JP5909664B2 - Power converter - Google Patents

Description

  The present invention relates to a power converter that converts input power into desired AC power and outputs the AC power to a pair of AC lines.

  Known conversion circuits for obtaining desired AC power include inverter circuits that convert DC power to AC power, circuits that multiply AC power, and circuits such as cycle converters. An element is used, and input power is converted into desired AC power by turning on / off the switch element. (For example, the switch element is driven at several kHz to several tens of kHz.) Also, such a device has a switching power supply for driving the switch element, and the switch element in the switching power supply is also predetermined. Conduction / cutoff is repeated according to the frequency (for example, several tens of kHz to several hundreds of kHz).

  When such a conversion circuit operates, noise (several kHz to several hundreds of kHz) is generated due to conduction / interruption of the switching element as described above. Such noise is superimposed on a pair of AC lines and affects the load (for example, home appliances used in the consumer) that receives power supply via the AC line, resulting in load malfunction and reduced efficiency. It may cause.

  In order to prevent noise from being output from the conversion circuit, there is a countermeasure provided by providing a capacitor on the output side of the power conversion device. For example, a capacitor that connects a pair of AC lines (generally referred to as “X capacitor”), or two capacitors that connect each of the pair of AC lines and the ground potential level line (generally referred to as “Y capacitor”). By providing this, such noise is attenuated through the X capacitor and the Y capacitor, and is prevented from being transmitted to the outside from the pair of AC lines.

  On the other hand, Patent Document 1 describes a device that improves the operation efficiency of circuit components mounted on an electrical board of a power conversion device. According to the circuit component mounting structure described in Patent Document 1, bus bars (a pair of AC lines) are arranged on a substrate so as to face each other. Electronic components such as capacitors are arranged on both sides of the pair of bus bars and connected to the bus bars using connection wiring.

JP 2011-142251 A

However, as described in Patent Document 1, when an X capacitor or a Y capacitor is connected, the reactor component and the capacitor of the connection wiring constitute a resonance circuit. When the reactor component of the connection wiring at this time is L and the capacitance of the capacitor is C, the resonance frequency f is represented by f = 1 / (2π (LC) ^1/2 ). The frequency of noise that can be attenuated by the X capacitor and Y capacitor is noise below this resonance frequency f. Therefore, when the reactor component L of the connection wiring increases, the resonance frequency f decreases, and the frequency band of noise that can be attenuated decreases sufficiently. Noise attenuation effect could not be obtained.

  In addition, each of the pair of Y capacitors needs to be connected to the ground potential level line, but this ground potential level line can only be arranged outside the pair of AC lines. For this reason, the distance to the ground point of the ground potential level line is increased, the reactor component of the ground potential level line is increased, the frequency band of noise that can be removed is lowered, and a sufficient noise attenuation effect cannot be obtained. .

  The present invention has been made in view of such problems of the prior art, and a power conversion device capable of attenuating noise flowing to a load through a pair of AC lines by devising the arrangement of capacitors. The purpose is to provide.

  In order to achieve the above object, a power conversion device according to the present invention is a power conversion device that converts input power into AC power by ON / OFF operation of a plurality of switch elements, and outputs the AC power. A heat sink having conductivity to dissipate heat generated during operation, a conversion circuit supported on the heat sink via a support having conductivity, and having a pair of wiring patterns for outputting the AC power to a load; and An island between the pair of wiring patterns on the conversion circuit to which the connection point of both the capacitors of the series circuit and the series circuit of the first capacitor and the second capacitor connected between the pair of wiring patterns is connected. And the support supports the conversion circuit in the conductive region and is electrically connected to the conductive region. And wherein the are.

  According to the present invention, the reactance on the conversion circuit is reduced and noise flowing to the load through the AC line can be reduced.

