Electrical power conversion device

Abstract

Electrical power conversion device (1) comprising: a semiconductor module (10) or several semiconductor modules (10), each comprising built-in semiconductor elements (11), a positive electrode terminal (11p), a negative electrode terminal (11n) and a control terminal (13); a control circuit board (20) which is connected to the control port (13) of the semiconductor module (10) and is able to control the built-in semiconductor elements (11); a main P-bus (30p) connected to the positive electrode terminal (11p) of the semiconductor module (10), through which DC power is supplied; a main N busbar (30n) which is connected to the negative electrode terminal (11n) of the semiconductor module (10) through which the DC power is supplied; a capacitor module (40) comprising a first capacitor (41), a capacitor P-bus (42p) and a capacitor N-bus (42n), wherein the first capacitor (41), the capacitor P-bus (42p) and the capacitor N-bus (42n) are encased in a capacitor molding resin (46), wherein the capacitor P-bus (42p) is connected to a positive electrode terminal (41p) of the first capacitor (41) and the capacitor N-bus is connected to a negative electrode terminal (41n) of the first capacitor (41); an input P-bus (5p) connected to a positive electrode terminal (2p) of a DC power source (2); and an input N busbar (5n) connected to a negative electrode terminal (2n) of the DC power source (2), the input N busbar (5n) comprising a first N connection section (51n) and a second N connection section (52n), the first N connection section (51n) being connected to the capacitor N busbar (42n) and the second N connection section (52n) being connected to the main N busbar (30n), the main N busbar (30n) being located outside the capacitor mold resin (46) with which the first capacitor (41), the capacitor P busbar (42p) and the capacitor N busbar (42n) are encased.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The present invention relates to electrical power conversion devices or electrical power converters that are capable of converting direct current power into alternating current power. 2. Description of the related prior art

[0002] An electrical power conversion device generally comprises semiconductor modules, a capacitor, an input power rail, a capacitor power rail, and so on. The semiconductor modules convert direct current (DC) power into alternating current (AC) power. The capacitor smooths the electrical power. The input power rail is connected to a DC power source. The capacitor is connected to the input power rail via the capacitor power rail. According to patent publication JP 2013-55840A, which discloses a conventional technique, a capacitor module is used that has a structure in which the capacitor and the capacitor power rail are assembled and molded or encased in a resin or plastic, respectively. The capacitor power rail is connected to a main power rail.This main power rail is connected to the semiconductor modules to supply electrical power to the semiconductor devices.

[0003] The electrical power supplied via the main power rail is further supplied to the input power rail via the capacitor power rail, which is formed or cast into the capacitor module.

[0004] The design of the electrical power conversion device disclosed in JP 2013-55840A, described above, has a disadvantage. This disadvantage is that, because the electrical power, which includes a direct current (DC) component, is supplied to the capacitor bus, the DC component generates heat energy as it passes through the bus. Furthermore, because the capacitor bus is integrated with the capacitor module and molded or cast into it, the heat energy generated in the bus increases the temperature of the capacitor and sometimes causes the module to crack. This leads to deterioration of the capacitor module and reduces the lifespan of the capacitor.

[0005] Document US 2014 / 0313671A1 describes a power conversion device comprising a coolant supply and discharge section and a layered body. The coolant supply and discharge section performs a supply and discharge of coolant with respect to the radiator. The coolant supply and discharge section is located at a first end face of the layered body, the first end face intersecting a first vertical direction perpendicular to a layering direction in the layered body. One of the terminal sections and the electrode terminal of the semiconductor module is located at a second end face of the layered body, the second end face intersecting the first vertical direction.

[0006] Document US 2014 / 0118909A1 describes a power conversion device comprising a main circuit section containing a semiconductor module with a switching element and a main electrode terminal, a capacitor containing a capacitor element and a capacitor terminal, and a busbar connecting the main electrode terminal and the capacitor terminal. The capacitor terminal extends from a capacitor body containing the capacitor element toward the main circuit section. The busbar provides a bend section at a base end of a connecting section between the busbar and the capacitor terminal. The busbar and the capacitor terminal are connected such that they overlap in a state where their respective tip directions coincide. SUMMARY

[0007] It is therefore desirable to provide a highly reliable electrical power conversion device capable of suppressing a temperature rise in the capacitor within it.

