WO2014038000A1 - Power conversion device - Google Patents

Power conversion device Download PDF

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Publication number
WO2014038000A1
WO2014038000A1 PCT/JP2012/072493 JP2012072493W WO2014038000A1 WO 2014038000 A1 WO2014038000 A1 WO 2014038000A1 JP 2012072493 W JP2012072493 W JP 2012072493W WO 2014038000 A1 WO2014038000 A1 WO 2014038000A1
Authority
WO
WIPO (PCT)
Prior art keywords
metal body
insulated
conversion device
unit
power conversion
Prior art date
Application number
PCT/JP2012/072493
Other languages
French (fr)
Japanese (ja)
Inventor
勇一郎 吉武
Original Assignee
株式会社日立製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社日立製作所 filed Critical 株式会社日立製作所
Priority to PCT/JP2012/072493 priority Critical patent/WO2014038000A1/en
Publication of WO2014038000A1 publication Critical patent/WO2014038000A1/en

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K7/00—Constructional details common to different types of electric apparatus
    • H05K7/14—Mounting supporting structure in casing or on frame or rack
    • H05K7/1422—Printed circuit boards receptacles, e.g. stacked structures, electronic circuit modules or box like frames
    • H05K7/1427—Housings
    • H05K7/1432—Housings specially adapted for power drive units or power converters
    • H05K7/14325—Housings specially adapted for power drive units or power converters for cabinets or racks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/003—Constructional details, e.g. physical layout, assembly, wiring or busbar connections

