Filter device and power conversion device

Abstract

To provide a filter device and a power conversion device which can achieve cost reduction, miniaturization, and noise reduction in parallel.SOLUTION: A filter device having one end connected to a DC power supply side and the other end connected to a power conversion circuit side includes a positive electrode wiring, a negative electrode wiring, and a first capacitor and a second capacitor which are connected to each other in parallel between the positive electrode wiring and the negative electrode wiring. The positive electrode wiring includes a first positive electrode connection portion connected to the first capacitor on the one end side thereof, and a second positive electrode connection portion connected to the second capacitor on the other end side thereof. The negative electrode wiring includes a first negative electrode connection portion connected to the second capacitor on the one end side thereof, and a second negative electrode connection portion connected to the second capacitor on the other end side thereof, and the positive electrode wiring and the negative electrode wiring cross each other.SELECTED DRAWING: Figure 8

Description

[Technical field]

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

[0002] Power conversion devices installed in hybrid and electric vehicles must meet the unique standards established by each car manufacturer based on the high-voltage conducted noise standard added to the international standard for dealing with conducted noise caused by leakage current. At the same time, in recent years, there has been an increasing demand for miniaturization and cost reduction of power conversion devices in line with the development of electric vehicles in which they are installed. Therefore, there is a strong demand for filter devices installed in power conversion devices to improve their high-frequency noise attenuation performance while maintaining low cost and small size.

[0003] As background art to the present invention, the following Patent Document 1 discloses a technique showing a structure in which an inductance component that passes low frequency components and a resistance component that passes high frequency components are connected in parallel for large current applications. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-273207 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the case of high-voltage / high-current applications such as vehicle-mounted inverters, the challenge is how to freely control the inductance component of the DC wiring and easily align it with the ESL (Equivalent Series Inductance) component of the capacitor in a limited installation space due to high-voltage / high-current applications and miniaturization. However, with the technology of Patent Document 1, it is difficult to align the inductance component of the DC wiring with the ESL component of the capacitor to improve high-frequency noise attenuation performance while maintaining low cost and miniaturization in a limited installation space due to high-voltage / high-current applications and miniaturization.

[0006] In view of this, an object of the present invention is to provide a filter device and a power conversion device that simultaneously achieve low cost, small size, and low noise. [Means for solving the problem]

[0007] The filter device of the present invention and a power conversion device including the same are a filter device having one end connected to a DC power supply side and the other end connected to a power conversion circuit side, and include a positive electrode wiring, a negative electrode wiring, and a first capacitor and a second capacitor connected in parallel between the positive electrode wiring and the negative electrode wiring, the positive electrode wiring has a first positive electrode connection portion connected to the first capacitor on the one end side and a second positive electrode connection portion connected to the second capacitor on the other end side, the negative electrode wiring has a first negative electrode connection portion connected to the second capacitor on the one end side and a second negative electrode connection portion connected to the second capacitor on the other end side, and the positive electrode wiring and the negative electrode wiring intersect. Effect of the Invention

[0008] According to the present invention, it is possible to provide a filter device and a power conversion device that simultaneously achieve low cost, small size, and low noise. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing an overall configuration of a power conversion device according to an embodiment of the present invention. [Diagram 2]FIG. 1 is an equivalent circuit diagram of a noise filter for reducing normal mode high voltage conduction noise. [Diagram 3] FIG. 2 is an equivalent circuit diagram including the parasitic components of the noise filter. [Figure 4] FIG. 4 is a characteristic diagram showing an insertion loss of the noise filter of FIG. [Diagram 5] FIG. 1 is a diagram illustrating an example of the structure of a noise filter. [Figure 6] FIG. 1 is an equivalent circuit diagram including parasitic components of a noise filter to which a conventional technique is applied. [Figure 7] FIG. 7 is a characteristic diagram showing an insertion loss of the noise filter of FIG. [Figure 8] 1 is a diagram showing a structure of a noise filter according to a first embodiment. [Figure 9] FIG. 9 is a characteristic diagram showing an insertion loss of the noise filter of FIG. 8. [Figure 10] 5A and 5B are diagrams illustrating a structure of a noise filter according to a second embodiment. [Figure 11] 13A and 13B are diagrams illustrating a structure of a noise filter according to a third embodiment. [Figure 12] FIG. 1 is a diagram showing a comparison between the prior art, the first embodiment, and the second embodiment.

