Power Conversion Equipment

Abstract

To solve such a problem that noise is generated due to parasitic capacitance occurring between a power conversion circuit and a metal housing, in a power conversion device.SOLUTION: A power conversion device 10 includes: a metal housing 20 connect to the ground; a power conversion circuit 30 located inside the metal housing 20 and converting voltage; and a filter circuit 40 located between the power conversion circuit 30 and the metal housing 20. The power conversion circuit 30 has a plurality of output terminals and a switching element. The filter circuit 40 includes a first common mode choke coil 41 and a second common mode choke coil 46 connected in series between the plurality of output terminals and the metal housing 20. The first common mode choke coil 41 includes a first coil 42 that is connected to the ground through the metal housing 20, and a second coil 43 and a third coil 44 that are not connected to the ground. The second common mode choke coil 46 includes a fourth coil 47 and a fifth coil 48 that are not connected to the ground.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses a power conversion device. This power conversion device includes a DC power supply, a power conversion circuit, a common mode choke coil, two external terminals, and a ground terminal. The power conversion circuit includes a boost converter and an inverter. Power supplied from the DC power supply is input to the inverter via the boost converter. The inverter converts the input DC power into single-phase AC power and outputs it from the external terminal. The ground terminal is connected to the power conversion circuit. The common mode choke coil is composed of two inductors inserted between the power conversion circuit and the external terminal, and an inductor inserted between the power conversion circuit and the ground terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-188976 A Summary of the Invention [Problem to be solved by the invention]

[0004] In many cases, the power conversion circuit of the power conversion device described in Patent Document 1 is mounted inside a metal case. In this case, parasitic capacitance may occur between each element constituting the power conversion circuit and the metal case. When a current flows due to this parasitic capacitance, noise is generated. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention is a power conversion device comprising: a metal casing connected to ground; a power conversion circuit located inside the metal casing and converting a voltage; and a filter circuit located inside the metal casing and between the power conversion circuit and the metal casing, wherein the power conversion circuit has a plurality of output terminals and a switching element, and the filter circuit comprises a first common mode choke coil connected in series between the plurality of output terminals and the metal casing, and a second common mode choke coil connected in series to the first common mode choke coil and not connected to the ground, and the first common mode choke coil includes a first coil connected to the ground through the metal casing, and a second coil and a third coil not connected to the ground.

[0006] According to the above configuration, the power conversion circuit includes a first common mode choke coil including a coil connected to the ground terminal, and a second common mode choke coil not including the first common mode choke coil, thereby reducing noise caused by parasitic capacitance generated between each element constituting the power conversion circuit and the metal housing. Effect of the Invention

[0007] Noise caused by parasitic capacitance occurring between the power conversion circuit and the metal case can be reduced. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a circuit diagram of a power conversion device. [Diagram 2] FIG. 2 is a diagram of a first common mode choke coil. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <One embodiment of a power conversion device> Hereinafter, an embodiment of a power conversion device will be described with reference to the drawings. Note that the drawings may show components enlarged for ease of understanding. The dimensional ratios of the components may differ from those in the actual drawings or from those in other drawings.

[0010] (Configuration of power conversion device) First, the circuit configuration of the power conversion device 10 will be described. 1, the power conversion device 10 includes a metal housing 20. The power conversion device 10 includes a power conversion circuit 30, a filter circuit 40, and a control and drive circuit 50 inside the metal housing 20.

[0011] The metal housing 20 has a box shape with a space inside. The material of the metal housing 20 is a conductive metal. The metal housing 20 has a plurality of external connection terminals. The plurality of external connection terminals include a first high potential external input terminal 21A, a second high potential external input terminal 21B, a first external output terminal 23A, a second external output terminal 23B, and a ground terminal 24.

[0012] The first high potential external input terminal 21A is connected to a high potential terminal of the first DC power supply 80A. The first low potential external input terminal 22A is connected to a low potential terminal of the first DC power supply 80A. The first DC power supply 80A is installed outside the metal casing 20. The first DC power supply 80A is, for example, a solar power generation panel.

