Power conversion device

Abstract

Provided is a power conversion device comprising power semiconductor modules (4U, 4V, 4W) and a capacitor element (1b) for smoothing the amount of electricity. The thermal resistance between the power semiconductor modules (4U, 4V, 4W) and the capacitor element (1b) is configured to be greater than the thermal resistance between the capacitor element (1b) and capacitor module cooling channels (1e, 1h).

Description

Power Conversion Device

[0001] The present disclosure relates to a power conversion device.

[0002] Electrically driven vehicles such as hybrid cars and electric vehicles (hereinafter simply referred to as vehicles) are equipped with an AC rotating electric machine for driving the vehicle and a power conversion device that converts power between the AC rotating electric machine and an on-board battery. However, the space available for installing a power conversion device is usually limited, and the power conversion device installed in the vehicle is required to be compact. Therefore, in order to reduce the size of the power conversion device installed in the vehicle, efforts have traditionally been focused on reducing the size of components that make up the main circuit of the power conversion device, such as power semiconductor modules and smoothing capacitors.

[0003] When installing a power conversion device in a vehicle, the most important thing is to reduce the projected floor area of ​​the power conversion device. For this reason, the smoothing capacitor, which is a large component of the power conversion device, and the other components are often arranged so that their projected areas overlap with the projected areas of the other components of the power conversion device.

[0004] For example, a conventional power conversion device disclosed in Patent Document 1 includes a capacitor module having a capacitor cooling flow path embedded in a capacitor case, and a power semiconductor module having an integrated power semiconductor cooler with a power semiconductor cooling flow path provided therein, the capacitor case and the power semiconductor cooler being joined in surface contact, and the condenser cooling flow path and the power semiconductor cooling flow path being directly connected to each other to circulate a cooling medium. In the conventional power conversion device disclosed in Patent Document 1, the capacitor module and the power semiconductor module are arranged overlapping each other so that the projected area of ​​the power semiconductor module overlaps the projected area of ​​the capacitor module.

[0005] Patent No. 7052447

[0006] The conventional power conversion device disclosed in Patent Document 1 is configured based on the premise that the cooling capacity of the power semiconductor cooler is lower than the cooling capacity of the capacitor module, and by joining the power semiconductor cooler and the top surface of the capacitor module in a surface-to-surface contact state, it is possible to dissipate heat generated in the power semiconductor module not only to the power semiconductor module cooler but also to the capacitor module, thereby making it possible to efficiently cool the power semiconductor module.

[0007] However, in the conventional power conversion device disclosed in Patent Document 1, heat generated in the power semiconductor module is transferred to the capacitor module joined to the power semiconductor module in a surface-to-surface contact state, and then transferred to the capacitor element provided inside the capacitor module. Therefore, in the case of this conventional power conversion device, it is necessary to increase the size of the capacitor module cooling flow path for cooling the capacitor element, which leads to a problem of increasing the size of the power conversion device.

[0008] In reality, there are almost no cases where the cooling capacity of a power semiconductor module cooler that cools a power semiconductor module is lower than the cooling capacity of a cooler that cools a capacitor module. Conversely, the cooling capacity of a power semiconductor module cooler is actually higher than the cooling capacity of a cooler that cools a capacitor module.

[0009] The present disclosure discloses a technique for solving the above-mentioned problems, and aims to provide a power conversion device that achieves miniaturization.

[0010] a power semiconductor module cooler that cools the power semiconductor module; and a capacitor module that is connected to a DC terminal of the power conversion circuit and includes a capacitor element that smooths a voltage and a current of the DC terminal. The capacitor module has: a capacitor case that houses the capacitor element; a wiring board that is housed in the capacitor case; a capacitor module cooling flow path that is housed in the capacitor case and cools the capacitor element; and a jacket that, when combined with the power semiconductor module cooler, forms the power semiconductor module cooling flow path that cools the power semiconductor module. The power semiconductor module cooling flow path and the capacitor module cooling flow path are connected to each other, and the thermal resistance between the power semiconductor module and the capacitor element is configured to be larger than the thermal resistance between the capacitor element and the capacitor module cooling flow path.

[0011] According to the power conversion device of the present disclosure, a power conversion device that can be made compact can be obtained.

[0012] 4 is a perspective view schematically showing the overall configuration of a power conversion device according to embodiments 1, 4, 5, and 6. FIG. 4 is a cross-sectional view of a power conversion device according to embodiment 1 taken along line A-A in FIG. 1 , viewed from the direction of arrow S. FIG. 4 is a cross-sectional view of a power conversion device according to embodiment 1 taken along line B-B in FIG. 1 , viewed from the direction of arrow S. FIG. 4 is a perspective view schematically showing the overall configuration of a power conversion device according to embodiments 2 and 3. FIG. 4 is a cross-sectional view of a power conversion device according to embodiment 2 taken along line C-C in FIG. 4 , viewed from the direction of arrow S. FIG. 4 is a cross-sectional view of a power conversion device according to embodiment 3 taken along line C-C in FIG. 4 , viewed from the direction of arrow S. FIG. 4 is a cross-sectional view of a power conversion device according to embodiment 4 taken along line A-A in FIG. 1 , viewed from the direction of arrow S. FIG. 4 is a cross-sectional view of a power conversion device according to embodiment 5 taken along line A-A in FIG. 1 , viewed from the direction of arrow S. 1. FIG. 10 is a cross-sectional view of the power converter according to the sixth embodiment taken along line A-A in FIG. 1, viewed from the direction of arrow S.

[0013] As is well known, a three-phase power conversion device includes a power conversion circuit configured with a three-phase bridge circuit including a U-phase arm consisting of a series connection of a U-phase upper arm power semiconductor element and a U-phase lower arm power semiconductor element, a V-phase arm consisting of a series connection of a V-phase upper arm power semiconductor element and a V-phase lower arm power semiconductor element, and a W-phase arm consisting of a series connection of a W-phase upper arm power semiconductor element and a W-phase lower arm power semiconductor element.

