Transformer, power converter unit and power converter

Abstract

The present invention provides a transformer, a power converter unit and a power converter, wherein the transformer comprises a primary core (2a) on which a primary winding (3a) is installed, a secondary core (2b) on which a secondary winding (3b) is installed, an insulating spacer (5) arranged on opposite surfaces of the primary core (2a) and the secondary core (2b), and two potential fixing parts (7a, 7b) fixing the primary core (2a) and the secondary core (2b) at different potentials.

Description

Technical Field

[0001] The present invention relates to a transformer, a power converter unit using the same, and a power converter. Background Art

[0002] In recent years, the application of solid-state transformers (hereinafter referred to as SSTs) has been studied as transformers used in grid-connected systems of several kV to tens of kV for railways and industrial equipment. The SST consists of a high-frequency transformer driven at a high frequency of several kHz to 100 kHz, a converter driving the high-frequency transformer, and an inverter that uses the output voltage of the converter as a power source and converts it into an AC voltage of tens of Hz, the same frequency as the system, replacing the existing transformer driven by industrial frequency.

[0003] According to the structure of SST, a power converter such as a converter and an inverter is added to the transformer, and the transformer is driven at a high frequency of several kHz to 100kHz, which makes it possible to achieve a significantly smaller and lighter transformer than the existing transformer.

[0004] In addition, in the transformer used for system grid connection, a high voltage of several kV is superimposed on the ground in the winding connected to the system (hereinafter referred to as the secondary winding), so it is necessary to ensure the insulation withstand voltage between the winding connected to the low-voltage side (hereinafter referred to as the primary winding) and the secondary winding on the high-voltage side.

[0005] In addition, generally speaking, from the perspective of cooling and structure, the magnetic core (hereinafter referred to as the core) of the transformer is installed in a manner that is at the same potential as the ground or low-voltage side. Therefore, it is necessary to ensure the insulation withstand voltage between the secondary winding with superimposed high voltage and the core with the potential of the ground or low-voltage side.

[0006] As a method of ensuring the insulation withstand voltage, there is a method of providing an air gap between the bobbin on which the winding is mounted and the core, and alleviating the local electric field concentration by adjusting the electrostatic capacitance ratio determined by the material properties of the bobbin, the thickness of the bobbin, and the distance of the air gap.

[0007] However, when the air gap between the winding frame and the core body is uneven, that is, when the air gap between the winding frame and the core body is locally reduced, there is a problem that electric field concentration occurs in a part between the winding and the core body, and the insulation performance is reduced. Therefore, in order to increase the withstand voltage of the transformer, it is necessary to consider the unevenness of the air gap and make the air gap between the winding frame and the core body larger, which leads to the problem of large-scale transformer.

[0008] Regarding this problem, Patent Document 1 discloses a structure including a primary core having a primary winding mounted thereon, a secondary core having a secondary winding mounted thereon, and an insulator, wherein the primary core and the secondary core are fixedly disposed on the insulator so as to face each other with the insulator interposed therebetween.

[0009] According to the disclosed technology of Patent Document 1, the parasitic capacitance between the primary and secondary windings can be reduced while ensuring the insulation between the primary and secondary windings. Thus, in a high-voltage insulation transformer, the parasitic capacitance between the primary and secondary windings is reduced and the insulation transformer is miniaturized.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: International Publication No. 2011 / 154993 Summary of the invention

[0013] Problems to be solved by the invention

[0014] However, in the technology disclosed in Patent Document 1, the potential of the secondary core is a floating potential, so the potential of the secondary core varies depending on the structure of the housing in which the transformer is mounted. Therefore, considering the reliability of insulation, it is assumed that the secondary core becomes the potential of the low-voltage side, and the insulation distance between the secondary winding superimposed with a high voltage and the core needs to be the same as that between the primary and secondary windings, so there is a problem that the transformer is difficult to miniaturize.

[0015] The present invention is invented in view of the above-mentioned problems, and its problem is to provide a power converter unit and a power converter having the transformer, which ensures the insulation (insulation withstand voltage) between the primary and secondary parts and between the winding and the core, while realizing the miniaturization of the transformer.

[0016] Technical solutions to solve problems

[0017] In order to solve the above-mentioned problems, the present invention is configured as follows.

[0018] That is, the transformer of the present invention is characterized in that it includes: a primary core body on which a primary winding is installed; a secondary core body on which a secondary winding is installed; an insulating spacer arranged on opposite surfaces of the primary core body and the secondary core body; and two potential fixing parts that fix the primary core body and the secondary core body at different potentials.

[0019] In addition, the power converter unit of the present invention is characterized in that it includes: the transformer; and a power conversion unit having a primary side circuit and a secondary side circuit separated by the transformer, the potential fixing part of the primary side core is connected to the reference potential of the primary side circuit, and the potential fixing part of the secondary side core is connected to the reference potential of the secondary side circuit.

[0020] In addition, the power converter of the present invention is characterized by comprising a plurality of the power converter units; the inputs of the plurality of power conversion parts of the plurality of the power converter units are connected in parallel, and the outputs are connected in series.

[0021] In addition, other technical solutions are described in the embodiments of the invention.

[0022] Effects of the Invention

[0023] According to the present invention, the insulation between the primary and secondary parts of the transformer and between the winding and the core can be ensured, while the miniaturization of the transformer can be achieved.

[0024] Furthermore, a power converter unit and a power converter having the above-mentioned transformer can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a diagram showing an example of the configuration of a transformer according to the first embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0026] Figure 2 1 is a diagram showing a transformer according to the first embodiment of the present invention as viewed from the X-axis direction. Figure 1 A diagram showing an example of a cross section of the II-II cross section.

[0027] Figure 3 This is a diagram showing an example of the side surface of the transformer according to the first embodiment of the present invention as viewed from the Y-axis direction.

[0028] Figure 4 This is a diagram showing an example of the configuration of a transformer according to a second embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0029] Figure 5 1 is a diagram showing a transformer according to a second embodiment of the present invention viewed from the X-axis direction. Figure 4 A diagram showing an example of a cross section of the VV cross section.

[0030] Figure 6 This is a diagram showing an example of a side surface of a transformer according to a second embodiment of the present invention as viewed from the Y-axis direction.

[0031] Figure 7 This is a diagram showing an example of the configuration of a transformer according to a third embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0032] Figure 8 1 is a diagram showing a transformer according to a third embodiment of the present invention viewed from the X-axis direction. Figure 6 A diagram showing an example of a cross section of section VIII-VIII in FIG.

[0033] Fig. 9This is a diagram showing an example of the structure of a transformer according to a fourth embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0034] Fig.10 1 is a diagram showing a transformer according to a fourth embodiment of the present invention as viewed from the X-axis direction. Figure 8 A diagram showing an example of a cross section of section XX.

[0035] Fig.11 This is a diagram showing an example of the configuration of a transformer according to a fifth embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0036] Fig.12 1 is a diagram showing a transformer according to a fifth embodiment of the present invention viewed from the X-axis direction. Fig.11 A diagram showing an example of a cross section of section XII-XII in FIG.

[0037] Fig.13 It is a diagram showing a circuit configuration example of a power converter (power converter unit) according to a sixth embodiment of the present invention.

[0038] Fig.14 It is a diagram showing a circuit configuration example of a power converter (power converter unit) according to a seventh embodiment of the present invention.

[0039] Fig.15 It is a diagram showing a circuit block configuration example of a power converter according to an eighth embodiment of the present invention.

[0040] Fig.16 It is a diagram showing a circuit block configuration example of a power converter according to a ninth embodiment of the present invention. DETAILED DESCRIPTION

[0041] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described with reference to the drawings as appropriate.

