JP2013219919A - Noise reduction filter and electric power conversion device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce radiation noise generated near a noise source.SOLUTION: A noise reduction filter includes: a Y capacitor 28a formed by sandwiching an insulator 26a between a P conductor 23 and an extension portion of a ground conductor 25 mounting a module 21 thereon; and a Y capacitor 28b arranged on a side opposite to the P conductor 23 using the extension portion of the ground conductor 25 as a reference, and formed by sandwiching an insulator 26b between an N conductor 24 and the extension portion of the ground conductor 25.

Description

  The present invention relates to a noise reduction filter and a power conversion device using the same.

  Conventionally, as a document disclosing a technique for reducing noise generated from power conversion means, for example, there is Patent Document 1 below. In this Patent Document 1, as power wiring for supplying DC power from a battery to a power conversion means, a plurality of conductors having a wide shape and facing each other at a predetermined interval in the thickness direction, and at least so as to generate capacitance between the conductors. A power wiring structure having a dielectric interposed between conductors is disclosed.

JP 05-236611 A

  However, the power wiring assumed in the conventional literature is a power cable. In the case of the power converter, the power cable is a cable connected to an AC / DC converter circuit (hereinafter referred to as “converter circuit”) such as a rectifier circuit. In the power converter, a converter circuit, a smoothing circuit for storing DC power, a converter is provided between a DC / AC converter circuit (hereinafter referred to as “inverter circuit”) on which a switching element as a noise source is mounted and a power cable. A DC bus for electrically connecting the circuit and the smoothing circuit is interposed. For this reason, the conventional technique has a problem that radiation noise generated in the vicinity of the noise source cannot be effectively suppressed.

  The prior art is a technique that utilizes the characteristics of capacitance (so-called “X capacitor”) generated between one and the other of the power cable. The X capacitor is effective for normal mode noise, but is not effective for the common mode dominant as radiation noise. That is, the conventional technique has a problem that the common mode noise cannot be effectively suppressed.

  The present invention has been made in view of the above, and can effectively suppress radiated noise generated in the vicinity of a noise source and effectively suppress common mode noise dominant as radiated noise. An object of the present invention is to obtain a noise reduction filter and a power conversion device using the same.

  In order to solve the above-described problems and achieve the object, a noise reduction filter according to the present invention is a noise reduction filter configured to be able to reduce a noise current generated by a power conversion unit, and the power conversion unit includes A first insulator is sandwiched between a positive electrode conductor forming a DC bus on the positive electrode side to be connected and a first conductor portion extending from a ground conductor for mounting a switching element module provided in the power conversion portion. A first Y capacitor formed by: a negative electrode conductor that forms a DC bus on the negative electrode side that is disposed on the opposite side of the positive electrode conductor with respect to the first conductor portion and is connected to the power conversion unit; A second Y capacitor formed by sandwiching a second insulator between the first conductor portion and the first conductor portion is configured as a filter circuit element.

  According to the present invention, it is possible to effectively suppress radiation noise generated in the vicinity of a noise source. In addition, according to the present invention, there is an effect that common mode noise dominant as radiation noise can be effectively suppressed.

FIG. 1 is a diagram illustrating a configuration example of a power conversion device according to the first embodiment. FIG. 2 is a diagram schematically showing a wiring structure according to the first embodiment. FIG. 3 is a diagram schematically showing an equivalent circuit when the wiring structure shown in FIG. 2 is used. FIG. 4 is a diagram schematically showing a wiring structure according to the second embodiment. FIG. 5 is a diagram schematically showing an equivalent circuit when the wiring structure shown in FIG. 4 is used. FIG. 6 is a diagram schematically showing a wiring structure according to the third embodiment. FIG. 7 is a diagram schematically showing an equivalent circuit when the wiring structure shown in FIG. 6 is used. FIG. 8 is a diagram schematically showing an equivalent circuit when the wiring structure according to the fourth embodiment is used. FIG. 9 is a diagram schematically showing a wiring structure according to the fifth embodiment. FIG. 10 is a diagram schematically showing an equivalent circuit when the wiring structure according to the sixth embodiment is used. FIG. 11 is a diagram schematically showing a wiring structure according to the seventh embodiment. FIG. 12 is a diagram schematically showing another wiring structure according to the seventh embodiment. FIG. 13 is a diagram schematically showing a wiring structure according to the eighth embodiment. FIG. 14 is a diagram schematically illustrating another wiring structure according to the eighth embodiment. FIG. 15 is a diagram schematically showing still another wiring structure according to the eighth embodiment.