[0013] The second high potential external input terminal 21B is connected to a high potential terminal of the second DC power supply 80B. The second low potential external input terminal 22B is connected to a low potential terminal of the second DC power supply 80B. The second DC power supply 80B is installed outside the metal casing 20. The second DC power supply 80B is a solar power generation panel separate from the first DC power supply 80A.

[0014] The first external output terminal 23A and the second external output terminal 23B are connected to a power system 91 via power lines 90 extending from each external output terminal to the outside of the metal housing 20. The power lines 90 include electrical equipment (not shown) such as a distribution board, a watt-hour meter, and a socket (outlet). The power lines 90 are also connected to a load circuit 92. The load circuit 92 is an electrical device that operates using AC power from the power lines 90. The load circuit 92 is, for example, a lighting fixture, a television, a refrigerator, a washing machine, an air conditioner, a microwave oven, an air purifier, etc.

[0015] The ground terminal 24 is connected to the metal housing 20 inside the metal housing 20. The ground terminal 24 is also grounded outside the metal housing 20. The power conversion circuit 30 includes a DC / DC converter 60. The input terminals of the DC / DC converter 60 are connected to a first high potential external input terminal 21A, a first low potential external input terminal 22A, a second high potential external input terminal 21B, and a second low potential external input terminal 22B. The output terminals of the DC / DC converter 60 are connected to a first external output terminal 23A and a second external output terminal 23B. The DC / DC converter 60 transforms a DC voltage input via each input terminal of the metal casing 20 and outputs the transformed voltage.

[0016] The power conversion circuit 30 includes a first upper stage switching element 31A, a first lower stage switching element 32A, a second upper stage switching element 31B, and a second lower stage switching element 32B. Each switching element is an n-channel type MOSFET (metal oxide semiconductor field effect transistor). Therefore, a first terminal of each switching element is a drain terminal. A second terminal of each switching element is a source terminal. A third terminal of each switching element is a gate terminal.

[0017] A first terminal of the first upper stage switching element 31A is connected to the high potential side terminal of the DC / DC converter 60. A second terminal of the first upper stage switching element 31A is connected to the first external output terminal 23A.

[0018] A first terminal of the first lower stage switching element 32A is connected to a second terminal of the first upper stage switching element 31A and the first external output terminal 23A. A second terminal of the first lower stage switching element 32A is connected to a low potential side terminal of the DC / DC converter 60.

[0019] A first terminal of the second upper stage switching element 31B is connected to the high potential side terminal of the DC / DC converter 60. A second terminal of the second upper stage switching element 31B is connected to the second external output terminal 23B.

[0020] A first terminal of the second lower-stage switching element 32B is connected to a second terminal of the second upper-stage switching element 31B and the second external output terminal 23B. A second terminal of the second lower-stage switching element 32B is connected to a low potential side terminal of the DC / DC converter 60. That is, the power conversion circuit 30 includes a full bridge circuit.

[0021] The control and drive circuit 50 is connected to the third terminals of the switching elements. The control and drive circuit 50 outputs a first switching signal S1 to the third terminal of the first upper-stage switching element 31A. The first switching signal S1 is a PWM signal, and is a signal that periodically switches between high and low potentials. This causes the first upper-stage switching element 31A to switch between on and off. Similarly, the control and drive circuit 50 outputs a second switching signal S2 to the third terminal of the first lower-stage switching element 32A. The control and drive circuit 50 outputs a third switching signal S3 to the third terminal of the second upper-stage switching element 31B. The control and drive circuit 50 outputs a fourth switching signal S4 to the third terminal of the second lower-stage switching element 32B. The control and drive circuit 50 adjusts the pulse width of each switching signal, for example, by a PWM (pulse width modulation) method, so that the AC voltage output to the power line 90 approaches a sine wave. Therefore, the power conversion circuit 30 converts the DC voltage from the DC / DC converter 60 into an AC voltage by the on / off operation of each switching element. That is, the power conversion circuit 30 functions as an inverter.