[0014] A U-phase AC terminal is led out from the series connection portion between the U-phase upper arm power semiconductor element and the U-phase lower arm power semiconductor element, a V-phase AC terminal is led out from the series connection portion between the V-phase upper arm power semiconductor element and the V-phase lower arm power semiconductor element, and a W-phase AC terminal is led out from the series connection portion between the W-phase upper arm power semiconductor element and the W-phase lower arm power semiconductor element.

[0015] The U-phase arm, V-phase arm, and W-phase arm are connected in parallel with one another, with a positive DC terminal extending from the upper arm of each parallel-connected phase and a negative DC terminal extending from the lower arm of each parallel-connected phase, and a smoothing capacitor connected between the positive DC terminal and the negative DC terminal.

[0016] The aforementioned U-phase AC terminal, V-phase AC terminal, and W-phase AC terminal are connected to, for example, the armature windings of a three-phase AC rotating electric machine, the positive DC terminal is connected to, for example, the positive electrode of a battery mounted on a vehicle, and the negative DC terminal is connected to the negative electrode of the battery.

[0017] 1 is a perspective view showing a schematic overall configuration of a power conversion device according to embodiments 1, 4, 5, and 6, and shows an example of the above-mentioned three-phase power conversion device, and shows a power conversion device 100 according to embodiment 1, a power conversion device 400 according to embodiment 4, a power conversion device 500 according to embodiment 5, and a power conversion device 600 according to embodiment 6. In the following description of FIG. 1 , the power conversion device 100 according to embodiment 1 will be described.

[0018] 1, a power conversion device 100 includes a capacitor module 1, and a U-phase power semiconductor module 4U, a V-phase power semiconductor module 4V, and a W-phase power semiconductor module 4W mounted via a power semiconductor module cooler (not shown) on an upper surface 11 of the capacitor module 1. In the following description, the U-phase power semiconductor module 4U, the V-phase power semiconductor module 4V, and the W-phase power semiconductor module 4W may be collectively referred to as the power semiconductor modules 4U, 4V, and 4W of each phase.

[0019] The capacitor module 1 has a smoothing capacitor (not shown) embedded in a synthetic resin such as epoxy resin or silicone resin, and includes an internal capacitor module cooling flow path through which a refrigerant such as water flows to cool the smoothing capacitor. The capacitor module cooling flow path is connected to a refrigerant input hole 101 and a refrigerant output hole 102 that open to a bottom surface 12 of the capacitor module 1. The refrigerant input hole 101 and the refrigerant output hole 102 form a refrigerant input / output means.

[0020] The refrigerant input hole 101 opens in the bottom surface 12 on the side closer to the first side surface 13 and the second side surface 14 of the capacitor module 1, and is connected to an external cooling channel (not shown) provided outside the capacitor module 1, for inputting the refrigerant from the external cooling channel. The refrigerant output hole 102 opens in the bottom surface 12 on the side closer to the third side surface 15 and the second side surface 14 opposite the first side surface 13 of the capacitor module 1, and is connected to the external cooling channel for outputting the refrigerant that has flowed through the power semiconductor module cooling channel and the capacitor module cooling channel, which will be described later, to the external cooling channel. The fourth side surface 16 is a sidewall portion facing the second side surface 14.

[0021] The U-phase power semiconductor module 4U is configured such that the U-phase upper arm power semiconductor element and the U-phase lower arm power semiconductor element that constitute the U-phase arm are sealed with, for example, a semiconductor sealing epoxy resin whose main components are an epoxy-based thermosetting resin and a filler.

[0022] The V-phase power semiconductor module 4V is configured such that the V-phase upper arm power semiconductor element and the V-phase lower arm power semiconductor element that constitute the V-phase arm are sealed with, for example, a semiconductor sealing epoxy resin whose main components are an epoxy-based thermosetting resin and a filler.

[0023] The W-phase power semiconductor module 4W is configured such that the W-phase upper arm power semiconductor element and the W-phase lower arm power semiconductor element that constitute the W-phase arm are sealed with, for example, a semiconductor sealing epoxy resin whose main components are an epoxy-based thermosetting resin and a filler.

[0024] Fig. 2 is a cross-sectional view of the power conversion device according to embodiment 1 taken along line A-A in Fig. 1 and viewed from the direction of arrow S, and Fig. 3 is a cross-sectional view of the power conversion device according to embodiment 1 taken along line B-B in Fig. 1 and viewed from the direction of arrow S. In Figs. 1, 2, and 3, the power conversion device 100 is broadly composed of a capacitor module 1, a U-phase power semiconductor module 4U, a V-phase power semiconductor module 4V, a W-phase power semiconductor module 4W, and a bus bar assembly 5.

[0025] The capacitor module 1 is composed of a capacitor case 1a, a capacitor element 1b housed in the capacitor case 1a, a flat wiring board 1c housed in the capacitor case 1a and positioned opposite the upper surface of the capacitor element 1b with a gap therebetween, a connection bus bar 1d whose end is housed in the capacitor case 1a and connected by welding or soldering to wiring (not shown) on the wiring board 1c, a synthetic resin 1f that fills the internal space of the capacitor case 1a and embeds the capacitor element 1b, the wiring board 1c, and a portion of the connection bus bar 1d, and a water jacket 1g that is placed on the upper surface of the synthetic resin 1f that has been filled in the capacitor case 1a and serves as a jacket made of synthetic resin. The wiring board 1c is, for example, a printed circuit board in which wiring and the like are printed on an insulating substrate.

[0026] The capacitor case 1a is configured as a roughly rectangular parallelepiped with an open top and is made of metal or synthetic resin. The capacitor element 1b constitutes a smoothing capacitor that smoothes the DC current and DC voltage of the DC terminals in the power conversion circuit. The capacitor element 1b is housed inside the capacitor case 1a. Note that there may be one or more capacitor elements 1b.

[0027] The synthetic resin 1f filled in the internal space of the capacitor case 1a is, for example, an epoxy resin, but instead of epoxy resin, silicone resin (silicone rubber) may be used as the synthetic resin 1f.