  A noise reduction filter and a power conversion device including the noise reduction filter according to embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of a power conversion apparatus according to Embodiment 1 of the present invention. The power conversion device 11 according to Embodiment 1 includes a converter circuit 12 as a first power conversion unit that converts an AC voltage supplied from an AC power supply 2 into a desired DC voltage, and a DC that is converted by the converter circuit 12. A smoothing circuit 13 having a capacitor (smoothing capacitor) 13a for smoothing the voltage, and an inverter circuit 14 as a second power conversion unit for converting the smoothed DC voltage into a desired AC voltage by switching control and supplying it to the load 3 And comprising. As the converter circuit 12, a rectifier circuit, a regenerative converter circuit, a PWM converter circuit, or the like is used.

  The AC power supply 2 and the converter circuit 12 are connected by an input wiring 16, and the inverter circuit 14 and the load 3 are connected by an output wiring 18. Note that the input wiring 16 and the output wiring 18 may be configured and connected separately inside and outside the power converter. The converter circuit 12 and the inverter circuit 14 are connected by a positive electrode wiring (hereinafter abbreviated as “P wiring”) 17 a forming a positive DC bus and a negative wiring (hereinafter abbreviated as “N wiring”) 17 b forming a negative DC bus. Connected. Smoothing capacitor 13a is connected between P wiring 17a and N wiring 17b so as to have a parallel relationship with converter circuit 12 and inverter circuit 14.

  The inverter circuit 14 includes a positive arm composed of switching elements UPI, VPI, WPI (for example, UPI in U phase) and a negative arm composed of switching elements UNI, VNI, WNI (for example, UNI in U phase). Each have a series circuit (leg) connected in series. That is, the inverter circuit 14 is configured with a three-phase bridge circuit having three sets of legs (for U phase, V phase, and W phase).

  The inverter circuit 14 converts the input DC voltage into a desired AC voltage by applying PWM control to the switching elements UPI, VPI, WPI, UNI, VNI, and WNI, and applies it to the load 3.

  The switching elements UPI, VPI, WPI, UNI, VNI, WNI are modularized and mounted on a conductor substrate. There are various units to be modularized, which may be all switching elements, or may be modularized in units of legs. When modularized in units of legs, from the modularized switching element module (hereinafter simply referred to as “module”), a terminal for obtaining an electrical connection with the P wiring 17a and the N wiring 17b A terminal for obtaining an electrical connection and a terminal for obtaining an electrical connection with the output wiring 18 are provided.

  FIG. 2 is a diagram schematically showing a wiring structure according to the first preferred embodiment used for the power conversion device 11 shown in FIG. 1, for example. In FIG. 2, the module 21 is assumed to be a module constituting the inverter circuit 14. In this module 21, an output conductor 22, a P conductor 23, and an N conductor 24 are connected to each predetermined terminal. The output conductor 22 is, for example, a flat conductor that forms the output wiring 18 in the circuit configuration of FIG. Similarly, the P conductor 23 is a flat conductor that forms the P wiring 17a, and the N conductor 24 is a flat conductor that forms the N wiring 17b.

  Of these output conductors 22, P conductors 23, and N conductors 24, in the wiring structure according to the first embodiment, first, the ground conductor 25 arranged on the module mounting surface side is extended, and the property as a dielectric is also provided. A P conductor 23 is formed in the vicinity of the module 21 with an insulator 26a sandwiched therebetween, and an N conductor 24 is formed in the vicinity of the module 21 with a similar insulator 26b sandwiched on the opposite side of the ground conductor 25. . An equivalent circuit with this configuration is represented as shown on the right side of FIG.