Definitions

  • the present invention relates to a power converter, and more particularly to isolation of the power converter.
  • Power converters are important key components in power electronics, and improving the conversion efficiency of power converters is an important issue.
  • miniaturization of the power converter board is also an important issue from the viewpoint of space saving and direct reduction of material cost.
  • Power converters such as inverters, converters, power conditioners and the like that exceed the rated 500 V are usually configured in units called unit cells.
  • power converter boards such as an inverter board, have a structure which stores a plurality of unit cells.
  • Patent documents 1 to 4 and Non-patent document 1 relate to an electric device having a high voltage conductor such as a pipeline bus bar or a winding conductor.
  • Patent Document 1 relates to an electrical device having a high voltage conductor: "The high voltage conductor is coated with two or more kinds of materials having different characteristics, for example, a material having good adhesion to metal, and the outside is further insulated It is described as “coating with the superior material of (2) to improve both the adhesion and the insulation” (see the summary). In addition, as a material having excellent insulating properties, it is described that "a method of coating an insulator such as epoxy or fluorine resin can be used” (see paragraph 0009).
  • Patent Documents 1 to 4 and Non-patent Document 1 it is difficult to apply the method of complex insulation disclosed in Patent Documents 1 to 4 and Non-patent Document 1 to a unitized power converter to complex insulation.
  • thermosetting resin as solid insulation
  • preheating of the unit body is required.
  • the inverter unit incorporated in the unit main body includes equipment with low heat resistance such as a capacitor, it is difficult to preheat the unit main body after assembling the inverter unit into the unit main body.
  • the unit case is assembled with, for example, a metal having a thickness of about 2 to 3 mm, the unit angle (bending radius) R is as small as, for example, 0.1 mm. For this reason, when solid insulation is mounted, swelling and peeling of the insulator tend to occur at the corners. On the other hand, since a thin (for example, 1 mm thick as described later) insulating coating is required in a wide area of the flat portion of the unit housing, it is required to maintain the strength of the insulator.
  • this invention makes it a subject to provide the power converter device which can be reduced in size and improved in reliability.
  • the present invention is a power converter characterized by providing a solid insulator so that an electric field concentration part of a sharp high voltage part may be covered.
  • FIG. 1 is an overall view of a power conversion device 1.
  • the power conversion device 1 includes a plurality of unit cells 2, a ventilation duct 7 for air cooling the unit cells 2, a panel case 8 for supporting the unit cells 2, and an insulating plate 9. Is equipped.
  • a power conversion device 1 such as an inverter, a converter, or a power conditioner is configured in units called unit cells 2.
  • power converter 1 is explained as what is a high voltage direct inverter.
  • the unit cell 2 has a switching element 23 (see FIG. 3) and the like, and since the switching element 23 (see FIG. 3) and the like generate heat, a ventilation duct 7 for air cooling the unit cell 2 is provided.
  • the unit cell 2 is disposed on the shelf plate 81 of the panel case 8 via the insulating plate 9.
  • the panel case 8 is a case of the power conversion device 1, and the shelf board 81 supports the unit cell 2.
  • the panel case 8 and the shelf plate 81 are formed of metal (for example, iron, SUS (Steel Use Stainless; stainless steel), hot-dip galvanized steel sheet, aluminum). Moreover, the panel case 8 and the shelf plate 81 are electrically grounded.
  • the high voltage direct inverter since a high voltage is applied to the unit cell 2 or components in the unit cell 2, it is necessary to insulate from the ground region, and it is necessary to secure the space insulation distance and the creepage insulation distance. Similarly, since the potentials and phases of the unit cells 2 are different from each other, it is necessary to secure a space insulation distance and a creepage insulation distance between the unit cells 2. Further, in the high voltage direct inverter, since the phase is different in each stage, it is recommended to secure the insulation distance defined by the standard.
  • the power conversion device 1 is a ground metal casing that supports the unit cell 2 and the unit cell 2 by laying the insulating plate 9 that is an insulator under the unit cell 2. It is possible to secure the insulation distance between the shelf board 81 and the like.
  • the space insulation distance is 60 mm, which is a large value.
  • the power converter may be miniaturized in order to secure the space insulation distance (for example, 60 mm for a 6 kV class inverter). It was difficult. Furthermore, when the switching element fails, the generation of the conductive gas significantly reduces the insulation and may cause a short circuit. For this reason, it was necessary to secure a longer distance between the upper surface of the unit cell 2 and the shelf plate 81 thereabove in consideration of the decrease in insulation due to the generation of the conductive gas.
  • FIG. 2 is a side view around the unit cell 2 of the power conversion device 1 according to the first embodiment as viewed in the direction of arrow A in FIG.
  • the shelf board 81 supporting the unit cell 2 is formed with a beam 82 for maintaining the structural strength.
  • the unit cell 2 (the unit case 21; see FIG. 3) has a high potential, so that the unit cell 2 (the unit case 21; see FIG. 3) and the shelf board 81 have a convex shape in the direction of the unit cell 2. Between the beam 82, the highest electric field is obtained. In order to shorten the space insulation distance between the unit cell 2 and the beam 82, it is necessary to improve the insulation.
  • the power conversion device 1 includes the metal body 5 to be insulated, which is the metal body 3 having the insulator 4 applied to the surface thereof.
  • the high electric field portion field concentration portion to be described later
  • a part of the unit cell 2 is covered with the metal body 5 to be insulated.
  • the space insulation distance between the unit cell 2 and the beam 82 can be shortened.
  • the conventional standard is established. Even if the space insulation distance is shortened (for example, about 50 to 90%), it is possible to have insulation properties equal to or more than conventional air insulation.
  • FIG. 3 is a schematic view for explaining the metal object 5 to be insulated of the power conversion device 1 according to the first embodiment, and is a cross-sectional view taken along the line BB of FIG.
  • the unit cell 2 includes a unit casing 21 formed by combining metal plates (for example, iron, SUS (Steel Use Stainless; stainless steel), aluminum), a switching element 23 such as an IGBT, and an IGBT.
  • a bus bar 26 which is a conductor (for example, copper, aluminum) electrically connecting the radiation fin 24 for cooling, the smoothing capacitor 25 electrically connected to the switching element 23, and the switching element 23 and the smoothing capacitor 25.
  • a control board (not shown).
  • the unit casing 21 is structured to have a potential (for example, the emitter potential of the IGBT) with respect to the ground (the shelf plate 81 and the beam 82).
  • the thickness of the beam 82 of the shelf plate 81 is about 5 mm, and the angle R (bending radius) of the end 83 is, for example, about 0.5 mm.
  • the unit housing 21 is formed of a metal plate having a thickness of about 2 mm, and the corner R (bending radius) of the end 22 is, for example, about 0.1 mm.
  • the unit cell 2 is solid-insulated. That is, the metal object 5 to be insulated is disposed so as to cover the electric field concentration portion.
  • the electric field concentration portion indicates a place where a voltage is applied, the geometric shape is sharp, and the distance to the ground plane is short.
  • the beam 82 of the shelf plate 81 is a thick member as compared with the unit housing 21 and the electric field concentration is alleviated by rounding the corner of the longitudinal end 83 of the beam 82 (increasing the bending radius R). can do.
  • unit housing 21 has a thickness of about 2 mm, and it is difficult to round the corner of its end 22 structurally, so the bending radius R can not be easily increased, and the geometrical shape is sharp.
  • the electric field is concentrated. For this reason, the to-be-insulated metal body 5 is arrange
  • the to-be-insulated metal body 5 includes the metal body 3 and the insulator 4 applied to the surface of the metal body 3 as described above, and as shown in FIG. It is done.
  • the metal body 3 is a substantially U-shaped member opened downward as shown in FIG. 3 and is made of a metal plate (for example, iron, SUS (Steel Use Stainless; stainless steel), molten steel plate, aluminum). It is formed by bending. Here, the metal body 3 is bent so as to form a bulge 31 that bulges outward. In addition, screw holes (not shown) for fixing to the unit housing 21 with the screws 32 are provided at both end portions of the metal body 3.
  • a metal plate for example, iron, SUS (Steel Use Stainless; stainless steel), molten steel plate, aluminum. It is formed by bending.
  • the metal body 3 is bent so as to form a bulge 31 that bulges outward.
  • screw holes (not shown) for fixing to the unit housing 21 with the screws 32 are provided at both end portions of the metal body 3.
  • the insulator 4 is an inner surface of the metal body 3 (a surface on the side of the unit case 21 when the metal body 5 covers the unit case 21), an outer surface (the metal case 5 to be insulated covers the unit case 21).
  • both ends of the metal body 3 fixed with the screws 32 are not covered with the insulator 4 and the metal body 3 is exposed. ing.
  • the thickness of the insulator 4 is preferably about 0.1 mm to 1.0 mm in a 6 kV class inverter and about 0.1 mm to 2.0 mm in an 11 kV class inverter. Thereby, since it can be set as the compound insulation structure of the insulator 4 and air, the insulation distance of the unit housing
  • the insulation improvement can be secured, so if the thickness is made excessive, the cost of the insulator 4 becomes Rising and undesirable.
  • the powder coating method is most desirable in terms of shortening the manufacturing time while preventing microdischarge by improving the adhesion to the metal body 3.
  • the thickness of the metal body 3 is desirably about 1 to 5 mm.
  • the insulator 4 is applied by fluid immersion. For this reason, when the plate thickness of the metal body 3 is less than 1 mm, the heat quantity of preheating is insufficient, and the thickness of the insulator 4 in one fluid immersion does not become a desired thickness, which is not desirable.
  • the plate thickness of the metal body 3 is made larger than 5 mm, the effect of shortening the insulation distance by the plate thickness of the metal body 3 is reduced, which is not desirable.
  • the substantially U-shaped metal body 3 which opens downward is provided on the outside (unit housing) at a portion corresponding to the end 22 of the unit housing 21 when the metal body 5 to be insulated is fitted into the unit cell 2. It is bent so as to form a bulge 31 which bulges on the side opposite to the end 22 of the body 21. And the insulator 4 is given so that the inner surface, the outer surface, and the side of the metal body 3 may be covered. By thus forming the bulge portion 31 in the metal body 3, the manufacturing cost of the metal body 5 to be insulated can be reduced.
  • the insulator 4 when the insulator 4 is applied to the surface of the metal body 3 when the metal body 3 is bent at a right angle without forming the bulge portion 31, the insulator 4 is accumulated in a fillet shape at the inner corner of the metal body 3.
  • the thickness is increased, which makes it difficult to mount the metal object 5 to be insulated on the unit cell 2 (unit housing 21). For this reason, the process of shaving a part of insulator 4 of the inner corner part of the metal body 3 etc. is needed, and the manufacturing cost of the to-be-insulated metal body 5 becomes high.
  • the process of scraping a part of the insulator 4 is Although not necessary, the masking process requires an artificial process, and the manufacturing cost of the metal object 5 to be insulated is increased.
  • the bulged portion 31 in the metal body 3 it is possible to absorb the stagnation of the insulator 4 generated in the inner corner portion of the metal body 3 and eliminate the process of scraping the insulator 4 partially.
  • the manufacturing cost of the metal object 5 to be insulated can be reduced.
  • the insulator 4 can be applied to both surfaces of the metal body 3 by forming the bulge portion 31 in the metal body 3, masking processing is also unnecessary, and the manufacturing cost of the metal body 5 to be insulated can be reduced. it can.
  • the above-described effect can be obtained by forming the bulging portion 31 so as to expand, for example, by about 0.5 to 2.0 mm on the outer side (the side opposite to the end 22 of the unit housing 21, the left and right direction in FIG. You can get it.
  • the bulge 31 may be about 1 mm.
  • the geometrical shape of the bent portion of the metal body 3 is also gentler compared to the case where it is bent at a right angle, but a sufficient electric field relaxation effect can be obtained (for example, bending The radius R is not 5 mm or more).
  • the to-be-insulated metal body 5 since it can be set as the compound insulation structure of the insulator 4 and air, the insulation distance of the unit housing
  • the insulator 4 is not applied to the metal body 3 at both end portions (peripheral portions of screw holes not shown) of the metal object 5 to be insulated, and the metal body 3 is exposed.
  • the metal body 3 and the unit housing 21 are made to have the same potential by covering the unit metal 2 with the metal body 5 to be insulated and fixing the metal body 3 of the metal body 5 to be insulated and the unit housing 21 with the screws 32. It is possible to Thereby, discharge can be prevented from occurring between the metal body 3 and the unit housing 21. Further, since the metal body 3 and the beam 82 can bear the potential difference between the unit case 21 and the beam 82, a composite insulating structure of the insulator 4 and air can be obtained.
  • the exposed area (the position of the screw 32) of the metal body 3 of the metal body 5 to be insulated is formed at a position separated from the beam 82 (the shelf plate 81) by the space insulation distance or more, to secure insulation. It is possible to
  • the metal object 5 to be insulated there is a region where the metal member 3 is exposed around the screw holes at both ends of the metal member 5 to be insulated, and the metal member 3 and the unit housing 21 have the same potential with the screw 32. Although it has been described that they are fixed as described above, the present invention is not limited to this.
  • the insulator 4 is removed, and the metal body 3 and the unit case 21 are electrically connected by a wire to make the same potential. It may be.
  • the insulation property is significantly lowered by the change between the air atmosphere and the conductive gas atmosphere between the unit housing 21 and the beam 82. May cause a short circuit.
  • the space between the unit case 21 (metal body 3) and the beam 82 has a composite insulation structure of the insulator 4 and air.
  • the distance from the metal object 5) to the beam 82 is short. For this reason, even if it changes from an air atmosphere to a conductive gas atmosphere, the decrease in the insulation property is slight, and the insulation can be secured by the insulator 4, so that the occurrence of a short circuit can be prevented.
  • the exposed area (the position of the screw 32) of the metal body 3 of the metal object 5 to be insulated is not a composite insulation structure, and the insulation property is secured by air alone.
  • FIG. 7 is a graph showing the relationship between the dielectric breakdown voltage in the air atmosphere and the dielectric breakdown voltage in the conductive gas atmosphere.
  • the dielectric breakdown voltage in the air atmosphere is 1.0
  • the dielectric breakdown voltage in the conductive gas atmosphere is 1.5.
  • switching is performed by forming the exposed area (the position of the screw 32) of the metal body 3 of the metal object 5 to be insulated at a position 1.5 times or more the space insulation distance from the beam 82 (shelf plate 81). Even when the element fails and a conductive gas is generated, insulation can be secured to prevent the occurrence of a short circuit.
  • the substantially U-shaped insulated metal body 5 forms the insulated metal body 5 using the metal body 3 long in the longitudinal direction, and the exposed area of the metal body 3 of the insulated metal body 5 (
  • the position of the screw 32 at a position at least 1.5 times the space insulation distance from the beam 82 (shelf plate 81)
  • insulation can be secured and short circuit can be prevented from occurring. That is, the distance from the unit cell 2 (insulated metal body 5) to the beam 82 is shorter than the distance between the unit casing 21 and the beam 82 of the configuration in which the insulating property is ensured by the conventional air alone. Even if the switching element fails and a conductive gas is generated as it is, insulation can be secured to prevent occurrence of a short circuit.
  • the power conversion device 1 using the metal object 5 to be insulated can have an electric field concentration part as a composite insulation structure, and compared with a power conversion device having a configuration in which the insulation property is secured with conventional air alone, Even if the distance from the cell 2 to the beam 82 is shortened, insulation can be ensured to prevent a short circuit from occurring.
  • the power converter 1 can be miniaturized, and the integration rate of the unit cells 2 can be increased.
  • the metal member 3 can be used as an inner core of the insulator 4, and the strength of the insulator 4 can be maintained.
  • the unit metal 2 is covered with the metal object 5 to be insulated, it is not necessary to provide a solid insulator directly on the unit housing 21.
  • metal body 5 to be insulated is disposed so as to cover the unit cell 2. Therefore, when the unit cell 2 is taken out from the panel case 8, the metal object 5 to be insulated can be taken out together.
  • the metal body 5 to be insulated can be replaced or inspected in accordance with the replacement or inspection of the unit cell 2, and the workability of the replacement operation or the inspection operation can be improved. Further, if the metal object 5 to be insulated is also exchanged together with the unit cell 2, the reliability of the metal object 5 to be insulated can be secured.
  • the metal object 5 to be insulated is disposed so as to cover a part of the unit cell 2, the case of insulating the entire surface of the unit cell 2 or the case of insulating the lower surface of the shelf plate 81 and the entire surface of the beam 82 In comparison, the cost of the insulator can be reduced.
  • the metal object 5 to be insulated can improve productivity and improve attachment to the unit cell 2.
  • the power conversion device 1 using the metal object 5 can ensure insulation and prevent the occurrence of a short circuit. Thereby, the reliability of the power converter 1 can be improved.
  • FIG. 4 is a schematic view for explaining the insulated metal body 5A of the power conversion device according to the second embodiment, and is a cross-sectional view taken along the line BB in FIG.
  • the power converter according to the second embodiment differs from the power converter 1 according to the first embodiment (see FIGS. 1 to 3) in the configuration of the metal body 5 to be insulated.
  • 5 A of insulated metal bodies with which the power converter device which concerns on 2nd Embodiment is provided are demonstrated.
  • the same reference numerals are given to parts in common with the first embodiment, and duplicate explanations are omitted.
  • An insulated metal body 5A shown in FIG. 4 has a metal body 3A and an insulator 4A.
  • the metal body 3A is different from the metal body 3 of the first embodiment in that the bulge portion 31 is not formed.
  • the insulator 4A is different in that it is not applied to the inner surface of the metal body 3A (the surface on the side of the unit case 21 when the metal body 5A covers the unit case 21).
  • the metal body 3A is bent into a U shape by bending, the inner surface of the metal body 3A is masked, the insulator 4A is applied to the metal body 3A by a powder coating method or the like, and the masking is removed. An insulating metal body 5A is to be produced.
  • the order of the bending process of the metal body 3A and the masking process of the inner surface of the metal body 3A may be reversed.
  • the power conversion device insulated metal body 5A according to the second embodiment can eliminate the need for the bulge 31 of the metal body 3. For this reason, even metals which are difficult to process can be applied to the metal body 3A.
  • FIG. 5 is a schematic view for explaining the metal object 5B of the power conversion device according to the third embodiment, and is a cross-sectional view taken along the line BB of FIG.
  • the power converter according to the fourth embodiment differs from the power converter 1 according to the first embodiment (see FIGS. 1 to 3) in the configuration of the metal body 5 to be insulated.
  • the metal body 5B to be insulated provided in the power converter according to the third embodiment will be described below.
  • the same reference numerals are given to parts in common with the first embodiment, and duplicate explanations are omitted.
  • An insulated metal body 5B shown in FIG. 6 has a metal body 3B and an insulator 4B.
  • the metal body 3B includes an electric field relaxation member 33 attached to the end 22 (electric field concentration portion) of the unit housing 21 and a screw 32B for fixing the electric field relaxation member 33 to the unit housing 21 so as to be energized.
  • the insulator 4B is different in that the insulator 4B is provided on the outer surface of the metal body 3B and the upper portion of the unit housing 21.
  • the electric field relaxation member 33 is attached to the end 22 (field concentration portion) of the unit housing 21 with the screw 32B to form the metal body 3B, and the outer surface of the metal body 3B and the upper part of the unit housing 21 are coated by powder coating method or the like.
  • the insulator 4B is applied to form the metal object 5B to be insulated.
  • the electric field concentration is alleviated.
  • the electric field at the end 22 of the unit housing 21 having the highest electric field is alleviated, and the insulation distance can be further shortened.
  • the electric field reducing member 33 is directly attached to the unit housing 21.
  • the present invention is not limited to this.
  • the electric field relaxation member 33 may be provided on the metal object 5 to be insulated in the first embodiment. That is, the electric field relaxation member 33 is attached to the bent metal body 3 so that current can be supplied, the insulator 4 is applied to the metal body 3 to which the electric field relaxation member 33 is attached by powder coating method, etc. You may create Similarly, the electric field relaxation member 33 may be provided in the metal body 5A to be insulated of the second embodiment.
  • FIG. 6 is a schematic cross-sectional view of a unit cell 2A for explaining the composite insulation structure of the power conversion device according to the fourth embodiment.
  • the power conversion device 1 according to the first to third embodiments has been described as having a structure in which the unit housing 21 has a potential with respect to the ground (the shelf plate 81 and the beam 82), but the fourth embodiment
  • the unit cell 2A of the power conversion device according to the embodiment has a structure in which the unit casing 21 is grounded.
  • the same reference numerals are given to parts in common with the first embodiment, and duplicate explanations are omitted.
  • the unit cell 2A includes a unit casing 21 formed by combining metal plates (for example, iron, SUS, hot-dip galvanized steel sheet, aluminum), a switching element 23 such as an IGBT, and a radiation fin 24 for cooling the IGBT.
  • a smoothing capacitor 25 electrically connected to the switching element 23, a bus bar 26 which is a conductor (for example, copper, aluminum) electrically connecting the switching element 23 and the smoothing capacitor 25, a radiation fin 24 and a unit housing It has an insulation heat transfer member 27 which can insulate the body 21 and can transfer heat from the radiation fins 24 to the unit casing 21, a control board (not shown), and the like.
  • the switching element 23 such as an IGBT and the radiation fin 24 may have a potential due to neutral point grounding and the like.
  • insulation is secured with the unit housing 21 to short circuit. It is required to prevent the occurrence of
  • Insulators 41A and 41B are applied to the electric field concentration portion to shorten the insulation distance.
  • Insulating materials 41A and 41B are applied to the switching element 23, the radiation fin 24 and the bus bar 26 which are close to the side plate surfaces 21A and 21B of the unit casing 21 which are grounded, to form a composite insulating structure.
  • Insulators 41A and 41B may be provided only at the corner portions of the switching element 23, the radiation fin 24, and the bus bar 26 in which the electric field is particularly concentrated to form a composite insulation structure. Thereby, the insulation at the electric field concentration portion can be secured, and the unit cell 2A can be miniaturized.
  • the power converter concerning this embodiment is not limited to the composition of the above-mentioned embodiment, A various change is possible within the range which does not deviate from the meaning of an invention .
  • the power conversion device 1 according to the present embodiment has been described as a high voltage direct inverter, the present invention is not limited to this, and can be applied to a converter, a power conditioner, and the like.
  • the composite insulation of the unit housing 21 and the beam 83 will be described
  • the composite insulation of the switching element 23, the radiation fin 24, the bus bar 26 and the unit housing 21 the present invention is not limited to this, and can be applied to the entire space insulation between different potentials.