[0022] The power conversion circuit 30 includes a first inductor 33A and a second inductor 33B. A first end of the first inductor 33A is connected to a second terminal of the first upper stage switching element 31A and a first terminal of the first lower stage switching element 32A. A second end of the first inductor 33A is connected to the first external output terminal 23A. That is, the first inductor 33A is located between the first upper stage switching element 31A and the first external output terminal 23A, and between the first lower stage switching element 32A and the first external output terminal 23A.

[0023] A first end of the second inductor 33B is connected to a second terminal of the second upper stage switching element 31B and a first terminal of the second lower stage switching element 32B. A second end of the second inductor 33B is connected to the second external output terminal 23B. That is, the second inductor 33B is located between the second upper stage switching element 31B and the second external output terminal 23B, and between the second lower stage switching element 32B and the second external output terminal 23B.

[0024] The power conversion circuit 30 includes an output capacitor 35. A first end of the output capacitor 35 is connected to a second end of the first inductor 33A. The first end of the output capacitor 35 is connected to the first external output terminal 23A. On the other hand, a second end of the output capacitor 35 is connected to a second end of the second inductor 33B. The second end of the output capacitor 35 is connected to the second external output terminal 23B.

[0025] The power conversion circuit 30 has a plurality of output terminals. Specifically, the power conversion circuit 30 has a first output terminal 36A and a second output terminal 36B. The first output terminal 36A of the power conversion circuit 30 is a first end of the output capacitor 35. The second output terminal 36B of the power conversion circuit 30 is a second end of the output capacitor 35.

[0026] The filter circuit 40 includes a first common mode choke coil 41 and a second common mode choke coil 46 . The first common mode choke coil 41 has a first coil 42, a second coil 43, a third coil 44, and a magnetic core 45 described later. The three coils share one magnetic core 45. That is, the three coils of the first common mode choke coil 41 are magnetically coupled.

[0027] A first end of a first coil 42 constituting the first common mode choke coil 41 is connected to the metal housing 20. A second end of the first coil 42 is connected to the ground terminal 24. That is, the first common mode choke coil 41 is connected to the ground through the metal housing 20.

[0028] A first end of the second coil 43 constituting the first common mode choke coil 41 is connected to the second output terminal 36B of the power conversion circuit 30 via the second common mode choke coil 46. A second end of the second coil 43 is connected to the second external output terminal 23B. In other words, the second coil 43 is not connected to ground.

[0029] A first end of the third coil 44 constituting the first common mode choke coil 41 is connected to the first output terminal 36A of the power conversion circuit 30 via the second common mode choke coil 46. A second end of the third coil 44 is connected to the first external output terminal 23A. In other words, the third coil 44 is not connected to ground.

[0030] In this manner, the first common mode choke coil 41 is located between the second terminals of the upper switching elements and the external output terminals, and between the first terminals of the lower switching elements and the external output terminals. That is, the first common mode choke coil 41 is connected in series between the output terminals and the metal housing 20.

[0031] The second common mode choke coil 46 has a fourth coil 47, a fifth coil 48, and one core. The two coils share the one core. That is, the two coils of the second common mode choke coil 46 are magnetically coupled.

[0032] A first end of a fourth coil 47 constituting the second common mode choke coil 46 is connected to the second output terminal 36B of the power conversion circuit 30. A second end of the fourth coil 47 is connected to the first external output terminal 23A via the first common mode choke coil 41. In other words, the fourth coil 47 is not connected to ground.

[0033] A first end of a fifth coil 48 constituting the second common mode choke coil 46 is connected to the first output terminal 36A of the power conversion circuit 30. A second end of the fifth coil 48 is connected to the second external output terminal 23B via the first common mode choke coil 41. That is, the fifth coil 48 is not connected to ground. Therefore, the second common mode choke coil 46 is connected in series with the first common mode choke coil 41. And the second common mode choke coil 46 is not connected to ground.