[0042] "First Embodiment - Transformer 10"

[0043] Regarding the transformer 10 of the first embodiment of the present invention, refer to Figure 1 to Figure 3 Provide explanation.

[0044] <Structure of transformer 10>

[0045] Figure 1 This is a diagram showing an example of the configuration of the transformer 10 according to the first embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0046] Figure 2 The transformer 10 according to the first embodiment of the present invention is shown as viewed from the X-axis direction. Figure 1 A diagram showing an example of a cross section of the II-II cross section.

[0047] Figure 3 This is a diagram showing an example of the side surface of the transformer 10 according to the first embodiment of the present invention as viewed from the Y-axis direction.

[0048] like Figure 1 , Figure 2 , Figure 3 As shown, the transformer 10 includes a primary core 2a, a secondary core 2b, a primary winding 3a, a secondary winding 3b, a winding frame 4a, 4b, and winding frame support portions 4a1, 4a2, 4b1, 4b2 ( Figure 2 )、Insulating spacer 5、Core support parts 6b2、6b3、Core support parts 6a2、6a3( Figure 2 )、the potential fixing parts 7a, 7b, the potential fixing wirings 71a, 71b ( Figure 3 ), supporting parts 81a~81d.

[0049] The primary core 2a has a cylindrical central magnetic core (primary core) 2a1 and two side magnetic cores (primary core) 2a2, 2a3. The secondary core 2b has a cylindrical central magnetic core (secondary core) 2b1 and two side magnetic cores (secondary core) 2b2, 2b3.

[0050] The central magnetic core column (primary core) 2a1 and the side magnetic core columns (primary core) 2a2 and 2a3 are of equal length in the Z-axis direction. The central magnetic core column (secondary core) 2b1 and the side magnetic core columns (secondary core) 2b2 and 2b3 are of equal length in the Z-axis direction.

[0051] The central magnetic core column (primary core) 2a1, side magnetic core columns (primary core) 2a2, 2a3 and the central magnetic core column (secondary core) 2b1 and side magnetic core columns (secondary core) 2b2, 2b3 are arranged with their respective surfaces having magnetic core columns facing each other via an insulating spacer 5 to form a closed magnetic circuit.

[0052] Electric power is transmitted from the primary winding 3 a to the secondary winding 3 b via the closed magnetic circuit formed by the primary core 2 a and the secondary core 2 b .

[0053] The primary winding 3a is mounted on the bobbin 4a, and the secondary winding 3b is mounted on the bobbin 4b.

[0054] The bobbin 4a has a bobbin support portion 4a1 ( Figure 2 ), and a bobbin support portion 4a2 ( Figure 2 ).

[0055] The bobbin 4b has a bobbin support portion 4b2 ( Figure 2 ), and a bobbin support portion 4b1 ( Figure 2 ).

[0056] In addition, the bobbin 4a is arranged so as to surround the central magnetic core leg (primary core) 2a1 ( Figure 2 ). In addition, the winding frame 4b is arranged so as to surround the central magnetic core column (secondary core) 2b1 ( Figure 2 ).

[0057] The insulating spacer 5 has core support parts 6a2, 6a3, 6b2, 6b3 for holding the primary core 2a and the secondary core 2b. The primary core 2a and the secondary core 2b are arranged with the insulating spacer 5 interposed therebetween to determine the positional relationship between the primary core 2a and the secondary core 2b.

[0058] The insulating spacer 5 is made of an insulating material made of a resin material such as PBT (Polybutylene terephthalate) or nylon.

[0059] In addition, gaps (not shown) are provided between the respective opposing surfaces of the primary core 2a and the secondary core 2b and the insulating spacer 5. The gaps are molded with a resin material (not shown).

[0060] In addition, the insulating spacer 5 has a plurality of protrusions 51, 52, and 53 on the surface. By adopting a structure having the protrusions 51, 52, and 53, the creepage distance required for the insulation between the primary and secondary is made longer. By adopting a shape that can ensure a long creepage distance, it is easy to ensure a withstand voltage, and the miniaturization of the transformer 10 is achieved.

[0061] The potential fixing parts 7a and 7b are made of a conductive metal material such as aluminum or stainless steel, for example. The potential fixing part 7a is arranged in contact with the primary core 2a, and the potential fixing part 7b is arranged in contact with the secondary core 2b.

[0062] Furthermore, the potential fixing portions 7a and 7b are joined to the support portions 81a to 81d to fix the primary core 2a, the secondary core 2b, and the bobbins 4a and 4b.

[0063] Furthermore, the support portions 81 a to 81 d are formed of an insulator made of a resin material such as PBT or nylon, or an insulator made of an inorganic material such as ceramic.

[0064] In addition, the potential fixing parts 7a and 7b have screw terminals 8a and 8b, respectively. The potential fixing part 7a uses a bus bar or a cable, etc., through the screw terminal 8a and the potential fixing wiring 71a ( Figure 3 ), and the following Fig.13 The potential fixing portion 7b is connected to the reference potential N1 of the primary side circuit 110 of the power converter 100 shown in FIG. Figure 3 ), and the following Fig.13 The secondary side circuit 120 of the power converter 100 shown is connected to a reference potential N2.

[0065] With this structure, the potential of the primary side core 2a is fixed to the primary side circuit 110 ( Fig.13 ) of the reference potential N1. In addition, the potential of the secondary side core 2b is fixed to the reference potential N2 of the secondary side circuit 120.

[0066] As described above, by arranging the primary side core 2a on which the primary winding 3a is installed and the secondary side core 2b on which the secondary winding 3b is installed relative to each other with the insulating spacer 5 sandwiched therebetween, and connecting the potential fixing parts 7a and 7b to the respective reference potentials of the primary side circuit and the secondary side circuit, respectively, the primary side core 2a and the secondary side core 2b can be fixed at different potentials (for example, reference potentials N1 and N2), respectively.

[0067] This structure and connection can reduce the electric field between the core and the winding, so the transformer can be miniaturized while ensuring insulation between the core and the winding.

[0068] <Effects of the First Embodiment>

[0069] Through the above structure and connection, the electric field between the core and the winding can be reduced, so that the insulation between the primary and secondary of the transformer and between the winding and the core can be ensured, and the miniaturization of the transformer can be achieved.

[0070] "Second Embodiment - Transformer 20"

[0071] For the transformer 20 of the second embodiment of the present invention, refer to Figures 4 to 6 Provide explanation.

[0072] <Structure of transformer 20>

[0073] Figure 4 This is a diagram showing an example of the configuration of a transformer 20 according to a second embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0074] Figure 5 The figure shows the transformer 20 according to the second embodiment of the present invention as viewed from the X-axis direction. Figure 4A diagram showing an example of a cross section of the VV cross section.

[0075] Figure 6 This is a diagram showing an example of the side surface of the transformer 20 according to the second embodiment of the present invention as viewed from the Y-axis direction.

[0076] like Figure 4 , Figure 5 , Figure 6 As shown, the transformer 20 includes a primary core 2a, a secondary core 2b, a primary winding 32a, a secondary winding 32b, bobbins 4a, 4b, bobbin supports 4a1, 4a2, 4b1, 4b2, potential fixing portions 7a, 7b, and supports 81a to 81d.

[0077] In addition, the transformer 20 has winding midpoints 32aN, 32bN ( Figure 6 )、winding covers 41a, 41b, insulating spacers 52a, 52b, insulating plate 9, core support parts 62a2, 62a3, 62b2, 62b3 ( Figure 5 )、Potential fixing wirings 71a, 71b ( Figure 6 ).