[0028] The capacitor module cooling flow path 1e connected to the refrigerant inlet hole 101 and the capacitor module cooling flow path 1h connected to the refrigerant outlet hole 102 are embedded in synthetic resin 1f filled in the capacitor case 1a and are provided close to the side surface of the capacitor element 1b that faces the second side surface 14 shown in Fig. 1. The capacitor element 1b is cooled by the refrigerant flowing through the capacitor module cooling flow paths 1e and 1h.

[0029] The synthetic resin material that forms the water jacket 1g is, for example, epoxy resin or silicone resin (silicone rubber). The water jacket 1g is disposed between the capacitor case 1a and the power semiconductor modules 4U, 4V, 4W of each phase that are disposed on the upper surface portion 11 of the capacitor module 1. The water jacket 1g is provided with a power semiconductor module cooling flow path 2 that is open on the upper surface side.

[0030] The positional relationship of the components in the capacitor module 1 is, from the top surface 11 side to the bottom surface 12 side, the order of the water jacket 1g made of synthetic resin, the wiring board 1c, and the capacitor element 1b.

[0031] The power semiconductor module cooling flow path 2 in the water jacket 1g is formed to a size corresponding to the bottom surfaces of all of the power semiconductor modules 4U, 4V, 4W of each phase, and is connected to the above-mentioned capacitor module cooling flow paths 1e, 1h. A power semiconductor module cooler 3 is fitted onto the upper surface of the water jacket 1g, and the open upper surface of the power semiconductor module cooling flow path 2 is closed by the power semiconductor module cooler 3. In this way, the power semiconductor module cooling flow path 2 is formed by combining the power semiconductor module cooler 3 and the water jacket 1g.

[0032] The power semiconductor module cooler 3 is made of metal such as aluminum die-cast or aluminum sheet metal, and is joined in surface contact with the bottom surface of each of the power semiconductor modules 4U, 4V, 4W of each phase. Therefore, the power semiconductor modules 4U, 4V, 4W of each phase are cooled via the power semiconductor module cooler 3 by the cooling medium flowing through the power semiconductor module cooling flow path 2.

[0033] Each of the power semiconductor modules 4U, 4V, and 4W of each phase has a positive DC terminal 41 and an AC terminal 42. The positive DC terminal 41 of each of the power semiconductor modules 4U, 4V, and 4W of each phase is connected to a connection bus bar 1d by welding or soldering, and is connected to a terminal (not shown) of the capacitor element 1b via the wiring board 1c.

[0034] The negative DC terminals (not shown) of the power semiconductor modules 4U, 4V, 4W of each phase are connected to the negative terminal (not shown) of the capacitor element 1b.

[0035] The connection bus bar 1d may be composed of three connection bus bars corresponding to the positive DC terminals 41 of the power semiconductor modules 4U, 4V, and 4W of each phase, or may be composed of a single wide connection bus bar.

[0036] The bus bar assembly 5 is configured integrally with three output bus bars 5a corresponding to the U, V, and W phases, respectively, and U, V, and W phase current sensors 5b attached to these output bus bars 5a. The three output bus bars 5a corresponding to the U, V, and W phases, respectively, are connected to the AC terminals 42 of the power semiconductor modules 4U, 4V, and 4W of each phase by welding, soldering, or the like.

[0037] The bottom surfaces of the current sensors 5b for the U, V, and W phases in the bus bar assembly 5 are joined in surface contact with the upper surface of the power semiconductor module cooler 3. The power semiconductor module cooler 3, the power semiconductor modules 4, and the current sensors 5b are thermally coupled using thermal coupling members (not shown), such as heat dissipation grease or a heat dissipation sheet.

[0038] The capacitor module cooling channels 1e and 1h are directly connected to the power semiconductor module cooling channel 2. The refrigerant that flows into the refrigerant input hole 101 from outside the power conversion device 100 flows through the capacitor module cooling channel 1e, the power semiconductor module cooling channel 2, and the capacitor module cooling channel 1h in that order, and then flows out of the power conversion device 100 from the refrigerant output hole 102. By flowing the refrigerant in the above manner, the capacitor module 1, the power semiconductor modules 4U, 4V, and 4W of each phase, and the current sensor 5b of each phase are efficiently cooled.

[0039] The power conversion device 100 according to the first embodiment is configured so that the composite equivalent thermal resistance Rtha [K / W] of the water jacket 1g made of synthetic resin, the synthetic resin 1f, and the wiring board 1c, which are located between the power semiconductor modules 4U, 4V, 4W of each phase and the capacitor element 1b, is larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f, which is located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h.

[0040] A specific means for making the above synthetic equivalent thermal resistance Rtha [K / W] larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f is a so-called material-based method in which the materials of the synthetic resin and the wiring board are selected so that the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h is smaller than the thermal resistance of the synthetic resin constituting the water jacket 1g and the thermal resistance of the wiring board 1c, and the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g.

[0041] In addition to the above-mentioned method based on material factors, a so-called structural method may also be used, in which the total thickness of the synthetic resin constituting the water jacket 1g, the thickness of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g, and the thickness of the wiring board 1c is made larger than the thickness of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h.

[0042] According to the power conversion device of embodiment 1 configured as described above, the synthetic resin water jacket 1g, which is a component located between the power semiconductor modules 4U, 4V, 4W of each phase and the capacitor element 1b, the synthetic resin 1f, and the wiring board 1c are configured so that the composite equivalent thermal resistance Rtha of the synthetic resin 1f and the wiring board 1c is larger than the thermal resistance Rthb of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow path 1e. Therefore, all of the heat generated in the power semiconductor modules 4U, 4V, 4W of each phase is dissipated to the power semiconductor module cooler 3, and heat flow into the capacitor module 1 is eliminated via the synthetic resin water jacket 1g, and the capacitor element 1b is effectively cooled by the capacitor module cooling flow paths 1e, 1h.

[0043] As a result, the capacitor element 1b is prevented from receiving heat due to heat generated by the power semiconductor modules 4U, 4V, and 4W of each phase, and the capacitor module 1 can be made smaller.