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0011] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0012] (Overall configuration of the present invention) FIG. 1 is a block diagram showing an overall configuration of a power conversion device according to an embodiment of the present invention.

[0013] Various circuit blocks and elements are housed in the power conversion device 1 (hereinafter, inverter 1). The inverter 1 is also connected to a high-voltage battery 2 that supplies a high DC voltage, and an electric motor 6 that is driven by the AC voltage converted from the DC voltage by the inverter 1.

[0014] The housing of the inverter 1 is a metal case, which is connected to a GND plane 9 via a GND strap 8, and is configured to be placed on an insulator 7 having a height of, for example, 5 mm, in compliance with the international standard CISPR25.

[0015] The inverter 1 has a switching circuit 14 to convert a DC voltage into an AC voltage. The switching circuit 14 has three unit switching circuits SW1 to SW3 having the same configuration, and switches these circuits periodically. Each of the unit switching circuits SW1 to SW3 has insulated gate bipolar transistors (hereinafter, transistors) TR1 and TR2, and diodes D1 and D2. Although not shown, the inverter 1 has a control circuit board that generates a control signal for the switching circuit 14.

[0016] Diodes D1 and D2 are connected between the collector and emitter of transistors TR1 and TR2, respectively. The collector of transistor TR1 is electrically connected to positive wiring 11, which is a DC wiring, and the emitter of transistor TR2 is electrically connected to negative wiring 12, which is also a DC wiring. The emitter of transistor TR1 is connected to the collector of transistor TR2. A connection node connected between the emitter and collector is an output node, which is connected to coils 6-U to 6-W of electric motor 6 from each of unit switching circuits SW1 to SW3 via high-voltage AC cables 5.

[0017] The flow of the control signal of the inverter 1 will be described. A switch control signal from a control circuit board (not shown) is supplied to the gates of the transistors TR1 and TR2 of the unit switching circuits SW1 to SW3. The transistors TR1 and TR2 are switched and controlled by this switch control signal so as to be complementarily turned on and off. Furthermore, as the transistors TR1 and TR2 are complementarily turned on and off, a positive voltage and a negative voltage, that is, an AC voltage, are periodically output to the output node.

[0018] In addition, due to voltage fluctuations at the output section caused by the cyclic on / off of the transistors TR1 and TR2, stray capacitance (parasitic capacitance) occurs between the switching circuit 14 and the housing of the inverter 1. In FIG. 1, this stray capacitance is shown as stray capacitance 1-Cs.

[0019] The high-voltage power supply impedance stabilization network (LISN) 3 will be described. The high-voltage battery 2 supplies power to the inverter 1 via the high-voltage power supply impedance stabilization network (LISN) 3. This housing 3 has a positive LISN circuit section 31 connected to the positive electrode terminal HVP of the high-voltage battery 2 and a negative LISN circuit section 32 connected to the negative electrode terminal HVN of the high-voltage battery 2, and these are stored in a metal housing. The housing of the LISN 3 is connected to the GND plane 9. The positive LISN circuit section 31 and the negative LISN circuit section 32 are electrically connected to the positive wiring 11 and the negative wiring 12, which are the DC wiring of the inverter 1, via the high-voltage DC cable 4.