[0078] Among them, regarding the primary side core 2a, the secondary side core 2b, the primary winding 32a, the secondary winding 32b, the winding frame 4a, the winding frame 4b, the winding frame support parts 4a1, 4a2, 4b1, 4b2, the potential fixing parts 7a, 7b, and the support parts 81a to 81d, because Figure 1 , Figure 2 The transformer 10 of the first embodiment shown is the same, so duplicate descriptions are omitted as appropriate.

[0079] The following describes the winding midpoints 32aN, 32bN, winding covers 41a, 41b, insulating spacers 52a, 52b, insulating plates 9, core support parts 62a2, 62a3, 62b2, 62b3, and potential fixing wirings 71a, 72b of the transformer 20 of the second embodiment which is different from the transformer 10 of the first embodiment.

[0080] The winding covers 41a and 42b are made of resin material and are respectively arranged near the primary core 2a and the secondary core 2b, and the primary winding 32a and the secondary winding 32b. By arranging the winding covers 41a and 41b, the spatial distance between the primary winding 32a and the primary core 2a, and between the secondary winding 32b and the secondary core 2b is ensured.

[0081] The insulating spacer 52a and the insulating spacer 52b have core support portions 62a2 and 62a3 ( Figure 5) and core support portions 62b2, 62b3, maintain the positional relationship between the primary side core 2a and the secondary side core 2b.

[0082] The insulating spacers 52a and 52b are made of an insulating material such as PBT or nylon. The insulating plate 9 is made of an inorganic material such as ceramic or mica.

[0083] Insulating spacer 52a (first insulating layer) and insulating spacer 52b (third insulating layer) have a sandwich structure sandwiching insulating plate 9 (second insulating layer). Insulating spacers 52a, 52b and insulating plate 9 are bonded with an adhesive material to form an integrated insulating spacer (52a, 9, 52b).

[0084] Here, the insulating spacers 52a and 52b are referred to as "insulating spacers", and as described above, the product obtained by integrating the insulating spacers 52a and 52b with the insulating plate 9 (52a, 9, 52b) is also appropriately referred to as "insulating spacers".

[0085] In addition, the insulating spacers 52a and 52b have a structure in which a plurality of protrusions (protrusions 52a1, 52a2, 52a3, 52b1, 52b2, 52b3) are provided on the surface, thereby ensuring the creepage distance required for insulation between the primary and secondary sides and achieving miniaturization.

[0086] The transformer 10 ( Figure 1 When there is a tiny air gap between the core (2a, 2b) and the insulating spacer 5, there is a possibility that local discharge will occur between the core (2a, 2b) and the insulating spacer 5 due to the concentration of the electric field in the air gap.

[0087] When partial discharge occurs repeatedly over a long period of time, there is a risk that insulation breakdown may occur between the primary and secondary discharges due to the progress of degradation of the insulating spacer 5 .

[0088] On the other hand, the transformer 20 according to the second embodiment has a sandwich structure in which the insulating plate 9 made of ceramic or mica is sandwiched between insulating spacers 52 a and 52 b made of a resin material.

[0089] With this structure, even when deterioration of the insulating spacers (52a, 52b) progresses due to partial discharge between the cores (2a, 2b) and the insulating spacers (52a, 52b), the insulating plate 9 can prevent insulation breakdown between the primary and secondary layers.

[0090] In addition, in the transformer 20 of the second embodiment, as Figure 6As shown, the potential fixing wirings 71a and 71b are connected to the winding midpoint 32aN which is the midpoint of the primary winding 32a and the winding midpoint 32bN which is the midpoint of the secondary winding 32b, respectively.

[0091] That is, in the first embodiment, the potential fixing parts 7a and 7b are connected to the potential fixing parts 7a and 7b, for example, Fig.13 The reference potentials (potential neutral points) N1 and N2 of the power converter 100 shown in the figure are connected to the midpoint of the primary winding 32a, i.e., the winding midpoint 32aN, and the midpoint of the secondary winding 32b, i.e., the winding midpoint 32bN, respectively in the second embodiment.

[0092] Therefore, the potentials of the primary core 2a and the secondary core 2b are fixed at the intermediate potentials of the primary winding 32a and the secondary winding 32b, respectively.

[0093] By setting the midpoint of the primary winding 32a and the secondary winding 32b to the core potential, the wiring length of the potential fixing wires 71a and 71b can be shortened compared to the transformer 10 of the first embodiment. Therefore, the transformer 20 can be reduced in cost and size.

[0094] <Effects of the Second Embodiment>

[0095] With the above-described configuration, the transformer 20 of the second embodiment can achieve a higher withstand voltage than the transformer 10 of the first embodiment. Therefore, higher reliability of insulation can be expected.

[0096] Furthermore, the transformer 20 according to the second embodiment can achieve cost reduction compared to the transformer 10 according to the first embodiment.

[0097] "Third Embodiment - Transformer 30"

[0098] For the transformer 30 of the third embodiment of the present invention, refer to Figure 7 , Figure 8 Provide explanation.

[0099] <Structure of transformer 30>

[0100] Figure 7 This is a diagram showing an example of the structure of a transformer 30 according to a third embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0101] Figure 8 The figure shows a transformer 30 according to the third embodiment of the present invention as viewed from the X-axis direction. Figure 6 A diagram showing an example of a cross section of section VIII-VIII in FIG.

[0102] like Figure 7 , Figure 8As shown, the transformer 30 includes a primary core 2a, a secondary core 2b, a primary winding 3a, a secondary winding 3b, a potential fixing portion 7a, winding covers 41a, 41b, an insulating plate 9, and core support portions 62a2, 62a3, 62b2, 62b3.

[0103] The transformer 30 also includes a fixing portion 73c, a potential fixing portion 73b, a resin sheet 91, a bobbin 43a on which the primary winding 3a is mounted, a bobbin 43b on which the secondary winding 3b is mounted, and insulating spacers 53a and 53b.

[0104] Among them, the primary core 2a, the secondary core 2b, the primary winding 3a, the secondary winding 3b, the potential fixing portion 7a, the winding covers 41a, 41b, the insulating plate 9, the core support portions 62a2, 62a3, 62b2, 62b3, because Figure 4 , Figure 5 The transformer 20 of the second embodiment shown is the same, so duplicate descriptions are omitted as appropriate.

[0105] The fixing portion 73c, the potential fixing portion 73b, the resin sheet 91, the bobbin 43a on which the primary winding 3a is mounted, the bobbin 43b on which the secondary winding 3b is mounted, and the insulating spacers 53a and 53b of the transformer 30 are different from those of the transformer 20 and thus will be described below.

[0106] The fixing portion 73c is used to fix the transformer 30, and does not give it a special potential. That is, it does not perform the same as the transformer 10 in the first embodiment and the following description. Fig.13 The electrical connections of the converter unit, ie the power converter 100, are shown.

[0107] By using the fixing portion 73c, the first embodiment does not need to be Figure 1 and the second embodiment Figure 4 The supporting parts 81a~81d in the middle.

[0108] The potential fixing portion 73b is arranged in such a manner that the resin sheet 91 is sandwiched between the secondary core 2b and the fixing portion 73c and that the potential fixing portion 73b is in contact with the secondary core 2b. The potential fixing portion 73b has a screw terminal 8b and is connected to the secondary core 2b described later through a bus bar or a cable. Fig.13 The reference potential N2 of the secondary side circuit 120 of the illustrated converter unit, ie, the power converter 100 is connected so that the secondary side core 2 b is fixed to the potential (reference potential N2 ).

[0109] In addition, the potential fixing portion 7a has a screw terminal 8a similar to the transformer 10 in the first embodiment, and is connected to the transformer described later through a bus bar, a cable, etc. Fig.13The primary side core 2a is fixed at a predetermined potential by connecting the reference potential N1 of the primary side circuit 110 of the power converter (converter unit) 100 shown in FIG. Fig.10 The reference potentials N1 and N2 of the primary side circuit and the secondary side circuit of the illustrated power converter (converter unit) 100 are connected so that the primary side core 2a and the secondary side core 2b are fixed at different potentials.