[0044] In the power conversion device according to embodiment 1, the current sensors 5b of each phase are thermally coupled to the power semiconductor module cooler 3, similar to the power semiconductor modules 4U, 4V, and 4W of each phase. However, when the output power is small and the heat generation in the current sensors 5b of each phase is small, the same effect as described above can be obtained even if the current sensors 5b of each phase are not thermally coupled to the power semiconductor module cooler 3.

[0045] Furthermore, in the power conversion device according to embodiment 1, the water jacket 1g made of synthetic resin and the synthetic resin 1f of the capacitor module 1 are separate components, but these may also be made into an integrated synthetic resin structure, and in this case the same effect as described above can be obtained.

[0046] Furthermore, in the power conversion device according to embodiment 1, the connection bus bar 1 d and the output bus bar 5 a are metal bus bars, but instead of metal bus bars, means for conducting electricity such as cables or wiring boards may be used, and in this case, the same effects as those described above can be obtained.

[0047] Second Embodiment Next, a power conversion apparatus according to a second embodiment will be described. Fig. 4 is a perspective view schematically showing the overall configuration of a power conversion apparatus according to the second and third embodiments, showing an example of the three-phase power conversion apparatus described above. In Fig. 4, a refrigerant input port 101 serving as a refrigerant input / output means opens in the bottom surface 12 on the side close to the first side surface 13 and the fourth side surface 16 of the capacitor module 1, and is connected to an external cooling flow path (not shown) provided outside the capacitor module 1, so that the refrigerant is input from the external cooling flow path.

[0048] The refrigerant output hole 102 serving as a refrigerant input / output means opens in the bottom surface 12 on the side closer to the first side surface 13 and the second side surface 14 of the capacitor module 1, is connected to an external cooling flow path, and outputs the refrigerant that has flowed through the power semiconductor module cooling flow path and the capacitor module cooling flow path to the external cooling flow path. The other configurations in Fig. 4 are the same as those shown in Fig. 1.

[0049] In the capacitor module 1, the capacitor module cooling channel 1i connected to the refrigerant inlet hole 101 is embedded in the synthetic resin 1f filled in the capacitor case 1a, and is provided close to the bottom surface of the capacitor element 1b that faces the bottom surface 12 shown in Fig. 4. The capacitor module cooling channel 1i has a planar shape that corresponds to the entire bottom surface of the capacitor element 1b, but may also have a shape that corresponds to only a portion of the bottom surface of the capacitor element 1b.

[0050] The capacitor module cooling flow path 1i is connected to the power semiconductor module cooling flow path 2 by a connection flow path (not shown) provided in a position close to the side portion of the capacitor element 1b facing the second side portion 14 shown in Figure 4 or the side portion of the capacitor element 1b facing the fourth side portion 16.

[0051] Furthermore, the capacitor module cooling flow path 1j connected to the refrigerant output hole 102 is embedded in the synthetic resin 1f filled in the capacitor case 1a, is provided close to the side surface of the capacitor element 1b facing the second side surface portion 14 shown in Figure 4, and is connected to the power semiconductor module cooling flow path 2 of the water jacket 1g. The capacitor element 1b is cooled by the refrigerant flowing through the capacitor module cooling flow paths 1i and 1j and the aforementioned connecting flow paths.

[0052] The refrigerant that flows into the refrigerant input hole 101 from outside the power conversion device 200 circulates in the order of the capacitor module cooling flow path 1i, the connecting flow path (not shown), the power semiconductor module cooling flow path 2, and the capacitor module cooling flow path 1j, and is discharged from the refrigerant output hole 102 to the outside of the power conversion device 200. By the refrigerant flowing in the above manner, the capacitor module 1, the power semiconductor modules 4U, 4V, and 4W of each phase, and the current sensor 5b of each phase are efficiently cooled.

[0053] The power conversion device 200 according to the second embodiment is configured so that the composite equivalent thermal resistance Rtha [K / W] of the water jacket 1g made of synthetic resin, the synthetic resin 1f, and the wiring board 1c, which are located between the power semiconductor modules 4U, 4V, 4W of each phase and the capacitor element 1b, is larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1i, 1j.

[0054] A specific means for making the above synthetic equivalent thermal resistance Rtha [K / W] larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f is a so-called material-based method in which the materials of the synthetic resin and the wiring board are selected so that the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1i, 1j is smaller than the thermal resistance of the synthetic resin constituting the water jacket 1g and the thermal resistance of the wiring board 1c, and the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g.

[0055] In addition to the above-mentioned method based on material factors, a so-called method based on structural factors may also be used, in which the total thickness of the synthetic resin constituting the water jacket 1g, the thickness of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g, and the thickness of the wiring board 1c is made larger than the thickness of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1i, 1j.

[0056] The other configurations are the same as those in the first embodiment.

[0057] In the power conversion device according to the second embodiment configured as described above, the composite equivalent thermal resistance Rtha of the synthetic resin water jacket 1g, which is a component located between the power semiconductor modules 4U, 4V, and 4W of each phase and the capacitor element 1b, the synthetic resin 1f, and the wiring board 1c is configured so as to be greater than the thermal resistance Rthb of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow path 1e. Therefore, all of the heat generated in the power semiconductor modules 4U, 4V, and 4W of each phase is dissipated to the power semiconductor module cooler 3, heat flow into the capacitor module 1 is prevented via the synthetic resin water jacket 1g, and the capacitor element 1b is cooled by the capacitor module cooling flow paths 1i and 1j and the connecting flow path. As a result, heat reception by the capacitor element 1b due to heat generated by the power semiconductor modules 4U, 4V, and 4W of each phase is avoided, and the capacitor module 1 can be made smaller.

[0058] Furthermore, according to the power conversion device of embodiment 2, the refrigerant input hole 101, the refrigerant output hole 102, and the capacitor module cooling flow path 1i are arranged on the bottom side of the capacitor element 1b, so that there is no positional interference between the capacitor element 1b and the capacitor module cooling flow paths 1i and 1j, and therefore the refrigerant input hole 101 and the refrigerant output hole 102 can be arranged at any position on the bottom side of the capacitor element 1b.

