JP7363151B2 - inverter device - Google Patents

Description

The present invention includes a switching element unit having a plurality of switching elements constituting an inverter circuit, a smoothing capacitor for smoothing a voltage on the DC side of the inverter circuit, and a discharge resistor connected in parallel with the smoothing capacitor. It relates to an inverter device.

An example of such an inverter device is disclosed in Patent Document 1 below. Hereinafter, in the description of this background art, the reference numerals in Patent Document 1 will be cited in parentheses.

In the inverter device of Patent Document 1, a plurality of capacitor elements (C1) of a smoothing capacitor (C) are arranged between a positive electrode connection member (P) and a negative electrode connection member (N) connected to a DC power source (BAT). and is housed in a capacitor case (2). A discharge resistor (R) is arranged inside the capacitor case (2) in a region opposite to the DC power supply (BAT) side with respect to the plurality of capacitor elements (C1).

In this manner, in the inverter device of Patent Document 1, the discharge resistor (R) that generates heat when energized is placed away from the capacitor element (C1) on the DC power supply (BAT) side, where the temperature tends to increase. In this way, with a simple configuration, the temperature inside the capacitor case (2) is made uniform, and the difference in deterioration between the plurality of capacitor elements (C1) is reduced.

Japanese Patent Application Publication No. 2009-278794

However, in the inverter device of Patent Document 1, heat generation of the positive electrode connecting member (P) and the negative electrode connecting member (N) due to energization is not taken into consideration. Therefore, the heat of the positive electrode connecting member (P) and the negative electrode connecting member (N) and the heat of the discharge resistor (R) may accelerate deterioration of the capacitor element (C1).

Therefore, it is desired to realize an inverter device that has a simple configuration and can reduce deterioration of the capacitor elements of the smoothing capacitor due to heat.

In view of the above, the characteristic configuration of the inverter device is as follows:
a switching element unit having a plurality of switching elements constituting an inverter circuit;
a smoothing capacitor that smoothes the voltage on the DC side of the inverter circuit;
a discharge resistor connected in parallel with the smoothing capacitor;
a positive electrode connecting member that is electrically connected to a positive electrode of a DC power supply and that electrically connects the positive electrodes of the switching element unit, the smoothing capacitor, and the discharge resistor;
An inverter device comprising: a negative electrode connecting member that is electrically connected to the negative electrode of the DC power supply and that electrically connects the negative electrodes of the switching element unit, the smoothing capacitor, and the discharge resistor;
The smoothing capacitor includes at least one capacitor element having a positive electrode surface and a negative electrode surface facing opposite to the positive electrode surface,
The capacitor element is arranged in a rectangular parallelepiped arrangement area,
The positive electrode connecting member includes a positive electrode body portion formed along the positive electrode surface, and a positive electrode first terminal formed to protrude from the positive electrode body portion and electrically connected to the positive electrode of the DC power source. , a positive electrode second terminal formed to protrude from the positive electrode main body and electrically connected to the positive electrode of the switching element unit,
The negative electrode connecting member includes a negative electrode body portion formed along the negative electrode surface, and a negative electrode first terminal formed to protrude from the negative electrode body portion and electrically connected to the negative electrode of the DC power source. , a negative electrode second terminal formed to protrude from the negative electrode main body and electrically connected to the negative electrode of the switching element unit,
four surfaces in the arrangement region of the capacitor element along a direction intersecting the positive electrode surface and the negative electrode surface are respectively defined as capacitor side surfaces;
The discharge resistor is adjacent to a surface of the four capacitor side surfaces on which none of the positive first terminal, the positive second terminal, the negative first terminal, and the negative second terminal are arranged. It is located at the point where it is located.

According to this characteristic configuration, among the four side surfaces of the capacitor, the temperature of the positive electrode first terminal and the positive electrode second terminal tends to become higher than that of the positive electrode main body, and the temperature of the positive electrode second terminal tends to rise higher than that of the negative electrode main body. A discharge resistor is disposed adjacent to the surface on which neither the first negative terminal nor the second negative terminal is disposed. In other words, the discharge resistor that generates heat when energized is placed away from the first positive terminal and the second positive terminal, and the first negative terminal and the second negative terminal, which tend to have relatively high temperatures. Thereby, it is possible to suppress the temperature around the discharge resistor from rising excessively. As described above, according to the present configuration, deterioration due to heat of the capacitor element of the smoothing capacitor can be reduced with a simple configuration.

A diagram showing a circuit of an inverter device according to an embodiment A perspective view showing a capacitor element, a positive electrode connecting member, and a negative electrode connecting member A perspective view showing a smoothing capacitor, a discharge resistor, a positive electrode connecting member, and a negative electrode connecting member. Side sectional view of an inverter device according to an embodiment A plan view of an inverter device according to an embodiment

Below, an inverter device 100 according to an embodiment will be described with reference to the drawings. As shown in FIG. 1, in the present embodiment, the inverter device 100 is connected to the battery BT and the rotating electric machine MG, so that the DC current of the battery BT and the multiple phases (here, U phase, U phase, Converts power between AC and 3-phase (V-phase and W-phase) alternating current. The rotating electrical machine MG has a function as a motor (electric motor) that receives power and generates power, and a generator (generator) that receives power and generates power. Note that in this embodiment, the battery BT corresponds to a "DC power source."