[0020] The electric motor 6 will be described. The electric motor 6 is a three-phase electric motor, and includes a rotor and a stator (not shown). The housing of the electric motor 6 is connected to a GND plane 9. The electric motor 6 supplies a three-phase AC voltage generated by an inverter 1 to three-phase coils 6-U, 6-V, and 6-W of U, V, and W arranged on the stator via a high-voltage AC cable 5. As a result, the three-phase coils 6-U, 6-V, and 6-W generate magnetic fields corresponding to the three-phase AC voltages, respectively, and the rotor rotates. In FIG. 1, the stray capacitance (parasitic capacitance) generated between the three-phase coils 6-U, 6-V, and 6-W and the housing of the motor 6 is shown as stray capacitance 6-Cs. Although not particularly limited, the housing of the electric motor 6 is connected to the GND plane 9.

[0021] In the inverter 1, a smoothing capacitor Cx for smoothing the DC voltage and a noise filter device 13 are provided between the positive electrode wiring 11 and the negative electrode wiring 12. The smoothing capacitor Cx suppresses the ripple voltage and ripple current generated in the DC wirings 11 and 12, which are bus bars connected to the DC high voltage, during the switching operation of the switching circuit 14. The smoothing capacitors Cx1 and Cx2 are for reducing normal mode noise. The reduction effect or attenuation performance is generally expressed by the insertion loss of the filter. The reduction mechanism by the capacitors will be explained below. The principle is to suppress the outflow of noise to the outside by providing a low impedance path between the DC wirings by implementing a noise filter. In addition, in order to suppress high voltage conduction noise in a wide frequency band, two capacitors with different capacities connected in parallel are generally used.

[0022] The noise filter device 13 has a magnetic core Lc surrounding the DC wiring including the positive wiring 11 and the negative wiring 12, a first grounding capacitor Cy1 connected to the DC wirings 11, 12 in the front stage of the magnetic core Lc, and a second grounding capacitor Cy2 connected to the DC wirings 11, 12 in the rear stage of the magnetic core Lc. The grounding capacitors Cy1 and Cy2 and the magnetic core Lc are for reducing common mode noise.

[0023] The first ground capacitor Cy1 is composed of a ground capacitor Cy11 connected between the positive wiring 11 and the first ground point G1, and a ground capacitor Cy12 connected between the negative wiring 12 and the first ground point G1. Similarly, the second ground capacitor Cy2 is composed of a ground capacitor Cy21 connected between the positive wiring 11 and the second ground point G2, and a ground capacitor Cy22 connected between the negative wiring 12 and the second ground point G2.

[0024] The noise filter device 13 inputs the high DC voltage to a switching circuit 14, which is a power conversion unit, while attenuating noise in the high DC voltage supplied from the high voltage battery 2. The noise current that causes the noise is a current leaking into the power supply wiring or cable connected between the high DC voltage battery 2 and the inverter 1, and is a common mode current since it flows between the GND.

[0025] The common mode current is caused by voltage fluctuations to ground that occur during switching operations in which the transistors TR1 and TR2 are periodically turned on and off. Due to the voltage fluctuations that occur at the output of the switching circuit 14, a common mode current flows between the inverter 1 and the housing of the motor 6 through the stray capacitance 1-Cs that is parasitic between the switching circuit 14 and the housing of the inverter 1 and the stray capacitance 6-Cs that exists between the coils 6-U to 6-W of the motor 6 and the housing, and this current generates high-voltage conducted noise. Therefore, in order to reduce the high-voltage conducted noise, it is necessary to reduce the common mode current. In the inverter 1, the configuration of the noise filter device 13 is used to deal with the noise current, which is the main cause of high-voltage conducted noise, and to attenuate the noise while complying with the high-voltage conducted noise standard.

[0026] (Regarding noise standards) The high-voltage conducted noise standard will be explained. Noise standards generally prescribe regulatory values ​​in the frequency band from 0.15 MHz to 108 MHz. The high-voltage conducted noise standard is a standard added to CISPR25 Ed4, an international standard created by the International Special Committee on Radio Interference (CISPR) in October 2016. This standard regulates noise in the FM broadcast frequency band (76 MHz to 108 MHz), which is used for various purposes, to be lower than other frequency bands. High-voltage conducted noise may cause malfunction of in-vehicle electric and electronic devices, for example. Therefore, the amount of high-voltage conducted noise generated by the inverter 1 must be measured before shipping, and the amount of noise must be equal to or lower than the regulatory value prescribed by the laws and regulations of each country and the customer's required specifications. Therefore, the inverter 1 employs a noise filter device 13 to comply with the high-voltage conducted noise standard and to have an effective filter configuration.