It is an appearance perspective view of the power converter of an embodiment. It is an exploded perspective view of the power converter of an embodiment. It is a component arrangement | positioning figure of the power converter device of embodiment. It is a circuit diagram of the power converter of an embodiment. It is a top view which shows the arrangement | positioning state of a 1st and 2nd through hole.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated in detail using drawing. However, each embodiment shown below exemplifies a power converter in order to understand the technical idea of the present invention, and is not intended to specify the present invention as this power converter. The invention can also be applied to various changes made without departing from the technical idea shown in the claims.

  The structure of the power converter device of embodiment is demonstrated using FIG.1 and FIG.2. As shown in FIG. 1, the power conversion device 1 of the embodiment is surrounded by a front panel 2, a back panel 3, a top panel 4, a bottom main panel 5, a bottom auxiliary panel 6, a right side panel 7, and a left side panel 8. The housing has a substantially rectangular parallelepiped shape covered with the. In addition, as for this power converter device 1, the back panel 3 is attached to the wall surface (illustration omitted) so that the surface panel 2 side may become a front surface.

  The front panel 2 is made of metal or synthetic resin. As shown in FIG. 2, the front panel 2 is provided with a display unit 10. The upper surface panel 4, the lower surface main panel 5, the lower surface auxiliary panel 6, the right side panel 7 and the left side panel 8 constitute a frame, and the surface panel 2 is attached to the frame so that it can be attached and detached. . Each frame is formed of a metal such as an iron plate, and is attached to the back panel 3 which is also formed of a metal such as an iron plate by screwing or welding.

  The lower surface main panel 5 is formed with a ventilation hole 5a and a ventilation slit 5b, and the flow of cooling air corresponding to the ventilation hole 4a (see FIG. 2) and the ventilation slit (not shown) of the upper panel 4 respectively. I'm making it. A heat sink 21 that is fixed to the rear panel 3 by screws and maintained at the ground potential level is disposed between the ventilation slits 5b. The air that has entered through the ventilation slit 5b between the fins 21a of the heat sink 21 flows toward the ventilation slit of the top panel 4. The lower surface auxiliary panel 6 is detachably attached to the lower surface main panel 5 and the right side panel 7 from the lower surface main panel 5. The right side panel 7 is appropriately provided with a power switch 7b, an AC outlet 7c, and the like.

  A terminal block 17 having a DC input terminal and an AC output terminal is disposed on the upper side of the lower surface auxiliary panel 6. The terminal block 17 is fixed between the terminal block holding plate 18 attached to the back panel 3 and the right side panel 7. The terminal block 17 is connected to a DC input wiring or an AC output wiring (both not shown) introduced into the power converter 1 through a notch 3a formed in the back panel 3. . The DC input wiring and AC output wiring may be provided with an opening in the bottom auxiliary panel and connected to the terminal block through this opening.

  A main board 20 including a conversion circuit that converts DC input power into AC power by ON / OFF operation of a plurality of switch elements is attached to the housing on a heat sink 21 at predetermined intervals via conductive supports 23 and 23a. It has been. The conductive support 23 used here is processed into a male screw shape on one end side, and is screwed into a female screw hole formed in the heat sink 21. The specific arrangement and function of the conductive supports 23 and 23a will be described later.

  The switch element module 24 is constructed by incorporating a plurality of switch elements in a switch element fixing holder 25. The switch element fixing holder 25 is fixed onto the heat sink 21 through the opening 20c, thereby enabling the heat dissipation of the switch element to the heat sink 21. The specific configuration of the main board 20 and the grounding of the main board 20 to the heat sink 21 will be described later.

  Further, a DC reactor DCL (first reactor) and an AC reactor ACL (second reactor) are arranged side by side on the left side panel 8 side of the heat sink 21. Further, a sub-board 26 is disposed on the right side panel 7 side of the heat sink 21, and the sub-board 26 is an interconnection relay that performs electrical connection and disconnection between the AC output from the main board 20 and the system. A plurality of RLYs, here four, are provided. The sub-board 26 is attached to the back panel 3 by a conductive support (not shown) whose one end is processed into a male screw shape. These interconnection relays RLY1 to RLY4 are for disconnecting the inverter device from the system when the DC reactor DCL, the booster circuit 36, the inverter circuit 37, etc. are abnormal or when the system is abnormal, and preventing electric shock during repair and inspection. The circuit is shut off even when the power converter is shut down.