Abstract

Provided is a more compact power conversion device having improved reliability.　A solid insulator (4) is provided so as to cover an electrical field concentrated section (22) of a sharp high-voltage section (21). The electrical field concentrated section (22) is covered by an insulated metal body (5) being the solid insulator (4) applied to a metal body (3). The metal body (3) is electrically connected to the high-voltage section (21). The metal body (3) has a bent section and a bulging section (31) is provided in the bent section. The insulated metal body (5) has the solid insulator (4) applied to both surfaces of the metal body (3).

Description

電力変換装置Power converter
　本発明は、電力変換装置に関し、特に電力変換装置の絶縁に関する。 The present invention relates to a power converter, and more particularly to isolation of the power converter.
　環境調和型社会を実現する上での重要な技術の一つとして、電気エネルギの有効活用が挙げられる。電気エネルギを有効に活用するためには、電気の形を最適に変えることができるパワーエレクトロニクス技術が必要不可欠である。 One of the important technologies to realize an environment-friendly society is the effective use of electrical energy. In order to make effective use of electrical energy, power electronics technology capable of optimally changing the form of electricity is essential.
　電力変換装置は、パワーエレクトロニクスにおける重要なキーコンポーネントであり、電力変換装置の変換効率を向上することが重要な課題となっている。また、電力、鉄道、産業などに用いられる大型の電力変換装置においては、省スペース化や直接材料費削減の観点から電力変換器盤の小型化も重要な課題となっている。 Power converters are important key components in power electronics, and improving the conversion efficiency of power converters is an important issue. In addition, in the case of large-sized power converters used for electric power, railways, industry, etc., miniaturization of the power converter board is also an important issue from the viewpoint of space saving and direct reduction of material cost.
　定格５００Ｖを超えるインバータ、コンバータ、パワーコンディショナなどの電力変換装置は、通常、ユニットセルと呼ばれる単位で構成される。そして、インバータ盤などの電力変換器盤は、複数のユニットセルを格納する構造となっている。 Power converters such as inverters, converters, power conditioners and the like that exceed the rated 500 V are usually configured in units called unit cells. And power converter boards, such as an inverter board, have a structure which stores a plurality of unit cells.
　ユニットと盤筐体（電力変換器盤の筐体）の間、もしくは、ユニットの相互間には、空間絶縁距離および沿面絶縁距離を設けて、異なる電位を保つ必要がある。絶縁が保てなくなると、電力変換装置としての機能を失するばかりでなく、短絡時のアーク放電により電力変換器盤自体を大きく損傷するおそれがある。 It is necessary to provide a space insulation distance and a creepage insulation distance between the unit and the chassis (the casing of the power converter board) or between the units to maintain different potentials. If the insulation can not be maintained, not only the function as the power conversion device is lost, but also the power converter board itself may be greatly damaged by arc discharge at the time of short circuit.
　従来の電力変換器盤では、前述の空間絶縁距離を空気のみで絶縁しているため、絶縁距離を大きくとる必要があり、電力変換器盤の小型化が難しい状況にある。 In the conventional power converter board, since the above-mentioned space insulation distance is insulated only with air, it is necessary to take a large insulation distance, and it is difficult to miniaturize the power converter board.
　ところで、母線やスイッチギヤ（ＧＩＳ(Gas Insulated Switch gear；ガス絶縁開閉装置)等の開閉装置）において、絶縁性に優れる固体と空気の複合絶縁構造を適用することで絶縁距離を短縮することが実用化されている。なお、複合絶縁の手法としては、特許文献１～４や非特許文献１に開示されている。 By the way, it is practical to shorten the insulation distance by applying a composite insulation structure of solid and air which is excellent in insulation property to a bus bar or a switchgear (switching device such as GIS (Gas Insulated Switch gear)). It has been The methods of composite insulation are disclosed in Patent Documents 1 to 4 and Non-Patent Document 1.
特開平５－１９０３５６号公報JP-A-5-190356 特開平８－２０３７５５号公報JP-A-8-203755 特開２００９－９９３３２号公報JP, 2009-99332, A 特開２０１０－９７８６５号公報Unexamined-Japanese-Patent No. 2010-97865
　特許文献１～４や非特許文献１は、管路母線や巻線導体等の高電圧導体を有する電気機器に関するものである。 Patent documents 1 to 4 and Non-patent document 1 relate to an electric device having a high voltage conductor such as a pipeline bus bar or a winding conductor.
　例えば、特許文献１は、高電圧導体を有する電気機器に関して、「高電圧導体を特性の異る２種類以上の材料、例えば金属との接着性の良い材料で被覆し、更にその外側を絶縁特性の優れた材料で被覆し、接着性を絶縁性の両方を向上させる」と記載されている（要約参照）。また、絶縁特性の優れた材料としては、「例えば、エポキシやフッ素樹脂等の絶縁物をコーティングする手法を用いることができる」と記載されている（段落０００９参照）。 For example, Patent Document 1 relates to an electrical device having a high voltage conductor: "The high voltage conductor is coated with two or more kinds of materials having different characteristics, for example, a material having good adhesion to metal, and the outside is further insulated It is described as "coating with the superior material of (2) to improve both the adhesion and the insulation" (see the summary). In addition, as a material having excellent insulating properties, it is described that "a method of coating an insulator such as epoxy or fluorine resin can be used" (see paragraph 0009).
　しかしながら、特許文献１～４や非特許文献１で開示された複合絶縁の手法を、ユニット構成の電力変換装置に適用して複合絶縁化することは困難である。 However, it is difficult to apply the method of complex insulation disclosed in Patent Documents 1 to 4 and Non-patent Document 1 to a unitized power converter to complex insulation.
　即ち、特許文献１～４や非特許文献１で開示された複合絶縁の手法では、固体絶縁として熱硬化性樹脂を適用するため、ユニット本体の予熱が必要となる。一方、ユニット本体に組み込まれるインバータユニットにはコンデンサなど耐熱性の低い機器が存在するため、ユニット本体にインバータユニットを組んだ後、ユニット本体を予熱することは困難である。 That is, in the method of composite insulation disclosed in Patent Documents 1 to 4 and Non-Patent Document 1, in order to apply a thermosetting resin as solid insulation, preheating of the unit body is required. On the other hand, since the inverter unit incorporated in the unit main body includes equipment with low heat resistance such as a capacitor, it is difficult to preheat the unit main body after assembling the inverter unit into the unit main body.
　また、ユニット筐体は、例えば厚さ２～３ｍｍ程度の金属で組み立てられるため、ユニット角（曲げ半径）Ｒは、例えば０．１ｍｍと小さい。このため、固体絶縁を実装すると角部で絶縁物の膨らみや剥離が生じやすい。その一方で、ユニット筐体の平面部の広域に、薄い（例えば、後述するように厚さ１ｍｍ）絶縁塗装が必要であるため、絶縁物の強度を保つことが要求される。 Further, since the unit case is assembled with, for example, a metal having a thickness of about 2 to 3 mm, the unit angle (bending radius) R is as small as, for example, 0.1 mm. For this reason, when solid insulation is mounted, swelling and peeling of the insulator tend to occur at the corners. On the other hand, since a thin (for example, 1 mm thick as described later) insulating coating is required in a wide area of the flat portion of the unit housing, it is required to maintain the strength of the insulator.
　さらに、電力変換装置のスイッチング素子（例えばＩＧＢＴ(Insulated Gate Bipolar Transistor；絶縁ゲートバイポーラトランジスタ)）に異常が生じた場合、スイッチング素子由来の導電性ガスが生じることが報告されている。これにより、異電位間において、絶縁性が顕著に低下し、短絡を生じる事象が報告されている。 Furthermore, it has been reported that when an abnormality occurs in a switching element (for example, an IGBT (Insulated Gate Bipolar Transistor)) of a power converter, a conductive gas derived from the switching element is generated. As a result, the insulation property significantly decreases between different potentials, and an event causing a short circuit has been reported.
　そこで、本発明は、小型化と信頼性向上が可能な電力変換装置を提供することを課題とする。 Then, this invention makes it a subject to provide the power converter device which can be reduced in size and improved in reliability.
　このような課題を解決するために、本発明は、尖鋭した高電圧部の電界集中部を覆うように、固体絶縁物を設けることを特徴とする電力変換装置である。 In order to solve such a subject, the present invention is a power converter characterized by providing a solid insulator so that an electric field concentration part of a sharp high voltage part may be covered.
　本発明によれば、小型化と信頼性向上が可能な電力変換装置を提供することができる。 According to the present invention, it is possible to provide a power converter that can be miniaturized and improved in reliability.
電力変換装置の全体図である。It is a general view of a power converter. 図１の矢印Ａ方向に見た第１実施形態に係る電力変換装置のユニットセル周辺における側面図である。It is a side view in the unit cell periphery of a power converter concerning a 1st embodiment seen in the arrow A direction of FIG. 第１実施形態に係る電力変換装置の被絶縁金属体を説明する模式図であり、図２のＢ－Ｂ線断面図である。It is a schematic diagram explaining the to-be-insulated metal body of the power converter device which concerns on 1st Embodiment, and is a BB sectional drawing of FIG. 第２実施形態に係る電力変換装置の被絶縁金属体を説明する模式図であり、図２のＢ－Ｂ線断面図である。It is a schematic diagram explaining the to-be-insulated metal body of the power converter device which concerns on 2nd Embodiment, and is a BB sectional drawing of FIG. 第３実施形態に係る電力変換装置の被絶縁金属体を説明する模式図であり、図２のＢ－Ｂ線断面図である。It is a schematic diagram explaining the to-be-insulated metal body of the power converter device which concerns on 3rd Embodiment, and is a BB sectional drawing of FIG. 第４実施形態に係る電力変換装置の複合絶縁構造説明するユニットセルの模式断面図である。It is a schematic cross section of a unit cell explaining the compound insulation structure of the power converter concerning a 4th embodiment. 空気雰囲気における絶縁破壊電圧と導電性ガス雰囲気における絶縁破壊電圧の関係を示すグラフである。It is a graph which shows the relationship between the dielectric breakdown voltage in air atmosphere, and the dielectric breakdown voltage in electroconductive gas atmosphere.
　以下、本発明を実施するための形態（以下「実施形態」という）について、適宜図面を参照しながら詳細に説明する。なお、各図において、共通する部分には同一の符号を付し重複した説明を省略する。 Hereinafter, modes for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate. In each of the drawings, the same reference numerals are given to the common parts, and the duplicated explanation is omitted.
≪第１実施形態≫
　第１実施形態に係る電力変換装置１について、図１から図３を用いて説明する。図１は、電力変換装置１の全体図である。 First Embodiment
The power converter 1 according to the first embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is an overall view of a power conversion device 1.
　図１に示すように、電力変換装置１は、複数のユニットセル２と、ユニットセル２を空冷するための通風ダクト７と、ユニットセル２を支持する盤筐体８と、絶縁板９と、を備えている。 As shown in FIG. 1, the power conversion device 1 includes a plurality of unit cells 2, a ventilation duct 7 for air cooling the unit cells 2, a panel case 8 for supporting the unit cells 2, and an insulating plate 9. Is equipped.
　インバータ、コンバータ、パワーコンディショナなどの電力変換装置１は、ユニットセル２と呼ばれる単位で構成されている。なお、以下の説明において、電力変換装置１は、高圧ダイレクトインバータであるものとして説明する。 A power conversion device 1 such as an inverter, a converter, or a power conditioner is configured in units called unit cells 2. In the following description, power converter 1 is explained as what is a high voltage direct inverter.
　ユニットセル２は、スイッチング素子２３（図３参照）等を有し、スイッチング素子２３（図３参照）等が発熱するため、ユニットセル２を空冷するための通風ダクト７が設けられている。 The unit cell 2 has a switching element 23 (see FIG. 3) and the like, and since the switching element 23 (see FIG. 3) and the like generate heat, a ventilation duct 7 for air cooling the unit cell 2 is provided.
　ユニットセル２は、絶縁板９を介して、盤筐体８の棚板８１の上に配置されている。盤筐体８は、電力変換装置１の筐体であり、棚板８１は、ユニットセル２を支持する。盤筐体８および棚板８１は、金属（例えば、鉄、ＳＵＳ(Steel Use Stainless；ステンレス鋼)、溶融鍍金鋼板、アルミニウム）で形成されている。また、盤筐体８および棚板８１は、電気的に接地されている。 The unit cell 2 is disposed on the shelf plate 81 of the panel case 8 via the insulating plate 9. The panel case 8 is a case of the power conversion device 1, and the shelf board 81 supports the unit cell 2. The panel case 8 and the shelf plate 81 are formed of metal (for example, iron, SUS (Steel Use Stainless; stainless steel), hot-dip galvanized steel sheet, aluminum). Moreover, the panel case 8 and the shelf plate 81 are electrically grounded.
　ここで、高圧ダイレクトインバータでは、ユニットセル２またはユニットセル２内部の部品に高電圧が印加されるため、接地領域と絶縁する必要があり、空間絶縁距離および沿面絶縁距離を確保する必要がある。同様に、ユニットセル２同士の電位および位相も異なるためそれぞれのユニットセル２の間において、空間絶縁距離および沿面絶縁距離を確保する必要がある。また、高圧ダイレクトインバータでは、各段で位相が異なるため、規格で定められる絶縁距離を確保することを推奨されている。 Here, in the high voltage direct inverter, since a high voltage is applied to the unit cell 2 or components in the unit cell 2, it is necessary to insulate from the ground region, and it is necessary to secure the space insulation distance and the creepage insulation distance. Similarly, since the potentials and phases of the unit cells 2 are different from each other, it is necessary to secure a space insulation distance and a creepage insulation distance between the unit cells 2. Further, in the high voltage direct inverter, since the phase is different in each stage, it is recommended to secure the insulation distance defined by the standard.
　このため、第１実施形態に係る電力変換装置１は、ユニットセル２の下に絶縁物である絶縁板９を敷くことにより、ユニットセル２とこのユニットセル２を支持する接地金属筐体である棚板８１との間の絶縁距離を確保することができるようになっている。 Therefore, the power conversion device 1 according to the first embodiment is a ground metal casing that supports the unit cell 2 and the unit cell 2 by laying the insulating plate 9 that is an insulator under the unit cell 2. It is possible to secure the insulation distance between the shelf board 81 and the like.