[0027] FIG. 2 is an equivalent circuit diagram of a noise filter device 13 for reducing normal mode high voltage conduction noise.

[0028] Capacitors Cx1 and Cx2 are connected in parallel to the positive DC wiring 11 and the negative DC wiring 12. P1 and N1 are connection parts between Cx1 and the positive DC wiring 11 and the negative DC wiring 12, respectively, and P2 and N2 are connection parts between Cx2 and the positive DC wiring 11 and the negative DC wiring 12, respectively. Furthermore, Pin and Nin are input terminals on the positive and negative sides, respectively, and represent connection parts between the switching circuit 14, which is a noise source, and the positive DC wiring 11 and the negative wiring 12. Similarly, Pout and Nout are output terminals on the positive and negative sides, respectively, and represent connection parts between the positive DC wiring 11, the negative wiring 12, and the high-voltage DC cable 4.

[0029] The noise reduction effect NS is expressed by the following equation (1) using the input voltage Vin (simulating a noise source) input between Pin and Nin, and the output voltage Vout output between Pout and Nout.

[0030] NS=|Vout / Vin|…Equation (1)

[0031] To obtain the desired noise reduction effect NS, ideally it is sufficient to simply select constants for the capacitors Cx1 and Cx2 that provide low impedance in the target frequency band, but actual components (elements) have parasitic components. For example, capacitor components and DC wiring have parasitic inductance (hereinafter referred to as ESL) components such as lead wires.

[0032] FIG. 3 is an equivalent circuit diagram including parasitic components of the noise filter device 13 in FIG.

[0033] In Fig. 3, the parasitic inductances of the first capacitor Cx1 and the second capacitor Cx2 are represented by equivalent series inductances Lc1 and Lc2, respectively. The inductance component of the positive DC wiring 11 between the positive connecting parts P1 and P2 is represented by equivalent series inductance Lp1, and the inductance component of the negative DC wiring 12 between the negative connecting parts N1 and N2 is represented by equivalent series inductance Ln1. Similarly, Lp0 is the inductance component of the positive DC wiring between Pout-P1, and Lp2 is the inductance component of the positive DC wiring between Pin-P2, and Ln0 is the inductance component of the negative DC wiring between Nout-N1, and Ln2 is the inductance component of the negative DC wiring between Nin-N2.

[0034] k1 is the coupling coefficient between inductors having inductances Lp1 and Ln1. The coupling coefficients between inductors having inductance components Lp0 and Ln0, and Lp2 and Ln2 are not shown in the figure, but are used in the actual calculations. The * marks next to inductors Lp1 and Ln1 indicate the direction in which the magnetic field is generated.

[0035] Power supply Gn is an AC voltage source that simulates the noise voltage generated by the switching circuit 14, and V1 is a voltmeter that measures power supply Gn. Resistors R3 and R4 respectively simulate the internal resistance of power supply Gn and the equivalent resistance of the components connected to the output side. V2 is a voltmeter that measures the voltage of resistor R4.

[0036] FIG. 4 is a characteristic diagram showing the insertion loss of the noise filter device 13 of FIG.

[0037] In the characteristic diagram of Fig. 4, the horizontal axis indicates frequency F (Frequency [MHz]) and the vertical axis indicates the insertion loss of the noise filter device 13, i.e., the ratio of voltages V2 and V1 shown in Fig. 3, expressed in decibels (dB). The smaller the ratio of voltages V2 and V1 is, the higher the insertion loss of the filter becomes and the better the attenuation performance becomes.

