40.

Then, after the hole of the case 40 for drawing out the coil 11 is closed, the inside of the case 40 is filled with a resin material. That is, the coil 11, a part of the core 20 (core member 20b portion), and the bobbin 30 (lower half of the bobbin 30) in a state of being housed in the case 40 are sealed with a resin material. In the case of filling the resin material, evacuation may be performed in order to suppress the occurrence of molding defects such as voids. That is, the resin material may be filled into the case 40 in a vacuum atmosphere.

[ Effect of embodiment 1 ]

In embodiment 1, the following effects can be obtained.

In embodiment 1, as described above, the coil 11 (high-voltage side coil) is sealed with the resin member 50 together with a part of the core 20 in a state of being wound around the leg portion 21 of the core 20. Thus, the coil 11 and a part of the core 20 can be sealed by the resin member 50 having a small dielectric constant (high insulating performance), and therefore, the insulating strength of the coil 11 can be improved as compared with a case where the coil 11 is exposed. As described above, the winding 12 (low-voltage side winding) is exposed in a state of being wound around the leg portion 21 of the core 20. This allows heat to be released from the exposed portion of the winding 12 and the core 20 wound by the winding 12. Therefore, compared to the case where both the

windings

11 and 12 are sealed by the resin member 50 together with the entire core 20, the temperature rise of the transformer 2 can be suppressed. As a result, it is not necessary to increase the size of the winding 10 (the winding 11 and the winding 12) and the core 20 in order to suppress the temperature increase, and therefore, the insulation strength can be improved, and the temperature increase can be suppressed while suppressing the increase in size.

In embodiment 1, as described above, the transformer 2 includes the case 40 (high-voltage side winding case) that houses the winding 11 (high-voltage side winding) of the winding 10, and the winding 11 is sealed with the resin member 50 that fills the inside of the case 40 together with a part of the core 20 in a state housed in the case 40. This allows the resin material to be filled into the case 40 while the coil 11 wound around the leg 21 of the core 20 is housed in the case 40 together with the core 20. Therefore, the coil 11 can be easily sealed together with a part of the core 20 by the resin member 50.

In embodiment 1, as described above, in order to wind the winding 10 around the leg 21 of the core 20, the bobbin 30 holding the winding 10 is further provided, 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 of being held by the bobbin 30 and wound around the leg 21 of the core 20. Thus, by holding the winding 10 by the bobbin 30, the winding 10 can be easily arranged to be wound around the core 20. In addition, since the winding 11 is sealed by the resin member 50 together with the bobbin 30 and the part of the core 20, the winding 11, the bobbin 30, and the core 20 can be sealed integrally. Therefore, for example, it is possible to suppress a decrease in the insulation strength due to the presence of the air layer between the core 20 and the bobbin 30. As a result, the coil 10 can be easily arranged around the core 20 by the bobbin 30, and the reduction in insulation can be suppressed to realize a high withstand voltage.

In embodiment 1, as described above, the winding 11 (high-voltage side winding) and the winding 12 (low-voltage side winding) are wound around the leg portion 21 of the core 20 in a state of being separated from each other in the extending direction (Z direction) of the leg portion 21, the winding 11 is sealed with the resin member 50 together with a part of the core 20 in a state of being wound around one side (Z2 direction side) of the leg portion 21, and the winding 12 is exposed in a state of being wound around the other side (Z1 direction side) of the leg portion 21. Thus, since the winding 11 is wound toward one side of the leg portion 21, by sealing only one side of the leg portion 21 with the resin member 50, the winding 12 wound toward the other side can be exposed and the winding 11 can be more easily sealed. Therefore, the winding 12 can be exposed while the work load for sealing the winding 11 is further reduced.

Further, in embodiment 1, as described above, the air blower 4 for cooling the winding 12 (low-voltage side winding) of the transformer 2 is further provided. Accordingly, by sending cooling air from the blower 4 to the exposed coil 12, the coil 12 and the portion of the leg portion 21 of the core 20 around which the coil 12 is wound can be efficiently cooled. Therefore, the temperature rise of the entire transformer 2 can be effectively suppressed.