[0034] As described above, the filter circuit 40 is located between the power conversion circuit 30 and the metal housing 20. In addition, the first common mode choke coil 41 is located between the second common mode choke coil 46 and the metal housing 20. In addition, the second common mode choke coil 46 is located between each output terminal of the power conversion circuit 30 and the first common mode choke coil 41.

[0035] The inductance of the second coil 43 is smaller than the inductance of the fourth coil 47. The inductance of the third coil 44 is smaller than the inductance of the fifth coil .

[0036] The power conversion device 10 includes a first capacitor 34A and a second capacitor 34B. A first end of the first capacitor 34A is connected to the first output terminal 36A. Meanwhile, a second end of the first capacitor 34A is connected to the ground terminal 24 via the first coil 42 of the first common mode choke coil 41. That is, the first capacitor 34A functions as a Y capacitor.

[0037] A first end of the second capacitor 34B is connected to the second output terminal 36B. On the other hand, a second end of the second capacitor 34B is connected to the ground terminal 24 via the first coil 42 of the first common mode choke coil 41. That is, the second capacitor 34B functions as a Y capacitor.

[0038] (Regarding the first common mode choke coil) Of the power conversion circuit 30 configured as described above, the portions other than the first common mode choke coil 41 are mounted on a substrate 70. Note that in Fig. 2, illustration of each element mounted on the substrate 70 is omitted.

[0039] As shown in FIG. 2, the first common mode choke coil 41 includes a first wiring 42W, a second wiring 43W, a third wiring 44W, and a magnetic core 45. A first end of the first wiring 42W is connected to the metal housing 20 via a connection terminal 71. A second end of the first wiring 42W is connected to the ground terminal 24. This first wiring 42W constitutes the first coil 42 of the first common mode choke coil 41.

[0040] A first end of the second wiring 43W is connected to a second end of the fourth coil 47 of the second common mode choke coil 46 via a connection terminal 71. A second end of the second wiring 43W is connected to the second external output terminal 23B. This second wiring 43W constitutes the second coil 43 of the first common mode choke coil 41.

[0041] A first end of the third wiring 44W is connected to a second end of the fifth coil 48 of the second common mode choke coil 46 via a connection terminal 71. A second end of the third wiring 44W is connected to the first external output terminal 23A. This third wiring 44W constitutes the third coil 44 of the first common mode choke coil 41.

[0042] Although not shown, the first wiring 42W, the second wiring 43W, and the third wiring 44W each have a conductor wiring and an insulating film that covers the conductor wiring. The magnetic core 45 is substantially cylindrical. The material of the magnetic core 45 includes a magnetic material such as ferrite. The magnetic core 45 surrounds the first wiring 42W, the second wiring 43W, and the third wiring 44W. In other words, the first wiring 42W, the second wiring 43W, and the third wiring 44W pass through a central hole of the magnetic core 45.

[0043] Here, the length of the magnetic core 45 of the first common mode choke coil 41 in the direction along the central axis of the magnetic core 45 is defined as the length dimension L1 of the magnetic core 45. In this case, the length dimension L1 of the magnetic core 45 is 1 / 10 or more of the wiring length L2 of one wiring selected from the first wiring 42W, the second wiring 43W, and the third wiring 44W. The central axis of the magnetic core 45 is defined as follows. That is, the central axis is a straight line connecting the geometric center of a planar figure formed by the opening edge of each external output terminal side of the metal housing 20 and the geometric center of a planar figure formed by the opening edge of each output terminal side of the power conversion circuit 30 in the through hole of the cylindrical magnetic core 45. The wiring length L2 of the first wiring 42W is the length of the wiring from the ground terminal 24 to the connection terminal 71. The wiring length L2 of the second wiring 43W is the length of the wiring from the second external output terminal 23B to the connection terminal 71. The wiring length L2 of the third wiring 44W is the length of the wiring from the first external output terminal 23A to the connection terminal 71. Note that in Fig. 2, the wiring length L2 of the first wiring 42W is shown.