[0038] Characteristic curve GLb1 shows the change in insertion loss with a change in frequency F when the equivalent series inductances Lc1 and Lc2 of capacitors Cx1 and Cx2 are set to 0 nH, respectively. On the other hand, characteristic curve GLb0 shows the change in insertion loss when the equivalent series inductances Lc1 and Lc2 are set to a typical value of 40 nH, respectively. Note that the parameters of the circuit elements other than Lc1 and Lc2 are the same when calculating characteristic curves GLb0 and GLb1.

[0039] Comparing characteristic curves GLb0 and GLb1, in the target frequency band of 20 MHz or higher, the filter insertion loss of characteristic curve GLb0 is worse than that of characteristic curve GLb1. As mentioned above, the high-voltage conducted noise standard prescribes regulation values ​​for the frequency band from 0.15 MHz to 108 MHz, and in particular, in the high-frequency band of 20 MHz or higher, which includes the FM frequency band (76 MHz to 108 MHz) used for various purposes, the regulation values ​​are lower than other frequency bands, so it is necessary to improve the filter insertion loss.

[0040] FIG. 5 is a diagram illustrating an example of the structure of a noise filter.

[0041] In this example of the noise filter structure, the wiring 111 and 121 between the connecting parts are each about 10 mm long and about 15 mm wide, and their inductance components are calculated to be about 10 nH. Using these values, the equivalent circuit (Figure 6) is used to calculate the insertion loss of the filter. The calculation results are shown in Figure 7.

[0042] (Conventional technology and its problems) FIG. 6 is an equivalent circuit diagram including parasitic components of a noise filter to which the conventional technology is applied.

[0043] In Fig. 6, in the equivalent circuit shown in Fig. 3, the connection wiring between the first capacitor Cx1 and the positive wiring 11 and the connection wiring between the second capacitor Cx2 and the positive wiring 11 are crossed. Note that an example in which the first capacitor Cx1 and the second capacitor Cx2 are structurally crossed using this circuit configuration is shown in Fig. 12(b) described later.

[0044] The purpose of this crossing of the connection wiring will be explained below. Conventional techniques for canceling out ESL components include using capacitors with short leads or cutting and shortening the leads, but this requires the addition of custom parts or cutting work, which creates a new issue of increased manufacturing costs for the power conversion device. To solve this issue, the circuit configuration shown in Figure 6 is used to cancel out the ESL components.

[0045] Another key point of this configuration is that the inductance components Lp1 and Ln1 of the wiring between the connecting parts can be aligned to the ESL components Lc1 and Lc2 of the capacitor. This makes it possible to improve the insertion loss of the filter. For example, in the case of low-voltage, low-current applications such as control boards, most capacitors are surface-mounted types without leads and have an ESL component of around a few nH, so by adjusting the length and width of the board wiring traces, the inductance components of the wiring between the connecting parts can be easily aligned to the ESL components of the capacitor.

[0046] However, in the case of high voltage / high current applications such as vehicle inverters, the capacitors used in noise filters are high voltage compatible types, and since they have lead wires and are larger in size than low voltage compatible types, they are correspondingly larger than those for low voltage / low current applications such as ESL component control boards, at about 40 to 50 nH. In this case, in order to maintain thermal feasibility, it is necessary to make the DC wiring wider, and since the arrangement space for the DC wiring is limited due to the demand for miniaturization, it is also necessary to shorten the bus bar. In other words, the inductance component of the DC wiring tends to become smaller, making it difficult to match it with the ESL component of the capacitor, which becomes larger. As a result, a problem arises in which the effect of improving the insertion loss of the filter cannot be obtained. The present invention is intended to structurally solve this problem while utilizing the properties of the circuit shown in FIG. 6.

[0047] FIG. 7 is a characteristic diagram showing the insertion loss of the noise filter of FIG.

[0048] Characteristic curve GLb2 shows the change in insertion loss of the filter with a change in frequency F when inductors Lp1 and Ln1 are set to 10 nH. Characteristic curve GLb0 shows the change in insertion loss when there are no crossover wirings, and is the same as GLb0 in Figure 4. Note that the parameters of the circuit elements other than the crossover wiring configuration when calculating characteristic curves GLb0 and GLb2 are the same as those in Figure 3.