  Next, the circuit configuration of the power conversion device 1 of the embodiment will be described with reference to FIGS. 3 and 4. The DC power from the solar cell module 30 is input to the DC input terminals 17a and 17b of the terminal block 17, and the DC input terminals 17a and 17b are connected to the input terminals 20a and 20b of the main board 20 through lead wires 19a and 19b, respectively. Is input. The input terminals 20a and 20b are connected to a pair of DC power lines 31 and 32 formed on the main board 20, respectively. The pair of DC power lines 31 and 32 are formed as wiring patterns on the back side of the main substrate 20.

  The DC power input to the pair of DC power lines 31 and 32 is input to the first noise filter circuit CMF1 disposed on the main board 20, and normal mode noise and common mode noise included in the DC power are attenuated. . The first noise filter circuit CMF1 will be described later.

  The direct current output from the first noise filter circuit CMF1 is input to the switch element module 24 that forms an inverter via the direct current reactor DCL. The switch element module 24 is formed by connecting in parallel three first to third arm circuits each including a parallel circuit of a transistor and a freewheeling diode connected in series, and is provided on the negative side of the arm circuit on the noise filter circuit CMF1 side. The booster circuit 36 is configured using the transistor, the DC reactor DCL, and the smoothing capacitor CON, and the inverter circuit 37 is configured using the remaining two arm circuits.

  The input side of the DC reactor DCL is connected to the positive electrode of the solar cell module 30 via the first noise filter circuit CMF1, and the output side is the input side A point of the arm circuit (the connection point of the two switch elements of the arm circuit). Connected to. Further, both ends B and C of the arm circuit are connected in parallel to the smoothing capacitor CON, and the points B and C are connected to the input side (DC side) of the inverter circuit 37. Further, the output point D and E point (AC side) of the inverter circuit 37 are respectively connected to the AC reactor ACL.

  The booster circuit 36 and the inverter circuit 37 are controlled by signals from a control circuit provided on the control circuit board 15 (see FIGS. 4 and 5), respectively. Therefore, detailed description thereof is omitted.

  The direct current reactor DCL and the alternating current reactor ACL are required to have a large reactance with respect to a low frequency alternating current having a frequency of 50 Hz to 60 Hz. Similarly, since the smoothing capacitor CON also needs a large capacity, the power converter 1 according to the embodiment uses eight capacitors connected in parallel so that the height and width are reduced.

  The AC power from the pair of AC reactors ACL passes through the second noise filter circuit CMF2 interposed in the pair of AC power lines 38 and 39 arranged in parallel to the main board 20, and the interconnection relay RLY1 of the sub board 26. Through the RLY4, it is superimposed on the commercial power system and supplied to the load. The pair of AC power lines 38 and 39 is formed as a wiring pattern on the back side of the main board 20.

  Next, specific configurations of the first noise filter circuit CMF1 and the second noise filter circuit CMF2 arranged on the main board 20 will be described. As shown in FIG. 4, the first noise filter circuit includes a pair of DC power lines 31 and 32, a first X capacitor X1 for attenuating normal mode noise, and a first DC capacitor for attenuating common mode noise. The first to fourth Y capacitors Y1 to Y4 and the first choke coil L1 for attenuating common mode noise are connected. The second noise filter circuit also includes a pair of AC power lines 38 and 39 for the second to fourth X capacitors X2 to X4 for attenuating normal mode noise and a common mode noise. Fifth to eighth Y capacitors Y5 to Y8 (first capacitor and second capacitor) and second and third choke coils L2 and L3 for attenuating common mode noise are connected. ing.