[0059] In the power conversion device according to the second embodiment, the current sensors 5b of each phase are thermally coupled to the power semiconductor module cooler 3 in the same manner as the power semiconductor modules 4U, 4V, and 4W of each phase. However, when the output power is small and the heat generation in the current sensors 5b of each phase is small, the same effect as described above can be obtained even if the current sensors 5b of each phase are not thermally coupled to the power semiconductor module cooler 3.

[0060] Furthermore, in the power conversion device according to embodiment 2, the water jacket 1g made of synthetic resin and the synthetic resin 1f of the capacitor module 1 are separate components, but these may also be integrated using synthetic resin, and in this case the same effect as described above can be obtained.

[0061] Furthermore, in the power conversion device according to embodiment 2, the connection bus bar 1 d and the output bus bar 5 a are metal bus bars, but instead of metal bus bars, means for conducting electricity such as cables or wiring boards may be used, and in this case, the same effects as those described above can be obtained.

[0062] Third Embodiment Next, a power converter according to a third embodiment will be described. Fig. 6 is a cross-sectional view of the power converter according to the third embodiment taken along line C-C in Fig. 4, viewed from the direction of arrow S. In Figs. 4 and 6, a capacitor module 1 includes a capacitor case 1a, a capacitor element 1b housed in the capacitor case 1a, a flat wiring board 1c housed in the capacitor case 1a and facing the upper surface of the capacitor element 1b with a gap therebetween, a connection bus bar 1d whose end is housed in the capacitor case 1a and connected to the wiring board 1c by welding, soldering, or the like, a synthetic resin 1f that fills the internal space of the capacitor case 1a and in which the capacitor element 1b, the wiring board 1c, and a portion of the connection bus bar 1d are embedded, and a water jacket 1gi formed of metal and placed on the upper surface of the capacitor case 1a.

[0063] The coolant that flows into the coolant input hole 101 from outside the power conversion device 300 circulates in the order of the capacitor module cooling flow path 1i, the connecting flow path (not shown), the power semiconductor module cooling flow path 2 provided in the water jacket 1gi made of metal, and the capacitor module cooling flow path 1j, and then flows out of the power conversion device 200 from the coolant output hole 102. By the coolant flowing in the above manner, the capacitor module 1, the power semiconductor modules 4U, 4V, 4W of each phase, and the current sensor 5b of each phase are efficiently cooled.

[0064] The power conversion device 300 according to the third embodiment is configured so that the composite equivalent thermal resistance Rtha [K / W] of the water jacket 1gi made of synthetic resin, the synthetic resin 1f, and the wiring board 1c, which are located between the power semiconductor modules 4U, 4V, 4W of each phase and the capacitor element 1b, is larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1i, 1j.

[0065] A specific means for making the above-mentioned synthetic equivalent thermal resistance Rtha [K / W] larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f is a so-called material-based method in which the materials of the synthetic resin and the wiring board are selected so that the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1i, 1j is smaller than the thermal resistance of the metals constituting the water jacket 1gi and the thermal resistance of the wiring board 1c, and the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1gi.

[0066] In addition to the above-mentioned method based on material factors, a so-called method based on structural factors may also be used, in which the total thickness of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1gi and the thickness of the wiring board 1c is made larger than the thickness of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1i, 1j.

[0067] The other configurations are the same as those in the first embodiment.

[0068] In the power conversion device according to the third embodiment configured as described above, the composite equivalent thermal resistance Rtha of the metal water jacket 1gi, synthetic resin 1f, and wiring board 1c, which are components located between the power semiconductor modules 4U, 4V, and 4W of each phase and the capacitor element 1b, is configured to be greater than the thermal resistance Rthb of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow path 1e. Therefore, all of the heat generated in the power semiconductor modules 4U, 4V, and 4W of each phase is dissipated to the power semiconductor module cooler 3, heat flow into the capacitor module 1 is prevented via the metal water jacket 1gi, and the capacitor element 1b is cooled by the capacitor module cooling flow paths 1i and 1j and the connecting flow path. As a result, heat received by the capacitor element 1b due to heat generated by the power semiconductor modules 4U, 4V, and 4W of each phase is prevented, and the capacitor module 1 can be made smaller.

[0069] According to the power conversion device of the third embodiment, most of the heat generated in the power semiconductor modules 4U, 4V, and 4W of each phase is dissipated by the power semiconductor module cooler 3 fitted in the water jacket 1gi made of metal, but some of the heat is thermally conducted to the wiring board 1c via the metal water jacket 1gi and the synthetic resin 1f. However, when the wiring board 1c is formed of a printed wiring board, for example, the thermal conductivity of the wiring board 1c is high in the planar direction but low in the thickness direction, and as a result, the heat conducted to the wiring board 1c is not thermally conducted to the capacitor element 1b.

[0070] Therefore, the capacitor element 1b is sufficiently cooled by the capacitor module cooling channels 1i and 1j, which prevents the capacitor element 1b from receiving heat generated by the power semiconductor modules 4U, 4V, and 4W of each phase, thereby enabling the capacitor module 1 to be made smaller.

[0071] Therefore, in the case of the power conversion device according to embodiment 3, like the power conversion device according to embodiment 2, the composite equivalent thermal resistance Rtha [K / W] of the metal water jacket 1gi, synthetic resin 1f, and wiring board 1c located between the power semiconductor modules 4U, 4V, 4W of each phase and the capacitor element 1b is configured to be larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1i, 1j.

[0072] Other configurations of the power conversion device according to the third embodiment are similar to those of the power conversion device according to the second embodiment.

[0073] According to the power conversion device of the third embodiment configured as described above, heat generated in the power semiconductor modules 4U, 4V, and 4W of each phase is dissipated to the power semiconductor module cooler 3 and the metal water jacket 1gi, preventing heat from flowing into the capacitor module 1, and cooling of the capacitor element 1b by the capacitor module cooling flow paths 1i and 1j and the connecting flow paths. As a result, heat received by the capacitor element 1b due to heat generated by the power semiconductor modules 4U, 4V, and 4W of each phase is prevented, and the capacitor module 1 can be made smaller.