  As shown in the equivalent circuit of FIG. 2, one Y capacitor (P conductor Y capacitor) 28 a is formed between the P conductor 23 and the extended portion (first conductor portion) of the ground conductor 25, and the N conductor 24 and the extending portion of the ground conductor 25 form another Y capacitor (N conductor Y capacitor) 28b. Since these Y capacitors 28a and 28b sandwich the insulators 26a and 26b, the capacitance values increase as the relative dielectric constant of the insulators 26a and 26b increases. Further, these Y capacitors 28a and 28b have larger capacitance values as the insulators 26a and 26b are thinner. Furthermore, the capacitance values of these Y capacitors 28a and 28b increase as the opposing area between the conductors increases. Therefore, a desired capacitance value can be obtained by adjusting at least one of the values of the relative permittivity, the thickness of the insulator, and the facing area between the conductors.

  FIG. 3 is a diagram schematically showing an equivalent circuit when the wiring structure shown in FIG. 2 is used as the power conversion device. When the wiring structure shown in FIG. 2 is not employed, only the stray capacitance 32 exists equivalently between the inverter circuit 14 and the ground potential. On the other hand, when the wiring structure as shown in FIG. 2 is adopted, a large number of P conductor Y capacitors 28a are formed between the P wiring 17a and the ground potential, and a large number between the N wiring 17b and the ground potential. N conductor Y capacitor 28 b is formed, and these Y capacitors 28 a and 28 b are added to the stray capacitance 32. As a result, the capacitance value formed with the ground potential increases, and the noise current generated in the switching element flows out to the ground potential side in the vicinity of the switching element that is the noise source, and the noise current is a very short distance. Therefore, the noise is prevented from flowing out to the outside.

  As described above, in the first embodiment, the Y capacitor 28a formed by sandwiching the insulator 26a between the P conductor 23 and the extended portion of the ground conductor 25 on which the module 21 is mounted, and the ground conductor 25. A filter circuit element including a Y capacitor 26b disposed on the opposite side of the P conductor 23 with respect to the extending portion of the N conductor 24 and formed by sandwiching an insulator 28b between the extending portion of the N conductor 24 and the ground conductor 25. Therefore, radiation noise generated near the noise source can be effectively suppressed, and common mode noise dominant as radiation noise can be effectively suppressed.

Embodiment 2. FIG.
FIG. 4 is a diagram schematically showing a wiring structure according to the second embodiment. In the wiring structure of the first embodiment shown in FIG. 2, the structure sandwiching the insulators 26a and 26b is adopted for the P conductor 23 and the N conductor 24. However, in the wiring structure of the second embodiment, as shown in FIG. In addition, the insulator 26 c is sandwiched between the output conductor 22 and the ground conductor 25.

  FIG. 5 is a diagram schematically showing an equivalent circuit when the wiring structure shown in FIG. 4 is used as the power conversion device. When the wiring structure as shown in FIG. 4 is employed, a large number of output conductor Y capacitors 28c are formed between the output wiring 18 and the ground potential. Of the noise generated in the switching element, the noise current that tends to flow out to the output wiring side flows out to the ground potential side in the vicinity of the switching element that is the noise source, so that outflow to the outside is suppressed. In particular, the output wiring 18 is a power wiring for obtaining an electrical connection with the load 3 and is exposed to the outside outside the power converter, so that the reduction of noise current to the output wiring 18 side suppresses radiation noise. It is effective.

  As described above, in the second embodiment, the Y capacitor 28c formed by sandwiching the insulator 26c between the output conductor 22 and the extended portion of the ground conductor 25 on which the module 21 is mounted is configured as a filter circuit element. Therefore, radiation noise generated near the noise source can be effectively suppressed, and common mode noise dominant as radiation noise can be effectively suppressed.

Embodiment 3 FIG.
6 is a diagram schematically showing a wiring structure according to the third embodiment, and FIG. 7 is a diagram schematically showing an equivalent circuit when the wiring structure shown in FIG. 6 is used as a power conversion device. . The wiring structure according to this embodiment is a wiring structure that employs both the wiring structure according to the first embodiment as shown in FIG. 2 and the wiring structure according to the second embodiment as shown in FIG. Specifically, as shown in FIG. 6, the P conductor 23 and the N conductor 24 face the extended portion (first conductor portion) of the ground conductor 25 with the insulator 26a and the insulator 26b interposed therebetween, respectively. The output conductor 22 is configured to face the extended portion (second conductor portion) of the ground conductor 25 different from the first conductor portion with the insulator 26c interposed therebetween.