The inverter device 100 includes a switching element unit 1, a smoothing capacitor 2, a positive electrode connection member 3P, a negative electrode connection member 3N, and a discharge resistor 4. The switching element unit 1 has a plurality of switching elements 11 forming an inverter circuit 11C. The smoothing capacitor 2 is a capacitor that smoothes the DC side voltage (DC link voltage) of the inverter circuit 11C. The positive electrode connecting member 3P is a member that is electrically connected to the positive electrode of the battery BT and also electrically connects the positive electrodes of the switching element unit 1, the smoothing capacitor 2, and the discharge resistor 4. The negative electrode connecting member 3N is a member that is electrically connected to the negative electrode of the battery BT and also electrically connects the negative electrodes of the switching element unit 1, the smoothing capacitor 2, and the discharge resistor 4. The discharge resistor 4 is connected in parallel with the smoothing capacitor 2.

The switching element 11 includes an IGBT (Insulated Gate Bipolar Transistor), a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), a SiC-MOSFET (Silicon Carbide - Metal Oxide Semiconductor FET), a SiC-SIT (SiC - Static Induction Transistor), and a GaN - It is preferable to use a power semiconductor element that can operate at high frequencies, such as a MOSFET (Gallium Nitride - MOSFET). Here, an IGBT is used as the switching element 11. Freewheeling diodes 12 are provided in each of the plurality of switching elements 11 in parallel, with the direction from the negative electrode to the positive electrode (direction from the lower stage side to the upper stage side) being the forward direction.

As shown in FIG. 2, the smoothing capacitor 2 includes at least one capacitor element 21. The capacitor element 21 is formed with a positive electrode surface 21P and a negative electrode surface 21N facing opposite to the positive electrode surface 21P. In this embodiment, the capacitor element 21 is formed into a rectangular parallelepiped shape. A pair of surfaces facing opposite to each other in the capacitor element 21 are configured as a positive electrode surface 21P and a negative electrode surface 21N, respectively.

The capacitor element 21 is arranged in a rectangular parallelepiped arrangement region AR. The placement area AR is a virtual three-dimensional area indicating an area where the capacitor element 21 is placed. The arrangement region AR includes four capacitor side surfaces SF, which are four surfaces along a direction intersecting the positive electrode surface 21P and the negative electrode surface 21N of the capacitor element 21. When one capacitor element 21 is arranged in the arrangement region AR, the one capacitor element 21 is formed in the shape of a rectangular parallelepiped. Further, when a plurality of capacitor elements 21 are arranged in the arrangement region AR, a set of the plurality of capacitor elements 21 is arranged to form a rectangular parallelepiped shape. Here, "rectangular parallelepiped shape" means that the general shape as a whole is a rectangular parallelepiped even if it has some irregularly shaped parts. Hereinafter, the same shall apply to other expressions used with the addition of "shape" regarding shapes, etc.

In this embodiment, the surface along the positive electrode surface 21P and negative electrode surface 21N of the capacitor element 21 in the arrangement region AR is formed in a rectangular shape. Therefore, in the following description, the direction along the long side of the surface along the positive electrode surface 21P and the negative electrode surface 21N in the arrangement region AR will be referred to as the "longitudinal direction X", and the direction along the short side will be referred to as the "shorter side direction Y". One side in the longitudinal direction X is defined as a "first longitudinal side X1", and the other side in the longitudinal direction X is defined as a "second longitudinal side X2". Further, one side in the transversal direction Y is referred to as a "transverse direction first side Y1", and the other side in the transverse direction Y is referred to as a "transverse direction second side Y2". Further, the direction in which the positive electrode surface 21P and the negative electrode surface 21N are lined up is defined as a "height direction Z." In the height direction Z, the side of the positive electrode surface 21P is defined as the "positive electrode surface side Z1", and the side of the negative electrode surface 21N is defined as the "negative electrode surface side Z2".

In this embodiment, a plurality of capacitor elements 21 are arranged in a matrix. In the illustrated example, the plurality of capacitor elements 21 are arranged so that six capacitor elements 21 are lined up in the longitudinal direction X, one or two capacitor elements 21 are lined up in the width direction Y, and one capacitor element 21 is lined up in the height direction Z.

The negative electrode connecting member 3N includes a negative electrode main body 31N formed along the negative electrode surface 21N of the capacitor element 21, and a negative electrode formed to protrude from the negative electrode main body 31N and electrically connected to the negative electrode of the battery BT. It includes a first terminal 32N and a second negative terminal 33N that is formed to protrude from the negative electrode main body 31N and is electrically connected to the negative electrode of the switching element unit 1. In this embodiment, the negative electrode connecting member 3N also includes a negative third terminal 34N electrically connected to the negative electrode of the discharge resistor 4.

The negative electrode main body portion 31N is formed into a plate shape extending along the longitudinal direction X and the transverse direction Y. In this embodiment, the negative electrode main body portion 31N has a negative electrode joint portion 311N joined to each of the negative electrode surfaces 21N of the plurality of capacitor elements 21. In the illustrated example, the negative electrode junction portion 311N is formed into a plate shape having an area smaller than the area of the negative electrode surface 21N of the capacitor element 21.