[ 2 nd embodiment ]

Next, the configuration of the power converter 200 according to embodiment 2 will be described with reference to fig. 6 to 8. In embodiment 2, the winding 212 on the secondary side is wound so as to be sandwiched between the two

windings

211a and 211b on the divided primary sides. Note that the same components as those in embodiment 1 are denoted by the same reference numerals, and description thereof is omitted.

(configuration of Power conversion device in embodiment 2)

As shown in fig. 6, the power converter 200 according to embodiment 2 includes an inverter unit 1, a transformer 202, a converter unit 3, and a blower 4. Further, as in embodiment 1, the power conversion device 200 includes a DCDC converter that converts the voltage of the input dc power and outputs the dc power whose voltage has been converted. Transformer 202 transforms ac power from inverter unit 1, as in transformer 2 of embodiment 1. The transformer 202 outputs the transformed ac power to the converter unit 3.

As shown in fig. 7, in embodiment 2, the transformer 202 includes a winding 210, a core 220, a bobbin 230, a case 240a, and a case 240b. The case 240a is an example of the "case for high-voltage side winding" and the "case 1" in the claims. The case 240b is an example of the "case for high-voltage side winding" and the "2 nd case" in the claims.

In embodiment 2, winding 210 includes winding 211a, winding 211b, and winding 212. The

windings

211a, 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. Further, the winding 211a is an example of "primary winding", "high-voltage side winding", and "1 st high-voltage side winding" in the claims. In addition, the winding 211b is an example of the "primary winding", the "high voltage side winding", and the "2 nd high voltage side winding" in the claims. In addition, the winding 212 is an example of "secondary winding" and "low-voltage side winding" in the claims.

As in embodiment 1, the core 220 is an EE-type ferrite core in which a pair of

E-shaped core members

220a and 220b are combined. As in the core 20 of embodiment 1, the core 220 has a leg portion 221 that forms a magnetic path by a current flowing through the winding 210 in a state where the pair of

core members

220a and 220b are combined. The

windings

211a and 211b and the winding 212 are arranged to be wound around the quadrangular prism-shaped leg 221. In fig. 7, the outer leg portion disposed outside the winding 210 of the core 220 is not shown.

The bobbin 230 holds the winding 210 (the

windings

211a, 211b and the winding 212) so that the winding 210 is wound around the leg 221 of the core 220, as in the bobbin 30 of embodiment 1.

In embodiment 2, 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 portion 221 so as to be sandwiched between the winding 211a and the winding 211b in the extending direction (Z direction) of the leg portion 221 of the core 220. 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.

In embodiment 2, the case 240a accommodates the winding 211a from one side (Z1 direction side) of the leg 221. The case 240b accommodates the winding 211b from the other side (Z2 direction side) of the leg 221 so as to face the case 240a. Specifically, the case 240a houses: the winding 211a, the core 220 including the wound part of the leg 221 by the winding 211a, and the part of the bobbin 230. Further, the case 240b houses: the winding 211b, the portion of the core 220 and the bobbin 230 that includes the part of the leg 221 wound by the winding 211b.

In embodiment 2, the

windings

211a and 211b are wound around the leg 221 with the winding 212 interposed therebetween, and are sealed together with a part of the core 220 by the resin member 250. Specifically, the coil 211a is housed in the case 240a and sealed by the resin member 250 filled into the case 240a together with a part of the core 220. In a state where coil 211b is housed in case 240b, it is sealed by resin member 250 filled into case 240b together with a part of core 220.