　また、ユニットセル２の上面とその上部の接地金属筐体である棚板８１との間の空間絶縁距離を確保することが必要となる。ちなみに、例えば、６ｋＶ級インバータでは空間絶縁距離は６０ｍｍであり、大きな値となっている。 In addition, it is necessary to secure a space insulation distance between the upper surface of the unit cell 2 and the shelf plate 81 which is a ground metal casing on the upper side thereof. Incidentally, for example, in the 6 kV class inverter, the space insulation distance is 60 mm, which is a large value.
　ここで、従来の空気のみで絶縁性を確保している構成の電力変換装置は、この空間絶縁距離（例えば、６ｋＶ級インバータで６０ｍｍ）を確保するために、電力変換装置を小型化することが困難であった。さらに、スイッチング素子が故障した際に導電性ガスが生じることで、絶縁性が顕著に低下し、短絡が生じるおそれがある。このため、導電性ガスの発生による絶縁性の低下を考慮して、ユニットセル２の上面とその上部の棚板８１との間の距離をより長く確保する必要があった。 Here, in the conventional power converter having a configuration in which insulation is ensured only by air, the power converter may be miniaturized in order to secure the space insulation distance (for example, 60 mm for a 6 kV class inverter). It was difficult. Furthermore, when the switching element fails, the generation of the conductive gas significantly reduces the insulation and may cause a short circuit. For this reason, it was necessary to secure a longer distance between the upper surface of the unit cell 2 and the shelf plate 81 thereabove in consideration of the decrease in insulation due to the generation of the conductive gas.
＜複合絶縁構造＞
　次に、第１実施形態に係る電力変換装置１のユニットセル２の上面とその上部の棚板８１との間の絶縁構造（複合絶縁構造）について、図２を用いて説明する。図２は、図１の矢印Ａ方向に見た第１実施形態に係る電力変換装置１のユニットセル２周辺における側面図である。 <Composite insulation structure>
Next, the insulation structure (composite insulation structure) between the upper surface of the unit cell 2 of the power conversion device 1 and the shelf plate 81 thereabove according to the first embodiment will be described with reference to FIG. FIG. 2 is a side view around the unit cell 2 of the power conversion device 1 according to the first embodiment as viewed in the direction of arrow A in FIG.
　図２に示すように、ユニットセル２を支持する棚板８１は、構造強度を保つための梁８２が形成されている。ユニットセル２（ユニット筐体２１；図３参照）が高電位となることで、ユニットセル２（ユニット筐体２１；図３参照）と、棚板８１からユニットセル２の方向に凸形状となる梁８２との間が、最も高電界となる。このユニットセル２と梁８２との空間絶縁距離を短縮するため、絶縁性の向上が必要となる。 As shown in FIG. 2, the shelf board 81 supporting the unit cell 2 is formed with a beam 82 for maintaining the structural strength. The unit cell 2 (the unit case 21; see FIG. 3) has a high potential, so that the unit cell 2 (the unit case 21; see FIG. 3) and the shelf board 81 have a convex shape in the direction of the unit cell 2. Between the beam 82, the highest electric field is obtained. In order to shorten the space insulation distance between the unit cell 2 and the beam 82, it is necessary to improve the insulation.
　そこで、図２に示すように、第１実施形態に係る電力変換装置１は、絶縁物４を表面に施した金属体３である被絶縁金属体５を備え、ユニットセル２の上面と梁８２による高電界部（後記する電界集中部）において、被絶縁金属体５でユニットセル２の一部を被覆するようになっている。 Therefore, as shown in FIG. 2, the power conversion device 1 according to the first embodiment includes the metal body 5 to be insulated, which is the metal body 3 having the insulator 4 applied to the surface thereof. In the high electric field portion (field concentration portion to be described later) according to the above, a part of the unit cell 2 is covered with the metal body 5 to be insulated.
　これにより、ユニットセル２と梁８２との空間絶縁距離を短縮することが可能になる。換言すると、被絶縁金属体５の絶縁物４と、ユニットセル２（被絶縁金属体５）から梁８２までの間の空気との複合絶縁構造を適用することで、従来の規格に定められた空間絶縁距離を短縮（例えば、５０～９０％程度）しても、従来の空気絶縁と同等以上の絶縁特性を有することが可能となる。 As a result, the space insulation distance between the unit cell 2 and the beam 82 can be shortened. In other words, by applying the composite insulation structure of the insulator 4 of the metal object 5 to be insulated and the air from the unit cell 2 (metal object 5 to be insulated) to the beam 82, the conventional standard is established. Even if the space insulation distance is shortened (for example, about 50 to 90%), it is possible to have insulation properties equal to or more than conventional air insulation.
＜被絶縁金属体＞
　次に、第１実施形態に係る電力変換装置１が備える被絶縁金属体５について、図３を用いて更に説明する。図３は、第１実施形態に係る電力変換装置１の被絶縁金属体５を説明する模式図であり、図２のＢ－Ｂ線断面図である。 <Insulated metal body>
Next, the to-be-insulated metal body 5 with which the power converter device 1 which concerns on 1st Embodiment is provided is further demonstrated using FIG. FIG. 3 is a schematic view for explaining the metal object 5 to be insulated of the power conversion device 1 according to the first embodiment, and is a cross-sectional view taken along the line BB of FIG.
　ユニットセル２は、金属板（例えば、鉄、ＳＵＳ(Steel Use Stainless；ステンレス鋼)、溶融鍍金鋼板、アルミニウム）を組み合せて形成されたユニット筐体２１と、ＩＧＢＴなどのスイッチング素子２３と、ＩＧＢＴを冷却するための放熱フィン２４と、スイッチング素子２３と電気的に接続される平滑コンデンサ２５と、スイッチング素子２３および平滑コンデンサ２５を電気的に接続する導電体（例えば、銅、アルミニウム）であるバスバ２６と、制御基板（図示せず）等を有している。なお、ユニット筐体２１は、接地（棚板８１、梁８２）に対して電位（例えば、ＩＧＢＴのエミッタ電位）を持つ構造となっている。 The unit cell 2 includes a unit casing 21 formed by combining metal plates (for example, iron, SUS (Steel Use Stainless; stainless steel), aluminum), a switching element 23 such as an IGBT, and an IGBT. A bus bar 26 which is a conductor (for example, copper, aluminum) electrically connecting the radiation fin 24 for cooling, the smoothing capacitor 25 electrically connected to the switching element 23, and the switching element 23 and the smoothing capacitor 25. And a control board (not shown). The unit casing 21 is structured to have a potential (for example, the emitter potential of the IGBT) with respect to the ground (the shelf plate 81 and the beam 82).
　ここで、棚板８１の梁８２の厚みは、おおよそ５ｍｍ程度であり、その端部８３の角Ｒ（曲げ半径）は、例えば０．５ｍｍ程度である。一方、ユニット筐体２１は、厚さ２ｍｍ程度の金属板で形成されており、その端部２２の角Ｒ（曲げ半径）は、例えば０．１ｍｍ程度である。 Here, the thickness of the beam 82 of the shelf plate 81 is about 5 mm, and the angle R (bending radius) of the end 83 is, for example, about 0.5 mm. On the other hand, the unit housing 21 is formed of a metal plate having a thickness of about 2 mm, and the corner R (bending radius) of the end 22 is, for example, about 0.1 mm.
　このように、梁８２の端部８３よりもユニット筐体２１の端部２２の方が、幾何形状が鋭く、電界集中が高いので、ユニットセル２側を固体絶縁化する。即ち、被絶縁金属体５は、電界集中部を覆うように配置される。ここで、電界集中部とは、電圧が印加されており、幾何形状が鋭く、かつ、接地面との距離が短い場所を示すものとする。 As described above, since the end 22 of the unit housing 21 has a sharper geometric shape and higher electric field concentration than the end 83 of the beam 82, the unit cell 2 is solid-insulated. That is, the metal object 5 to be insulated is disposed so as to cover the electric field concentration portion. Here, the electric field concentration portion indicates a place where a voltage is applied, the geometric shape is sharp, and the distance to the ground plane is short.
　棚板８１の梁８２は、ユニット筐体２１と比較して肉厚の部材であり、梁８２の長手方向の端部８３の角を丸める（曲げ半径Ｒを大きくする）ことで電界集中を緩和することができる。一方、ユニット筐体２１は、板厚２ｍｍ程度であり、かつ、構造的にその端部２２の角を丸めることが難しいため、容易に曲げ半径Ｒを大きくすることはできず、幾何形状が鋭くなり、電界が集中する。このため、被絶縁金属体５は、ユニットセル２の一部（電界集中部）を覆うように配置される。 The beam 82 of the shelf plate 81 is a thick member as compared with the unit housing 21 and the electric field concentration is alleviated by rounding the corner of the longitudinal end 83 of the beam 82 (increasing the bending radius R). can do. On the other hand, unit housing 21 has a thickness of about 2 mm, and it is difficult to round the corner of its end 22 structurally, so the bending radius R can not be easily increased, and the geometrical shape is sharp. The electric field is concentrated. For this reason, the to-be-insulated metal body 5 is arrange | positioned so that a part (electric field concentration part) of the unit cell 2 may be covered.
　被絶縁金属体５は、前述したように、金属体３と、金属体３の表面に施された絶縁物４と、を備え、図３に示すように、ネジ３２でユニット筐体２１に固定されている。 The to-be-insulated metal body 5 includes the metal body 3 and the insulator 4 applied to the surface of the metal body 3 as described above, and as shown in FIG. It is done.
　金属体３は、図３に示すように、下に開口する略コの字状の部材であり、金属板（例えば、鉄、ＳＵＳ(Steel Use Stainless；ステンレス鋼)、溶融鍍金鋼板、アルミニウム）を折り曲げ加工して形成される。ここで、金属体３は、外側に膨らむ膨らみ部３１が形成されるように折り曲げ加工される。なお、金属体３の両端部には、ネジ３２でユニット筐体２１に固定されるためのネジ穴（図示せず）が設けられている。 The metal body 3 is a substantially U-shaped member opened downward as shown in FIG. 3 and is made of a metal plate (for example, iron, SUS (Steel Use Stainless; stainless steel), molten steel plate, aluminum). It is formed by bending. Here, the metal body 3 is bent so as to form a bulge 31 that bulges outward. In addition, screw holes (not shown) for fixing to the unit housing 21 with the screws 32 are provided at both end portions of the metal body 3.
　絶縁物４は、金属体３の内面（被絶縁金属体５がユニット筐体２１を覆う際、ユニット筐体２１の側となる面）、外面（被絶縁金属体５がユニット筐体２１を覆う際、ユニット筐体２１の反対側となる面）および側面を覆うように施され、ネジ３２で固定される金属体３の両端部は、絶縁物４で覆われず、金属体３が露出している。 The insulator 4 is an inner surface of the metal body 3 (a surface on the side of the unit case 21 when the metal body 5 covers the unit case 21), an outer surface (the metal case 5 to be insulated covers the unit case 21). When covering the opposite side of the unit case 21 and the side, both ends of the metal body 3 fixed with the screws 32 are not covered with the insulator 4 and the metal body 3 is exposed. ing.
　絶縁物４の厚さは、６ｋＶ級インバータで０．１ｍｍ～１．０ｍｍ程度、１１ｋＶ級インバータで０．１ｍｍ～２．０ｍｍ程度とすることが望ましい。これにより、絶縁物４と空気との複合絶縁構造とすることができるので、ユニット筐体２１と梁８２との絶縁距離を短くすることができる。なお、厚さを０．１ｍｍ未満とすると、絶縁物４による絶縁性の向上が小さく、望ましくない。一方、厚さを６ｋＶ級インバータで１．０ｍｍ程度（１１ｋＶ級インバータで２．０ｍｍ程度）とすることにより、絶縁性の向上を確保できるため、厚さを過大とすると、絶縁物４のコストが上昇し、望ましくない。 The thickness of the insulator 4 is preferably about 0.1 mm to 1.0 mm in a 6 kV class inverter and about 0.1 mm to 2.0 mm in an 11 kV class inverter. Thereby, since it can be set as the compound insulation structure of the insulator 4 and air, the insulation distance of the unit housing | casing 21 and the beam 82 can be shortened. When the thickness is less than 0.1 mm, the improvement of the insulation property by the insulator 4 is small, which is not desirable. On the other hand, by setting the thickness to about 1.0 mm with a 6 kV class inverter (about 2.0 mm with an 11 kV class inverter), the insulation improvement can be secured, so if the thickness is made excessive, the cost of the insulator 4 becomes Rising and undesirable.
　折り曲げ加工された金属体３に、エポキシ樹脂による加圧成形、粉体塗装、スプレー絶縁などが適用され、金属体３の表面に絶縁物４が施されるようになっている。特に、金属体３との密着性向上により微小放電を防止しながら製造時間を短縮する点において、粉体塗装法が最も望ましい。 Pressure molding with epoxy resin, powder coating, spray insulation and the like are applied to the metal body 3 subjected to bending processing, and the insulator 4 is applied to the surface of the metal body 3. In particular, the powder coating method is most desirable in terms of shortening the manufacturing time while preventing microdischarge by improving the adhesion to the metal body 3.
　なお、金属体３の板厚は、１～５ｍｍ程度とすることが望ましい。粉体塗装法において金属体３の表面に絶縁物４を施す場合、金属体３を予熱した後、流動浸漬により絶縁物４を施す。このため、金属体３の板厚を１ｍｍ未満とすると、予熱の熱量が不足して、一度の流動浸漬による絶縁物４の厚さが所望の厚さとならず、望ましくない。一方、金属体３の板厚を５ｍｍよりも過大とすると、金属体３の板厚の分だけ絶縁距離を短縮する効果が小さくなり、望ましくない。 The thickness of the metal body 3 is desirably about 1 to 5 mm. In the case of applying the insulator 4 to the surface of the metal body 3 in the powder coating method, after the metal body 3 is preheated, the insulator 4 is applied by fluid immersion. For this reason, when the plate thickness of the metal body 3 is less than 1 mm, the heat quantity of preheating is insufficient, and the thickness of the insulator 4 in one fluid immersion does not become a desired thickness, which is not desirable. On the other hand, when the plate thickness of the metal body 3 is made larger than 5 mm, the effect of shortening the insulation distance by the plate thickness of the metal body 3 is reduced, which is not desirable.
　また、下に開口する略コの字状の金属体３は、ユニットセル２に被絶縁金属体５を嵌め込んだ際、ユニット筐体２１の端部２２に対応する部分に、外側（ユニット筐体２１の端部２２と反対側）に膨らむ膨らみ部３１が形成されるように折り曲げ加工される。そして、金属体３の内面、外面および側面を覆うように絶縁物４が施されるようになっている。このように、金属体３に膨らみ部３１を形成することにより、被絶縁金属体５の製作コストを低減させることができる。 In addition, the substantially U-shaped metal body 3 which opens downward is provided on the outside (unit housing) at a portion corresponding to the end 22 of the unit housing 21 when the metal body 5 to be insulated is fitted into the unit cell 2. It is bent so as to form a bulge 31 which bulges on the side opposite to the end 22 of the body 21. And the insulator 4 is given so that the inner surface, the outer surface, and the side of the metal body 3 may be covered. By thus forming the bulge portion 31 in the metal body 3, the manufacturing cost of the metal body 5 to be insulated can be reduced.
　即ち、金属体３に膨らみ部３１を形成せず、直角に折り曲げた場合、金属体３の表面に絶縁物４を施すと、金属体３の内側角部に絶縁物４がフィレット状に溜まって厚みが増してしまい、ユニットセル２（ユニット筐体２１）に被絶縁金属体５を装着することが困難となる。このため、金属体３の内側角部の絶縁物４の一部を削るなどの工程が必要となり、被絶縁金属体５の製作コストが高くなる。 That is, when the insulator 4 is applied to the surface of the metal body 3 when the metal body 3 is bent at a right angle without forming the bulge portion 31, the insulator 4 is accumulated in a fillet shape at the inner corner of the metal body 3. The thickness is increased, which makes it difficult to mount the metal object 5 to be insulated on the unit cell 2 (unit housing 21). For this reason, the process of shaving a part of insulator 4 of the inner corner part of the metal body 3 etc. is needed, and the manufacturing cost of the to-be-insulated metal body 5 becomes high.