[0049] As shown in FIG. 7, if the parasitic inductance and capacitor ESL components are not aligned, no improvement in the filter insertion loss can be obtained, as can be seen from the fact that there is almost no change in the characteristic curves GLb0 and GLb2.

[0050] (First embodiment) FIG. 8 is a diagram showing a structure of the noise filter device 13 according to the first embodiment.

[0051] Fig. 8(a) is a circuit diagram of a noise filter device 13 according to a first embodiment of the present invention, and Fig. 8(b) is a diagram showing the configuration of the three-dimensional structure thereof. Fig. 8(a) shows the noise filter device 13, of the circuit blocks and components housed in the housing of the inverter 1, with one end (the left side of Fig. 8(a)) connected to the DC power supply (high-voltage battery 2) and the other end (the right side of Fig. 8(a)) connected to the power conversion circuit (switching circuit 14).

[0052] The present invention is characterized in that the positive wiring 111 connecting the first positive connection part P1 and the second positive connection part P2 intersects with the negative wiring 121 connecting the first negative connection part N1 and the second negative connection part N2. This intersection is laminated as shown in Fig. 8(b), and by adjusting the area and interval of this part and the length and width of the wiring, the inductance components of the positive wiring 111 and the negative wiring 121 can be controlled and aligned to the ESL components Lc1 and Lc2 of the first capacitor Cx1 and the second capacitor Cx2.

[0053] FIG. 9 is a characteristic diagram showing the insertion loss of the noise filter of FIG.

[0054] The characteristic curve GLb3 of the present invention shows the change in insertion loss with change in frequency F when the inductance components of Lp1 and Ln1 are approximately 40 nH, and an improvement in insertion loss of 20 dB or more can be obtained in the high frequency band of 20 MHz or more.

[0055] Second Embodiment Fig. 10 is a diagram showing the structure of a noise filter device 13 according to the second embodiment. Note that Fig. 10(a) is the same as Fig. 8(a).

[0056] In FIG. 10(b), the intersection of the positive wiring 111 and the negative wiring 121 is arranged so as to follow multiple faces of the first capacitor Cx1 and the second capacitor Cx2, which are polyhedral capacitors. Furthermore, when the capacitance of the capacitor Cx2 is smaller than that of the capacitor Cx1, the busbar intersection follows the bottom surface of the capacitor Cx2. The bottom surface of the capacitor Cx2 is the side on which the case (the housing of the inverter 1) is installed. This makes it possible to further secure the area for routing the busbar, and to increase the inductance component of the positive wiring 111 and the negative wiring 121.

[0057] In addition, the intersecting positive and negative wirings 111 and 121 are arranged along multiple faces of the first and second capacitors, and the busbar intersections are routed in a meandering manner, thereby further ensuring a routing area for the busbars.

[0058] For example, the bus bar intersections may be arranged along only the side of the capacitor closer to the noise source or closer to the output terminal.

[0059] (Third embodiment) Fig. 11 is a diagram showing the structure of a noise filter device 13 according to a third embodiment. Note that Fig. 11(a) is the same as Fig. 8(a) and Fig. 10(a).

[0060] In Fig. 11(b), the intersection is arranged only along the side of the capacitor that is closer to the noise source (the power conversion device side). By doing so, it is possible to prevent the size from becoming large in the height direction.

[0061] Fig. 12 is a diagram showing a comparison between the conventional technology, the first embodiment, and the second embodiment. Fig. 12(a) shows a noise filter having the same structure as Fig. 5, and Fig. 12(b) shows a noise filter obtained by structuring the circuit diagram of Fig. 6. Fig. 12(c) shows the first embodiment, and Fig. 12(d) shows the second embodiment.

[0062] In Fig. 12, in comparison with the cases of Fig. 12(a) and Fig. 12(b), the inductance component is increased in the first embodiment shown in Fig. 12(c) and the second embodiment shown in Fig. 12(d). Furthermore, the second embodiment, which has a larger busbar area than the first embodiment, has an inductance component that is further increased compared to the first embodiment.