That is, the coil 211a, the portion of the bobbin 230 holding the coil 211a, and the part of the core 220 wound with the coil 211a (the portion on the Z1 direction side) are integrally sealed by the resin member 250 while being arranged inside the case 240a. The coil 211b, the portion of the bobbin 230 holding the coil 211b, and the part of the core 220 wound around the coil 211b (the portion on the Z2 direction side) are integrally sealed by the resin member 250 while being arranged inside the case 240b. The winding 212 is not housed in the case 240a and the case 240b and is exposed. That is, the winding 212 is not sealed by the resin member 250, but is exposed.

Other configurations of embodiment 2 are the same as those of embodiment 1.

(method of assembling transformer in embodiment 2)

Next, an assembly method (manufacturing method) of the transformer 202 according to embodiment 2 will be described with reference to fig. 8.

As shown in fig. 8, in embodiment 2, first, a winding 211a and a winding 211b, which are primary-side coils, are arranged to be wound around a core 220 together with a bobbin 230. For example, the lower side (Z2 direction side) winding 211b is housed in the case 240b together with a part of the bobbin 230 and the core member 220 b. Then, the case 240b in which the coil 211b, the bobbin 230, and the core member 220b are accommodated is filled with a resin material. As for the winding 211a, the winding 211a is housed in the case 240a together with the bobbin 230 and the core member 220a, similarly to the winding 211b. Then, the case 240a in which the coil 211a, the part of the bobbin 230, and the core member 220a are accommodated is filled with a resin material.

Then, the primary-

side windings

211a and 211b are sealed with the resin member 250, and thereafter, the two primary-

side windings

211a and 211b are combined so as to sandwich the secondary-side winding 212 therebetween.

[ Effect of embodiment 2 ]

In embodiment 2, the following effects can be obtained.

In embodiment 2, as described above, the power conversion device 200 includes the winding 211a (1 st high-voltage side winding) and the winding 211b (2 nd high-voltage side winding) that are divided into two and wound around the leg 221 of the core 220, 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 extending direction (Z direction) of the leg 221 of the core 220, and the winding 211a and the winding 211b are sealed together with a part of the core 220 by the resin member 250 in a state of being wound around the leg 221 so as to sandwich the winding 212. Accordingly, since winding is performed so that winding 212 is sandwiched between winding 211a and winding 211b, magnetic coupling between the high-voltage side winding and the low-voltage side winding can be improved. Therefore, leakage inductance (leakage inductance) from winding 210 can be reduced, and thus electrical loss due to the leakage inductance can be reduced.

In embodiment 2, as described above, the transformer 202 includes the case 240a (1 st case) housing the winding 211a (1 st high-voltage side winding) from one side (Z1 direction side) of the leg 221, and the case 240b (2 nd case) housing the winding 211b (2 nd high-voltage side winding) from the other side (Z2 direction side) of the leg 221 so as to face the case 240a, the winding 211a is sealed with the resin member 250 filled into the case 240a together with the part of the core 220 in a state of being housed in the case 240a, and the winding 211b is sealed with the resin member 250 filled into the case 240b together with the part of the core 220 in a state of being housed in the case 240b. Thus, by filling the resin material into case 240a in a state where winding 211a is housed in case 240a together with core 220, winding 211a and a part of core 220 can be easily sealed together. In addition, by filling the resin material into case 240b in a state where winding 211b is housed in case 240b together with core 220, winding 211b can be easily sealed together with a part of core 220. Therefore, even in the case where the two

windings

211a and 211b are arranged to sandwich 1 winding 212 (low-voltage side winding), each of the two

windings

211a and 211b can be easily sealed.

Other effects of embodiment 2 are similar to those of embodiment 1.

[ embodiment 3 ]

Next, the configuration of a power converter 300 according to embodiment 3 will be described with reference to fig. 9 to 11. In embodiment 3, the plurality of windings 311a to 311c on the primary side and the plurality of windings 312a to 312c on the secondary side are alternately arranged in the extending direction of the leg 321 of the core 320. Note that the same components as those in embodiment 1 are denoted by the same reference numerals, and description thereof is omitted.