[0044] (Effects of this embodiment) (1) In the above embodiment, the power conversion circuit 30 includes a second common mode choke coil 46 that is not connected to ground, in addition to the first common mode choke coil 41 including the first coil 42 connected to the ground terminal 24. This makes it possible to reduce noise caused by parasitic capacitance formed between each element constituting the power conversion circuit 30 and the metal housing 20.

[0045] (2) According to the above embodiment, the power conversion circuit 30 includes a half-bridge circuit or a full-bridge circuit, which can improve the power conversion efficiency of the power conversion circuit 30.

[0046] (3) According to the above embodiment, the first common mode choke coil 41 is disposed between the second common mode choke coil 46 and the metal housing 20. Since the first common mode choke coil 41 including the first coil 42 connected to the ground terminal 24 is disposed on the metal housing 20 side, it is easy to reduce noise generated near the contact points between the metal housing 20 and each wiring.

[0047] (4) According to the above embodiment, the first common mode choke coil 41 of the power conversion circuit 30 has a substantially cylindrical magnetic core 45. The first wiring 42W, the second wiring 43W, and the third wiring 44W of the first common mode choke coil 41 are bundled by this magnetic core 45. This physically separates the metal housing 20 from the above wirings compared to when the first common mode choke coil 41 is directly mounted on the substrate 70. This reduces the parasitic capacitance formed between the wirings of the first common mode choke coil 41 and the metal housing 20. This reduces the noise caused by the parasitic capacitance.

[0048] (5) According to the above embodiment, the length dimension L1 of the magnetic core 45 is 1 / 10 or more of the wiring length L2 from the metal housing 20 to the substrate 70. This allows a physical distance to be maintained between the metal housing 20 and the substrate 70. Since parasitic capacitance is likely to occur in the wiring near the contact point with the metal housing 20, noise caused by this parasitic capacitance can be efficiently reduced.

[0049] (6) According to the above embodiment, the inductance of the first common mode choke coil 41 is smaller than the inductance of the second common mode choke coil 46. With these configurations, it is possible to reduce noise in a wide frequency band that is difficult to reduce using only either the first common mode choke coil 41 or the second common mode choke coil 46.

[0050] (7) According to the above embodiment, the power conversion circuit 30 includes the first capacitor 34A and the second capacitor 34B that function as a Y capacitor, which can further reduce noise such as common mode noise.

[0051] (8) According to the above embodiment, the first wiring 42W, the second wiring 43W, and the third wiring 44W are cables in which the outer surfaces of the conductor wiring are covered with an insulator. This reduces the magnitude of the parasitic capacitance formed between the wirings of the first common mode choke coil 41 and between the wirings and the metal housing 20. This reduces noise such as common mode noise.

[0052] <Example of change> The above embodiment and the following modified examples can be implemented in combination with each other to the extent that no technical contradiction occurs.

[0053] The number of high potential external input terminals and low potential external input terminals provided on the metal housing 20 is not limited to two pairs. There may be one pair, or three or more pairs. The metal housing 20 may not have some or all of the external connection terminals. For example, the metal housing 20 may have holes that communicate the inside and outside of the metal housing 20, instead of the first external output terminal 23A, the second external output terminal 23B, and the ground terminal 24. In that case, the first wiring 42W, the second wiring 43W, and the third wiring 44W may extend to the outside of the metal housing 20 through the holes. However, in such a case, parasitic capacitance may occur between each wiring and the metal housing 20 near the boundary between the inside and the outside of the metal housing 20 at the holes. Therefore, for example, when calculating the wiring length L2, the boundary is regarded as an external connection terminal and the wiring length L2 is calculated.

[0054] The power conversion circuit 30 does not have to include the DC / DC converter 60, or the power conversion circuit 30 may include only the DC / DC converter 60. The power conversion circuit 30 does not have to include a half-bridge circuit or a full-bridge circuit. Even in this case, the effect described in (1) can be obtained.