  Further, in FIG. 6, among noises generated in the switching element, a noise current that tends to travel toward the converter circuit 12 inside the power conversion device can be suppressed by the action of the Y capacitors 28 a and 28 b. In addition, among the noise generated in the switching element, the noise current going to the outside of the power converter can be suppressed by the action of the Y capacitor 28c. For this reason, when the wiring structure according to the third embodiment is employed, the noise current can be effectively directed to the ground potential side.

Embodiment 4 FIG.
FIG. 8 is a diagram schematically showing an equivalent circuit when the wiring structure according to the fourth embodiment is used. In the fourth embodiment, in the wiring structure according to the third embodiment shown in FIG. 6, the conductor surfaces of the P wiring 17a, the N wiring 17b, and the output wiring 18 are covered with a material having a higher resistivity than the material forming each wiring. Like to do. The equivalent circuit at this time has a large number of high resistance components 36 or 37 connected in series as shown in FIG. 8, and these high resistance components 36 or 37 are connected to a P conductor Y capacitor 28a, an N conductor Y capacitor 28b, and an output. A distributed constant RC filter circuit in which any one of the capacitive components of the conductor Y capacitor 28c is added in parallel is configured.

  The power conversion device according to the present invention is intended to reduce radiation noise in a frequency band of 30 MHz or higher, for example, and current in such a frequency band has a property of flowing on the surface of the conductor (skin effect). Therefore, if the surface of a conductor through which high-frequency noise current flows is covered with a material having a higher resistance than that of the conductor, it will not affect the low-frequency current that transmits power, and will attempt to flow through the conductor surface due to the skin effect It becomes possible to reduce the noise current in the high frequency band by covering with a high resistance material. Furthermore, since the RC filter can be configured in the vicinity of the module together with the capacitor between the conductors described above, the radiation noise suppression effect can be further enhanced as compared with the power converters of the first to third embodiments. It becomes possible.

  In FIG. 8, the P wiring 17a, the N wiring 17b, and the output wiring 18 have been described as being covered with a material with high and low efficiency. However, either of them may be covered to suppress radiation noise. The effect is increased.

Embodiment 5 FIG.
FIG. 9 is a diagram schematically showing a wiring structure according to the fifth embodiment. In the wiring structure of the third embodiment shown in FIG. 6, the P conductor 23 and the N conductor 24 are provided on both sides (upper side and lower side) of the ground conductor 25 with insulators 26a and 26b interposed therebetween. However, in the wiring structure of the fifth embodiment, as shown in FIG. 9, the P-conductor 23 and the N-conductor 24 are provided on both sides with the insulator 26d at the center, and each outside (upper side and lower side) is provided. In the structure, the extending portion of the ground conductor 25 is provided on the side) with the insulators 26a and 26b interposed therebetween. In the structure of the fifth embodiment, since the extended portion of the ground conductor 25 is also provided on the upper side of the P conductor 23, the output conductor 22 is sandwiched between the insulator 26c and the ground conductor using this structure. It is made to oppose 25 extended parts.

  In the case of the wiring structure of FIG. 9, an X capacitor 29 is configured in addition to the Y capacitors 28a and 28b as in the equivalent circuit shown on the right side. 6, the series connection circuit of the Y capacitors 28a and 28b can be regarded as an X capacitor arranged between the P conductor 23 and the N conductor 24, but the capacitance value is Y because of the series connection. It becomes 1/2 of the capacitance value of the capacitor. On the other hand, in the case of FIG. 9, only the X capacitor 29 is disposed between the P conductor 23 and the N conductor 24. Therefore, if the conditions are the same, the capacitance value of the X capacitor 29 is Y capacitor 28a (28b). And the same value as that in FIG.

  The X capacitor 29 provides a path closest to the module 21 with respect to a noise current traveling between the P conductor 23 and the N conductor 24. Therefore, the wiring structure of the fifth embodiment that can form the X capacitor 29 having the same capacity as that of the Y capacitor 28a (28b) is less in the radiation noise than the wiring structure according to the third embodiment shown in FIG. The suppression effect can be further enhanced.