The negative electrode first terminal 32N is formed to protrude toward the first longitudinal side X1 from the capacitor side surface SF on the first longitudinal side X1. In this embodiment, the negative electrode first terminal 32N protrudes from the end of the first longitudinal side X1 of the negative electrode main body 31N on the first side Y1 in the transverse direction to the negative electrode surface side Z2, and further extends in the transverse direction. It is formed so as to protrude in the longitudinal direction toward the first side X1 as it goes toward the first side Y1.

The negative electrode second terminal 33N is formed so as to protrude toward the first side Y1 in the transverse direction from the side surface SF of the capacitor on the first side Y1 in the transverse direction. In the present embodiment, the negative electrode second terminal 33N protrudes from the edge of the negative electrode main body 31N on the first side Y1 in the short direction to the negative electrode surface side Z2, and then protrudes to the first side Y1 in the short direction, and further extends to the first side Y1 in the short direction. It is formed so that it protrudes toward the surface side Z2, and finally the tip portion protrudes toward the second side Y2 in the lateral direction. Moreover, in this embodiment, the three negative electrode second terminals 33N are arranged at intervals in the longitudinal direction X.

The negative third terminal 34N is formed to protrude toward the first longitudinal side X1 from the capacitor side surface SF on the first longitudinal side X1. In this embodiment, the negative electrode third terminal 34N protrudes from the edge of the first longitudinal side X1 of the negative electrode main body 31N to the negative electrode surface side Z2, then protrudes to the longitudinal direction first side X1, and then further extends to the positive electrode surface side. It is formed to protrude in Z1.

The positive electrode connecting member 3P includes a positive electrode main body 31P formed along the positive electrode surface 21P of the capacitor element 21, and a positive electrode formed to protrude from the positive electrode main body 31P and electrically connected to the positive electrode of the battery BT. It includes a first terminal 32P and a second positive terminal 33P that is formed to protrude from the positive electrode body 31P and is electrically connected to the positive electrode of the switching element unit 1. In this embodiment, the positive electrode connecting member 3P also includes a positive electrode third terminal 34P that is electrically connected to the positive electrode of the discharge resistor 4.

The positive electrode main body portion 31P is formed in a plate shape extending along the longitudinal direction X and the transverse direction Y. In this embodiment, the positive electrode main body portion 31P has a positive electrode joint portion joined to each of the positive electrode surfaces 21P of the plurality of capacitor elements 21. Although not shown, the shape of the positive electrode body 31P including the positive electrode joint is similar to the shape of the negative electrode body 31N.

The positive electrode first terminal 32P is formed to protrude toward the first longitudinal side X1 from the capacitor side surface SF on the first longitudinal side X1. In this embodiment, the positive electrode first terminal 32P protrudes from the end edge of the first longitudinal side X1 of the positive electrode main body 31P toward the negative electrode surface side Z2, and further extends toward the first longitudinal side Y1 in the longitudinal direction. It is formed to protrude in the direction toward side X1. In the present embodiment, the positive electrode first terminal 32P has a distal end in the longitudinal direction X at the same position as the distal end of the negative first terminal 32N in the longitudinal direction X, and The position of the tip of the positive electrode first terminal 32P in the height direction Z is the same as the position of the tip of the negative electrode first terminal 32N in the height direction Z. Furthermore, in this embodiment, the tip of the first positive terminal 32P and the tip of the first negative terminal 32N are arranged adjacent to each other in the lateral direction Y. In other words, the first positive terminal 32P and the first negative terminal 32N are arranged adjacent to each other. In the illustrated example, the positive electrode first terminal 32P is arranged adjacent to the negative electrode first terminal 32N on the second side Y2 in the lateral direction.

The positive electrode second terminal 33P is formed so as to protrude toward the first side Y1 in the transverse direction from the side surface SF of the capacitor on the first side Y1 in the transverse direction. In this embodiment, the positive electrode second terminal 33P protrudes from the edge of the positive electrode main body part 31P on the first side Y1 in the transverse direction to the negative electrode side Z2, then protrudes to the first side Y1 in the transverse direction, and further protrudes to the first side Y1 in the transverse direction. It is formed so that it protrudes toward the surface side Z2, and finally the tip portion protrudes toward the second side Y2 in the lateral direction. In the present embodiment, the positive electrode second terminal 33P has the same position in the widthwise direction Y of the tip of the positive electrode second terminal 33P as the position in the widthwise direction Y of the tip of the negative electrode second terminal 33N. Moreover, the position of the tip of the positive electrode second terminal 33P in the height direction Z is formed to be the same as the position of the tip of the negative electrode second terminal 33N in the height direction Z. Moreover, in this embodiment, the three positive electrode second terminals 33P are arranged at intervals in the longitudinal direction X. In this embodiment, the three sets of positive second terminals 33P and negative second terminals 33N are arranged in a line along the longitudinal direction X so that the second positive terminals 33P and the second negative terminals 33N are arranged alternately. It is located in

The positive third terminal 34P is formed to protrude toward the first longitudinal side X1 from the capacitor side surface SF on the first longitudinal side X1. In this embodiment, the positive electrode third terminal 34P protrudes from the edge of the first longitudinal side X1 of the positive electrode main body part 31P to the negative electrode surface side Z2, then protrudes to the longitudinal direction first side X1, and then further extends to the positive electrode surface side. It is formed to protrude in Z1. In the present embodiment, the positive third terminal 34P is such that the position in the longitudinal direction X of the tip of the positive third terminal 34P is the same as the position in the longitudinal direction X of the tip of the negative third terminal 34N, and The position of the tip of the positive third terminal 34P in the height direction Z is the same as the position of the tip of the negative third terminal 34N in the height direction Z. Furthermore, in this embodiment, the positive third terminal 34P and the negative third terminal 34N are arranged adjacent to each other in the transverse direction Y.

