JP2009296015A - In-vehicle power conversion device - Google Patents

Abstract

An in-vehicle power conversion device that can suppress iron loss during high-frequency operation, is easy to manufacture, and can increase the degree of freedom of a core shape.
An in-vehicle power conversion device that converts battery direct current power into alternating current rated power necessary for driving a motor, and includes a reactor unit, a conversion device unit, and an inverter unit, and the reactor unit 21 includes: In the reactor core 23 including the powder magnetic bodies 23a to 23f divided into a plurality of parts, the cross-sectional shape of the portion where the coil 25 is mounted on the outer periphery is rounded at the corners of the cross-sectional shape. The reactor includes a reactor having a reactor core in which a magnetic gap is interposed between the powder magnetic bodies 23a to 23f.
[Selection] Figure 1

Description

  The present invention relates to an in-vehicle power converter.

  8 and 9 are a plan view and a side view of a conventional reactor. As shown in FIGS. 8 and 9, the conventional reactor 1 includes a core 3 and coils 5 and 7 extrapolated to the core 3. The core 3 has a substantially rectangular annular shape in a plan view, and is configured such that six divided bodies 3a to 3f are bonded to each other with nonmagnetic members (for example, ceramic plates) 9a to 9f forming a magnetic gap. Yes. As shown in FIG. 9, each of the divided bodies 3 a to 3 f is configured by laminating and bonding a plurality of silicon steel plates 11 a to 11 f punched into a predetermined shape. Such a core 3 is provided with coil mounting portions 13 and 15 at two locations, and the coils 5 and 7 are extrapolated to the coil mounting portions 13 and 15.

  However, in the conventional reactor 1 described above, the iron loss is suppressed by stacking the electromagnetic steel plates 11a to 11f to form the core 3, but eddy currents are generated in the electromagnetic steel plates 11a to 11f, so Large iron loss during operation. Moreover, since the core 3 is formed by stacking the punched electromagnetic steel sheets, it takes time and effort to manufacture and the degree of freedom in designing the core shape is small.

  Therefore, the problem to be solved by the present invention is to provide an in-vehicle power conversion device that can suppress iron loss during high-frequency operation, can be easily manufactured, and can expand the degree of freedom of the core shape.

  In order to solve the above-described problems, the invention of claim 1 is an in-vehicle power conversion device that converts battery DC power into AC rated power necessary for driving a motor, and includes a reactor unit, a conversion device unit, and an inverter. The reactor unit is a reactor core that includes a powder magnetic material divided into a plurality of parts, and the cross-sectional shape of the portion where the coil is mounted on the outer periphery is rounded at the corner of the cross-sectional shape The reactor has a shape and is provided with a reactor having a magnetic gap between the powder magnetic bodies.

  The invention according to claim 2 is the in-vehicle power converter according to the invention according to claim 1, wherein in the reactor core, the cross-sectional shape of the magnetic gap is also a shape with rounded corners. .

  Moreover, in invention of Claim 3, it is the vehicle-mounted power converter device of Claim 1 or Claim 2, Comprising: In the said reactor core, the part formed with the said powder magnetic body is in the said reactor core. A plurality of partial bodies coupled to each other at a coupling plane parallel to the magnetic circuit to be formed are provided.

  Moreover, in invention of Claim 4, it is the vehicle-mounted power converter device as described in any one of Claims 1-3, Comprising: In the said reactor, a coil closely_contact | adheres to the said reactor core and winds without gap. It was turned.

  Moreover, in invention of Claim 5, it is the vehicle-mounted power converter device of Claim 3, Comprising: The said divided | segmented dust magnetic body comprised by combining these several partial bodies is made into one sheet. The reactor core was configured by bonding the magnetic gaps therebetween.

  The invention according to claim 6 is the in-vehicle power conversion device according to any one of claims 1 to 5, wherein the dust magnetic body is a metal magnetic particle having a multilayer insulation coating. It is a molded product of.

  According to the first aspect of the present invention, since at least a part of the reactor core is formed of the powder magnetic material, it is possible to suppress the iron loss at the time of high frequency operation and improve the operation efficiency, and to manufacture the reactor. Is easy and the flexibility of the core shape can be expanded. For example, by rounding the cross-sectional shape of the part where the coil of the core is attached, the coil can be wound in close contact with the core, thereby eliminating the gap generated between the core and the coil. The reactor can be downsized. In addition, it is possible to provide a reactor that can improve the operating efficiency by suppressing iron loss during high-frequency operation, and that can be easily manufactured and can increase the degree of freedom of the core shape. In addition, since the cross-sectional shape of the part where the coil is mounted on the outer periphery is a shape in which the corners of the cross-sectional shape are rounded, the coil is closely attached to the outer periphery of the reactor core and there is no gap. Winding can be performed (overbank can be eliminated), and as a result, the reactor can be downsized.