  In FIG. 9, the extended portion of the ground conductor 25 provided on the upper side of the P conductor 23 is used, and the output conductor 22 is opposed to the extended portion of the ground conductor 25 with the insulator 26c interposed therebetween. However, the output conductor 22 may be provided on the lower side of the ground conductor 25 with an insulator interposed therebetween, and the same effect as that shown in FIG. 9 can be obtained.

Embodiment 6 FIG.
FIG. 10 is a diagram schematically showing an equivalent circuit when the wiring structure according to the sixth embodiment is used. In the fourth embodiment, as shown in FIG. 8, the surfaces of the conductors in the P wiring 17a, the N wiring 17b, and the output wiring 18 are covered with a conductor having a high resistivity. The conductor surface of the input wiring 16 and the portion of the P wiring 17a and the N wiring 17b between the converter circuit 12 and the smoothing circuit (smoothing capacitor 13a) are covered with a conductor having a high resistivity.

  When the conductor surface of the input wiring 16 and the portion between the converter circuit 12 and the smoothing circuit in the P wiring 17a and the N wiring 17b are covered with a conductor having high resistivity, the input wiring 16 side is viewed from the inverter circuit 14 which is a noise source. The impedance is larger than that in the case of the fourth embodiment. For this reason, it is possible to pull back the noise current that tends to flow out to the input wiring 16 side to the module side in the vicinity of the module like the noise current K1 that passes through the stray capacitance 32 having a lower impedance. Thereby, radiation noise from the input wiring 16 can be suppressed.

  Since the impedance on the input wiring 16 side increases, noise current tends to flow to the output wiring 18 side near the module rather than the input wiring 16, but the conductor surface of the output wiring 18 is also a conductor with high resistivity. Since it is covered, it can be pulled back to the module side as indicated by the noise current K2, and it becomes possible to confine the noise current causing the generation of radiation noise in the power converter.

Embodiment 7 FIG.
FIG. 11 is a diagram schematically showing a wiring structure according to the seventh embodiment. In the first to sixth embodiments, the module provided in the inverter circuit 14 is assumed. However, in the seventh embodiment, the converter circuit 12 is assumed to be a PWM converter circuit, for example. That is, the module 41 shown in FIG. 11 is a module of the converter circuit 12 on which a switching element is mounted. In this module 41, an input conductor 42, a P conductor 43, and an N conductor 44 are connected to each predetermined terminal. The input conductor 42 is, for example, a flat conductor forming the input wiring 16 in the circuit configuration of FIG. Similarly, the P conductor 43 is, for example, a flat conductor that forms the P wiring 17a on the converter circuit 12, and the N conductor 44 is, for example, a flat conductor that forms the N wiring 17b on the converter circuit 12 side. is there.

  The wiring structure is the same as the wiring structure shown in FIG. 6 except that the output conductor 22 replaces the input conductor 42. Specifically, in the wiring structure according to the seventh embodiment, the ground conductor 45 disposed on the module mounting surface side is extended, the P conductor 43 is configured with the insulator 46a interposed therebetween, and the ground conductor An N conductor 44 is formed on the opposite side of 45 by sandwiching a similar insulator 46b, and further, an earth conductor 45 is extended to the input conductor side, and an insulator is provided between the extended portion of the earth conductor 45 and the input conductor 42. 46c is sandwiched. An equivalent circuit with this configuration is represented as shown on the right side of FIG.

  In FIG. 11, similarly to the equivalent circuit shown in FIG. 6, a P conductor Y capacitor 48 a is formed between the P conductor 43 and the ground conductor 45, and between the N conductor 44 and the extended portion of the ground conductor 45. An N conductor Y capacitor 48 b is formed, and an input conductor Y capacitor 48 c is formed between the input conductor 42 and the extended portion of the ground conductor 45.

  When the wiring structure as shown in FIG. 11 is adopted as the power conversion device, a large number of input conductor Y capacitors 48c are formed between the input wiring and the ground conductor. Of the noise generated in the switching element, the noise current that is about to flow out to the input wiring side flows out to the ground potential side in the vicinity of the switching element that is the noise source, so that outflow to the outside is suppressed. In particular, the input wiring 16 is a power wiring for obtaining an electrical connection with the AC power supply 2 and is exposed to the outside outside the power conversion device. Therefore, the noise current to the input wiring 16 is reduced due to radiation noise. It is effective for suppression. For this reason, when the wiring structure according to the seventh embodiment is employed, radiation noise from the noise source can be effectively suppressed.