As described above, the first positive terminal 32P and the first negative terminal 32N protrude toward the first longitudinal side X1 from the capacitor side surface SF on the first longitudinal side X1. Therefore, the first positive terminal 32P and the first negative terminal 32N are arranged on the first longitudinal side X1 with respect to the arrangement region AR. Further, the second positive terminal 33P and the second negative terminal 33N protrude toward the first side Y1 in the transverse direction from the side surface SF of the capacitor on the first side Y1 in the transverse direction. Therefore, the second positive terminal 33P and the second negative terminal 33N are arranged on the first side Y1 in the transverse direction with respect to the arrangement region AR. Further, the third positive terminal 34P and the third negative terminal 34N protrude toward the first longitudinal side X1 from the capacitor side surface SF on the first longitudinal side X1. Therefore, the third positive terminal 34P and the third negative terminal 34N are arranged on the first longitudinal side X1 with respect to the arrangement region AR.

As shown in FIG. 3, the smoothing capacitor 2 includes a capacitor case 22 in this embodiment. The capacitor case 22 has a part of the positive electrode connecting member 3P and the negative electrode connecting member 3N so that at least the first positive terminal 32P, the second positive terminal 33P, the first negative terminal 32N, and the second negative terminal 33N are exposed to the outside. and a capacitor element 21. In this embodiment, the first positive terminal 32P and the first negative terminal 32N, the second positive terminal 33P and the second negative terminal 33N, and the third positive terminal 34P and the third negative terminal 34N are exposed to the outside of the capacitor case 22. are doing.

The capacitor case 22 is formed in a rectangular parallelepiped shape along the arrangement area AR. In other words, the arrangement area AR is defined by the capacitor case 22. The capacitor case 22 also has a top surface 22a facing the positive electrode surface 21P of the capacitor element 21, a bottom surface 22b facing the negative electrode surface 21N of the capacitor element 21, and a height direction Z between the top surface 22a and the bottom surface 22b. It has four side surfaces 22c arranged so as to surround the space between them. The four side surfaces 22c of the capacitor case 22 correspond to the four capacitor side surfaces SF of the arrangement area AR. That is, the outer surface of the capacitor case 22 forms four capacitor side surfaces SF. In this embodiment, the capacitor case 22 is a hollow box member.

In this embodiment, the capacitor case 22 includes a holding portion 23 that holds a second positive terminal 33P and a second negative terminal 33N. The holding portion 23 is made of an electrically insulating material. The holding part 23 is interposed between the positive electrode second terminal 33P and the negative electrode second terminal 33N so as to avoid contact with each other.

Further, in this embodiment, the capacitor case 22 includes a protection portion 24 that protects the positive third terminal 34P and the negative third terminal 34N. In this embodiment, three protection parts 24 are provided. The first protection part 24 is arranged between the positive third terminal 34P and the negative third terminal 34N. The second protection portion 24 is arranged adjacent to the first side Y1 in the transverse direction with respect to the third positive terminal 34P. The third protection part 24 is arranged adjacent to the second negative terminal 34N on the second side Y2 in the lateral direction. In the illustrated example, each of the three protection parts 24 is formed in a plate shape that protrudes from the side surface 22c of the first longitudinal side X1 to the first longitudinal side X1 and extends along the height direction Z. ing.

The discharge resistor 4 is a resistor for discharging the charges accumulated in the smoothing capacitor 2. The discharge resistor 4 is electrically connected to the positive third terminal 34P and the negative third terminal 34N via a pair of connecting members 41. The discharge resistor 4 is adjacent to the surface on which none of the first positive terminal 32P, the second positive terminal 33P, the first negative terminal 32N, and the second negative terminal 33N are arranged among the four capacitor side surfaces SF. It is located. Here, among the four capacitor side surfaces SF, the surface on which none of the positive electrode first terminal 32P, the positive electrode second terminal 33P, the negative electrode first terminal 32N, and the negative electrode second terminal 33N are arranged is the longitudinal direction second These are the capacitor side surface SF on the side X2 and the capacitor side surface SF on the second side Y2 in the transverse direction. In this embodiment, the discharge resistor 4 is arranged adjacent to the side of the four capacitor side surfaces SF opposite to the side where the positive first terminal 32P and the negative first terminal 32N are located with respect to the capacitor element 21. has been done. That is, the discharge resistor 4 is arranged adjacent to the capacitor side surface SF on the second longitudinal side X2, which is separated from the first positive terminal 32P and the first negative terminal 32N in the longitudinal direction X.

As shown in FIGS. 4 and 5, in this embodiment, the inverter device 100 further includes a case 5 that houses the switching element unit 1, the smoothing capacitor 2, and the discharge resistor 4.