  According to the third aspect of the present invention, the portion formed of the powder magnetic material of the reactor core can be divided and formed into a plurality of partial bodies. As a result, the reactor can be manufactured more easily and at a lower cost.

  Moreover, since the several partial body which comprises a core is mutually couple | bonded by the coupling surface parallel to a magnetic circuit, it can suppress that magnetoresistance increases in the coupling part between partial bodies.

It is a top view of the reactor which concerns on 1st Embodiment relevant to this invention. It is a side view of the reactor of FIG. It is sectional drawing along the AA line of FIG. It is the schematic diagram which expanded and showed the surface of the core. It is a side view of the reactor which concerns on 2nd Embodiment of this invention. It is a circuit diagram of the vehicle-mounted power converter device to which the reactor of FIG.1 and FIG.5 was applied. It is a figure which shows typically the planar structure of the power conversion module with which the vehicle-mounted power converter device of FIG. 6 is equipped. It is a top view of the conventional reactor. It is a side view of the reactor of FIG.

<First Embodiment>
FIG.1 and FIG.2 is the top view and side view of the reactor which concern on 1st Embodiment relevant to this invention. As shown in FIGS. 1 and 2, the reactor 21 includes a core 23 and at least one (for example, two) coils 25 and 27 extrapolated to the core 23. Note that the symbol C in FIG. 1 indicates a magnetic circuit formed in the core 23.

  The core 23 has a substantially rectangular annular shape in plan view, and a plurality of (for example, six) divided bodies so that the magnetic circuit C generated therein is divided into a plurality of sections (for example, six sections). It is divided into 23a to 23f. In addition, these division bodies 23a-23f are a different concept from the partial body which concerns on this invention (a partial body is demonstrated in 2nd Embodiment). In the present embodiment, the core 23 is configured by combining the plurality of divided bodies 23a to 23f. However, the core 23 may be integrally formed.

  The divided bodies 23a and 23b have a substantially U-shape in plan view, and the divided bodies 23c to 23f have a substantially rectangular shape in plan view. And these division bodies 23a-23f are bonded together by the adhesive etc. in the substantially rectangular ring shape on both sides of the nonmagnetic member (for example, ceramic board) 29a-29f which forms a magnetic gap, and the core 23 is comprised by this. Yes.

  The core 23 is provided with coil mounting portions 31 and 33 at least at one location (for example, two locations), and the coils 25 and 27 are extrapolated to the coil mounting portions 31 and 33. As shown in FIG. 3, the coil mounting portions 31 and 33 have a substantially rectangular cross-sectional shape, and each corner portion 35 of the substantially rectangular shape is rounded. As a result, the coils 25 and 27 can be wound around the outer circumferences of the coil mounting portions 31 and 33 over the entire circumference without any gaps (overbanks can be eliminated). Here, the coil mounting portions 31 and 33 are provided at portions where the non-magnetic members 29a to 29f of the core 23 are inserted, and the corner portions 35 of the non-magnetic bodies 29a to 29f are also rounded in the same manner. ing.

  In addition, you may make it apply such a cross-sectional shape which rounded the corner | angular part 35 not only to the coil mounting parts 31 and 33 but to the other part (for example, the whole core 23) of the core 23. .

  Each division body 23a-23f of such a core 23 is formed with the powder magnetic body. FIG. 4 is an enlarged schematic view showing the surface of the core 23. With reference to FIG. 4, the plurality of dust particles 41 constituting each divided body 23 a to 23 f of the core 23 includes a metal magnetic particle 43 and an insulating coating 45 surrounding the surface of the metal magnetic particle 43. An organic substance 47 is interposed between the plurality of dust particles 41. Each of the dust particles 41 is joined by an organic substance 47 or joined by meshing unevenness of the dust particles 41.

  The metal magnetic particles 43 include, for example, iron (Fe), iron (Fe) -silicon (Si) alloy, iron (Fe) -nitrogen (N) alloy, iron (Fe) -nickel (Ni) alloy, iron (Fe) -carbon (C) alloy, iron (Fe) -boron (B) alloy, iron (Fe) -cobalt (Co) alloy, iron (Fe) -phosphorus (P) alloy, iron (Fe ) -Nickel (Ni) -cobalt (Co) alloy, iron (Fe) -aluminum (Al) -silicon (Si) alloy, and the like. The metal magnetic particles 43 may be a single metal or an alloy.

  The insulating coating 45 is formed by subjecting the metal magnetic particles 43 to phosphoric acid treatment. Preferably, the insulating coating 45 contains an oxide. As the insulating coating 45 containing this oxide, in addition to iron phosphate containing phosphorus and iron, manganese phosphate, zinc phosphate, calcium phosphate, aluminum phosphate, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, etc. The oxide insulator can be used. The insulating coating 45 may be formed in one layer as shown in the figure, or may be formed in multiple layers.