[0074] Furthermore, according to the power conversion device of embodiment 3, the refrigerant input hole 101, the refrigerant output hole 102, and the capacitor module cooling flow path 1i are arranged on the underside of the capacitor element 1b, so that there is no positional interference between the capacitor element 1b and the capacitor module cooling flow paths 1i and 1j, and therefore the refrigerant input hole 101 and the refrigerant output hole 102 can be arranged at any position on the bottom side of the capacitor element 1b.

[0075] In the power conversion device according to the third embodiment, the current sensors 5b of each phase are thermally coupled to the power semiconductor module cooler 3 in the same manner as the power semiconductor modules 4U, 4V, and 4W of each phase. However, when the output power is small and the heat generation in the current sensors 5b of each phase is small, the same effect as described above can be obtained even if the current sensors 5b of each phase are not thermally coupled to the power semiconductor module cooler 3.

[0076] Furthermore, in the power conversion device according to embodiment 3, the connection bus bar 1 d and the output bus bar 5 a are metal bus bars, but instead of metal bus bars, means for conducting electricity such as cables or wiring boards may be used, and in this case, the same effect as described above can be obtained.

[0077] Fourth Embodiment Next, a power converter according to a fourth embodiment will be described. Fig. 7 is a cross-sectional view of the power converter according to the fourth embodiment taken along line A-A in Fig. 1, viewed from the direction of arrow S. In Figs. 1 and 7, a capacitor module 1 includes a capacitor case 1a, a capacitor element 1b housed in the capacitor case 1a, a flat wiring board 1c housed in the capacitor case 1a and facing the upper surface of the capacitor element 1b across a gap, and a discharge means 1k, such as a discharge resistor, disposed on the upper surface of the wiring board 1c. The discharge means 1k is a means for discharging residual charge in the capacitor element 1b as necessary.

[0078] The capacitor module 1 also includes a connection bus bar 1d, the end of which is housed in the capacitor case 1a and connected to the wiring board 1c by welding or soldering, a synthetic resin 1f that fills the internal space of the capacitor case 1a and embeds the capacitor element 1b, the wiring board 1c, the discharge means 1k, and a portion of the connection bus bar 1d, and a water jacket 1g that is formed from synthetic resin and placed on the top surface of the capacitor case 1a.

[0079] The power conversion device 400 according to the fourth embodiment is configured, similarly to the power conversion device according to the first embodiment described above, so that the composite equivalent thermal resistance Rtha [K / W] of the water jacket 1g made of synthetic resin, the synthetic resin 1f, the discharge means 1k, and the wiring board 1c, which are located between the power semiconductor modules 4U, 4V, 4W of each phase and the capacitor element 1b, is larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f, which is located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h.

[0080] A specific means for making the above synthetic equivalent thermal resistance Rtha [K / W] larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f is a so-called material-based method in which the materials of the synthetic resin and the wiring board are selected so that the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h is smaller than the thermal resistance of the synthetic resin constituting the water jacket 1g, the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g, and the thermal resistance of the wiring board 1c.

[0081] In addition to the above-mentioned method based on material factors, a so-called structural method may also be used, in which the total thickness of the synthetic resin constituting the water jacket 1g, the thickness of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g, and the thickness of the wiring board 1c is made larger than the thickness of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h.

[0082] Other configurations of the power conversion device according to the fourth embodiment are similar to those of the power conversion device according to the first embodiment.

[0083] In the power conversion device according to the fourth embodiment configured as described above, the composite equivalent thermal resistance Rtha of the synthetic resin water jacket 1g, synthetic resin 1f, discharge means 1k, and wiring board 1c, which are components located between the power semiconductor modules 4U, 4V, and 4W of each phase and the capacitor element 1b, is configured to be larger than the thermal resistance Rthb of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow path 1e. Therefore, all of the heat generated in the power semiconductor modules 4U, 4V, and 4W of each phase is dissipated to the power semiconductor module cooler 3, heat flow into the capacitor module 1 is prevented via the synthetic resin water jacket 1g, and the capacitor element 1b is cooled by the capacitor module cooling flow paths 1e and 1h. As a result, heat reception by the capacitor element 1b due to heat generated by the power semiconductor modules 4U, 4V, and 4W of each phase is avoided, and the capacitor module 1 can be made smaller.

[0084] In the power conversion device according to the fourth embodiment, the current sensors 5b of each phase are thermally coupled to the power semiconductor module cooler 3 in the same manner as the power semiconductor modules 4U, 4V, and 4W of each phase. However, when the output power is small and the heat generation in the current sensors 5b of each phase is small, the same effect as described above can be obtained even if the current sensors 5b of each phase are not thermally coupled to the power semiconductor module cooler 3.

[0085] Furthermore, in the power conversion device according to embodiment 4, the water jacket 1g made of synthetic resin and the synthetic resin 1f of the capacitor module 1 are separate components, but these may also be integrated using synthetic resin, and in this case the same effect as described above can be obtained.

[0086] Furthermore, in the power conversion device according to embodiment 4, the connection bus bar 1 d and the output bus bar 5 a are metal bus bars, but instead of metal bus bars, means for conducting electricity such as cables or wiring boards may be used, and in this case, the same effects as those described above can be obtained.

[0087] Furthermore, according to the power conversion device of embodiment 4, the heat generated by the discharge means 1k for discharging the remaining charge in the capacitor module 1 can be dissipated in the planar direction of the wiring board 1c, making it possible to reduce the size of the discharge means 1k. Furthermore, since the heat generated by the discharge means 1k is not thermally conducted to the capacitor element 1b, heat reception by the capacitor element 1b is prevented, making it possible to reduce the size of the capacitor module 1.