In this embodiment, the case 5 includes a plurality of wall portions 51 arranged to face the four capacitor side surfaces SF (here, the side surfaces 22c of the capacitor case 22). Here, the four wall portions 51 are arranged to face the four capacitor side surfaces SF, respectively. Specifically, each of the four wall portions 51 is arranged parallel to the opposing capacitor side surface SF. Here, "parallel" does not necessarily mean being strictly parallel, but means being parallel or close to parallel. The state of being nearly parallel includes, for example, a state of being tilted by ±20° or less with respect to parallelism.

As shown in FIG. 4, in this embodiment, the case 5 includes a partition wall 52 that partitions the internal space of the case 5 in the height direction Z. As shown in FIG. The partition wall portion 52 is formed into a plate shape extending along the longitudinal direction X and the transverse direction Y. The partition wall portion 52 is integrally formed with the four wall portions 51. The smoothing capacitor 2, the positive electrode connecting member 3P, the negative electrode connecting member 3N, and the discharge resistor 4 are arranged on the positive electrode surface side Z1 with respect to the partition wall portion 52 in the internal space of the case 5. The switching element unit 1 is disposed closer to the negative electrode surface Z2 than the partition wall 52 in the internal space of the case 5.

A cooling path 10 through which a refrigerant flows is provided in the case 5. In this embodiment, a plurality of groove portions 52a are formed in the partition wall portion 52 and are recessed toward the negative electrode surface side Z2. The plurality of groove portions 52a are covered from the positive electrode side Z1 by a plate-shaped covering member 6 extending along the longitudinal direction X and the transverse direction Y. In this way, the cooling path 10 is formed by the inner surfaces of the plurality of grooves 52a and the surface of the covering member 6 on the negative electrode side Z2. In this embodiment, the switching element unit 1 is provided with a heat sink 13 for promoting cooling of the plurality of switching elements 11. A plurality of groove portions 52a communicate with spaces formed between a plurality of fins constituting the heat sink 13. That is, the cooling path 10 is formed such that the coolant flows between the plurality of fins that constitute the heat sink 13.

The inlet 10a of the cooling path 10 is formed to communicate the inside and outside of the case 5. In this embodiment, the inlet 10a of the cooling path 10 is formed to penetrate in the longitudinal direction X through the wall portion 51 of the second longitudinal side X2. A cylindrical supply member 71 is inserted into the entrance 10a of the cooling path 10. Further, as shown in FIG. 5, the outlet 10b of the cooling path 10 is also formed to communicate the inside and outside of the case 5. In this embodiment, the outlet 10b of the cooling path 10 is formed so as to penetrate in the widthwise direction Y through the wall portion 51 of the second side Y2 in the widthwise direction. A cylindrical discharge member 72 is inserted into the outlet 10b of the cooling path 10.

In this embodiment, the discharge resistor 4 is arranged so as to be in contact with the case 5. As shown in FIG. 4, in this example, the discharge resistor 4 is arranged so as to be in contact with one of the four walls 51 in which the inlet 10a of the cooling path 10 is formed. That is, the discharge resistor 4 is arranged so as to be in contact with the wall portion 51 of the second longitudinal side X2.

Specifically, a mounting portion 511 for mounting the discharge resistor 4 is formed on the wall portion 51 on the second longitudinal side X2 so as to protrude toward the first longitudinal side X1. The end surface of the positive electrode surface side Z1 of the mounting portion 511 is formed into a planar shape along the longitudinal direction X and the transverse direction Y. The discharge resistor 4 fixed to the fixing member 42 is placed on the end surface of the placement part 511 on the positive electrode side Z1.

Further, in the present embodiment, the pair of connecting members 41 that connect the discharge resistor 4 to the positive third terminal 34P of the positive connecting member 3P and the third negative terminal 34N of the negative connecting member 3N are connected to the top surface 22a of the capacitor case 22. is located along.

[Other embodiments]
(1) In the above embodiment, the discharge resistor 4 is arranged adjacent to the capacitor side surface SF on the second longitudinal side X2 as an example. However, the present invention is not limited to such a configuration, and a configuration may be adopted in which the discharge resistor 4 is arranged adjacent to the capacitor side surface SF on the second side Y2 in the transverse direction.

(2) In the above embodiment, the configuration in which the first positive terminal 32P and the first negative terminal 32N are arranged adjacent to each other has been described as an example. However, without being limited to such a configuration, for example, the positive electrode first terminal 32P and the negative electrode first terminal 32N may be arranged separately on the second widthwise side Y2 and the widthwise first side Y1, respectively. It's okay if it's done.

(3) In the above embodiment, the discharge resistor 4 is in contact with the wall portion 51 of the second longitudinal side X2 in which the inlet 10a of the cooling path 10 is formed. However, without being limited to such a configuration, for example, the discharge resistor 4 may be placed on the wall portion 51 of the first side Y1 in the transverse direction or on the second side in the transverse direction, where the inlet 10a of the cooling path 10 is not formed. It may be in contact with the wall portion 51 of Y2. Alternatively, the discharge resistor 4 may not be in contact with the case 5.

(4) In the above embodiment, the case 5 has been described as an example in which the case 5 includes four wall portions 51 arranged to face the four capacitor side surfaces SF, respectively. However, without being limited to such a configuration, the wall portion of the case 5 may have a shape that does not face part or all of the capacitor side surface SF.