  The insulating coating 45 functions as an insulating layer between the metal magnetic particles 43. By covering the metal magnetic particles 43 with the insulating coating 45, the electrical resistivity of the core 23 (each of the divided bodies 23a to 23f) can be increased. Thereby, it can suppress that an eddy current flows between the metal magnetic particles 43, and can reduce the iron loss resulting from an eddy current.

  Examples of the organic substance 47 include thermoplastic resins such as thermoplastic polyimide, thermoplastic polyamide, thermoplastic polyamideimide, polyphenylene sulfide, polyamideimide, portesulfone, polyetherimide, or polyetherethylketone, wholly aromatic polyester, or all Non-thermoplastic resins such as aromatic polyimides and higher fatty acids such as zinc stearate, lithium stearate, calcium stearate, lithium palmitate, calcium palmitate, lithium oleate or calcium oleate can be used. Moreover, these can also be mixed and used for each other.

  The organic substance 47 strongly joins between the plurality of dust particles 41 to improve the strength of the core 23 (each of the divided bodies 23a to 23f). Moreover, the organic substance 47 functions as a lubricant at the time of pressure molding for obtaining the divided bodies 23a to 23f. This prevents the dust particles 41 from rubbing against each other and the insulating coating 45 from being destroyed.

  The divided bodies 23a to 23f are produced as follows. First, the powder for forming the magnetic powder magnetic body is put into a predetermined molding die and pressure-molded at a predetermined pressure (for example, a pressure from 700 MPa to 1500 MPa). The atmosphere during the pressure molding is preferably an inert gas atmosphere or a reduced pressure atmosphere. In this case, it is possible to suppress the powder magnetic substance powder from being oxidized by oxygen in the atmosphere.

  Subsequently, the powder obtained by pressure molding is taken out of the mold and subjected to heat treatment to obtain divided bodies 23a to 23f.

  The divided bodies 23a to 23f obtained in this way are bonded to each other in a substantially rectangular ring shape with an adhesive or the like across the nonmagnetic members 29a to 29f, thereby forming the core 23.

  As described above, according to the present embodiment, since the core 23 is formed of a dust magnetic material, the core 21 can be prevented from iron loss at the time of high frequency operation and the operation efficiency can be improved. Is easy and the flexibility of the core shape can be expanded.

  In addition, since the cross-sectional shape of the coil mounting portions 31 and 33 of the core 23 is a shape in which the corner portion 35 of the cross-sectional shape is rounded, the coils 25 and 27 are placed on the outer periphery of the coil mounting portions 31 and 33. It can be tightly wound over the circumference and wound without gaps (overbanks can be eliminated), and as a result, the reactor 21 can be downsized.

Second Embodiment
FIG. 5 is a side view of a reactor according to the second embodiment of the present invention. The reactor 51 according to the present embodiment is substantially different from the reactor 21 according to the first embodiment described above in that each of the divided bodies 23a to 23f of the core 23 combines a plurality of partial bodies 231a to 231f and 232a to 232f. The parts corresponding to each other are denoted by the same reference numerals, and the description thereof is omitted.

  In the reactor 51 according to the present embodiment, each of the divided bodies 23a to 23f constituting the core 23 is combined with a plurality of (for example, two) partial bodies 231a to 231f and 232a to 232f as shown in FIG. It is configured. In each of the divided bodies 23a to 23f, the coupling surfaces 53 of the partial bodies 231a to 231f and 232a to 232f are parallel to the magnetic circuit C (see FIG. 1) formed in the core 23. In the present embodiment, each of the divided bodies 23a to 23f is divided into two by one coupling surface 53 parallel to the magnetic circuit C, but is divided into three or more by two or more coupling surfaces 53, respectively. It may be.

  That is, in the production of the divided bodies 23a to 23f, first, the partial bodies 231a to 231f and 232a to 232f are produced using the powder magnetic material, and then the produced partial bodies 231a to 231f and 232a to 232f are bonded. The divided bodies 23a to 23f are configured by being bonded with an agent or the like.

  As described above, according to the present embodiment, each of the divided bodies 23a to 23f of the core 23 can be divided and formed into a plurality of partial bodies 231a to 231f and 232a to 232f. The press shape at the time of pressing can be reduced, and as a result, the manufacture of the core 23 and the like becomes easier and less expensive.

  Further, since the plurality of partial bodies 231a to 231f and 232a to 232f constituting the respective divided bodies 23a to 23f of the core 23 are coupled to each other by the coupling surface 53 parallel to the magnetic circuit C, the partial bodies 231a to 231f and 232a are coupled. It is possible to suppress an increase in magnetic resistance at the coupling portion between ˜232f.