　また、金属体３に膨らみ部３１を形成せず、直角に折り曲げ、金属体３の内面全体をマスキングした後、絶縁物４を施す場合、前述の絶縁物４の一部を削るなどの工程は不要となるが、マスキング処理には人為的な処理が必要であるため、被絶縁金属体５の製作コストが高くなる。 Moreover, after forming the bulge part 31 in the metal body 3 and bending it at a right angle to mask the entire inner surface of the metal body 3 and then applying the insulator 4, the process of scraping a part of the insulator 4 is Although not necessary, the masking process requires an artificial process, and the manufacturing cost of the metal object 5 to be insulated is increased.
　これに対し、金属体３に膨らみ部３１を形成することにより、金属体３の内側角部に生じる絶縁物４の溜まりを吸収して、絶縁物４の一部を削るなどの工程が不要となり、被絶縁金属体５の製作コストを低減させることができる。また、金属体３に膨らみ部３１を形成することにより、金属体３の両面に絶縁物４を施すことができるので、マスキング処理も不要となり、被絶縁金属体５の製作コストを低減させることができる。 On the other hand, by forming the bulged portion 31 in the metal body 3, it is possible to absorb the stagnation of the insulator 4 generated in the inner corner portion of the metal body 3 and eliminate the process of scraping the insulator 4 partially. The manufacturing cost of the metal object 5 to be insulated can be reduced. In addition, since the insulator 4 can be applied to both surfaces of the metal body 3 by forming the bulge portion 31 in the metal body 3, masking processing is also unnecessary, and the manufacturing cost of the metal body 5 to be insulated can be reduced. it can.
　なお、膨らみ部３１は、外側（ユニット筐体２１の端部２２と反対側、図３の左右方向）に、例えば、０．５～２．０ｍｍ程度膨らむように形成することにより前述した効果を得ることができる。例えば、絶縁物４の厚さを１ｍｍとする場合、膨らみ部３１も１ｍｍ程度とすればよい。 In addition, the above-described effect can be obtained by forming the bulging portion 31 so as to expand, for example, by about 0.5 to 2.0 mm on the outer side (the side opposite to the end 22 of the unit housing 21, the left and right direction in FIG. You can get it. For example, when the thickness of the insulator 4 is 1 mm, the bulge 31 may be about 1 mm.
　ちなみに、膨らみ部３１を形成することにより、金属体３の折り曲げ部の幾何形状も、直角に折り曲げる場合と比較すれば緩やかになるが、十分に電界緩和効果を得ることができるほど（例えば、曲げ半径Ｒを５ｍｍ以上）ではない。しかし、被絶縁金属体５を用いることにより、絶縁物４と空気との複合絶縁構造とすることができるので、ユニット筐体２１と梁８２との絶縁距離を短くすることができる。このため、金属体３の膨らみ部３１は、電界緩和効果を目的としたものとは異なっている。 By the way, by forming the bulging portion 31, the geometrical shape of the bent portion of the metal body 3 is also gentler compared to the case where it is bent at a right angle, but a sufficient electric field relaxation effect can be obtained (for example, bending The radius R is not 5 mm or more). However, by using the to-be-insulated metal body 5, since it can be set as the compound insulation structure of the insulator 4 and air, the insulation distance of the unit housing | casing 21 and the beam 82 can be shortened. For this reason, the bulged portion 31 of the metal body 3 is different from that intended for the electric field relaxation effect.
　被絶縁金属体５の両端部（図示しないネジ穴の周辺部）は、図３に示すように、金属体３に絶縁物４が施されず、金属体３が露出するようになっている。被絶縁金属体５をユニットセル２に被せて、被絶縁金属体５の金属体３とユニット筐体２１をネジ３２で固定することにより、金属体３とユニット筐体２１を同電位とすることができるようになっている。これにより、金属体３とユニット筐体２１との間で放電が生じないようにすることができる。また、ユニット筐体２１と梁８２との電位差を金属体３と梁８２とで担うことができるので、絶縁物４と空気との複合絶縁構造とすることができる。 As shown in FIG. 3, the insulator 4 is not applied to the metal body 3 at both end portions (peripheral portions of screw holes not shown) of the metal object 5 to be insulated, and the metal body 3 is exposed. The metal body 3 and the unit housing 21 are made to have the same potential by covering the unit metal 2 with the metal body 5 to be insulated and fixing the metal body 3 of the metal body 5 to be insulated and the unit housing 21 with the screws 32. It is possible to Thereby, discharge can be prevented from occurring between the metal body 3 and the unit housing 21. Further, since the metal body 3 and the beam 82 can bear the potential difference between the unit case 21 and the beam 82, a composite insulating structure of the insulator 4 and air can be obtained.
　ここで、被絶縁金属体５の金属体３の露出する領域（ネジ３２の位置）は、梁８２（棚板８１）から空間絶縁距離以上離れた位置に形成されており、絶縁を確保することができるようになっている。 Here, the exposed area (the position of the screw 32) of the metal body 3 of the metal body 5 to be insulated is formed at a position separated from the beam 82 (the shelf plate 81) by the space insulation distance or more, to secure insulation. It is possible to
　なお、被絶縁金属体５は、被絶縁金属体５の両端部のネジ穴の周辺部に金属体３の露出する領域があり、ネジ３２で金属体３とユニット筐体２１が同電位となるように固定されるものとして説明したが、これに限られるものではなく、絶縁物４を削って、金属体３とユニット筐体２１の間を配線で導通させることにより、同電位化する構成であってもよい。 In the metal object 5 to be insulated, there is a region where the metal member 3 is exposed around the screw holes at both ends of the metal member 5 to be insulated, and the metal member 3 and the unit housing 21 have the same potential with the screw 32. Although it has been described that they are fixed as described above, the present invention is not limited to this. The insulator 4 is removed, and the metal body 3 and the unit case 21 are electrically connected by a wire to make the same potential. It may be.
＜導電性ガス＞
　ここで、スイッチング素子が故障した際に、導電性ガスが発生した場合について検討する。 <Conductive gas>
Here, the case where the conductive gas is generated when the switching element breaks down is examined.
　従来の空気のみで絶縁性を確保している構成の電力変換装置は、ユニット筐体２１と梁８２の間が、空気雰囲気から導電性ガス雰囲気へと変化することにより、絶縁性が顕著に低下し、短絡が生じるおそれがある。 In the conventional power converter having a configuration in which the insulation property is ensured only by air, the insulation property is significantly lowered by the change between the air atmosphere and the conductive gas atmosphere between the unit housing 21 and the beam 82. May cause a short circuit.
　これに対し、第１実施形態に係る電力変換装置１は、ユニット筐体２１（金属体３）と梁８２の間が、絶縁物４と空気の複合絶縁構造となっており、ユニットセル２（被絶縁金属体５）から梁８２までの間の距離が短くなっている。このため、空気雰囲気から導電性ガス雰囲気へと変化しても、絶縁性の低下はわずかであり、絶縁物４により絶縁を確保することができるので、短絡が生じることを防止することができる。 On the other hand, in the power conversion device 1 according to the first embodiment, the space between the unit case 21 (metal body 3) and the beam 82 has a composite insulation structure of the insulator 4 and air. The distance from the metal object 5) to the beam 82 is short. For this reason, even if it changes from an air atmosphere to a conductive gas atmosphere, the decrease in the insulation property is slight, and the insulation can be secured by the insulator 4, so that the occurrence of a short circuit can be prevented.
　また、被絶縁金属体５の金属体３の露出する領域（ネジ３２の位置）は、複合絶縁構造とはなっておらず、空気のみで絶縁性を確保している。 In addition, the exposed area (the position of the screw 32) of the metal body 3 of the metal object 5 to be insulated is not a composite insulation structure, and the insulation property is secured by air alone.
　ここで、空気雰囲気における絶縁破壊電圧と導電性ガス雰囲気における絶縁破壊電圧の関係について、図７を用いて説明する。図７は、空気雰囲気における絶縁破壊電圧と導電性ガス雰囲気における絶縁破壊電圧の関係を示すグラフである。
　図７に示すように、絶縁距離比１．０かつ空気雰囲気における絶縁破壊電圧と、絶縁距離比１．５かつ導電性ガス雰囲気における絶縁破壊電圧が略等しくなっている。換言すれば、電位の異なる金属間の最短距離を、その電位差の空間絶縁距離の１．５倍以上とすることで、導電雰囲気が生じても絶縁が保たれていることがわかる。 Here, the relationship between the dielectric breakdown voltage in the air atmosphere and the dielectric breakdown voltage in the conductive gas atmosphere will be described with reference to FIG. FIG. 7 is a graph showing the relationship between the dielectric breakdown voltage in the air atmosphere and the dielectric breakdown voltage in the conductive gas atmosphere.
As shown in FIG. 7, the dielectric breakdown voltage in the air atmosphere is 1.0, and the dielectric breakdown voltage in the conductive gas atmosphere is 1.5. In other words, by setting the shortest distance between metals having different potentials to be 1.5 times or more of the space insulation distance of the potential difference, it is understood that the insulation is maintained even if the conductive atmosphere is generated.
　即ち、被絶縁金属体５の金属体３の露出する領域（ネジ３２の位置）は、梁８２（棚板８１）から空間絶縁距離の１．５倍以上離れた位置に形成することにより、スイッチング素子が故障して導電性ガスが発生した場合でも、絶縁を確保して、短絡が生じることを防止することができる。 That is, switching is performed by forming the exposed area (the position of the screw 32) of the metal body 3 of the metal object 5 to be insulated at a position 1.5 times or more the space insulation distance from the beam 82 (shelf plate 81). Even when the element fails and a conductive gas is generated, insulation can be secured to prevent the occurrence of a short circuit.
　ここで、略コの字状の被絶縁金属体５は、長手方向に長い金属体３を用いて、被絶縁金属体５を作成し、被絶縁金属体５の金属体３の露出する領域（ネジ３２の位置）を梁８２（棚板８１）から空間絶縁距離の１．５倍以上離れた位置に形成することにより、絶縁を確保して、短絡が生じることを防止することができる。即ち、ユニットセル２（被絶縁金属体５）から梁８２までの間の距離を、従来の空気のみで絶縁性を確保している構成のユニット筐体２１と梁８２の間の距離よりも短くしたまま、スイッチング素子が故障して導電性ガスが発生した場合でも、絶縁を確保して、短絡が生じることを防止することができる。 Here, the substantially U-shaped insulated metal body 5 forms the insulated metal body 5 using the metal body 3 long in the longitudinal direction, and the exposed area of the metal body 3 of the insulated metal body 5 ( By forming the position of the screw 32 at a position at least 1.5 times the space insulation distance from the beam 82 (shelf plate 81), insulation can be secured and short circuit can be prevented from occurring. That is, the distance from the unit cell 2 (insulated metal body 5) to the beam 82 is shorter than the distance between the unit casing 21 and the beam 82 of the configuration in which the insulating property is ensured by the conventional air alone. Even if the switching element fails and a conductive gas is generated as it is, insulation can be secured to prevent occurrence of a short circuit.
＜作用・効果＞
　以下、被絶縁金属体５を用いた電力変換装置１の作用・効果について説明する。 <Operation and effect>
Hereinafter, the operation and effects of the power conversion device 1 using the insulated metal body 5 will be described.
　被絶縁金属体５を用いた電力変換装置１は、電界集中部を複合絶縁構造とすることができ、従来の空気のみで絶縁性を確保している構成の電力変換装置と比較して、ユニットセル２から梁８２までの間の距離を短くしても、絶縁を確保して、短絡が生じることを防止することができる。これにより、電力変換装置１を小型化できるとともに、ユニットセル２の集積率を上げることができる。 The power conversion device 1 using the metal object 5 to be insulated can have an electric field concentration part as a composite insulation structure, and compared with a power conversion device having a configuration in which the insulation property is secured with conventional air alone, Even if the distance from the cell 2 to the beam 82 is shortened, insulation can be ensured to prevent a short circuit from occurring. Thus, the power converter 1 can be miniaturized, and the integration rate of the unit cells 2 can be increased.
　被絶縁金属体５の絶縁物４は金属体３に施されているので、金属体３を絶縁物４の内芯とすることができ、絶縁物４の強度を保つことができる。また、被絶縁金属体５をユニットセル２に被せる構造をしているため、ユニット筐体２１に直接、固体の絶縁物を設ける必要がない。 Since the insulator 4 of the metal object 5 to be insulated is applied to the metal member 3, the metal member 3 can be used as an inner core of the insulator 4, and the strength of the insulator 4 can be maintained. In addition, since the unit metal 2 is covered with the metal object 5 to be insulated, it is not necessary to provide a solid insulator directly on the unit housing 21.
　ユニットセル２が故障した場合、被絶縁金属体５も損傷していることが想定される。本構成によれば、被絶縁金属体５はユニットセル２に被せるように配置されるため、ユニットセル２を盤筐体８から取り出すと、被絶縁金属体５も合わせて取り出すことができる。これにより、ユニットセル２の交換や点検にあわせて、被絶縁金属体５の交換や点検を行うことができ、交換作業や点検作業の作業性が向上する。また、ユニットセル２とともに被絶縁金属体５も交換すれば、被絶縁金属体５の信頼性も確保することができる。 When unit cell 2 fails, it is assumed that metal body 5 to be insulated is also damaged. According to this configuration, the metal object 5 to be insulated is disposed so as to cover the unit cell 2. Therefore, when the unit cell 2 is taken out from the panel case 8, the metal object 5 to be insulated can be taken out together. Thus, the metal body 5 to be insulated can be replaced or inspected in accordance with the replacement or inspection of the unit cell 2, and the workability of the replacement operation or the inspection operation can be improved. Further, if the metal object 5 to be insulated is also exchanged together with the unit cell 2, the reliability of the metal object 5 to be insulated can be secured.
　また、被絶縁金属体５は、ユニットセル２の一部を覆うように配置されるため、ユニットセル２の全面を絶縁する場合や、棚板８１の下面および梁８２の全面を絶縁する場合と比較して、絶縁物のコストを低減することができる。 Further, since the metal object 5 to be insulated is disposed so as to cover a part of the unit cell 2, the case of insulating the entire surface of the unit cell 2 or the case of insulating the lower surface of the shelf plate 81 and the entire surface of the beam 82 In comparison, the cost of the insulator can be reduced.
　また、被絶縁金属体５は、金属体３に膨らみ部３１を形成することにより、生産性を向上させるとともに、ユニットセル２への取り付け性を向上させることができる。 Further, by forming the bulged portion 31 in the metal body 3, the metal object 5 to be insulated can improve productivity and improve attachment to the unit cell 2.