[0110] The potential fixing portion 7a and the fixing portion 73c are respectively joined to the insulating spacers 53a and 53b by bolts or the like, thereby fixing the primary core 2a, the secondary core 2b, and the bobbins 43a and 43b.

[0111] The potential fixing portion 73b is made of a conductive metal. The resin sheet 91 is made of a silicone resin or the like.

[0112] In addition, the bobbins 43a, 43b and the insulating spacers 53a, 53b are made of a resin material.

[0113] In addition, the insulating spacers 53a and 53b are bonded to the insulating plate 9 by an adhesive material or the like to form an integrated insulating spacer.

[0114] The insulating spacer 53a and the primary core 2a are molded by a resin molding material 92a such as epoxy. Figure 8 )fixed.

[0115] The insulating spacer 53b and the secondary core 2b are molded by a resin molding material 92b such as epoxy. Figure 8 )fixed.

[0116] In addition, in the third embodiment Figure 8 The insulating spacers 53a and 53b shown in the figure are not provided with any other components corresponding to the second embodiment. Figure 4 The protrusions 52a1, 52a2, 52a3 and the protrusions 52b1, 52b2, 52b3 in the insulating spacers 52a and 52b are shown. The protrusions are preferably provided to ensure insulation withstand voltage and to reduce size, but the protrusions are not essential.

[0117] Figure 7 and Figure 8 The winding frames 43a and 43b in the embodiment include winding frame support portions 43a1 and 43a2 for ensuring the gap between the insulating spacers 53a and 53b and the primary winding 3a and the secondary winding 3b, and winding frame support portions 43b1 and 43b2 ( Figure 8 ).

[0118] In addition, the Z-axis dimension of the winding frames 43a and 43b including the winding frame support portions 43a1 to 43b2 is made larger than the height direction length of the columnar portion of each of the primary core 2a and the secondary core 2b. Figure 8 ) is easily flown into the structure between the primary side core 2a and the secondary side core 2b and the insulating spacer 53a and the insulating spacer 53b.

[0119] In addition, air gaps ( Figure 8 ). This air gap alleviates the electric field concentration in the minute air gaps respectively existing between the primary winding 3a and the secondary winding 3b and the winding frames 43a and 43b.

[0120] Thus, in the transformer 30 of the (third) embodiment, by adopting a structure in which the gap portion provided between the core (2a, 2b) and the insulating spacer (53a, 53b) is made into a resin molded portion (92a, 92b), the tiny air gap between the core and the insulating spacer (53a, 53b) which is the cause of local discharge can be reduced.

[0121] Furthermore, by alleviating the electric field concentration in the small air gap between the windings (3a, 3b) and the winding frame (43a, 43b), the partial discharge withstand voltage is improved. With this structure, compared with the transformer 10 described in the first embodiment, insulation degradation caused by partial discharge can be prevented, so the reliability of the transformer can be expected to be high.

[0122] <Effects of the Third Embodiment>

[0123] By providing air gaps between the resin molding materials 92a, 92b and the bobbins 43a, 43b, electric field concentration in minute air gaps between the primary winding 3a and the secondary winding 3b and the bobbins 43a, 43b is alleviated.

[0124] In addition, by adopting a structure in which the gap portion provided between the core (2a, 2b) and the insulating spacer (53a, 53b) is resin molded, the air gap between the core (2a, 2b) and the insulating spacer (53a, 53b) which is the cause of local discharge can be reduced.

[0125] Furthermore, by alleviating the electric field concentration in the minute air gap between the windings (3a, 3b) and the winding frames (43a, 43b), the partial discharge withstand voltage is improved.

[0126] With these structures, compared with the transformer 10 described in the first embodiment, insulation degradation due to partial discharge can be prevented, and thus higher reliability of the transformer can be expected.

[0127] "Fourth Embodiment - Transformer 40"

[0128] For the transformer 40 of the fourth embodiment of the present invention, refer to Fig. 9 , Fig.10 Provide explanation.

[0129] <Structure of transformer 40>

[0130] Fig. 9 This is a diagram showing an example of the structure of a transformer 40 according to a fourth embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0131] Fig.10 1 is a diagram showing a transformer 40 according to a fourth embodiment of the present invention as viewed from the X-axis direction. Fig. 9 A diagram showing an example of a cross section of section XX.

[0132] like Fig. 9 , Fig.10 As shown, the transformer 40 has a primary side core 2a (2a1, 2a2, 2a3), a secondary side core 2b (2b1, 2b2, 2b3), a primary winding 34a, a secondary winding 34b, a potential fixing part 7a, 7b, an insulating plate 9, a winding frame 44a, 44b, and a support part 84a~84d.

[0133] The transformer 40 also includes auxiliary cores 2a1s to 2a3s, 2b1s to 2b3s, insulating spacers 54a, 54b, core fixing portions 64b1 to 64b3, and core fixing portions 64a1 to 64a3 ( Fig.10 )、Conductive sheet 94 (conductive member: Fig.10 ).

[0134] Among them, the primary core 2a, the secondary core 2b, the primary winding 34a, the secondary winding 34b, the potential fixing parts 7a, 7b, the winding frames 44a, 44b, and the supporting parts 84a to 84d are Figure 1 , Figure 2 The transformer 10 of the first embodiment shown is the same, so duplicate descriptions are omitted as appropriate.

[0135] In addition, regarding the insulating plate 9, since Figure 4 , Figure 5 The transformer 20 of the second embodiment shown is the same, so duplicate descriptions are omitted as appropriate.

[0136] In the transformer 40, the auxiliary cores 2a1s to 2a3s, 2b1s to 2b3s, the insulating spacers 54a, 54b, the core fixing portions 64a1 to 64a3, 64b1 to 64b3, the conductive sheet 94 ( Fig.10 ), explained below.

[0137] Fig. 9 and Fig.10 In the embodiment, the auxiliary core 2a1s is arranged in a manner extending the primary core 2a1. Therefore, the cross-sectional shape of the magnetic core column of the auxiliary core 2a1s is formed to be the same as the cross-sectional shape of the magnetic core column of the primary core 2a1. In addition, the cross-sectional shape of the magnetic core column of each of the auxiliary cores 2a2s and 2a3s is formed to be the same as the cross-sectional shape of the magnetic core column of each of the primary cores 2a2 and 2a3, and each is arranged in an extended manner.

[0138] Similarly, the cross-sectional shape of the magnetic core legs of the auxiliary cores 2b1s, 2b2s, and 2b3s is formed to be the same as the cross-sectional shape of the magnetic core legs of the secondary cores 2b1, 2b2, and 2b3, and are arranged so as to extend.

[0139] The primary core 2a (2a1, 2a2, 2a3) and the auxiliary cores 2a1s to 2a3s, and the secondary core 2b (2b1, 2b2, 2b3) and the auxiliary cores 2b1s to 2b3s are bonded with an adhesive material to form an integrated primary core 24a and secondary core 24b.

[0140] By means of the structure of the integrated primary core 24a and secondary core 24b, the transformer 40 of the fourth embodiment can increase the window area of ​​the core for mounting the winding (34a, 34b) compared to the transformers 10 to 30 of the first to third embodiments. The "core window area" corresponds to the cross-sectional area of ​​the space of the winding receiving portion formed by the primary core and the secondary core.

[0141] By increasing the window area of ​​the core, the diameter of the winding cross section, that is, the cross-sectional area of ​​the conductor, can be increased, and the power capacity of the transformer can be increased.