<Application example>
6 is a circuit diagram of an in-vehicle power conversion device to which the reactors 21 and 51 according to the first and second embodiments described above are applied, and FIG. 7 is a plan view of a power conversion module provided in the in-vehicle power conversion device. FIG.

  As shown in FIG. 6, this in-vehicle power conversion device includes a voltage conversion unit 61 and an inverter unit 63. In addition, although the structure which uses the reactor 21 is demonstrated in the structure shown in this FIG. 6, the reactor 51 can also be used instead of the reactor 21. FIG.

  The converter 61 has a step-up / down conversion function, and includes a reactor 21 for power conversion, first and second switching elements S1 and S2 constituting a chopper circuit for power conversion, and a flywheel First and second diodes D1 and D2 and a capacitor C1 are provided. Then, by turning on and off the first switching element S1 and chopping a current input from a battery (not shown), the voltage boosted by the reactor 21 is supplied to the inverter unit 63 via the second diode D2. Is done. Further, by turning on and off the second switching element S2 and chopping the regenerative current input from the drive motor 65 via the inverter unit 63, the regenerative current stepped down by the reactor 21 is given to the battery side. It is done.

  The inverter unit 63 includes first to sixth switching elements S11 to S16 that constitute a three-phase bridge circuit, and first to sixth diodes D11 to D16 for a flywheel. Then, each switching element S11 to S16 is turned on and off, and AC conversion of the drive voltage supplied from the conversion unit 61 to the drive motor 65 side and DC conversion of the regenerative current supplied from the drive motor 65 side to the conversion unit 61 side are performed. Is done.

  Some components of such a power conversion device are unitized and mounted on a vehicle as a power conversion module 71 as shown in FIG. This power conversion module 71 includes a reactor unit 121, a conversion device unit (step-up converter unit) 161, and an inverter unit 163 that are unitized in a case 73. The reactor unit 121 includes a reactor 21, and the conversion device unit 161 includes first and second switching elements S1 and S2 and first and second diodes D1 and D2 (capacitor C1) of the conversion unit 61. Is included, and the inverter unit 163 includes the first to sixth switching elements S11 to S16 and the first to sixth diodes D11 to S16 of the inverter unit 63.

  Such a power conversion device realizes rated power of several tens of kW level necessary for driving the motor 65, so that the reactor is increased in size, which tends to increase the size of the entire device. Further, when a conventional magnetic steel sheet laminated core is used for the reactor, the energy loss due to iron loss at the time of high rotation of the motor 65 (during high frequency operation) increases.

  In this regard, according to this power conversion device, since the reactors 21 and 51 according to the first and second embodiments described above are employed as the reactor for power conversion, the power conversion efficiency during high-frequency operation can be improved. At the same time, the manufacture (particularly, the power conversion module 71) of the configuration can be facilitated and downsized.

21 Reactor 23 Core 23a-23f Divided body 25, 27 Coil 29a-29f Non-magnetic member 31, 33 Coil mounting part 35 Corner part 51 Reactor 231a-231f, 232a-232f Partial body 61 Conversion part 63 Inverter part 71 Power conversion module 73 Case 121 Reactor unit 161 Conversion device unit 163 Inverter unit

Claims (6)

An in-vehicle power conversion device that converts battery direct current power into alternating current rated power necessary for driving a motor,
A reactor unit, a conversion device unit, and an inverter unit;
The reactor unit is
A reactor core including a powder magnetic material divided into a plurality of parts, wherein a cross-sectional shape of a portion where a coil is mounted on the outer periphery is a shape in which corners of the cross-sectional shape are rounded, and the dust magnetic An in-vehicle power converter, comprising a reactor having a reactor core in which a magnetic gap is interposed between bodies. The in-vehicle power converter according to claim 1,
The in-vehicle power converter device in which the cross-sectional shape of the magnetic gap in the reactor core is a shape with rounded corners. The in-vehicle power converter according to claim 1 or 2,
In the reactor, the portion formed by the dust magnetic body is configured to include a plurality of partial bodies coupled to each other at a coupling surface parallel to a magnetic circuit formed in the reactor core. Power converter. It is an in-vehicle power converter according to any one of claims 1 to 3,
The on-vehicle power converter, wherein the coil is wound around the reactor in close contact with the reactor in the reactor. The in-vehicle power converter according to claim 3,
In-vehicle power conversion in which the reactor core is configured by laminating the divided powder magnetic bodies configured by joining the plurality of partial bodies with the magnetic gap interposed therebetween. apparatus. It is an in-vehicle power converter according to any one of claims 1 to 5,
The in-vehicle power conversion device, wherein the dust magnetic body is a molded body of metal magnetic particles having a multilayer insulation coating.

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