(5) In the above embodiment, the configuration in which the capacitor case 22 is a hollow box member has been described as an example. However, without being limited to such a configuration, for example, part or all of the capacitor case 22 may be made of resin that seals a part of the positive electrode connection member 3P, a part of the negative electrode connection member 3N, and the capacitor element 21. It may be configured by

(6) Note that the configurations disclosed in each of the embodiments described above can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs. Regarding other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of the present disclosure.

[Summary of the above embodiment]
Below, an overview of the inverter device (100) described above will be described.

The inverter device (100) includes a switching element unit (1) having a plurality of switching elements (11) constituting an inverter circuit (11C);
a smoothing capacitor (2) that smoothes the voltage on the DC side of the inverter circuit (11C);
a discharge resistor (4) connected in parallel with the smoothing capacitor (2);
a positive electrode connecting member that is electrically connected to the positive electrode of a DC power source (BT) and that electrically connects the positive electrodes of the switching element unit (1), the smoothing capacitor (2), and the discharge resistor (4); (3P) and
A negative electrode connection that is electrically connected to the negative electrode of the DC power supply (BT) and electrically connects the negative electrodes of the switching element unit (1), the smoothing capacitor (2), and the discharge resistor (4). An inverter device (100) comprising a member (3N),
The smoothing capacitor (2) includes at least one capacitor element (21) formed with a positive electrode surface (21P) and a negative electrode surface (21N) facing opposite to the positive electrode surface (21P),
The capacitor element (21) is arranged in a rectangular parallelepiped arrangement region (AR),
The positive electrode connecting member (3P) includes a positive electrode main body (31P) formed along the positive electrode surface (21P), and is formed to protrude from the positive electrode main body (31P), and is connected to the DC power source (BT). ) a positive electrode first terminal (32P) electrically connected to the positive electrode of the switching element unit (1), and a positive electrode first terminal (32P) formed to protrude from the positive electrode body (31P) and electrically connected to the positive electrode of the switching element unit (1) A positive electrode second terminal (33P),
The negative electrode connecting member (3N) is formed to protrude from the negative electrode main body (31N) and the negative electrode main body (31N) formed along the negative electrode surface (21N), and is connected to the DC power source (BT). ) a negative electrode first terminal (32N) electrically connected to the negative electrode of the switching element unit (1), and a negative electrode first terminal (32N) formed to protrude from the negative electrode main body (31N) and electrically connected to the negative electrode of the switching element unit (1). A negative electrode second terminal (33N),
In the arrangement region (AR) of the capacitor element (21), four surfaces along a direction intersecting the positive electrode surface (21P) and the negative electrode surface (21N) are respectively defined as capacitor side surfaces (SF),
The discharge resistor (4) is connected to the first positive terminal (32P), the second positive terminal (33P), the first negative terminal (32N), and the first negative terminal among the four capacitor side surfaces (SF). It is arranged adjacent to the surface where none of the two terminals (33N) are arranged.

According to this configuration, among the four capacitor side surfaces (SF), the positive electrode first terminal (32P) and the positive electrode second terminal (33P), which tend to have a higher temperature than the positive electrode main body (31P), and the negative electrode The discharge resistor (4) is placed adjacent to the surface where neither the negative electrode first terminal (32N) nor the negative electrode second terminal (33N), which tends to be higher in temperature than the main body (31N), are placed. has been done. In other words, the discharge resistor (4) that generates heat when energized is connected to the positive electrode first terminal (32P) and the positive electrode second terminal (33P), which tend to become relatively high in temperature, and to the negative electrode first terminal (32N) and the negative electrode second terminal. It is placed away from the terminal (33N). Thereby, it is possible to suppress the temperature around the discharge resistor (4) from rising excessively. As described above, according to the present configuration, deterioration due to heat of the capacitor element (21) of the smoothing capacitor (2) can be reduced with a simple configuration.

Here, the positive first terminal (32P) and the negative first terminal (32N) are arranged adjacent to each other,
The discharge resistor (4) is located on the side (of the four capacitor side surfaces (SF)) where the positive electrode first terminal (32P) and the negative electrode first terminal (32N) are located with respect to the capacitor element (21). It is preferable to arrange it adjacent to the surface on the opposite side (X2) to X1).

Generally, a positive first terminal (32P) and a negative first terminal (32N) connected to a DC power supply (BT) are connected to a positive second terminal (33P) and a negative first terminal connected to a switching element unit (1). The temperature tends to be higher than that of 2 terminals (33N). According to this configuration, the discharge resistor (4) is arranged apart from the positive first terminal (32P) and the negative first terminal (32N). Thereby, deterioration of the capacitor element (21) due to heat can be further reduced.

Further, it further includes a case (5) that accommodates the switching element unit (1), the smoothing capacitor (2), and the discharge resistor (4),
A cooling path (10) through which a refrigerant flows is provided in the case (5),
An inlet (10a) of the cooling path (10) is formed to communicate between the inside and outside of the case (5),
It is preferable that the discharge resistor (4) is placed in contact with the case (5).

According to this configuration, when the refrigerant passes through the inlet (10a) of the cooling path (10) provided in the case (5), the case (5) is cooled by the refrigerant. A discharge resistor (4) is placed in contact with the case (5). Thereby, the temperature rise of the discharge resistor (4) can be suppressed. Therefore, deterioration of the capacitor element (21) due to heat can be further reduced.