[0142] In addition, the conductive sheet 94 (conductive member: Fig.10 ) is configured in the secondary winding 34b ( Fig.10 ) and winding frame 44b( Fig.10 ), thereby reducing the windings (34a, 34b: Fig.10 ) and winding frame (44a, 44b: Fig.10 ) There is a tiny air gap between the winding and the bobbin. By reducing this air gap, partial discharge between the winding and the bobbin can be reduced.

[0143] The conductive sheet 94 is provided between the secondary winding 34b and the bobbin 44b, but not between the primary winding 34a and the bobbin 44a, because it is assumed that a higher voltage is generally applied to the secondary winding (secondary side circuit).

[0144] The insulating spacers 54a and 54b have core fixing portions 64a1 to 64a3 and core fixing portions 64b1 to 64b3.

[0145] Core fixing parts 64a1 to 64a3 ( Fig.10 ) and core fixing portions 64b1 to 64b3 ( Fig. 9 , Fig.10 ) respectively move the primary side core 2a and the auxiliary cores 2a1s~2a3s, the secondary side core 2b and the auxiliary cores 2b1s~2b3s, and maintain the positions of the primary side core 24a and the secondary side core 24b.

[0146] Furthermore, the core fixing portions 64a2, 64a3, 64b2, and 64b3 ensure the insulation distance between the winding and the core by lengthening the dimension of the winding side in the Y-axis direction.

[0147] By adopting such a structure, the fourth embodiment ( Fig. 9 , Fig.10 ) does not need to indicate the second embodiment Figure 4 and a third embodiment Figure 7 The winding covers 41a and 41b described in the specification can be used, so the number of parts can be reduced.

[0148] The fourth embodiment is shown Fig. 9 , Fig.10 In the figure, the support parts 84a~84d connect their two ends to the potential fixing parts 74a and 74b to maintain the core bodies (including auxiliary core bodies) 24a, 24b, and the windings (primary winding 34a, secondary winding 34b, winding frames 44a, 44b).

[0149] As described above, in the transformer 40 of the fourth embodiment, by adopting a structure in which an auxiliary core is added to the primary core and the secondary core, the window area of ​​the core where the winding is mounted can be increased. Therefore, the power capacity of the transformer can be increased.

[0150] Furthermore, by changing the number and size of the auxiliary cores, different power capacities can be handled, so that components can be shared among transformers with different power capacities, and cost reduction of the transformer can be expected.

[0151] <Effects of the Fourth Embodiment>

[0152] In the transformer 40 of the fourth embodiment, by adopting a structure in which an auxiliary core is added to the primary core and the secondary core, the window area of ​​the core where the winding is mounted can be increased, and the power capacity of the transformer can be increased.

[0153] Furthermore, by changing the number and size of the auxiliary cores, different power capacities can be handled, so that components can be shared among transformers with different power capacities, and cost reduction of the transformer can be expected.

[0154] "Fifth Embodiment-Transformer 50"

[0155] For the transformer 50 according to the fifth embodiment of the present invention, refer to Fig.11 and Fig.12 Provide explanation.

[0156] Fig.11 This is a diagram showing an example of the structure of a transformer 50 according to a fifth embodiment of the present invention in an exploded manner and viewed from above obliquely.

[0157] Fig.12 1 is a diagram showing a transformer 50 according to a fifth embodiment of the present invention as viewed from the X-axis direction. Fig.11 A diagram showing an example of a cross section of section XII-XII in FIG.

[0158] like Fig.11 , Fig.12 As shown, the transformer 50 includes primary cores 25a1, 25a2, secondary cores 25b1, 25b2, primary windings 35a1, 35a2, secondary windings 35b1, 35b2, bobbins 45a1, 45a2, 45b1, 45b2, bobbin supports 46a1, 46a2, 46b1, 46b2, 47a1, 47a2, 47b1, 47b2 ( Fig.12 )、Insulating spacer 55、Core support parts 65a1~65a4、65b1~65b4( Fig.12 ), potential fixing parts 75a, 75b, and supporting parts 85a~85d.

[0159] The above components constituting the transformer 50 constitute two transformers, namely the transformer 50A and the transformer 50B.

[0160] That is, the primary core 25a1, the secondary core 25b1, the primary winding 35a1, the secondary winding 35b1, the bobbins 45a1, 45b1, and the bobbin support parts 46a1, 46a2, 46b1, 46b2 ( Fig.12 )、Insulating spacer 55、Core support parts 65a1、65a2、65b1、65b2( Fig.12 ), potential fixing parts 75a, 75b constitute the transformer 50A.

[0161] The primary core 25a2, the secondary core 25b2, the primary winding 35a2, the secondary winding 35b2, the bobbins 45a2, 45b2, the bobbin support parts 47a1, 47a2, 47b1, 47b2 ( Fig.12 )、Insulating spacer 55、Core support parts 65a3、65a4、65b3、65b4( Fig.12 ), potential fixing parts 75a, 75b constitute a transformer 50B.

[0162] In addition, among the above, the insulating spacer 55 and the potential fixing portions 75 a and 75 b are commonly used by the transformer 50A and the transformer 50B.

[0163] Fig.11 , Fig.12 The structures and functions of the transformer 50A and the transformer 50B shown are respectively similar to those of Figure 1 , Figure 2 The transformer 10 shown is substantially the same, so repeated description is omitted.

[0164] pass Fig.11 , Fig.12 The structure of the transformer 50 shown in the figure comprises two transformers, a transformer 50A and a transformer 50B.

[0165] <Effects of the Fifth Embodiment>

[0166] In the transformer 50 of the fifth embodiment, the transformer 50A and the transformer 50B share the insulating spacer 55, the potential fixing parts 75a, 75b, and the supporting parts 85, 85d. By adopting this structure, the volume of the transformer can be reduced compared to the case of using two sets of the transformer 10 of the first embodiment, which has the effect of miniaturization and cost reduction.

[0167] 《Sixth Embodiment: Power Converter (Power Converter Unit)》

[0168] For the power converter (power converter unit) 100 according to the sixth embodiment of the present invention, refer to Fig.13 Provide explanation.

[0169] <Structure of power converter (power converter unit) 100>

[0170] Fig.13 1 is a diagram showing a circuit configuration example of a power converter (power converter unit) 100 according to a sixth embodiment of the present invention. The power converter (power converter unit) 100 configures a solid-state transformer (SST).

[0171] Fig.13In the embodiment, the power converter (power converter unit) 100 is composed of a converter 101, a DC-DC converter (resonant DC-DC converter) 102, and an inverter 103. The transformer 10 described in the first embodiment is used in the DC-DC converter 102. In addition, the primary side circuit 110 and the secondary side circuit 120 are DC-insulated by the transformer 10.

[0172] Converters 101

[0173] The converter 101 includes switching elements S11 to S14 , antiparallel diodes D11 to D14 , and smoothing capacitors C1 a and C1 b .

[0174] The switching elements S11 to S14 constitute a synchronous rectification circuit, and together with the anti-parallel diodes D11 to D14 of the bridge structure, rectify the AC voltage (AC power) input from the input terminals 1001 and 1002 to generate a DC voltage (DC power). In addition, the generated DC voltage contains a pulsating current component (AC component). The smoothing capacitors C1a and C1b connected in series smooth the pulsating current component (AC component) of the generated DC voltage.

[0175] In addition, a reference potential N1 is output from a midpoint (connection point) of the smoothing capacitors C1a and C1b connected in series.

[0176] In addition, since the smoothing capacitors C1a and C1b are provided between the two DC terminals of the DC voltage rectified by the converter 101, the reference potential N1 at the midpoint (connection point) of the smoothing capacitors C1a and C1b is also appropriately recorded as "the potential at the midpoint of the DC terminals of the primary side circuit 110".