  As shown in FIG. 3, the pair of AC power lines 31 and 32 and the pair of AC power lines 38 and 39 arranged on the main board 20 have two regions (first regions 31 a and 32 a and second regions, respectively). 31b, 32b) and three regions (first region 38a, 39a, second region 38b, 39b, third region 38c, 39c). The divided regions are connected by first to third choke coils L1 to L3.

  The first to fourth X capacitors X1 to X4 are respectively connected between the first regions 31a and 32a of the pair of DC power lines 31 and 32 and between the first regions 38a and 39a of the pair of AC power lines 38 and 39. The second regions 38b and 39b of the AC power lines 38 and 39 and the second regions 38c and 39c of the pair of AC power lines 38 and 39 are connected.

  The first to fourth X capacitors X1 to X4 are arranged so as to straddle the power lines in the regions to which the first to fourth X capacitors X1 to X4 are connected, and both the lead wires of the first to fourth X capacitors X1 to X4 are respectively Soldering is performed through through holes (not shown) formed in the main substrate 20. The through hole is provided on the side where the power lines face each other, and the first to fourth X capacitors X1 to X4 are arranged so as to cover the through hole with the first to fourth X capacitors X1 to X4. .

  Between the pair of first regions 31a, 32a of the DC power lines 38, 39, between the pair of second regions 31b, 32b, between the pair of second regions 38b, 39b of the AC power lines 38, 39, and a pair of first regions. Between the three regions 38c and 39c, island-shaped conductive regions 33a, 33b, 33c and 33d are formed, respectively.

  The first to eighth Y capacitors Y1 to Y8 are arranged such that the first, third, fifth, and seventh Y capacitors are the first capacitors C1, and the second, fourth, sixth, and eighth Y capacitors are used. The capacitor will be described as the second capacitor C2. This is because the Y capacitors Y1, Y3, Y5, and Y7 that are the first capacitors C1 and the Y capacitors Y2, Y4, Y6, and Y8 that are the second capacitors C2 are arranged only in different locations. This is because the direction is common.

  In the present embodiment, the first Y capacitor Y1 is disposed between one of the first regions 31a of the pair of DC power lines and the island-shaped conductive region 33a, and the second Y capacitor Y2 is a pair of DC power lines. It arrange | positions between the other 32a of the 1st area | region of a power line, and the island-shaped electroconductive area | region 33a. The third Y capacitor Y3 is disposed between one of the second regions 31b of the pair of DC power lines and the island-shaped conductive region 33b, and the fourth Y capacitor Y4 is the second of the pair of DC power lines. It arrange | positions between the other 32b of area | regions, and the island-shaped electroconductive area | region 33b. The fifth Y capacitor Y5 is disposed between one of the second regions 38b of the pair of AC power lines and the island-shaped conductive region 33c, and the sixth Y capacitor Y6 is the second of the pair of AC power lines. The other region 39b is disposed between the island-shaped conductive region 33c. The seventh Y capacitor Y7 is disposed between one of the third regions 38c of the pair of AC power lines and the island-shaped conductive region 33d, and the eighth Y capacitor Y8 is the third of the pair of AC power lines. It is disposed between the other side 39c of the region and the island-shaped conductive region 33d.

  The first capacitor C1 and the second capacitor C2 form a series circuit connected in series, and this series circuit is a pair of power lines (DC power lines 31, 38 or AC power lines 38, 39). ) Is electrically connected. The first capacitor C1 is disposed so as to straddle one of the pair of power lines and the conductive region 33, and the second capacitor C2 straddles the conductive region 33 and the other of the pair of power lines. Are arranged as follows. That is, the connection point between the first capacitor and the second capacitor is connected to the conductive region 33.

  Both lead wires (terminals) of the first capacitor C1 pass through a pair of first through holes TH1 (see FIG. 5A) formed in the main substrate 20, respectively, and one of the pair of power lines and the conductive region. 33 and soldered. The pair of first through holes TH1 is provided on one side of the pair of power lines and the side facing the conductive region 33, and the first capacitor C1 covers the first through hole TH1 with the first capacitor C1. Is arranged.