(configuration of Power conversion device in embodiment 3)

As shown in fig. 9, a power converter 300 according to embodiment 3 includes an inverter unit 1, a transformer 302, a converter unit 3, and a blower 4. Further, as in embodiment 1, the power conversion device 300 includes a DCDC converter that converts the voltage of the input dc power and outputs the dc power whose voltage has been converted. Transformer 302 transforms ac power from inverter unit 1, as in transformer 2 of embodiment 1. The transformer 302 outputs the transformed ac power to the converter unit 3.

As shown in fig. 10, in embodiment 3, the transformer 302 includes a winding 310, a core 320,

bobbins

330a, 330b, 330c, and

cases

340a, 340b, 340c. The cases 340a to 340c are examples of "a case for high-voltage side winding" and "a plurality of partial cases" in the claims.

In embodiment 3, the winding 310 includes a winding 311a, a winding 311b, and a winding 311c, which are windings (coils) on the primary side of the transformer 302 divided into a plurality of parts. The winding 310 includes a winding 312a, a winding 312b, and a winding 312c, which are secondary-side windings (coils) of the transformer 302 divided into a plurality of parts. In the transformer 302, the primary windings 311a to 311c are on the high-voltage side, and the secondary windings 312a to 312c are on the low-voltage side. In addition, the windings 311a to 311c are an example of "primary winding", "high-voltage side winding", and "multiple partial high-voltage side winding" in the claims. The windings 312a to 312c are examples of the "secondary winding", "low-voltage side winding", and "partial low-voltage side windings" in the claims.

The core 320 is an EI-type ferrite core in which an E-shaped core member 320a and an I-shaped core member 320b are combined. As in the case of the core 20 of embodiment 1, the core 320 has the leg 321 that forms a magnetic path by the current flowing through the winding 310 in a state where 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 quadrangular-prism-shaped leg portion 321. In fig. 10, the outer leg portion disposed outside the winding 310 of the core 320 is not shown.

Similarly to the bobbin 30 of embodiment 1, the bobbins 330a to 330c hold the winding 310 so that the winding 310 is wound around the leg 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. The bobbin 330c holds the winding 311c and the winding 312c.

In embodiment 3, the plurality of windings 311a to 311c and the plurality of windings 312a to 312c are alternately wound around the leg 321 in the extending direction (Z direction) of the leg 321 of the core 320. Specifically, the

windings

311a, 312a, 311b, 312b, 311c, and 312c are arranged in order from the Z2 direction side of the leg 321 along the extending direction (Z direction) of the leg 321.

In embodiment 3, cases 340a to 340c house the respective windings 311a to 311c. Specifically, the case 340a houses the winding 311a, part of the bobbin 330a, and part of the core 320 (core member 320 a). Likewise, the case 340b houses the winding 311b, a part of the bobbin 330b, and a part of the core 320 (core member 320 a). The case 340c accommodates the winding 311c, a part of the bobbin 330c, and a part of the core 320 (core member 320 a). Further, the length (thickness) of the case 340a in the Z direction is larger than the length (thickness) of the case 340b in the Z direction and the length (thickness) of the case 340c in the Z direction.

In embodiment 3, the windings 311a to 311c are sealed with the resin member 350 (see fig. 11) together with part of the core 320 in a state in which the windings 312a to 312c are alternately wound around the leg 321 of the core 320. Specifically, each of the windings 311a to 311c is sealed by the resin member 350 filled in the inside of each of the cases 340a to 340c together with a part of the core 320 in a state of being housed in each of the cases 340a to 340c.

That is, the winding 311a, the portion of the bobbin 330a holding the winding 311a, and the part of the core 320 wound with the winding 311a are integrally sealed by the resin member 350 in a state of being disposed inside the case 340a. Similarly, the winding 311b, the portion of the bobbin 330b holding the winding 311b, and the part of the core 320 wound with the winding 311b are integrally sealed by the resin member 350 in a state of being disposed inside the case 340b. The coil 311c, the portion of the bobbin 330c holding the coil 311c, and the part of the core 320 wound with the coil 311c are integrally sealed by the resin member 350 while being arranged inside the case 340c.