[0055] The power conversion circuit 30 is not limited to the so-called single-phase two-wire type as in the present embodiment. For example, it may be a single-phase three-wire type. In this example, the metal housing 20 only needs to have a third external output terminal. The power conversion circuit 30 only needs to have a third upper-stage switching element, a third lower-stage switching element, and a third inductor. In this example, the connection relationship of each element is the same as that of the first upper-stage switching element 31A, the first lower-stage switching element 32A, and the first inductor 33A. In this case, it is preferable that the first common mode choke coil 41 has a fourth coil connected to the third output terminal, and the second common mode choke coil 46 has a third coil connected to the third output terminal. In addition to this example, the power conversion device 10 may be a three-phase four-wire type, etc.

[0056] The switching elements are not limited to the examples in this embodiment. As long as the control and drive circuit 50 can operate the switching elements, elements other than MOSFETs may be used. The power conversion circuit 30 does not necessarily have to include the first inductor 33A, the second inductor 33B, and the output capacitor 35.

[0057] The power conversion circuit 30 does not have to include the first capacitor 34A and the second capacitor 34B. Even if these are not included, the effect described in (1) can be obtained. The inductance of the second coil 43 of the first common mode choke coil 41 may be equal to or greater than the inductance of the fourth coil 47 of the second common mode choke coil 46. Similarly, the inductance of the third coil 44 of the first common mode choke coil 41 may be equal to or greater than the inductance of the fifth coil 48 of the second common mode choke coil 46. As long as the second common mode choke coil 46 is provided in addition to the first common mode choke coil 41, common mode noise can be reduced compared to a case in which the second common mode choke coil 46 is not provided.

[0058] The first common mode choke coil 41 does not have to be located between the second common mode choke coil 46 and the metal housing 20. For example, the first common mode choke coil 41 may be located between the output capacitor 35 and the second common mode choke coil 46. Even if the positional relationship between the first common mode choke coil 41 and the second common mode choke coil 46 is different, it is possible to reduce both the noise caused by the parasitic capacitance generated between the power conversion circuit 30 and the metal housing 20 and the noise caused by the parasitic capacitance generated between the power conversion circuit 30 and the ground.

[0059] Among the components of the power conversion circuit 30, which elements and wiring are mounted on the substrate 70 is arbitrary. For example, if the first common mode choke coil 41 is configured as an element that can be mounted on the substrate 70, the first common mode choke coil 41 may be mounted on the substrate 70. Even if the first common mode choke coil 41 is mounted on the substrate 70, the effect of reducing noise can be obtained. Also, the second common mode choke coil 46 does not have to be mounted on the substrate 70, and in that case, the second common mode choke coil 46 may have a cylindrical core surrounding a plurality of wirings, similar to the first common mode choke coil 41.

[0060] The third wiring 44W, the second wiring 43W, and the first wiring 42W do not have to have an insulating film covering the conductor wiring. In that case, it is preferable that each conductor wiring is insulated by a method other than covering.

[0061] The power conversion circuit 30 does not have to have one magnetic core 45. For example, two magnetic cores 45 may surround the third wiring 44W, the second wiring 43W, and the first wiring 42W.

[0062] The shape of the magnetic core 45 is not limited to the example of this embodiment. For example, the third wiring 44W, the second wiring 43W, and the first wiring 42W may be wound around a columnar magnetic core 45. Also, for example, the third wiring 44W, the second wiring 43W, and the first wiring 42W may be surrounded by a plurality of annular magnetic cores 45.

[0063] In the direction along the central axis of the magnetic core 45, the length dimension L1 of the magnetic core 45 may be less than 1 / 10 of the wiring length L2 from each external output terminal to the substrate 70. As long as the first common mode choke coil 41 shares the magnetic core 45, common mode noise can be suppressed.

[0064] The magnetic core 45 only needs to surround at least one of the multiple wirings connected to each external output terminal, in addition to the first wiring 42W. For example, the magnetic core 45 may surround only the third wiring 44W and the first wiring 42W. If there is the first common mode choke coil 41 including a coil connected to the ground terminal 24, and the second common mode choke coil 46 not including this coil, the common mode noise can be reduced compared to the case where the second common mode choke coil 46 is not included.