  Both lead wires (terminals) of the second capacitor C2 pass through a pair of second through holes TH2 (see FIG. 5A) formed in the main substrate 20, respectively, and the other of the pair of power lines and the conductive region. 33 and soldered. The pair of second through holes TH2 is provided on the other side of the pair of power lines and on the opposite side of the conductive region 33, and the second capacitor C2 covers the second through hole TH2 with the second capacitor C2. Is arranged.

  The distance between the pair of through holes TH1 is substantially equal to the distance between the pair of through holes TH2.

  Next, a method of connecting the island-shaped conductive region 33 formed on the main substrate 20 to the ground potential level G will be described with reference to FIGS. As shown in FIGS. 3 and 4, a plurality of conductive supports 23 and 23 a having the same height are erected on the heat sink 21. The conductive supports 23 and 23a are intended to be fixed on the heat sink 21 with the main board 20 maintained at a predetermined height. However, among these, the four conductive supports 23a are not only fixed on the heat sink 21 with the main substrate 20 maintained at a predetermined height, but also four island-shaped conductive members formed on the main substrate 20. It has a function of electrically connecting the regions 33a to 33d to the heat sink 21 connected to the ground potential level G.

  That is, the main board 20 is formed with screw holes at positions corresponding to the conductive support 23, and has four island-like conductive regions 33a to 33d, specifically, island-like holes. An opening H for screwing is also formed between the first through hole TH1 and the second through hole TH2 in the conductive region. Therefore, the main substrate 20 is screwed to the top of the conductive support 23 from the opening formed in the main substrate 20 at a position corresponding to the conductive support 23, and is formed in four island-shaped conductive regions 33a to 33d. The screw is fixed to the top of the conductive support 23a from the position corresponding to the opened hole H. As a result, the main substrate 20 is held and fixed at a constant height on the heat sink 21 by the conductive supports 23 and 23a, and the four island-shaped conductive regions 33a to 33d formed on the main substrate 20 are electrically conductive. In electrical contact with the top of the sex support 23a.

  Therefore, the four island-shaped conductive regions 33a to 33d formed on the main substrate 20 are electrically connected to the heat sink 21 by the conductive support 23a and become the ground potential level.

Here, the X capacitor and the Y capacitor constitute a resonance circuit by the reactor component of the capacitor connection wiring (capacitor lead wire, wiring pattern provided on the wiring board, support 23a, etc.). For this reason, the frequency band of noise that can be actually removed by the X capacitor and the Y capacitor is from the resonance frequency f (f = 1 / (2π (LC) ^1/2 )), where C is the capacitance of the capacitor and L is the reactor component. Becomes a lower frequency band. The magnitude of the reactor component L is determined by the distance (length) of the wiring from the capacitor to the ground potential level. If this distance is long, the reactor component becomes large L, and if it is small, the reactor component L becomes small.

  In the present embodiment, as described above, since the first noise filter circuit CMF1 and the second noise filter circuit CMF2 are configured, the connection point of the lead wire of the first capacitor C1 in the conductive region 33, A connection point (opening H) connected to the ground potential level (heat sink 21) and a connection point of the lead wire of the second capacitor C2 are sequentially arranged. Thereby, the capacitors C1 and C2 sandwiched between the pair of power lines are connected to the ground potential level (heat sink 21) through the island-shaped conductive region 33 and the support 23a, and these capacitors C1 and C2 are installed at the shortest distance. Will be. In this case, since the reactor component of the connection wiring of the capacitors C1 and C2 becomes small, noise input from the solar cell module 30 side to the power conversion device 1 through the DC power lines 31 and 32, a pair of AC power lines 38, The noise flowing to the load through 39 can be satisfactorily attenuated.

  Further, since the capacitors C1 and C2 are installed with substantially the same wiring distance, the balance of the noise filter circuit CMF1 is improved, and the noise attenuating action of one side is not lowered.