The other structure of embodiment 3 is the same as embodiment 1.

(method of assembling transformer in embodiment 3)

Next, an assembling method (manufacturing method) of transformer 302 according to embodiment 3 will be described with reference to fig. 11.

As shown in fig. 11, in embodiment 3, first, the winding 311a and the winding 312a held by the bobbin 330a are arranged to be wound around the leg 321 of the core 320 (core member 320 a). Then, the winding 311a and part of the core 320 (core member 320 a) are housed in the case 340a.

Then, the case 340a in a state in which the coil 311a, the bobbin 330a, and the core member 320a are housed therein is filled with a resin material.

Next, the winding 311b and the winding 312b held by the bobbin 330b are arranged to be wound around the leg 321 of the core 320 (core member 320 a) so as to overlap with the winding 311a and the winding 312 a. Here, the winding 311b and a part of the core 320 are disposed so as to be housed in the case 340b. Then, the case 340b in a state in which the coil 311b, the bobbin 330b, and the core member 320a are housed therein is filled with a resin material.

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 320 a) so as to overlap the winding 311b and the winding 312b. Similar to the winding 311b, the winding 311c and a part of the core 320 are disposed so as to be accommodated in the case 340c. Then, the case 340c in a state in which the coil 311c, the bobbin 330c, and the core member 320a are housed therein is filled with a resin material. Then, by combining the I-shaped core member 320b, a magnetic path of the core 320 is formed by the core member 320a and the core member 320 b.

[ Effect of embodiment 3 ]

In embodiment 3, the following effects can be obtained.

In embodiment 3, as described above, the transformer 302 includes the windings 311a to 311c (partial high-voltage side windings) divided into a plurality of parts and the windings 312a to 312c (partial low-voltage side windings) divided into a plurality of parts, the plurality of windings 311a to 311c and the plurality of windings 312a to 312c are alternately wound around the leg portion 32 in the extending direction of the leg portion 321 of the core 320, and each of the plurality of windings 311a to 311c is sealed with the resin member 350 together with a part of the core 320 in a state where the plurality of windings 312a to 312c are alternately wound around the leg portion 321 of the core 320. Accordingly, since the plurality of windings 311a to 311c are arranged alternately with the plurality of windings 312a to 312c, the magnetic coupling between the high-voltage side winding and the low-voltage side winding can be further improved as compared with the case where 1 winding is arranged between two windings. Therefore, leakage inductance (leakage inductance) from winding 310 can be further reduced, and thus electrical loss due to the leakage inductance can be further reduced. Further, since the windings 311a to 311c and the windings 312a to 312c are divided into a plurality of parts, heat generated from the winding 310 can be dispersed. Therefore, a temperature rise due to heat generation from the winding 310 can be more suppressed.

In embodiment 3, the transformer 302 includes a plurality of cases 340a to 340c (partial cases) housing each of the plurality of windings 311a to 311c, and each of the plurality of windings 311a to 311c is sealed with a resin member 350 that fills the inside of each of the plurality of cases 340a to 340c together with a part of the core 320 in a state of being housed in each of the plurality of cases 340a to 340c. Accordingly, in a state where the plurality of windings 311a to 311c are housed in the plurality of cases 340a to 340c together with the core 320, respectively, the resin material is filled into the inside of each of the plurality of cases 340a to 340c, whereby the plurality of windings 311a to 311c can be easily sealed together with a part of the core 320. Therefore, even when the plurality of windings 311a to 311c are arranged so as to be alternately arranged with the plurality of windings 312a to 312c, the plurality of windings 311a to 311c can be easily sealed.

Other effects of embodiment 3 are similar to those of

embodiments

1 and 2.