　被絶縁金属体５を用いた電力変換装置１は、スイッチング素子が故障して導電性ガスが発生した場合でも、絶縁を確保して、短絡が生じることを防止することができる。これにより、電力変換装置１の信頼性を向上させることができる。 Even when the switching element is broken and a conductive gas is generated, the power conversion device 1 using the metal object 5 can ensure insulation and prevent the occurrence of a short circuit. Thereby, the reliability of the power converter 1 can be improved.
≪第２実施形態≫
　次に、第２実施形態に係る電力変換装置について、図４を用いて説明する。図４は、第２実施形態に係る電力変換装置の被絶縁金属体５Ａを説明する模式図であり、図２のＢ－Ｂ線断面図である。 Second Embodiment
Next, a power conversion device according to a second embodiment will be described with reference to FIG. FIG. 4 is a schematic view for explaining the insulated metal body 5A of the power conversion device according to the second embodiment, and is a cross-sectional view taken along the line BB in FIG.
　第２実施形態に係る電力変換装置は、第１実施形態に係る電力変換装置１（図１から図３参照）と比較して、被絶縁金属体５の構成が異なっている。以下、第２実施形態に係る電力変換装置の備える被絶縁金属体５Ａについて説明する。なお、第１実施形態と共通する部分には同一の符号を付し重複した説明を省略する。 The power converter according to the second embodiment differs from the power converter 1 according to the first embodiment (see FIGS. 1 to 3) in the configuration of the metal body 5 to be insulated. Hereinafter, 5 A of insulated metal bodies with which the power converter device which concerns on 2nd Embodiment is provided are demonstrated. The same reference numerals are given to parts in common with the first embodiment, and duplicate explanations are omitted.
　図４に示す被絶縁金属体５Ａは、金属体３Ａと絶縁物４Ａとを有している。金属体３Ａは、第１実施形態の金属体３と比較して、膨らみ部３１が形成されていない点で異なっている。また、絶縁物４Ａは、金属体３Ａの内面（被絶縁金属体５Ａがユニット筐体２１を覆う際、ユニット筐体２１の側となる面）には施されていない点で異なっている。 An insulated metal body 5A shown in FIG. 4 has a metal body 3A and an insulator 4A. The metal body 3A is different from the metal body 3 of the first embodiment in that the bulge portion 31 is not formed. Further, the insulator 4A is different in that it is not applied to the inner surface of the metal body 3A (the surface on the side of the unit case 21 when the metal body 5A covers the unit case 21).
　即ち、金属体３Ａを折り曲げ加工によりコの字状に折り曲げた後、金属体３Ａの内面をマスキングし、粉体塗装法等により金属体３Ａに絶縁物４Ａを施し、マスキングを除去して、被絶縁金属体５Ａを作成するようになっている。なお、金属体３Ａの折り曲げ加工と金属体３Ａの内面のマスキング処理の順番は逆でもよい。 That is, after the metal body 3A is bent into a U shape by bending, the inner surface of the metal body 3A is masked, the insulator 4A is applied to the metal body 3A by a powder coating method or the like, and the masking is removed. An insulating metal body 5A is to be produced. The order of the bending process of the metal body 3A and the masking process of the inner surface of the metal body 3A may be reversed.
　このように、第２実施形態に係る電力変換装置被絶縁金属体５Ａは、金属体３の膨らみ部３１を不要とすることができる。このため、加工しにくい金属であっても金属体３Ａに適用することができる。 Thus, the power conversion device insulated metal body 5A according to the second embodiment can eliminate the need for the bulge 31 of the metal body 3. For this reason, even metals which are difficult to process can be applied to the metal body 3A.
≪第３実施形態≫
　次に、第３実施形態に係る電力変換装置について、図５を用いて説明する。図５は、第３実施形態に係る電力変換装置の被絶縁金属体５Ｂを説明する模式図であり、図２のＢ－Ｂ線断面図である。 Third Embodiment
Next, a power conversion device according to a third embodiment will be described with reference to FIG. FIG. 5 is a schematic view for explaining the metal object 5B of the power conversion device according to the third embodiment, and is a cross-sectional view taken along the line BB of FIG.
　第４実施形態に係る電力変換装置は、第１実施形態に係る電力変換装置１（図１から図３参照）と比較して、被絶縁金属体５の構成が異なっている。以下、第３実施形態に係る電力変換装置の備える被絶縁金属体５Ｂについて説明する。なお、第１実施形態と共通する部分には同一の符号を付し重複した説明を省略する。 The power converter according to the fourth embodiment differs from the power converter 1 according to the first embodiment (see FIGS. 1 to 3) in the configuration of the metal body 5 to be insulated. The metal body 5B to be insulated provided in the power converter according to the third embodiment will be described below. The same reference numerals are given to parts in common with the first embodiment, and duplicate explanations are omitted.
　図６に示す被絶縁金属体５Ｂは、金属体３Ｂと絶縁物４Ｂとを有している。金属体３Ｂは、ユニット筐体２１の端部２２（電界集中部）に取り付けられる電界緩和部材３３と、電界緩和部材３３をユニット筐体２１と通電するように固定するネジ３２Ｂと、を備えている。また、絶縁物４Ｂは、金属体３Ｂの外面およびユニット筐体２１の上部に施されている点で異なっている。 An insulated metal body 5B shown in FIG. 6 has a metal body 3B and an insulator 4B. The metal body 3B includes an electric field relaxation member 33 attached to the end 22 (electric field concentration portion) of the unit housing 21 and a screw 32B for fixing the electric field relaxation member 33 to the unit housing 21 so as to be energized. There is. Further, the insulator 4B is different in that the insulator 4B is provided on the outer surface of the metal body 3B and the upper portion of the unit housing 21.
　即ち、ユニット筐体２１の端部２２（電界集中部）にネジ３２Ｂで電界緩和部材３３を取り付けて金属体３Ｂとし、金属体３Ｂの外面およびユニット筐体２１の上部に粉体塗装法等により絶縁物４Ｂを施して、被絶縁金属体５Ｂを作成するようになっている。 That is, the electric field relaxation member 33 is attached to the end 22 (field concentration portion) of the unit housing 21 with the screw 32B to form the metal body 3B, and the outer surface of the metal body 3B and the upper part of the unit housing 21 are coated by powder coating method or the like. The insulator 4B is applied to form the metal object 5B to be insulated.
　電界緩和部材３３の曲げ半径Ｒを大きく（例えば、５ｍｍ以上）することにより、電界集中を緩和するようになっている。これにより、最も電界が高いユニット筐体２１の端部２２の電界が緩和され、絶縁距離をさらに短縮することができる。 By increasing the bending radius R of the electric field relaxation member 33 (for example, 5 mm or more), the electric field concentration is alleviated. As a result, the electric field at the end 22 of the unit housing 21 having the highest electric field is alleviated, and the insulation distance can be further shortened.
　なお、第３実施形態において、電界緩和部材３３をユニット筐体２１に直接取り付けるものとして説明したが、これに限られるものではない。例えば、第１実施形態の被絶縁金属体５に電界緩和部材３３を設けてもよい。即ち、折り曲げ加工された金属体３に電界緩和部材３３を通電可能に取り付けて、電界緩和部材３３が取り付けられた金属体３に粉体塗装法等により絶縁物４を施し、被絶縁金属体５を作成してもよい。同様に、第２実施形態の被絶縁金属体５Ａに電界緩和部材３３を設けてもよい。 In the third embodiment, the electric field reducing member 33 is directly attached to the unit housing 21. However, the present invention is not limited to this. For example, the electric field relaxation member 33 may be provided on the metal object 5 to be insulated in the first embodiment. That is, the electric field relaxation member 33 is attached to the bent metal body 3 so that current can be supplied, the insulator 4 is applied to the metal body 3 to which the electric field relaxation member 33 is attached by powder coating method, etc. You may create Similarly, the electric field relaxation member 33 may be provided in the metal body 5A to be insulated of the second embodiment.
≪第４実施形態≫
　次に、第４実施形態に係る電力変換装置について、図６を用いて説明する。図６は、第４実施形態に係る電力変換装置の複合絶縁構造説明するユニットセル２Ａの模式断面図である。 Fourth Embodiment
Next, a power conversion device according to a fourth embodiment will be described using FIG. FIG. 6 is a schematic cross-sectional view of a unit cell 2A for explaining the composite insulation structure of the power conversion device according to the fourth embodiment.
　第１実施形態から第３実施形態に係る電力変換装置１は、ユニット筐体２１が接地（棚板８１、梁８２）に対して電位を持つ構造となっているものとして説明したが、第４実施形態に係る電力変換装置のユニットセル２Ａは、ユニット筐体２１が接地されている構造となっている。なお、第１実施形態と共通する部分には同一の符号を付し重複した説明を省略する。 The power conversion device 1 according to the first to third embodiments has been described as having a structure in which the unit housing 21 has a potential with respect to the ground (the shelf plate 81 and the beam 82), but the fourth embodiment The unit cell 2A of the power conversion device according to the embodiment has a structure in which the unit casing 21 is grounded. The same reference numerals are given to parts in common with the first embodiment, and duplicate explanations are omitted.
　ユニットセル２Ａは、金属板（例えば、鉄、ＳＵＳ、溶融鍍金鋼板、アルミニウム）を組み合せて形成されたユニット筐体２１と、ＩＧＢＴなどのスイッチング素子２３と、ＩＧＢＴを冷却するための放熱フィン２４と、スイッチング素子２３と電気的に接続される平滑コンデンサ２５と、スイッチング素子２３および平滑コンデンサ２５を電気的に接続する導電体（例えば、銅、アルミニウム）であるバスバ２６と、放熱フィン２４とユニット筐体２１とを絶縁するとともに放熱フィン２４からユニット筐体２１へ伝熱可能な絶縁伝熱部材２７と、制御基板（図示せず）等を有している。 The unit cell 2A includes a unit casing 21 formed by combining metal plates (for example, iron, SUS, hot-dip galvanized steel sheet, aluminum), a switching element 23 such as an IGBT, and a radiation fin 24 for cooling the IGBT. A smoothing capacitor 25 electrically connected to the switching element 23, a bus bar 26 which is a conductor (for example, copper, aluminum) electrically connecting the switching element 23 and the smoothing capacitor 25, a radiation fin 24 and a unit housing It has an insulation heat transfer member 27 which can insulate the body 21 and can transfer heat from the radiation fins 24 to the unit casing 21, a control board (not shown), and the like.
　中性点接地などにより、ＩＧＢＴなどのスイッチング素子２３と放熱フィン２４が電位を有することがある。この場合、スイッチング素子２３、放熱フィン２４、バスバ２６などの高電圧かつ金属がユニット筐体２１の内部空間に露出している部分で、ユニット筐体２１との間に絶縁を確保して、短絡が生じることを防止することが求められる。 The switching element 23 such as an IGBT and the radiation fin 24 may have a potential due to neutral point grounding and the like. In this case, in a portion where high voltage and metal such as the switching element 23, the radiation fin 24, and the bus bar 26 are exposed to the internal space of the unit housing 21, insulation is secured with the unit housing 21 to short circuit. It is required to prevent the occurrence of
　このため、図６に示すように、電界集中部に絶縁物４１Ａ，４１Ｂを施して、絶縁距離を短縮するようになっている。接地されたユニット筐体２１の側板面２１Ａ，２１Ｂと近接し、幾何形状の鋭いスイッチング素子２３、放熱フィン２４、バスバ２６に絶縁物４１Ａ，４１Ｂを施して複合絶縁構造とする。なお、特に電界集中するスイッチング素子２３、放熱フィン２４、バスバ２６の角部にのみ絶縁物４１Ａ，４１Ｂを施して複合絶縁構造としてもよい。これにより、電界集中部での絶縁を確保して、ユニットセル２Ａを小型化することができる。 For this reason, as shown in FIG. 6, insulators 41A and 41B are applied to the electric field concentration portion to shorten the insulation distance. Insulating materials 41A and 41B are applied to the switching element 23, the radiation fin 24 and the bus bar 26 which are close to the side plate surfaces 21A and 21B of the unit casing 21 which are grounded, to form a composite insulating structure. Insulators 41A and 41B may be provided only at the corner portions of the switching element 23, the radiation fin 24, and the bus bar 26 in which the electric field is particularly concentrated to form a composite insulation structure. Thereby, the insulation at the electric field concentration portion can be secured, and the unit cell 2A can be miniaturized.
≪変形例≫
　以上、本実施形態（第１～第４実施形態）に係る電力変換装置は、上記実施形態の構成に限定されるものではなく、発明の趣旨を逸脱しない範囲内で種々の変更が可能である。
　本実施形態に係る電力変換装置１は、高圧ダイレクトインバータであるものとして説明したが、これに限られるものではなく、コンバータ、パワーコンディショナなどにも適用することができる。
　また、第１から第３実施形態では、ユニット筐体２１と梁８３との複合絶縁について説明し、第４実施形態ではスイッチング素子２３、放熱フィン２４、バスバ２６とユニット筐体２１との複合絶縁について説明したが、これに限られるものではなく、異電位間の空間絶縁部全般に適用することができる。 «Modification»
As mentioned above, the power converter concerning this embodiment (the 1st-4th embodiment) is not limited to the composition of the above-mentioned embodiment, A various change is possible within the range which does not deviate from the meaning of an invention .
Although the power conversion device 1 according to the present embodiment has been described as a high voltage direct inverter, the present invention is not limited to this, and can be applied to a converter, a power conditioner, and the like.
In the first to third embodiments, the composite insulation of the unit housing 21 and the beam 83 will be described, and in the fourth embodiment, the composite insulation of the switching element 23, the radiation fin 24, the bus bar 26 and the unit housing 21. However, the present invention is not limited to this, and can be applied to the entire space insulation between different potentials.
１　　　　　　　　　　　　　　　電力変換装置
２，２Ａ　　　　　　　　　　　　ユニットセル
２１　　　　　　　　　　　　　　ユニット筐体（高電圧部）
２２　　　　　　　　　　　　　　端部（電界集中部、縁部）
２３　　　　　　　　　　　　　　スイッチング素子（電界集中部、高電圧部）
２４　　　　　　　　　　　　　　放熱フィン（電界集中部、高電圧部）
２５　　　　　　　　　　　　　　平滑コンデンサ
２６　　　　　　　　　　　　　　バスバ（電界集中部、高電圧部）
３，３Ａ，３Ｂ　　　　　　　　　金属体
３１　　　　　　　　　　　　　　膨らみ部
３２　　　　　　　　　　　　　　ネジ（露出部）
３２Ｂ　　　　　　　　　　　　　ネジ
３３　　　　　　　　　　　　　　電界緩和部材
４，４Ａ，４Ｂ，４１Ａ，４１Ｂ　絶縁物（固体絶縁物）
５，５Ａ，５Ｂ　　　　　　　　　被絶縁金属体（複合絶縁構造）
７　　　　　　　　　　　　　　　通風ダクト
８　　　　　　　　　　　　　　　盤筐体
８１　　　　　　　　　　　　　　棚板
８２　　　　　　　　　　　　　　梁
８３　　　　　　　　　　　　　　端部
９　　　　　　　　　　　　　　　絶縁板 1 Power converter 2, 2A unit cell 21 unit case (high voltage part)
22 end (field concentration portion, edge)
23 Switching element (field concentration part, high voltage part)
24 Heat radiation fin (electric field concentration part, high voltage part)
25 smoothing capacitor 26 bus bar (field concentrated part, high voltage part)
3, 3A, 3B metal body 31 bulged portion 32 screw (exposed portion)
32B screw 33 electric field relaxation member 4, 4A, 4B, 41A, 41B insulator (solid insulator)
5,5A, 5B Insulated metal body (composite insulation structure)
7 Ventilation duct 8 panel case 81 shelf plate 82 beam 83 end 9 insulating plate