[0177] DC-DC Converter 102

[0178] The DC-DC converter (resonant converter) 102 includes switching elements H1 to H4 , antiparallel diodes DH1 to DH4 , a resonant capacitor Cr, a transformer 10 , rectifying diodes Dr1 to Dr4 , and smoothing capacitors C2 a and C2 b .

[0179] The DC voltage is converted into an AC voltage by the switching elements H1 to H4 , the anti-parallel diodes DH1 to DH4 , and the resonant capacitor Cr, and is input to the primary side of the transformer 10 .

[0180] Furthermore, the frequency of the AC voltage input to the primary side of the transformer 10 is generally much higher than the frequency of the AC voltage at the input terminals 1001 and 1002 of the converter 101 .

[0181] Since the transformer 10 is excited at a relatively high frequency, the core of the transformer 10 can be made smaller in size compared to a transformer of a low frequency.

[0182] The transformer 10 steps up (or steps down) the primary-side voltage of the input AC and outputs the AC voltage to the secondary side.

[0183] in addition, Fig.10 In the transformer 10, the primary side core 2a, the secondary side core 2b, the primary winding 3a, and the secondary winding 3b are marked, which correspond to Figure 1 The transformer 10 includes a primary core 2a, a secondary core 2b, a primary winding 3a, and a secondary winding 3b.

[0184] The AC voltage on the secondary side of the transformer 10 is rectified by the rectifier diodes Dr1 to Dr4 in a bridge structure.

[0185] The smoothing capacitors C2a and C2b connected in series smooth the rectified DC voltage.

[0186] In addition, a reference potential N2 is output from a midpoint (connection point) of the smoothing capacitors C2a and C2b connected in series.

[0187] In addition, since the smoothing capacitors C2a and C2b are arranged between the two DC terminals of the DC voltage rectified by the rectifying diodes Dr1 to Dr4, the reference potential N2 at the midpoint (connection point) of the smoothing capacitors C2a and C2b is also appropriately recorded as the "potential of the midpoint of the DC terminal of the secondary side circuit 120".

[0188] The primary core 2 a of the transformer 10 is connected to a reference potential N1 which is a midpoint (connection point) of the smoothing capacitors C1 a and C1 b in the converter 101 .

[0189] The secondary side core 2 b of the transformer 10 is connected to a reference potential N2 which is a midpoint (connection point) of the smoothing capacitors C2 a and C2 b in the DC-DC converter 102 .

[0190] Therefore, the primary side core 2a and the secondary side core 2b of the transformer 10 can be fixed at different potentials ( Fig.10 reference potential N1, N2).

[0191] Through the above structure and connection, the transformer 10 can reduce the electric field between the core and the winding on the primary side and the secondary side.

[0192] Furthermore, with the above configuration, the DC-DC converter 102 converts the DC voltage (DC power) input from the converter 101 into a DC voltage (DC power) of a different voltage, and outputs the converted DC voltage to the inverter 103 described below.

[0193] Inverter 103

[0194] The inverter 103 includes switching elements S21 to S24 and anti-parallel diodes D21 to D24.

[0195] The inverter 103 converts the DC voltage (DC power) output from the DC-DC converter 102 into an AC voltage (AC power), and outputs the AC voltage from the output terminals 2001 and 2002 .

[0196] The output of the inverter 103 is the output of the power converter (power converter unit) 100 .

[0197] The frequency of the AC voltage output from the output terminals 2001 and 2002 of the inverter 103 may be substantially the same as the frequency of the AC voltage input from the input terminals 1001 and 1002 of the converter 101. That is, the frequency of the AC voltage output from the inverter 103 is lower than the frequency at which the transformer 10 is excited.

[0198] Supplementary description of power converter (power converter unit) 100

[0199] As described above, the power converter (power converter unit) 100 includes the converter 101 , the DC-DC converter 102 , and the inverter 103 , and converts the AC voltage (power) input from the input terminals 1001 , 1002 into a predetermined voltage and frequency, and outputs the voltage from the output terminals 2001 , 2002 .

[0200] Furthermore, as described above, in the transformer 10 in the power converter (power converter unit) 100 , the voltage is converted from the primary side to the secondary side at a relatively high frequency.

[0201] Furthermore, since the transformer 10 described in the first embodiment is used in the DC-DC converter 102 , the power converter (power converter unit) 100 can be miniaturized.

[0202] In addition, if Fig.13 As shown, the converter 101 and a part of the DC-DC converter 102 until the input to the transformer 10 are defined as a primary side circuit 110 . In addition, the inverter 103 and a part of the DC-DC converter 102 after the output from the transformer 10 are defined as a secondary side circuit 120 .

[0203] Then, the primary side circuit 110 and the secondary side circuit 120 are combined as a power conversion unit (110, 120). That is, the power converter (power converter unit) 100 can also be considered to have a transformer 10 and a power conversion unit (110, 120) having the primary side circuit 110 and the secondary side circuit 120 with the transformer 10 interposed therebetween.

[0204] <Effects of the Sixth Embodiment>

[0205] Fig.10 The power converter (power converter unit) 100 shown uses Figure 1 The transformer 10 shown. Figure 1 In the transformer 10 shown in the figure, the primary core 2a with the primary winding 3a installed and the secondary core 2b with the secondary winding 3b installed are arranged opposite to each other with the insulating spacer 5 interposed therebetween, and the potential fixing parts 7a and 7b are connected to the reference potentials of the primary circuit and the secondary circuit, respectively, so that the primary core 2a and the secondary core 2b can be fixed at different potentials ( Fig.10 reference potential N1, N2).

[0206] This structure and connection can reduce the electric field between the core and the winding, so that the transformer 10 and the power converter (power converter unit) 100 can be miniaturized while ensuring the insulation between the core and the winding.

[0207] <<Seventh Embodiment: Power Converter (Power Converter Unit)>>

[0208] For the power converter (power converter unit) 500 according to the seventh embodiment of the present invention, refer to Fig.14 Provide explanation.

[0209] Fig.14 1 is a diagram showing a circuit configuration example of a power converter (power converter unit) 500 according to the seventh embodiment of the present invention.

[0210] Fig.14 In the embodiment, the power converter (power converter unit) 500 is composed of a converter 101, a DC-DC converter 502, and an inverter 103. In the DC-DC converter 502, the power converter described in the fifth embodiment is used. Fig.11 , Fig.12 The transformer 50 is shown.

[0211] Fig.14 The converter 101 and the inverter 103 in Fig.12 The converter 101 and the inverter 103 have the same structure, so repeated description is omitted.

[0212] Fig.14The DC-DC converter 502 in FIG. 5 has a transformer 50 .

[0213] Fig.14 In the embodiment, the transformer 50 includes a transformer 50A and a transformer 50B.

[0214] The primary winding 35a1 of the transformer 50A is connected in series with the primary winding 35a2 of the transformer 50B. In addition, the secondary winding 35b1 of the transformer 50A is connected in series with the secondary winding 35b2 of the transformer 50B.

[0215] As described above, since the primary winding and the secondary winding of the transformer 50A and the transformer 50B are connected in series, respectively, it is easy to ensure the withstand voltage of the transformer 50A and the transformer 50B.

[0216] <Effects of the Seventh Embodiment>

[0217] Fig.14 The power converter (power converter unit) 500 shown uses Fig.11 Therefore, by connecting the potential fixing parts 75a and 75b to the reference potentials of the primary circuit and the secondary circuit, respectively, the primary cores 25a1 and 25a2 and the secondary cores 25b1 and 25b2 can be fixed at different potentials ( Fig.14 reference potential N1, N2).