  The through hole into which the lead wires of the first to fourth X capacitors X1 to X4 and the first to eighth Y capacitors Y1 to Y8 are inserted has a side where a pair of power lines face each other, or a power line and a conductive region. Provided on the opposite side. As a result, the connection point of one of the pair of power lines and the lead wire (terminal) of the first capacitor C1 disposed in the conductive region 33 is on the opposite side of one of the pair of power lines and the conductive region 33, respectively. The connection point between the other of the pair of power lines and the terminal of the second capacitor C2 disposed in the conductive region 33 is provided on the opposite side of the other of the pair of power lines and the conductive region 33, respectively. . Accordingly, the lengths of the lead wires are almost the same, and the balance of the noise filter circuit is improved.

  However, in the present invention, it is not always necessary to dispose the first and second capacitors C1 and C2 so as to cover the through holes provided in the main substrate 20, respectively. Furthermore, in the present invention, through holes for inserting the lead wires of the first and second capacitors C1 and C2 may be provided on the side where the pair of power lines face each other, or on the side where the power line and the conductive region 33 face each other. It is not necessarily a necessary condition. The formation state of such a through hole will be described with reference to FIG.

  5A shows the first capacitor C1 and the second capacitor C2 of the embodiment as a pair of power lines (DC power lines 31 and 32 or AC power lines 38 and 39) and an island-shaped conductive region 33. It is the bottom view which looked at the main board | substrate 20 from the back side which shows the arrangement | positioning state of the 1st and 2nd through-hole for attaching between. The first and second capacitors C1 and C2 are both indicated by broken lines. The first through hole TH1 is provided at a position where one of the pair of power lines and the island-shaped conductive region 33 are close to each other, that is, on opposite sides. The second through hole TH2 is also provided at a position where the other of the pair of power lines and the island-like conductive region 33 are close to each other, that is, on opposite sides.

  However, this arrangement may not be possible depending on the size and shape of the capacitor. For example, when the first and second capacitors C1 and C2 having a long distance between the lead wires are used, the first and second capacitors formed in the island-shaped conductive region 33 as shown in FIG. 5B. Even though the two through holes TH1 and TH2 are formed at the same positions as in the above-described embodiment, the through holes formed in the pair of power lines must be provided at positions away from the island-shaped conductive regions 33, respectively. You may not get. Even in such a case, since the lengths of the lead wires of the respective capacitors are shortened, substantially the same operational effects as those of the power conversion device 1 of the embodiment can be obtained.

  Further, when a disk-shaped ceramic capacitor or a multilayer capacitor is used as a capacitor, the through hole may not be substantially covered by the capacitor, but even in this case, the power conversion device 1 of the embodiment and Substantially similar effects can be achieved. Further, the first and second capacitors C1 and C2 do not have to be arranged linearly as shown in FIGS. 5A and 5B, and are arranged so as to be perpendicular to the pair of power lines. There is no need to do. For example, as shown in FIG. 5C, the first and second through-holes TH1 and TH2 are arranged so that the first and second capacitors C1 and C2 are arranged in a “C” shape. You may do it. Further, as shown in FIG. 5D, the first and second through holes TH1, TH2 are arranged so that the first and second capacitors C1, C2 are arranged obliquely with respect to the pair of power lines. May be arranged.

  In addition, the position of the through hole is not limited to the above-described position, and the resonance frequency of the resonance circuit constituted by the capacitors X1 to X4, Y1 to Y8 and the reactor component of the lead wire is higher than the frequency that is the main cause of noise. It is preferable to adjust so that the length of the lead wire is shortened (for example, 10 mm or less) so as to be smaller. The main causes of this noise are the switching frequency (several kHz to several tens of kHz) of the switching element of the switching element module 24 and the switching frequency (several tens of kHz to several hundred kHz) of the switching power supply that supplies power to the switching element module Etc. are considered.