[0063] As can be seen from the wiring structures in Figures 12(c) and 12(d), the current flows in the same direction at the intersections, generating a magnetic field in the same direction. Therefore, the mutual coefficient and mutual inductance at this point are positive values, and the inductance component of the entire wiring becomes larger. In other words, as mentioned above, by adjusting the area and spacing of the intersections and the length and width of the wiring, the inductance component of the wiring can be controlled to match the ESL component of the capacitor. This cancels the ESL component of the capacitor, improving the insertion loss characteristics of the filter and suppressing high-frequency normal mode high-voltage conduction noise.

[0064] According to the first to third embodiments of the present invention described above, the following advantageous effects can be obtained.

[0065] (1) The filter device 13 has one end connected to a DC power supply side and the other end connected to a power conversion circuit side, and includes a positive wiring 11, a negative wiring 12, and a first capacitor Cx1 and a second capacitor Cx2 connected in parallel between the positive wiring 11 and the negative wiring 12, the positive wiring 11 has a first positive electrode connection part P1 connected to the first capacitor Cx1 at one end side and a second positive electrode connection part P2 connected to the second capacitor Cx2 at the other end side, the negative wiring 12 has a first negative electrode connection part N1 connected to the second capacitor Cx2 at one end side and a second negative electrode connection part N2 connected to the second capacitor Cx2 at the other end side, and the positive wiring 11 and the negative wiring 12 cross each other. In this way, it is possible to provide a filter device and a power conversion device that are low in cost, small in size, and low in noise.

[0066] (2) In the filter device 13, the intersections of the positive and negative wirings 11 and 12 are laminated. In this way, by adjusting the area and interval of this portion and the length and width of the wiring, the inductance components of the positive and negative wirings 11 and 12 can be controlled and aligned to the ESL components Lc1 and Lc2 of the first and second capacitors Cx1 and Cx2.

[0067] (3) In the filter device 13, the positive electrode wiring 11 and the negative electrode wiring 12 are arranged along multiple faces of the first capacitor Cx1 and the second capacitor Cx2. In this manner, a wiring area for the bus bars 11 and 12 can be secured.

[0068] (4) In the filter device 13, when the capacitance of the second capacitor Cx2 is smaller than the capacitance of the first capacitor Cx1, the positive electrode wiring 11 and the negative electrode wiring 12 intersect on the lower surface of the second capacitor Cx2. This makes it possible to ensure a wiring area for the bus bars 11 and 12.

[0069] (5) In the filter device 13, the intersection between the positive electrode wiring 11 and the negative electrode wiring 12 meanders. This makes it possible to ensure a wiring area for the bus bars 11 and 12.

[0070] (6) In the filter device 13, the inductance between the positive electrode wiring 11 and the negative electrode wiring 12 is approximately equal to the inductance of the first capacitor Cx1 or the second capacitor Cx2. This can improve the insertion loss of the filter.

[0071] The present invention is not limited to the above-mentioned embodiment, and various modifications and other configurations can be combined without departing from the scope of the present invention. The present invention is not limited to the above-mentioned embodiment, and includes the above-mentioned embodiment with all the configurations described, and includes the above-mentioned embodiment with some of the configurations omitted. For example, the above-mentioned embodiment is described with the power conversion device mounted on a vehicle such as a hybrid vehicle or an electric vehicle, but the present invention is not limited to these and can be applied to a power conversion device used in a construction machine or a railway vehicle. [Explanation of symbols]