[0088] Fifth Embodiment Next, a power converter according to a fifth embodiment will be described. Fig. 8 is a cross-sectional view of the power converter according to the fifth embodiment taken along line A-A in Fig. 1, viewed from the direction of arrow S. In Figs. 1 and 8, a capacitor module 1 includes a capacitor case 1a, a capacitor element 1b housed in the capacitor case 1a, a flat wiring board 1c housed in the capacitor case 1a and facing the upper surface of the capacitor element 1b across a gap, and a connection bus bar 1d whose end is housed in the capacitor case 1a and connected to the wiring board 1c by welding, soldering, or the like.

[0089] The capacitor module 1 also includes a synthetic resin 1f that fills the internal space of the capacitor case 1a and embeds the capacitor element 1b, the wiring board 1c, and a portion of the connection bus bar 1d, and a water jacket 1g formed of synthetic resin that is placed on the upper surface of the capacitor case 1a.

[0090] Discharge means 1k for discharging residual charges in capacitor element 1b is disposed on the side of capacitor module 1 close to capacitor module cooling channels 1e and 1h.

[0091] The power conversion device 500 according to the fifth embodiment is configured so that the composite equivalent thermal resistance Rtha [K / W] of the water jacket 1g made of synthetic resin, the synthetic resin 1f, and the wiring board 1c, which are located between the power semiconductor modules 4U, 4V, 4W of each phase and the capacitor element 1b, is larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f, which is located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h.

[0092] A specific means for making the above synthetic equivalent thermal resistance Rtha [K / W] larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f is a so-called material-based method in which the materials of the synthetic resin and the wiring board are selected so that the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h is smaller than the thermal resistance of the synthetic resin constituting the water jacket 1g, the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g, and the thermal resistance of the wiring board 1c.

[0093] In addition to the above-mentioned method based on material factors, a so-called method based on structural factors may also be used, in which the total thickness of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g and the thickness of the wiring board 1c is made larger than the thickness of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h.

[0094] The other configurations of the power conversion device according to the fifth embodiment are similar to those of the power conversion device according to the first embodiment described above.

[0095] In the power conversion device according to the fifth embodiment configured as described above, the composite equivalent thermal resistance Rtha of the synthetic resin water jacket 1g, which is a component located between the power semiconductor modules 4U, 4V, and 4W of each phase and the capacitor element 1b, the synthetic resin 1f, and the wiring board 1c is configured so as to be larger than the thermal resistance Rthb of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow path 1e. Therefore, all of the heat generated in the power semiconductor modules 4U, 4V, and 4W of each phase is dissipated to the power semiconductor module cooler 3, heat flow into the capacitor module 1 is prevented via the synthetic resin water jacket 1g, and the capacitor element 1b is cooled by the capacitor module cooling flow paths 1e and 1h. As a result, heat reception by the capacitor element 1b due to heat generated by the power semiconductor modules 4U, 4V, and 4W of each phase is avoided, and the capacitor module 1 can be made smaller.

[0096] Furthermore, according to the power conversion device of embodiment 5, the heat generated by the discharge means 1k for discharging the remaining charge in the capacitor module 1 is disposed on the side of the capacitor module 1 close to the capacitor module cooling flow paths 1e and 1h, and therefore the heat generated by the discharge means 1k is dissipated to the capacitor module cooling flow paths 1e and 1h, making it possible to reduce the size of the discharge means 1k. Furthermore, since the heat generated by the discharge means 1k can be prevented from being conducted to the capacitor element 1b, the heat reception by the capacitor element 1b is prevented, and the capacitor module 1 can be reduced in size.

[0097] In the power conversion device according to the fifth embodiment, the current sensors 5b of each phase are thermally coupled to the power semiconductor module cooler 3 in the same manner as the power semiconductor modules 4U, 4V, and 4W of each phase. However, when the output power is small and the heat generation in the current sensors 5b of each phase is small, the same effect as described above can be obtained even if the current sensors 5b of each phase are not thermally coupled to the power semiconductor module cooler 3.

[0098] Furthermore, in the power conversion device according to embodiment 5, the water jacket 1g made of synthetic resin and the synthetic resin 1f of the capacitor module 1 are separate components, but these may also be integrated using synthetic resin, and in this case the same effect as described above can be obtained.

[0099] Furthermore, in the power conversion device according to embodiment 5, the connection bus bar 1 d and the output bus bar 5 a are metal bus bars, but instead of metal bus bars, means for conducting electricity such as cables or wiring boards may be used, and in this case, the same effects as those described above can be obtained.

[0100] Sixth Embodiment Next, a power conversion device according to a sixth embodiment will be described. Fig. 9 is a cross-sectional view of the power conversion device according to the sixth embodiment taken along line A-A in Fig. 1, viewed from the direction of arrow S. In Figs. 1 and 9, the bus bar assembly 5 integrally comprises three output bus bars 5a corresponding to the U, V, and W phases, respectively, and current sensors 5b for the U, V, and W phases attached to these output bus bars 5a. The three output bus bars 5a corresponding to the U, V, and W phases, respectively, are connected to the AC terminals 42 of the power semiconductor modules 4U, 4V, and 4W of each phase.

[0101] Three output bus bars 5a corresponding to the U, V, and W phases respectively extend parallel to the upper surface of the power semiconductor module cooler 3 at intervals from the upper surface, and are bent to follow the side surfaces of the water jacket 1g and the capacitor case 1a at intervals from the upper surface. A current sensor 5b for each phase is provided on each output bus bar 5a, and the bottom surface of the current sensor 5b is fixed to the side surface of the capacitor case 1a close to the capacitor module cooling channels 1e and 1h.

[0102] The power conversion device 600 according to the sixth embodiment is configured so that the composite equivalent thermal resistance Rtha [K / W] of the water jacket 1g made of synthetic resin, the synthetic resin 1f, and the wiring board 1c, which are located between the power semiconductor modules 4U, 4V, 4W of each phase and the capacitor element 1b, is larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f, which is located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h.

[0103] A specific means for making the above synthetic equivalent thermal resistance Rtha [K / W] larger than the thermal resistance Rthb [K / W] of the synthetic resin 1f is a so-called material-based method in which the materials of the synthetic resin and the wiring board are selected so that the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h is smaller than the thermal resistance of the synthetic resin constituting the water jacket 1g, the thermal resistance of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g, and the thermal resistance of the wiring board 1c.