  In the power converter according to the embodiment, the example in which the first noise filter circuit CMF1 and the second noise filter circuit CMF2 are provided has been described. The reason for adopting such a configuration is that the normal output superimposed on the AC output is used. This is because mode noise and common mode noise are reduced and high quality AC power is supplied to the system. Therefore, the pair of DC power lines 31 and 32 may be provided with at least a pair of Y capacitors, at least one X capacitor, and a choke coil. The pair of AC power lines 38 and 39 need not be provided with all the Y capacitors, the X capacitors, and the choke coils as described above. If the at least one pair of Y capacitors, at least one X capacitor and the choke coils are provided. Good.

  DESCRIPTION OF SYMBOLS 1 ... Power converter 2 ... Front panel 3 ... Back panel 3a ... Notch 4 ... Top panel 4a ... Air hole 5 ... Lower surface main panel 6 ... Lower surface auxiliary panel 7 ... Right side panel 8 ... Left side panel 20 ... Main board 21 ... Heat sink 21a ... Fin 23, 23a ... Conductive support 24 ... Switch element module 25 ... Switch element fixing holder 26 ... Sub-board 30 ... Solar cell module 31, 32 ... DC power line 31a, 32a ... First region 31b, 32b ... 2nd area | region 33 ... Conductive area | region 36 ... Booster circuit 37 ... Inverter circuit 38, 39 ... AC power line 38a, 39b ... 1st area | region 38a, 39b ... 2nd area | region 38c, 39c ... 3rd area | region 43, 44 ... AC power Line DCL ... DC reactor ACL ... AC reactor C N ... smoothing capacitor L1 to L3 ... choke coil X1 to X4 ... X capacitor Y1-Y8 ... Y capacitor RLY1～RLY4 ... connector relay TH1, TH2 ... through hole

Claims (5)

A booster circuit including a first switch element, a reactor, and a smoothing capacitor;
An inverter that has the smoothing capacitor connected to the input side, converts the input power input through the booster circuit to AC power by ON / OFF operation of a plurality of second switch elements, and outputs the AC power
A circuit,
A conductive heat sink that dissipates heat generated during ON / OFF operations of the plurality of second switch elements;
A conversion circuit that is supported on the heat sink via a conductive support and has a pair of wiring patterns for outputting the AC power to a load;
A series circuit including a first capacitor and a second capacitor , which are connected between the pair of wiring patterns and attenuate common mode noise ;
An island-like conductive region on the conversion circuit to which a connection point of both capacitors of the series circuit is connected and between the pair of wiring patterns;
The power converter is characterized in that the support supports the conversion circuit between connection points of both capacitors in the conductive region and is electrically connected to the conductive region. The pair of wiring patterns are arranged in parallel, and the connection points of one of the pair of wiring patterns and the terminal of the first capacitor arranged in the conductive region are respectively connected to one of the pair of wiring patterns and the conductive region. On the opposite side,
The connection point between the other of the pair of wiring patterns and a terminal of a second capacitor disposed in the conductive region is provided on the other side of the pair of wiring patterns and the side of the conductive region facing each other. The power converter according to 1. The distance between the connection point of the wiring pattern to which each terminal of the first capacitor is connected and the connection point of the conductive region is the distance between the connection point of the wiring pattern to which each terminal of the second capacitor is connected and the conductive region. 3. The power converter according to claim 1, wherein the distance is substantially equal to a distance to the connection point, and the distance is a distance between terminals of each capacitor. The pair of wiring patterns are divided into a first region and a second region, respectively,
The first region and the second region of the pair of wiring patterns are connected to each other by inductance,
4. The power conversion device according to claim 1, wherein the first capacitor and the second capacitor are provided in at least one of the first region and the second region. 5. Furthermore, a sub-substrate in which a pair of wiring patterns is formed along both side ends,
The output sides of the pair of wiring patterns formed on the main substrate are connected to the pair of wiring patterns formed on the sub substrate, respectively.
5. The pair of wiring patterns formed on the sub-board are connected to the output side via interconnection relays arranged on the sub-board, respectively. 6. Power converter.

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