In the configuration including the case (5),
The case (5) includes a plurality of walls (51) arranged to face the four capacitor side surfaces (SF),
The discharge resistor (4) is arranged to be in contact with the wall portion (51) in which the inlet (10a) of the cooling path (10) is formed among the plurality of wall portions (51). suitable.

According to this configuration, among the plurality of wall parts (51), the wall part (51) in which the inlet (10a) of the cooling path (10) is formed is most easily cooled by the refrigerant. The discharge resistor (4) is placed in contact with the wall (51) in which the entrance (10a) of the cooling path (10) is formed. Thereby, the temperature rise of the discharge resistor (4) can be further suppressed. Therefore, deterioration of the capacitor element (21) due to heat can be further reduced.

Further, the smoothing capacitor (2) has at least the positive first terminal (32P), the positive second terminal (33P), the negative first terminal (32N), and the negative second terminal (33N) externally. a capacitor case (22) housing a part of the positive electrode connection member (3P), a part of the negative electrode connection member (3N), and the capacitor element (21) so as to be exposed;
Preferably, the capacitor case (22) defines the arrangement area (AR), and the outer surface of the capacitor case (22) forms four capacitor side surfaces (SF).

According to this configuration, the rectangular parallelepiped arrangement area (AR) of the capacitor element (21) is defined by the capacitor case (22). Of the four capacitor side surfaces (SF) formed by the outer surface of the capacitor case (22), a positive electrode first terminal (32P) and a positive electrode second terminal are arranged so as to be exposed to the outside of the capacitor case (22). (33P), a discharge resistor (4) is arranged adjacent to the surface on which neither the first negative terminal (32N) nor the second negative terminal (33N) are arranged. Thereby, deterioration of the capacitor element (21) due to heat can be appropriately reduced.

The technology according to the present disclosure includes a switching element unit having a plurality of switching elements constituting an inverter circuit, a smoothing capacitor that smoothes the voltage on the DC side of the inverter circuit, and a discharge resistor connected in parallel with the smoothing capacitor. It can be used for inverter devices equipped with

100 : Inverter device 1 : Switching element unit 11C : Inverter circuit 11 : Switching element 2 : Smoothing capacitor 21 : Capacitor element 21P : Positive electrode surface 21N : Negative electrode surface 3P : Positive electrode connecting member 31P : Positive electrode body part 32P : Positive electrode first terminal 33P : Positive electrode second terminal 3N : Negative electrode connecting member 31N : Negative electrode body part 311N : Negative electrode junction part 32N : Negative electrode first terminal 33N : Negative electrode second terminal 4 : Discharge resistor BT : Battery (DC power supply)
AR: Placement area SF: Capacitor side

Claims (5)