  In FIG. 11, the P conductor 43 and the N conductor 44 and the input conductor 42 are separated and wired. However, as shown in FIG. 12, the P conductor 43, the N conductor 44 and the input conductor 42 are integrated. May be configured. In this case, similarly to FIG. 9, the insulator 46d is provided in the center, the P conductor 43 and the N conductor 44 are provided on both sides thereof, and the insulators 46a and 46b are provided on the respective outer sides (upper side and lower side). It is preferable to provide an extended portion of the ground conductor 45 sandwiched therebetween, and to make the input conductor 42 face the extended portion of the ground conductor 45 sandwiched by the insulator 46c. With such a structure, the Y capacitors 48a, 48b, and 48c can be formed, and the X capacitor 49 can be formed between the Y capacitor 48a and the Y capacitor 48b, so that the effect of suppressing radiation noise can be enhanced. It becomes.

  In FIG. 12, the extended portion of the ground conductor 45 provided on the upper side of the P conductor 43 is used, and the input conductor 42 is opposed to the extended portion of the ground conductor 45 with the insulator 46c interposed therebetween. However, the input conductor 42 may be provided on the lower side of the ground conductor 45 with an insulator interposed therebetween, and the same effect as that shown in FIG. 12 can be obtained.

  In the wiring structure according to the seventh embodiment, as shown in FIG. 10, the conductor surfaces of the input wiring 16, the P wiring 17a, the N wiring 17b, and the output wiring 18 are covered with a conductor having a high resistivity. As a result, the effect of suppressing radiation noise can be further enhanced.

Embodiment 8 FIG.
As a switching element used for an inverter circuit, a regenerative converter circuit, a PWM converter circuit, etc., a switching element (Si element) formed using Si (Silicon) is generally used, but recently, the band gap is larger. Switching elements formed using semiconductors, specifically, wide band gap semiconductors such as silicon carbide (SiC), gallium nitride (GaN), and diamond are often used.

  Switching elements formed of wide bandgap semiconductors have high voltage resistance and high allowable current density, and thus can be miniaturized. By using these miniaturized switching elements, these elements are incorporated. The semiconductor module can be downsized. In addition, since the power loss is low, the efficiency of the switching element can be increased, and as a result, the efficiency of the semiconductor module can be increased. On the other hand, since the switching speed is fast and there is a concern about an increase in radiation noise, the above measures are effective.

  The first to seventh embodiments described above are suitable for use in both a Si element module and a SiC element module.

  On the other hand, in the case of a SiC element module, a radiator that cools the module may be unnecessary, but in a Si element module, a radiator is usually required. In such a case, for example, as shown in FIG. 13, a radiator 50 may be disposed below the ground conductor 25. Further, for example, as shown in FIG. 14, the module 21 may be disposed on the fin base 52 of the radiator 50 and the fin base 52 and the ground conductor 25 may be electrically connected. Further, for example, as shown in FIG. 15, an end portion of the fin base 52 of the radiator 50 may be extended, and a part of the fin base 52 may be used as an extended portion of the ground conductor 25. The radiator 50 includes a fin base 52 and a heat radiating portion 54.

  The wiring structure of the eighth embodiment shown in FIGS. 13 to 15 applies the wiring structure of the first embodiment, but the other wiring structures shown in the second to seventh embodiments can be applied. Well, it is possible to obtain an effect specific to each embodiment.

  As described above, the present invention is useful as a noise reduction filter that can effectively suppress radiation noise generated in a power converter.