[ modified examples ]

In addition, all aspects of the embodiments of the present application are illustrative, and should not be construed as limiting the present invention. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and includes all modifications (variations) within the meaning and scope equivalent to the claims.

For example, in the above-described embodiments 1 to 3, the example in which the core 20 (220, 320) is configured by the pair of

core members

20a, 20b (220 a and 220b, 320a and 320 b) is shown, but the present invention is not limited thereto. In the present invention, as in the

transformers

402 and 502 of the modification shown in fig. 12, the number of the pair is not limited, and a plurality of 3 or more cores may be connected.

In addition, although the core 20 (220) has the EE shape in the above-described

embodiments

1 and 2, and the core 320 has the EI shape in the above-described embodiment 3, the present invention is not limited to this. For example, the core may have a shape such as an EER shape, a PQ shape, a UU shape, or a UI shape.

In addition, although the above-described embodiments 1 to 3 show examples in which the high-voltage side windings 11 (211 a and 211b, 311a to 311 c) are sealed by the resin member 50 (250, 350) which is partially filled into the case 40 (240 a and 240b, 340a to 340 c) together with the core 20 (220, 320) in a state of being housed in the case 40 (240 a and 240b, 340a to 340 c), the present invention is not limited to this. For example, the winding 11 (211 a and 211b, 311a to 311 c) and the core 20 (220, 320) may be partially and integrally sealed by the resin member 50 (250, 350) without providing a case in the transformer.

In addition, although the above-described embodiments 1 to 3 have shown examples in which the bobbin 30 (230, 330a to 330 c) holding the winding 10 (210, 320) is provided so that the winding 10 (210, 320) is wound around the leg portion 21 (221, 321) of the core 20 (220, 320), the present invention is not limited to this. For example, the windings may be insulated from each other or from the core by a plate-shaped insulating member or the like, without using a bobbin. In this case, the high-voltage side winding, the insulating member, and the core may be partially and integrally sealed with a resin material.

In addition, although the example in which the

windings

211a and 211b (high-voltage side windings) are respectively wound around the leg 221 with the winding 212 (low-voltage side winding) interposed therebetween and are sealed by the resin member 250 together with a part of the core 220 has been described in the above embodiment 2, the present invention is not limited thereto. For example, the two low-voltage-side windings may be arranged so as to sandwich 1 high-voltage-side winding.

In embodiment 3, an example is shown in which the primary-side windings 311a to 311c and the secondary-side windings 312a to 312c are divided into three windings, but the present invention is not limited to this. For example, the primary side winding and the secondary side winding may be divided into 4 or more. The number of primary-side division and the number of secondary-side division may be different from each other.

In addition, although the above-described embodiments 1 to 3 show examples of the blower 4 including the cooling coil 12 (212, 312a to 312 c), the present invention is not limited thereto. For example, cooling by water cooling may be performed instead of air cooling by the blower 4. Further, a heat dissipating member such as a heat sink may be provided in an exposed portion of the core 20 (220, 320).

In addition, although the above-described embodiments 1 to 3 show examples in which the primary-side winding 11 (211 a and 211b, 311a to 311 c) is on the high-voltage side and the secondary-side winding 12 (212, 312a to 312 c) is on the low-voltage side, the present invention is not limited thereto. For example, the primary side may be a low voltage and the secondary side may be a high voltage. In this case, the winding on the secondary side, which is the high-voltage side, is sealed together with a part of the core by a resin member, and the winding on the primary side, which is the low-voltage side, is exposed.

In addition, although the example in which the winding 10 (210, 310) is a round-shaped enameled wire or litz wire has been described in the above embodiments 1 to 3, the present invention is not limited to this. For example, the winding 10 (210, 310) may be a flat-plate (Edgewise) winding such as a flat wire or a braided wire. The transformer 2 (202, 302) may be a planar transformer in which the winding 10 (210, 310) is formed of a conductor pattern of a printed circuit board.