[0218] This structure and connection can reduce the electric field between the core and the winding, so that the transformer 50 and the power converter (power converter unit) 500 can be miniaturized while ensuring the insulation between the core and the winding.

[0219] <Eighth Embodiment: Power Converter 1u>

[0220] For the power converter 1u according to the eighth embodiment of the present invention, refer to Fig.15 Provide explanation.

[0221] Fig.15 It is a diagram showing a circuit block configuration example of a power converter 1u according to an eighth embodiment of the present invention.

[0222] Fig.15 In the power converter 1u Fig.13 The illustrated power converter (power converter unit) 100 has a three-stage series structure.

[0223] Then, the power converter 1u inputs a single-phase AC voltage (AC power) from a single-phase AC power supply (or one phase of a three-phase AC power supply) 3101 , converts the voltage (AC voltage) or frequency using the power converter 1u , and supplies it to a load (M) 3102 .

[0224] <Effects of the Eighth Embodiment>

[0225] Fig.15 The power converter 1u shown uses Fig.13 The power converter (power converter unit) 100 shown in the figure can realize miniaturization of the power converter 1u.

[0226] <<Ninth Embodiment: Power Converter 330>>

[0227] For the power converter 330 according to the seventh embodiment of the present invention, refer to Fig.16 Provide explanation.

[0228] Fig.16 1 is a diagram showing a circuit block configuration example of a power converter 330 according to a ninth embodiment of the present invention.

[0229] Fig.16 In the embodiment, the power converter 330 uses the equivalent Fig.15 The power converter 1u shown is configured to include three power converters 1u, 1v, and 1w.

[0230] The power converters 1u, 1v, and 1w in the power converter 330 receive the u-phase, v-phase, and w-phase of the three-phase AC voltage of the three-phase AC power source 3301, respectively.

[0231] In addition, one end of each input side of the power converters 1u, 1v, and 1w is commonly connected and grounded to the ground (ground) 3300.

[0232] The power converters 1u, 1v, and 1w in the power converter 330 convert voltage and frequency, respectively, and output them as U-phase, V-phase, and W-phase three-phase AC voltages, respectively.

[0233] The U-phase, V-phase, and W-phase of the three-phase AC voltage (three-phase AC power) output from the power converter 330 are supplied to a three-phase load (M: for example, a three-phase motor) 3302 .

[0234] In addition, one end of each output side of power converters 1u, 1v, 1w is commonly connected to neutral point 3330.

[0235] Through the above structure, the power converter 330 inputs three-phase AC voltage (power) from the three-phase AC power supply 3301, converts it into three-phase AC voltage (power) of specified three-phase AC voltage and frequency, and drives a three-phase load (such as a three-phase motor).

[0236] <Effects of the Ninth Embodiment>

[0237] Fig.16The power converter 330 shown uses Fig.15 The power converter 1u shown can therefore achieve miniaturization of the power converter 330.

[0238] 《Other Implementation Methods》

[0239] In addition, the present invention is not limited to the above-described embodiments, and further includes various modifications. For example, the above-described embodiments are described in detail to explain the present invention in an easy-to-understand manner, and are not limited to all structures that must be described. In addition, a part of the structure of a certain embodiment can be replaced with a part of the structure of another embodiment, and a part or all of the structure of another embodiment can be added, deleted, or replaced with respect to the structure of a certain embodiment.

[0240] Other embodiments and modifications will be further described below.

[0241] 《Primary winding 3a and secondary winding 3b》

[0242] The first embodiment is shown Figure 1 to Figure 3 In the figure, the primary winding 3a and the secondary winding 3b are shown as single wires, but twisted wires may also be used. The same is true for other embodiments.

[0243] The shape of the core

[0244] The first to fourth embodiments are shown. Figures 1 to 12 In the description, the primary core 2a and the secondary core 2b are described as EER type cores, but they are not limited to the EER type.

[0245] The same effect can be achieved by using PQ type, E type, UU core and other structures.

[0246] <<Shape of insulating spacer 5>>

[0247] The first embodiment is shown Figure 1 In the embodiment, the insulating spacer 5 has a structure in which the protrusions 51, 52, and 53 are provided, but it may be composed of a flat plate without the protrusions.

[0248] On the contrary, the number of protrusions of the protrusion portion may be increased. In addition, the shape of the protrusion is not limited to a rectangular parallelepiped. In addition, the intervals and heights of the protrusions of the protrusion portion do not need to be uniformly the same. The size and interval of the protrusion portion may also be changed according to the location of the insulating spacer 5.

[0249] 《Structure of insulating spacers》

[0250] The second embodiment is shown Figure 5, a sandwich structure is shown in which an insulating plate 9 (second insulating layer) is sandwiched between an insulating spacer 52a (first insulating layer) and an insulating spacer 52b (third insulating layer). As described above, a structure integrated into this sandwich structure is also called an "insulating spacer", but the "insulating spacer" formed by integrating multiple insulating layers is not limited to Figure 5 The structure shown.

[0251] For example, an "insulating spacer" having a structure in which the insulating spacer 52a (first insulating layer) and the insulating plate 9 (second insulating layer) are integrated is also effective. In addition, an "insulating spacer" having a structure in which the insulating spacer 52b (third insulating layer) and the insulating plate 9 (second insulating layer) are integrated is also effective.

[0252] In addition, an “insulating spacer” having a structure in which four or more insulating layers are integrated by combining a plurality of insulating spacers (first insulating layer or third insulating layer) with a plurality of insulating plates 9 (second insulating layer) is also effective.

[0253] 《Structure of the gap between the winding and the resin molding material》

[0254] In the first embodiment, the description is given of providing gaps between the respective opposing surfaces of the primary core 2 a and the secondary core 2 b and the insulating spacer 5 , and molding the gaps with a resin material.

[0255] In this structure, air gaps may be provided between the mold layer and the winding frames on which the primary winding 3a and the secondary winding 3b are mounted, respectively.

[0256] 《Application of the potential fixing unit 73》

[0257] The third embodiment is shown Figure 7 In the embodiment, the potential fixing portion 73 having a smaller shape than the fixing portion 83 is used only in the upper portion on the Z axis, and the potential fixing portion 7a having substantially the same shape as the fixing portion 83 is used in the lower portion. However, the present invention is not limited to this configuration.

[0258] The same structure as the fixing portion 83, the resin sheet 91, and the potential fixing portion 73 in the upper portion in the third embodiment may be used in the lower portion.

[0259] 《Conductive Sheet 94》

[0260] The fourth embodiment is shown Fig.10 In the embodiment, the conductive sheet 94 (conductive member) is provided between the secondary winding 34b and the bobbin 44b, but not provided between the primary winding 34a and the bobbin 44a, but the present invention is not limited thereto. Fig.10There is also a method of providing a conductive sheet (94) between the primary winding 34a and the winding frame 44a, which helps to further reduce partial discharge.

[0261] 《Number of transformer components》

[0262] The structure of the fifth embodiment is shown in FIG. Fig.12 In FIG. 5 , an example is shown in which the transformer 50 is composed of two transformers 50A and 50B. However, the number of transformers (50A, 50B) included in one transformer (50) is not limited to two (2).

[0263] Can also be shared Fig.12 The insulating spacer 55, the potential fixing portions 75a, 75b, and the supporting portions 85, 85d shown constitute three or more transformers.

[0264] 《Series and parallel structures of transformers》

[0265] A circuit configuration of a seventh embodiment is shown. Fig.14 In the embodiment, the transformer 50A and the transformer 50B are connected in series on the primary side and in series on the secondary side, but the connection method is not limited to this.

[0266] For example, it is effective to adopt a primary side series and secondary side parallel structure, or a primary side parallel and secondary side series structure, or a primary side parallel and secondary side parallel structure.