Claims (10)

  1. 　尖鋭した高電圧部の電界集中部を覆うように、固体絶縁物を設ける
    ことを特徴とする電力変換装置。     A power converter characterized in that a solid insulator is provided so as to cover an electric field concentration portion of a sharp high voltage portion.
  2. 　前記固体絶縁物を金属体に施した被絶縁金属体で前記電界集中部が覆われる
    ことを特徴とする請求項１に記載の電力変換装置。     The power conversion device according to claim 1, wherein the electric field concentration portion is covered with an insulated metal body in which the solid insulator is applied to a metal body.
  3. 　前記金属体は、
    　前記高電圧部と導通する
    ことを特徴とする請求項２に記載の電力変換装置。     The metal body is
    The power conversion device according to claim 2, which is electrically connected to the high voltage unit.
  4. 　前記金属体は、
    　屈折部を有し、該屈折部に膨らみ部を設ける
    ことを特徴とする請求項２または請求項３に記載の電力変換装置。     The metal body is
    The power conversion device according to claim 2 or 3, further comprising a refracting portion, wherein the refracting portion is provided with a bulging portion.
  5. 　前記被絶縁金属体は、
    　前記金属体の両面に前記固体絶縁物が施される
    ことを特徴とする請求項４に記載の電力変換装置。     The said to-be-insulated metal body is
    The power conversion device according to claim 4, wherein the solid insulator is applied to both surfaces of the metal body.
  6. 　前記金属体は、
    　一方の面で前記高電圧部と接するとともに、
    　他方の面に前記固体絶縁物が施される
    ことを特徴とする請求項２または請求項３に記載の電力変換装置。     The metal body is
    In contact with the high voltage section on one side,
    The said solid insulator is given to the other side, The power converter device of Claim 2 or Claim 3 characterized by the above-mentioned.
  7. 　前記被絶縁金属体は、
    　前記固体絶縁物が施されない前記金属体の露出部を有し、
    　前記露出部は、
    　前記高電圧部と電位の異なる異電圧部から、空間絶縁距離の規格値の１．５倍以上離れた位置に設けられる
    ことを特徴とする請求項３に記載の電力変換装置。     The said to-be-insulated metal body is
    It has an exposed portion of the metal body to which the solid insulator is not applied,
    The exposed portion is
    The power conversion device according to claim 3, wherein the power conversion device is provided at a position 1.5 or more times away from a standard value of a space insulation distance from a different voltage part having a potential different from the high voltage part.
  8. 　前記高電圧部は、ユニットセル筐体であり、
    　前記電界集中部は、前記ユニットセル筐体の縁部である
    ことを特徴とする請求項１に記載の電力変換装置。     The high voltage unit is a unit cell housing,
    The said electric field concentration part is an edge part of the said unit cell housing | casing, The power converter device of Claim 1 characterized by the above-mentioned.
  9. 　前記高電圧部は、スイッチング素子、該スイッチング素子の冷却フィン、バスバの少なくとも１つであり、
    　前記電界集中部は、前記スイッチング素子、前記冷却フィン、前記バスバの少なくとも１つの端部である
    ことを特徴とする請求項１に記載の電力変換装置。     The high voltage unit is at least one of a switching element, a cooling fin of the switching element, and a bus bar,
    The power conversion device according to claim 1, wherein the electric field concentration unit is at least one end of the switching element, the cooling fin, and the bus bar.
  10. 　前記固体絶縁物は、
    　粉体塗装により形成される
    ことを特徴とする請求項１に記載の電力変換装置。     The solid insulator is
    The power converter according to claim 1, which is formed by powder coating.
PCT/JP2012/072493 2012-09-04 2012-09-04 Power conversion device WO2014038000A1 (en)