2 AC power source 3 Load 11 Power converter 12 Converter circuit (first power converter)
13 Smoothing circuit 13a Smoothing capacitor 14 Inverter circuit (second power converter)
16 Input wiring 17a Positive wiring (P wiring)
17b Negative wiring (N wiring)
18 Output wiring 21, 41 Module 22 Output conductor 23, 43 P conductor 24, 44 N conductor 25, 45 Ground conductor 26a-26c, 46a-46c Insulator 28a, 48a Y capacitor (P conductor Y capacitor)
28b, 48b Y capacitor (N conductor Y capacitor)
28c Y capacitor (output conductor Y capacitor)
29, 49 X capacitor 32 Floating capacitance 36, 37 High resistance component 48c Y capacitor (input conductor Y capacitor)
50 Radiator 52 Fin base 54 Radiator

Claims (31)

A noise reduction filter configured to be able to reduce noise current generated by the power conversion unit,
A first conductor between a positive conductor forming a positive DC bus connected to the power converter and a first conductor extending a ground conductor for mounting a switching element module provided in the power converter. A first Y capacitor formed with an insulator of
A second conductor is disposed between the first conductor portion and the negative conductor, which is disposed on the opposite side of the positive conductor with respect to the first conductor portion and forms a negative DC bus connected to the power conversion portion. A second Y capacitor formed with an insulator of
A noise reduction filter characterized in that is configured as a filter circuit element.   An output conductor that forms an output wiring connecting the power conversion unit and the load, and a second conductor unit that extends a ground conductor on which the switching element module included in the power conversion unit is mounted. The noise reduction filter according to claim 1, wherein a third Y capacitor formed with three insulators interposed therebetween is configured as a filter circuit element.   The noise reduction filter according to claim 2, wherein each surface of the positive electrode conductor and the negative electrode conductor is covered with a material having a higher resistivity than a material forming the positive electrode conductor and the negative electrode conductor.   The noise reduction filter according to claim 2, wherein the surface of the output conductor is covered with a material having a higher resistivity than a material forming the output conductor.   Each surface of the positive electrode conductor and the negative electrode conductor is covered with a material having a higher resistivity than the material forming the positive electrode conductor and the negative electrode conductor, and the surface of the output conductor is made from the material forming the output conductor. The noise reduction filter according to claim 2, wherein the noise reduction filter is covered with a material having a high resistivity.   The surface of the input conductor constituting the input wiring connecting the power conversion unit and the AC power supply is covered with a material having a higher resistivity than the material forming the input conductor. 5. The noise reduction filter according to 5.   Between the input conductor which comprises the input wiring which connects between the said power conversion part and AC power supply, and the 2nd conductor part which extended the earth conductor which mounts the switching element module with which the said power conversion part is equipped The noise reduction filter according to claim 1, wherein a third Y capacitor formed with a third insulator interposed therebetween is configured as a filter circuit element.   The first Y capacitor is formed by disposing the positive electrode conductor and the negative electrode conductor inside the first and second insulators and sandwiching a third insulator between the positive electrode conductor and the negative electrode conductor. The noise reduction filter according to claim 1, wherein an X capacitor connected in series between the second Y capacitor and the second Y capacitor is configured as a filter circuit element.   The noise reduction filter according to claim 8, wherein each surface of the positive electrode conductor and the negative electrode conductor is covered with a material having a higher resistivity than a material forming the positive electrode conductor and the negative electrode conductor.   The noise reduction filter according to claim 8, wherein the surface of the output conductor is covered with a material having a higher resistivity than a material forming the output conductor.   Each surface of the positive electrode conductor and the negative electrode conductor is covered with a material having a higher resistivity than the material forming the positive electrode conductor and the negative electrode conductor, and the surface of the output conductor is made from the material forming the output conductor. The noise reduction filter according to claim 8, wherein the noise reduction filter is covered with a material having a high resistivity.   The surface of the input conductor constituting the input wiring connecting the power conversion unit and the AC power supply is covered with a material having a higher resistivity than the material forming the input conductor. The noise reduction filter according to 11.   The noise reduction filter according to claim 1, wherein each surface of the positive electrode conductor and the negative electrode conductor is covered with a material having a higher resistivity than a material forming the positive electrode conductor and the negative electrode conductor.   The noise reduction filter according to claim 13, wherein the surface of the output conductor is covered with a material having a higher resistivity than a material forming the output conductor. A noise reduction filter configured to be able to reduce noise current generated by the power conversion unit,