[0267] 《Application of Transformer》

[0268] Fig.13 In the power converter (power converter unit) 100 of the sixth embodiment shown in FIG. 1 , the power converter of the first embodiment is used as the transformer (10). Figure 1 to Figure 3 The structure of the transformer 10 is shown. However, Fig.13 The transformer (10) is not limited to transformer 10.

[0269] You can also use Figures 4 to 6 The transformer 20 of the second embodiment shown in FIG. Figure 7-Figure 8 The transformer 30 of the third embodiment shown in FIG. Figure 9-10 The transformer 40 of the fourth embodiment shown in FIG. Figure 11-12 A transformer 50 according to a fifth embodiment is shown.

[0270] 《Number of power converter units》

[0271] Fig.15 In the power converter 1u of the eighth embodiment shown, the number of stages of the power converters (power converter units) 100 connected in series is three, but the number is not limited to three. The configuration may be two or less or four or more stages.

[0272] 《Connection of power converter unit》

[0273] Fig.15 In the power converter 1u of the eighth embodiment shown, a configuration is shown in which both the input side and the output side of the power converter (power converter unit) 100 are connected in series, but the connection method is not limited to this.

[0274] For example, the AC voltage from the single-phase AC power supply 3101 may be input in parallel to the input sides of the three power converters (power converter units) 100 , and output in series to the output sides.

[0275] That is, there is also a method of connecting the input sides (power conversion parts) of the three power converters (power converter units) 100 in parallel and connecting the output sides (power conversion parts) in series. In this case, it is easy to obtain a higher voltage on the output side.

[0276] Furthermore, although the description has been given of a case where three power converters (power converter units) 100 are used, the configuration may be such that four or more power converters are used.

[0277] 《Number of Phases of Power Converters》

[0278] Fig.16 In the power converter 330 of the ninth embodiment shown, the case of three phases (u phase, v phase, w phase) is described, but it is not limited to three phases. For example, the power converter may be configured with four or more phases.

[0279] Description of Reference Numerals

[0280] 10, 20, 30, 40, 50, 50A, 50B transformers

[0281] 1u, 1v, 1w, 330 power converter

[0282] 100, 500 Power converter (power converter unit)

[0283] 101 Converter

[0284] 102, 502 DC-DC converter (resonant DC-DC converter)

[0285] 103 Inverter

[0286] 110 Primary side circuit (power conversion unit)

[0287] 120 Secondary side circuit (power conversion unit)

[0288] 2a, 24a, 25a1, 25a2 Primary side core

[0289] 2b, 24b, 25b1, 25b2 Secondary core

[0290] 2a1 Central magnetic core column (primary side core)

[0291] 2b1 Central magnetic core column (secondary core)

[0292] 2a2, 2a3 Side core column (primary core)

[0293] 2b2, 2b3 Side core column (secondary core)

[0294] 2a1s~2a3s、2b1s~2b3s Auxiliary core

[0295] 3a, 32a, 34a, 35a1, 35a2 Primary winding

[0296] 3b, 32b, 34b, 35b1, 35b2 Secondary winding

[0297] 32aN, 32bN Winding midpoint (midpoint)

[0298] 4a, 4b, 43a, 43b, 44a, 44b, 45a1, 45a2, 45b1, 45b2 winding frame

[0299] 4a1, 4a2, 4b1, 4b2, 43a1, 43a2, 43b1, 43b2, 46a1, 46a2, 46b1, 46b2, 47a1, 47a2, 47b1, 47b2 bobbin support portion

[0300] 41a, 41b Winding cover

[0301] 5.55 Insulation spacer

[0302] 52a, 53a, 54a Insulating spacer (first insulating layer)

[0303] 51-53, 52a1-52a3, 52b1-52b3 protrusions

[0304] 52b, 53b, 54b Insulating spacers (third insulating layer)

[0305] 6a2, 6a3, 6b2, 6b3, 62a2, 62a3, 62b2, 62b3, 65a1 to 65a4, 65b1 to 65b4 Core support portion

[0306] 64a1~64a3、64b1~64b3 Core fixing part

[0307] 7a, 7b, 73b, 75a, 75b Potential fixing portion

[0308] 71a, 71b Potential fixed wiring

[0309] 73c Fixed part

[0310] 8a, 8b Screw terminals

[0311] 81a to 81d, 84a to 84d, 85a to 85d Supporting parts

[0312] 9 Insulation board (second insulation layer)

[0313] 92a, 92b Resin molding material

[0314] 91 Resin Sheet

[0315] 94 Conductive sheet (conductive component)

[0316] N1, N2 reference potential.

Claims

1. A power converter unit, characterized in that: A power conversion unit including a transformer and a primary side circuit and a secondary side circuit sandwiching the transformer. The transformer comprises: A primary side core body having a primary winding installed therein; A secondary side core body having a secondary winding installed thereon; an insulating spacer disposed on opposing surfaces of the primary core and the secondary core; and The primary core and the secondary core are fixed to two potential fixing parts with different potentials. The potential fixing portion of the primary core is in surface contact with the primary core and connected to a reference potential of the primary circuit, and the potential fixing portion of the secondary core is in surface contact with the secondary core and connected to a reference potential of the secondary circuit.

2. The power converter unit according to claim 1, wherein: The insulating spacer includes a plurality of insulators made of different materials.

3. The power converter unit according to claim 1, wherein: The insulating spacer includes a first insulating layer including a resin material and a second insulating layer including an inorganic material.

4. The power converter unit according to claim 1, wherein: The insulating spacer is formed by sandwiching a second insulating layer containing an inorganic material between a first insulating layer containing a resin material and a third insulating layer containing a resin material.

5. The power converter unit according to claim 1, wherein: The insulating spacer has a plurality of protrusions.

6. The power converter unit according to claim 1, wherein: Gaps are provided between the opposing surfaces of the primary core and the secondary core and the insulating spacer, respectively. The gap is molded with a resin material.

7. The power converter unit according to claim 1, wherein: A mold layer made of a resin material is formed in a gap between the respective opposing surfaces of the primary core and the secondary core and the insulating spacer. An air gap is provided between the winding frames on which the primary winding and the secondary winding are respectively mounted and the mold layer.

8. The power converter unit according to claim 1, wherein: Conductive members are provided between the primary winding and the bobbin on which the primary winding is mounted, and between the secondary winding and the bobbin on which the secondary winding is mounted.

9. The power converter unit according to claim 1, wherein: an auxiliary core having a cross-sectional shape identical to the cross-sectional shape of the magnetic core columns of the primary core and the secondary core, The auxiliary core is arranged between the primary core and the insulating spacer, and a different auxiliary core is arranged between the secondary core and the insulating spacer.

10. The power converter unit according to claim 1, wherein: There are two or more sets of the primary side core body on which the primary winding is mounted and the secondary side core body on which the secondary winding is mounted, The two or more sets of the primary cores and the secondary cores share the insulating spacer.

11. The power converter unit according to claim 1, wherein: The potential fixing portion for fixing the potential of the primary core is connected to the midpoint of the primary winding, The potential fixing portion that fixes the potential of the secondary core is connected to the midpoint of the secondary winding.

12. The power converter unit according to claim 1, wherein: The reference potential of the primary side circuit is the potential of the midpoint of the DC terminal of the primary side circuit, and the reference potential of the secondary side circuit is the potential of the midpoint of the DC terminal of the secondary side circuit.

13. A power converter, characterized in that: A plurality of power converter units according to claim 1 are provided.

14. A power converter, characterized in that: A plurality of power converter units according to claim 1, The inputs of the plurality of power conversion parts of the plurality of power converter units are connected in multiple parallel connection, and the outputs of the plurality of power conversion parts of the plurality of power converter units are connected in multiple series connection.

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