Claims

1. A power conversion apparatus, wherein,

the power conversion device is provided with:

a power conversion unit that converts input direct-current power into alternating-current power; and

a transformer for transforming the AC power from the power conversion unit,

the transformer includes:

a core having a leg portion forming a magnetic path; and a winding wound around the leg portion of the core,

the winding has a high-voltage side winding as any one of a primary winding of a primary side and a secondary winding of a secondary side and a low-voltage side winding as the other of the primary winding and the secondary winding,

the high-voltage side winding is sealed by a resin member together with a part of the core in a state of being wound around the leg portion of the core,

the low-voltage side winding is exposed in a state of being wound around the leg portion of the core.

2. The power conversion apparatus according to claim 1,

the transformer further includes a high-voltage side winding case that houses the high-voltage side winding of the winding,

the high-voltage side winding is sealed by the resin member filled into the high-voltage side winding case together with a part of the core in a state of being housed in the high-voltage side winding case.

3. The power conversion apparatus according to claim 1 or 2,

the power conversion device further includes a bobbin that holds the winding so that the winding is wound around the leg portion of the core,

the high-voltage side winding is sealed by the resin member together with the bobbin and a part of the core in a state of being held by the bobbin and wound around the leg of the core.

4. The power conversion apparatus according to claim 1 or 2,

the high-voltage side winding and the low-voltage side winding are wound around the leg portion of the core in a state of being separated from each other in an extending direction of the leg portion,

the high-voltage side winding is sealed by the resin member together with a part of the core in a state of being wound toward one side of the leg portion,

the low-voltage side winding is exposed in a state of being wound close to the other side of the leg portion.

5. The power conversion apparatus according to claim 1 or 2,

the high-voltage side winding has a 1 st high-voltage side winding and a 2 nd high-voltage side winding that are divided into two and wound around the leg portion of the core,

the low-voltage side winding is wound around the leg portion so as to be sandwiched between the 1 st high-voltage side winding and the 2 nd high-voltage side winding in an extending direction of the leg portion of the core,

the 1 st high-voltage side winding and the 2 nd high-voltage side winding are each sealed by the resin member together with a part of the core in a state of being wound around the leg portion with the low-voltage side winding interposed therebetween.

6. The power conversion apparatus according to claim 5,

the high-voltage side winding case has a 1 st case that houses the 1 st high-voltage side winding from one side of the leg portion, and a 2 nd case that houses the 2 nd high-voltage side winding from the other side of the leg portion so as to be opposed to the 1 st case,

the 1 st high-voltage side winding is sealed by the resin member filled into the 1 st case together with a part of the core in a state of being housed in the 1 st case,

the 2 nd high-voltage side winding is sealed by the resin member filled into the inside of the 2 nd case together with a part of the core in a state of being housed in the 2 nd case.

7. The power conversion apparatus according to claim 1 or 2,

the high voltage side winding has a partial high voltage side winding divided into a plurality of sections,

the low voltage side winding has a partial low voltage side winding divided into a plurality of sections,

a plurality of the partial high-voltage side windings and a plurality of the partial low-voltage side windings are alternately wound around the leg portion of the core in an extending direction of the leg portion,

each of the plurality of partial high-voltage side windings is sealed together with a part of the core by the resin member in a state in which the partial high-voltage side winding and the plurality of partial low-voltage side windings are alternately wound around the leg portion of the core.

8. The power conversion apparatus according to claim 7,

the high-voltage side winding case has a plurality of partial cases for housing the respective partial high-voltage side windings among the plurality of partial high-voltage side windings,

each of the plurality of partial high-voltage side windings is sealed by the resin member filled into the inside of each of the plurality of partial cases together with a part of the core in a state of being housed in each of the plurality of partial cases.

9. The power conversion apparatus according to claim 1 or 2,

the power conversion device further includes a blower that cools the low-voltage side winding of the transformer.

10. A transformer, wherein,

the transformer is provided with:

a core having a leg portion forming a magnetic path; and

a winding wound around the leg portion of the core,