[0072] 1...Power conversion device (inverter) 1-Cs: Stray capacitance between switching circuit and housing 2…High voltage battery 3. High-Voltage Power Impedance Stabilization Network (LISN) 31…Positive LISN circuit section 32...Negative LISN circuit section 4…High voltage DC cable 5…High voltage AC cable 6. Electric motor 6-U…U phase coil 6-V…V-phase coil 6-W…W-phase coil 6-Cs: Stray capacitance between coil and housing 7…Insulator 8…GND strap 9…GND plane 10…Current 10a…Reverse current 10b… Current flowing in the same direction 11...Positive (DC) wiring 12...Negative electrode (DC) wiring 13...Noise filter device 14...Switching circuit 111...Positive electrode wiring connecting the first positive electrode connector P1 and the second positive electrode connector P2 121...Negative electrode wiring connecting the first negative electrode connector N1 and the second negative electrode connector N2 SW1~SW3...Unit switching circuit TR1, TR2...Insulated gate bipolar transistor D1, D2...Diode Cx: Smoothing capacitor Gn…Power supply Lc…Magnetic core Lc1, Lc2: equivalent series inductance Lp0~Lp3: Equivalent series inductance (positive wiring) Ln0~Ln3: Equivalent series inductance (negative wiring) k1: Coupling coefficient between positive and negative DC wiring Cy1, Cy2...ground capacitor Cy11, Cy21: Grounding capacitor between positive DC wiring and case Cy12, Cy22: Ground capacitor between negative DC wiring and case Cx1: The first capacitor between the positive and negative DC wiring Cx2: Second capacitor between positive and negative DC wiring P1: A first positive electrode connection part which is a connection part between the first capacitor Cx1 and the positive electrode wiring 11 P2: A second positive electrode connection portion which is a connection portion between the second capacitor Cx2 and the positive electrode wiring 11 N1: a first negative electrode connection portion which is a connection portion between the first capacitor Cx1 and the negative electrode wiring 12 N2: a second negative electrode connection portion which is a connection portion between the second capacitor Cx2 and the negative electrode wiring 12

Claims

1. A filter device having one end connected to a DC power supply side and the other end connected to a power conversion circuit side, A positive electrode wiring, a negative electrode wiring, and a first capacitor and a second capacitor connected in parallel between the positive electrode wiring and the negative electrode wiring, The positive wiring has a first positive electrode connection portion connected to the first capacitor on one end side of the positive wiring, and a second positive electrode connection portion connected to the second capacitor on the other end side of the positive wiring, The negative wiring has a first negative electrode connection portion connected to the second capacitor on one end side of the negative wiring, and a second negative electrode connection portion connected to the first capacitor on the other end side of the negative wiring, When a virtual plane is provided that passes through a midpoint between the first positive electrode connection portion and the first negative electrode connection portion and is perpendicular to a virtual line that connects the first positive electrode connection portion and the first negative electrode connection portion, the first positive electrode connection portion and the second positive electrode connection portion are located on different sides of the virtual plane, and the first negative electrode connection portion and the second negative electrode connection portion are located on different sides of the virtual plane. Filter device.

2. 2. The filter device according to claim 1, The positive electrode wiring and the negative electrode wiring are stacked on each other at least between the first capacitor and the second capacitor. Filter device.

3. 3. A filter device according to claim 2, The positive electrode wiring and the negative electrode wiring are arranged along at least a plurality of surfaces of the first capacitor and the second capacitor, respectively. Filter device.

4. 3. A filter device according to claim 2, When a surface of the first capacitor on which the first positive electrode connection portion and the second positive electrode connection portion are formed and a surface of the second capacitor on which the first negative electrode connection portion and the second negative electrode connection portion are formed are defined as upper surfaces, and a surface opposite to the upper surfaces is defined as a lower surface, When the capacitance of the second capacitor is smaller than the capacitance of the first capacitor, the positive electrode wiring and the negative electrode wiring are stacked on the lower surface of the second capacitor. Filter device.

5. 5. A filter device according to claim 4, The portion where the first capacitor and the second capacitor are stacked on each other is disposed from the upper surface of the first capacitor, passing between the first capacitor and the second capacitor, to the lower surface of the second capacitor. Filter device.

6. 2. The filter device according to claim 1, The inductance between the positive wiring and the negative wiring is approximately equal to the inductance of the first capacitor or the second capacitor. Filter device.

7. Equipped with a filter device according to any one of claims 1 to 6 Power conversion equipment.

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