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Application Number Priority Date Filing Date Title
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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2012/072493 WO2014038000A1 (en) 2012-09-04 2012-09-04 Power conversion device

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WO2014038000A1 true WO2014038000A1 (en) 2014-03-13

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3627982A1 (en) * 2018-09-18 2020-03-25 Delta Electronics, Inc. Insulated housing
EP4106504A1 (en) * 2021-06-15 2022-12-21 Hitachi Energy Switzerland AG Encapsulated converter cell module

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JP2000358360A (en) * 1999-06-14 2000-12-26 Densei Lambda Kk Dc-dc converter
JP2007129861A (en) * 2005-11-07 2007-05-24 Meidensha Corp High-voltage inverter device
JP2010225720A (en) * 2009-03-23 2010-10-07 Mitsubishi Electric Corp Power module
JP2011045234A (en) * 2009-08-21 2011-03-03 Alphana Technology Co Ltd Disk drive and method of manufacturing the disk drive
JP2012028552A (en) * 2010-07-23 2012-02-09 Nissan Motor Co Ltd Semiconductor module case structure

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000358360A (en) * 1999-06-14 2000-12-26 Densei Lambda Kk Dc-dc converter
JP2007129861A (en) * 2005-11-07 2007-05-24 Meidensha Corp High-voltage inverter device
JP2010225720A (en) * 2009-03-23 2010-10-07 Mitsubishi Electric Corp Power module
JP2011045234A (en) * 2009-08-21 2011-03-03 Alphana Technology Co Ltd Disk drive and method of manufacturing the disk drive
JP2012028552A (en) * 2010-07-23 2012-02-09 Nissan Motor Co Ltd Semiconductor module case structure

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3627982A1 (en) * 2018-09-18 2020-03-25 Delta Electronics, Inc. Insulated housing
US10986745B2 (en) 2018-09-18 2021-04-20 Delta Electronics, Inc. Insulated housing having a cylindrical structure
EP4106504A1 (en) * 2021-06-15 2022-12-21 Hitachi Energy Switzerland AG Encapsulated converter cell module

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