[0104] In addition to the above-mentioned method based on material factors, a so-called structural method may also be used, in which the total thickness of the synthetic resin constituting the water jacket 1g, the thickness of the synthetic resin 1f located between the capacitor element 1b and the water jacket 1g, and the thickness of the wiring board 1c is made larger than the thickness of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow paths 1e, 1h.

[0105] In the power conversion device according to the sixth embodiment configured as described above, the composite equivalent thermal resistance Rtha of the synthetic resin water jacket 1g, which is a component located between the power semiconductor modules 4U, 4V, and 4W of each phase and the capacitor element 1b, the synthetic resin 1f, and the wiring board 1c is configured so as to be larger than the thermal resistance Rthb of the synthetic resin 1f located between the capacitor element 1b and the capacitor module cooling flow path 1e. Therefore, all of the heat generated in the power semiconductor modules 4U, 4V, and 4W of each phase is dissipated to the power semiconductor module cooler 3, heat flow into the capacitor module 1 is prevented via the synthetic resin water jacket 1g, and the capacitor element 1b is cooled by the capacitor module cooling flow paths 1e and 1h. As a result, heat reception by the capacitor element 1b due to heat generated by the power semiconductor modules 4U, 4V, and 4W of each phase is avoided, and the capacitor module 1 can be made smaller.

[0106] Furthermore, in the power conversion device according to embodiment 6, the water jacket 1g made of synthetic resin and the synthetic resin 1f of the capacitor module 1 are separate components, but these may also be integrated using synthetic resin, and in this case the same effect as described above can be obtained.

[0107] Furthermore, in the power conversion device according to embodiment 6, the connection bus bar 1 d and the output bus bar 5 a are metal bus bars, but instead of metal bus bars, means for conducting electricity such as cables or wiring boards may be used, and in this case, the same effects as those described above can be obtained.

[0108] Furthermore, according to the power conversion device of embodiment 6, the heat generated by the current sensor 5b is disposed on the side of the capacitor module 1 close to the capacitor module cooling flow paths 1e and 1h, and is therefore dissipated into the capacitor module cooling flow paths 1e and 1h, making it possible to miniaturize the current sensor 5b. Furthermore, since it is possible to avoid thermal conduction of the heat generated by the current sensor 5b to the capacitor element 1b, it is possible to achieve miniaturization of the capacitor module 1.

[0109] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are anticipated within the scope of the technology disclosed in this application. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0110] 100, 200, 300, 400, 500, 600 Power conversion device, 101 Refrigerant input hole, 102 Refrigerant output hole, 1 Capacitor module, 1a Capacitor case, 1b Capacitor element, 1c Wiring board, 1d Connection bus bar, 1e, 1h, 1i, 1j Capacitor module cooling flow path, 1f Synthetic resin, 1g, 1gi Water jacket, 1k Discharge means, 11 Top surface portion, 12 Bottom surface portion, 13 First side surface portion, 14 Second side surface portion, 15 Third side surface portion, 16 Fourth side surface portion, 2 Power semiconductor module cooling flow path, 3 Power semiconductor module cooler, 4U U-phase power semiconductor module, 4V V-phase power semiconductor module, 4W W-phase power semiconductor module, 41 Positive side DC terminal, 42 AC terminal, 5 Bus bar assembly, 5a Output bus bar, 5b Current sensor

Claims

1. A power conversion device having a power conversion circuit composed of a plurality of power semiconductor devices, and performing power conversion between DC power and AC power by the switching operation of the power semiconductor devices, comprising: A power semiconductor module including the power semiconductor devices; A power semiconductor module cooler for cooling the power semiconductor module; A capacitor module connected to the DC terminals of the power conversion circuit and including capacitor elements for smoothing the voltage and current of the DC terminals. The capacitor module includes: A capacitor case for housing the capacitor elements; A wiring board housed in the capacitor case; A capacitor module cooling flow path housed in the capacitor case for cooling the capacitor elements; A jacket that forms a power semiconductor module cooling flow path for cooling the power semiconductor module when combined with the power semiconductor module cooler. The power semiconductor module cooling flow path and the capacitor module cooling flow path are interconnected. The thermal resistance between the power semiconductor module and the capacitor elements is configured to be greater than the thermal resistance between the capacitor elements and the capacitor module cooling flow path. A power conversion device characterized by the above.

2. The power conversion device according to claim 1, wherein the jacket is formed of a synthetic resin.

3. The power conversion device according to claim 1, wherein the jacket is formed of a metal.

4. The power conversion device according to any one of claims 1 to 3, wherein the capacitor module cooling flow path is configured to cool a plurality of surfaces of the capacitor elements.

5. The capacitor module cooling flow path includes a portion disposed to face the bottom surface of the capacitor module. The capacitor module includes refrigerant input / output means at the bottom surface of the capacitor case facing the bottom surface of the capacitor module. The capacitor module cooling flow path is configured to input and output the refrigerant to the outside of the capacitor module via the refrigerant input / output means. The power conversion device according to any one of claims 1 to 4, characterized by the above.

6. The power conversion device according to any one of claims 1 to 5, further comprising a current sensor that detects the current of the AC terminal of the power semiconductor module, wherein the current sensor is integrally formed with the AC terminal.

7. The power conversion device according to claim 6, wherein the current sensor is mounted on the cooler of the power semiconductor module.

8. The power conversion device according to claim 6, wherein the current sensor is disposed on a side surface portion of the capacitor case, and the side surface portion corresponds to the capacitor module cooling flow path.

9. The power conversion device according to any one of claims 1 to 8, further comprising a discharging means for discharging the charge of the capacitor element, wherein the discharging means is provided on the wiring board.

10. The power conversion device according to any one of claims 1 to 8, further comprising a discharging means for discharging the charge of the capacitor element, wherein the discharging means is provided on a side surface portion of the capacitor case.

Images