[0065] The material of the magnetic core 45 is not limited to ferrite. For example, permalloy may be used. <Additional Notes> The technical ideas that can be derived from the above-described embodiments and modifications will be described below.

[0066] [1] A metal housing connected to ground; a power conversion circuit located inside the metal housing and configured to convert a voltage; a filter circuit located inside the metal housing and between the power conversion circuit and the metal housing; Equipped with The power conversion circuit has a plurality of output terminals and a switching element, The filter circuit includes: a first common mode choke coil connected in series between the output terminals and the metal housing; a second common mode choke coil connected in series to the first common mode choke coil and not connected to the ground; Equipped with The power conversion device, wherein the first common mode choke coil includes a first coil connected to the ground through the metal casing, and a second coil and a third coil that are not connected to the ground.

[0067] [2] The power conversion device according to [1], wherein the power conversion circuit includes a half-bridge circuit or a full-bridge circuit.

[0068] [3] the second common mode choke coil is connected to the output terminal; The power conversion device according to [1] or [2], wherein the first common mode choke coil is disposed between the second common mode choke coil and the metal housing.

[0069] [4] The first coil, the second coil, and the third coil each include a wiring connected to the output terminal and a cylindrical magnetic core, The power conversion device according to any one of [1] to [3], wherein the magnetic core is disposed so as to surround the wiring that constitutes the first coil, the second coil, and the third coil.

[0070] [5] Further comprising a substrate; the second common mode choke coil is mounted on the substrate; The power conversion device according to [4], wherein the dimension along the central axis of the magnetic core is 1 / 10 or more of the wiring length from the metal casing to the substrate.

[0071] [6] the second common mode choke coil includes a fourth coil, The power conversion device according to any one of [1] to [5], wherein an inductance of the second coil is smaller than an inductance of the fourth coil.

[0072] [7] The power conversion device according to any one of [1] to [6], further comprising a capacitor connected between the output terminal of the power conversion circuit and the ground. [Explanation of symbols]

[0073] 10...Power conversion device 20…Metal case 21...External connection terminal 30...Power conversion circuit 40...Filter circuit 41…First common mode choke coil 46…Second common mode choke coil

Claims

1. A metal housing connected to ground; a power conversion circuit located inside the metal housing and configured to convert a voltage; a filter circuit located inside the metal housing and between the power conversion circuit and the metal housing; Equipped with The power conversion circuit has a plurality of output terminals and a switching element, The filter circuit includes: a first common mode choke coil connected in series between the output terminals and the metal housing; a second common mode choke coil connected in series to the first common mode choke coil and not connected to the ground; Equipped with The first common mode choke coil includes a first coil connected to the ground through the metal case, and a second coil and a third coil that are not connected to the ground. Power conversion equipment.

2. The power conversion circuit includes a half-bridge circuit or a full-bridge circuit. The power conversion device according to claim 1 .

3. the second common mode choke coil is connected to the output terminal; The first common mode choke coil is disposed between the second common mode choke coil and the metal housing. The power conversion device according to claim 1 .

4. The first coil, the second coil, and the third coil each include a wiring connected to the output terminal and a cylindrical magnetic core, The magnetic core is disposed so as to surround the wiring that constitutes the first coil, the second coil, and the third coil. The power conversion device according to any one of claims 1 to 3.

5. Further comprising a substrate; the second common mode choke coil is mounted on the substrate; The dimension of the magnetic core along the central axis is 1 / 10 or more of the wiring length from the metal case to the substrate. The power conversion device according to claim 4.

6. the second common mode choke coil includes a fourth coil, The inductance of the second coil is smaller than the inductance of the fourth coil. The power conversion device according to claim 1 .

7. A capacitor is connected between the output terminal of the power conversion circuit and the ground. The power conversion device according to claim 1 .

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