a switching element unit having a plurality of switching elements constituting an inverter circuit;
a smoothing capacitor that smoothes the voltage on the DC side of the inverter circuit;
a discharge resistor connected in parallel with the smoothing capacitor;
a positive electrode connecting member that is electrically connected to a positive electrode of a DC power supply and that electrically connects the positive electrodes of the switching element unit, the smoothing capacitor, and the discharge resistor;
An inverter device comprising: a negative electrode connecting member that is electrically connected to the negative electrode of the DC power supply and that electrically connects the negative electrodes of the switching element unit, the smoothing capacitor, and the discharge resistor;
The smoothing capacitor includes at least one capacitor element having a positive electrode surface and a negative electrode surface facing opposite to the positive electrode surface,
The capacitor element is arranged in a rectangular parallelepiped arrangement area,
The positive electrode connecting member includes a positive electrode body portion formed along the positive electrode surface, and a positive electrode first terminal formed to protrude from the positive electrode body portion and electrically connected to the positive electrode of the DC power source. , a positive electrode second terminal formed to protrude from the positive electrode main body and electrically connected to the positive electrode of the switching element unit,
The negative electrode connecting member includes a negative electrode body portion formed along the negative electrode surface, and a negative electrode first terminal formed to protrude from the negative electrode body portion and electrically connected to the negative electrode of the DC power supply. , a negative electrode second terminal formed to protrude from the negative electrode main body and electrically connected to the negative electrode of the switching element unit,
four surfaces in the arrangement region of the capacitor element along a direction intersecting the positive electrode surface and the negative electrode surface are respectively defined as capacitor side surfaces;
The discharge resistor is adjacent to a surface of the four capacitor side surfaces on which none of the positive first terminal, the positive second terminal, the negative first terminal, and the negative second terminal are arranged. placed ,
further comprising a case accommodating the switching element unit, the smoothing capacitor, and the discharge resistor,
A cooling path through which a refrigerant flows is provided in the case,
An inlet of the cooling path is formed to communicate between the inside and outside of the case,
In the above case,
a plurality of walls arranged to face the four side surfaces of the capacitor;
a partition wall that partitions an internal section of the case in a direction along a side surface of the capacitor, is integrally formed;
The cooling path is formed in the partition wall,
An inverter device , wherein the discharge resistor is arranged so as to be in contact with the wall portion of the case . a switching element unit having a plurality of switching elements constituting an inverter circuit;
a smoothing capacitor that smoothes the voltage on the DC side of the inverter circuit;
a discharge resistor connected in parallel with the smoothing capacitor;
a positive electrode connecting member that is electrically connected to a positive electrode of a DC power supply and that electrically connects the positive electrodes of the switching element unit, the smoothing capacitor, and the discharge resistor;
An inverter device comprising: a negative electrode connecting member that is electrically connected to the negative electrode of the DC power supply and that electrically connects the negative electrodes of the switching element unit, the smoothing capacitor, and the discharge resistor;
The smoothing capacitor includes at least one capacitor element having a positive electrode surface and a negative electrode surface facing opposite to the positive electrode surface,
The capacitor element is arranged in a rectangular parallelepiped arrangement area,
The positive electrode connecting member includes a positive electrode body portion formed along the positive electrode surface, and a positive electrode first terminal formed to protrude from the positive electrode body portion and electrically connected to the positive electrode of the DC power source. , a positive electrode second terminal formed to protrude from the positive electrode main body and electrically connected to the positive electrode of the switching element unit,
The negative electrode connecting member includes a negative electrode body portion formed along the negative electrode surface, and a negative electrode first terminal formed to protrude from the negative electrode body portion and electrically connected to the negative electrode of the DC power supply. , a negative electrode second terminal formed to protrude from the negative electrode main body and electrically connected to the negative electrode of the switching element unit,
four surfaces in the arrangement region of the capacitor element along a direction intersecting the positive electrode surface and the negative electrode surface are respectively defined as capacitor side surfaces;
The discharge resistor is adjacent to a surface of the four capacitor side surfaces on which none of the positive first terminal, the positive second terminal, the negative first terminal, and the negative second terminal are arranged. placed ,
further comprising a case accommodating the switching element unit, the smoothing capacitor, and the discharge resistor,
A cooling path through which a refrigerant flows is provided in the case,
An inlet of the cooling path is formed to communicate between the inside and outside of the case,
In the above case,
a plurality of walls arranged to face the four side surfaces of the capacitor;
a partition wall that partitions an internal section of the case in a direction along a side surface of the capacitor, is integrally formed;
The cooling path is formed in the partition wall,
The inverter device, wherein the discharge resistor is arranged so as to be in contact with the wall portion in which the inlet of the cooling path is formed among the plurality of wall portions. a switching element unit having a plurality of switching elements constituting an inverter circuit;
a smoothing capacitor that smoothes the voltage on the DC side of the inverter circuit;
a discharge resistor connected in parallel with the smoothing capacitor;
a positive electrode connecting member that is electrically connected to a positive electrode of a DC power supply and that electrically connects the positive electrodes of the switching element unit, the smoothing capacitor, and the discharge resistor;
An inverter device comprising: a negative electrode connecting member that is electrically connected to the negative electrode of the DC power supply and that electrically connects the negative electrodes of the switching element unit, the smoothing capacitor, and the discharge resistor;
The smoothing capacitor includes at least one capacitor element having a positive electrode surface and a negative electrode surface facing opposite to the positive electrode surface,
The capacitor element is arranged in a rectangular parallelepiped arrangement area,
The positive electrode connecting member includes a positive electrode body portion formed along the positive electrode surface, and a positive electrode first terminal formed to protrude from the positive electrode body portion and electrically connected to the positive electrode of the DC power source. , a positive electrode second terminal formed to protrude from the positive electrode main body and electrically connected to the positive electrode of the switching element unit,
The negative electrode connecting member includes a negative electrode body portion formed along the negative electrode surface, and a negative electrode first terminal formed to protrude from the negative electrode body portion and electrically connected to the negative electrode of the DC power supply. , a negative electrode second terminal formed to protrude from the negative electrode main body and electrically connected to the negative electrode of the switching element unit,
four surfaces in the arrangement region of the capacitor element along a direction intersecting the positive electrode surface and the negative electrode surface are respectively defined as capacitor side surfaces;
The discharge resistor is adjacent to a surface of the four capacitor side surfaces on which none of the positive first terminal, the positive second terminal, the negative first terminal, and the negative second terminal are arranged. placed ,
further comprising a case accommodating the switching element unit, the smoothing capacitor, and the discharge resistor,
A cooling path through which a refrigerant flows is provided in the case,
In the above case,
a plurality of walls arranged to face the four side surfaces of the capacitor;
a partition wall that partitions an internal section of the case in a direction along a side surface of the capacitor, is integrally formed;
The cooling path is formed in the partition wall,
An entrance of the cooling path is formed in one of the plurality of walls so as to communicate between the inside and outside of the case,
an outlet of the cooling path is formed in the wall portion different from the wall portion in which the inlet is formed;
The inverter device, wherein the discharge resistor is arranged so as to be in contact with the wall portion in which the inlet of the cooling path is formed among the plurality of wall portions. The positive first terminal and the negative first terminal are arranged adjacent to each other,
The discharge resistor is arranged adjacent to a side of the four capacitor side surfaces opposite to the side on which the positive first terminal and the negative first terminal are located with respect to the capacitor element. The inverter device according to any one of Items 1 to 3 . The smoothing capacitor includes a portion of the positive electrode connecting member and the negative electrode connecting member such that at least the first positive terminal, the second positive terminal, the first negative terminal, and the second negative terminal are exposed to the outside. a capacitor case housing a part of the capacitor element and the capacitor element;
the placement area is defined by the capacitor case;
The inverter device according to any one of claims 1 to 4, wherein the four capacitor side surfaces are formed by an outer surface of the capacitor case.

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