The output conductor forming the output wiring connecting the power conversion unit and the load, and the first conductor unit extending the ground conductor for mounting the switching element module provided in the power conversion unit A noise reduction filter characterized in that a Y capacitor formed by sandwiching one insulator is formed as a filter circuit element.   The noise reduction filter according to claim 15, wherein the surface of the output conductor is covered with a material having a higher resistivity than a material forming the output conductor.   The noise reduction filter according to claim 16, wherein each surface of the positive electrode conductor and the negative electrode conductor is covered with a material having a higher resistivity than a material forming the positive electrode conductor and the negative electrode conductor.   The first conductor portion is arranged on the opposite side of the positive conductor, and the first conductor portion is connected between the first conductor portion and an output conductor forming an output wiring connecting the power conversion portion and the load. 9. The noise reduction filter according to claim 8, wherein a third Y capacitor formed by sandwiching three insulators is configured as a filter circuit element.   Between the first conductor portion and the input conductor forming the input wiring connecting between the power conversion portion and the AC power supply, disposed on the opposite side of the positive conductor with respect to the first conductor portion. 9. The noise reduction filter according to claim 8, wherein the noise reduction filter is configured as a third Y capacitor filter circuit element formed with a fourth insulator interposed therebetween.   The second conductor is disposed on the opposite side of the negative conductor with respect to the second conductor, and the second conductor is connected between the second conductor and an output conductor forming an output wiring connecting the power converter and the load. 9. The noise reduction filter according to claim 8, wherein a third Y capacitor formed with 4 insulators interposed therebetween is configured as a filter circuit element.   Between the second conductor portion and the input conductor forming the input wiring connecting the power conversion portion and the AC power source, arranged on the opposite side of the negative electrode conductor with respect to the second conductor portion. The noise reduction filter according to claim 8, wherein a third Y capacitor formed with a fourth insulator interposed therebetween is configured as a filter circuit element.   The first conductor portion is arranged on the opposite side of the positive conductor, and the first conductor portion is connected between the first conductor portion and an output conductor forming an output wiring connecting the power conversion portion and the load. 13. The noise reduction filter according to claim 9, wherein a third Y capacitor formed by sandwiching three insulators is configured as a filter circuit element.   Between the first conductor portion and the input conductor forming the input wiring connecting between the power conversion portion and the AC power supply, disposed on the opposite side of the positive conductor with respect to the first conductor portion. The noise reduction filter according to any one of claims 9 to 12, wherein a third Y capacitor formed with a fourth insulator interposed therebetween is configured as a filter circuit element.   The second conductor is disposed on the opposite side of the negative conductor with respect to the second conductor, and the second conductor is connected between the second conductor and an output conductor forming an output wiring connecting the power converter and the load. The noise reduction filter according to any one of claims 9 to 12, wherein a third Y capacitor formed by sandwiching four insulators is configured as a filter circuit element.   Between the second conductor portion and the input conductor forming the input wiring connecting the power conversion portion and the AC power source, arranged on the opposite side of the negative electrode conductor with respect to the second conductor portion. The noise reduction filter according to any one of claims 9 to 12, wherein a third Y capacitor formed with a fourth insulator interposed therebetween is configured as a filter circuit element.   26. The noise reduction filter according to claim 1, wherein the ground conductor is disposed between the switching element module and a cooler that cools the switching element module.   2. The switching element module is mounted on a fin base of a cooler that cools the switching element module, and the ground conductor is electrically connected to the fin base and drawn out. The noise reduction filter according to any one of ˜25.   The said switching element module is mounted on the fin base of the cooler which cools this switching element module, The edge part of the said fin base is extended, and it comprises the said earth conductor. The noise reduction filter according to any one of ˜25.   The noise reduction filter according to any one of claims 1 to 28, wherein the switching element mounted on the switching element module is a switching element formed of a wide band gap semiconductor.   30. The noise reduction filter according to claim 1, wherein the wide band gap semiconductor is a semiconductor using silicon carbide, a gallium nitride-based material, or diamond. As the power conversion unit, a first power conversion unit that converts an AC voltage into a desired DC voltage, and a second power conversion unit that converts the DC voltage converted by the first power conversion unit into a desired AC voltage. And provided,
A configuration of the noise reduction filter according to any one of claims 1 to 30 is applied to at least one power conversion unit of the first and second power conversion units. Power converter.

Images