[0008] An exemplary embodiment provides an electrical power conversion device that is capable of performing a power conversion of direct current power into alternating current power.

[0009] This is achieved by an electrical power conversion device according to claim 1. Advantageous embodiments are specified in the dependent claims.

[0010] The electrical power conversion device comprises one or more semiconductor modules, a control circuit board, a main P-rail, a main N-rail, a capacitor module, an input P-rail, and an input N-rail. Each semiconductor module has an embedded semiconductor element, a positive electrode terminal, a negative electrode terminal, and a control terminal. The control circuit board is connected to the control terminal of each semiconductor module. The control circuit board controls the embedded semiconductor elements of the semiconductor modules. The main P-rail is connected to the positive electrode terminal of the semiconductor module, through which DC power is supplied. The main N-rail is connected to the negative electrode terminal of the semiconductor module, through which DC power is supplied.

[0011] The capacitor module comprises a first capacitor, a capacitor P-rail, and a capacitor N-rail. The first capacitor, the capacitor P-rail, and the capacitor N-rail are formed or encased in a capacitor resin. The capacitor P-rail is connected to a positive electrode terminal of the first capacitor, and the capacitor N-rail is connected to a negative electrode terminal of the first capacitor.

[0012] The input P-rail is connected to a positive electrode terminal of a DC power source.

[0013] The input N-bus is connected to a negative electrode terminal of the DC power source. The input N-bus has a first N-connection section and a second N-connection section. The first N-connection section is connected to the capacitor N-bus. The second N-connection section is connected to the main N-bus. The main N-bus is located outside the capacitor mold resin in which the first capacitor, the capacitor P-bus, and the capacitor N-bus are formed or encased.

[0014] The electrical power conversion device 1 has the improved design described above, in which the main neutral busbar is not connected to the input neutral busbar via the capacitor neutral busbar, and the capacitor neutral busbar is molded or cast into the capacitor resin. That is, the main neutral busbar is not molded or cast into the capacitor resin. In other words, the main neutral busbar is located outside the capacitor resin. This design prevents the DC current from flowing into the capacitor module. As a result, this design prevents the propagation of heat energy generated by the DC power to the capacitor, which is molded or cast into the capacitor module within the capacitor resin.This prevents the capacitor in the capacitor module from increasing in temperature and thus prevents deterioration and damage to the capacitor. Consequently, the present invention makes it possible to provide an electrical power conversion device with high reliability. BRIEF DESCRIPTION OF THE DRAWING

[0015] A preferred, non-limiting embodiment of the present invention is described by way of example with reference to the accompanying drawing. The drawing shows: Fig. 1 a representation showing a schematic cross-section of an electrical power conversion device according to an exemplary embodiment of the present invention; Fig. 2 a top view showing an input busbar module in the electrical power conversion device according to the exemplary embodiment, which is in Fig. 1 is shown; Fig. 3 a top view showing busbars electrically connected to the input busbar module in the electrical power conversion device according to the exemplary embodiment shown in Fig. 1 is shown; Fig. 4 a representation showing a cross-section of the input busbar module along line IV-IV, which is in Fig. 3 is shown; Fig. 5 a front view of a semiconductor module in the electrical power conversion device according to the exemplary embodiment shown in Fig. 1 is shown; and Fig. 6 a schematic representation showing a circuit diagram of the electrical power conversion device according to the exemplary embodiment shown in Fig. 1 is shown. DETAILED DESCRIPTION OF PREFERRED EXECUTION EXAMPLES

[0016] Various embodiments of the present invention are described below with reference to the accompanying drawing. In the following description of the various embodiments, identical reference numerals or numbers denote identical or equivalent components within the different diagrams.

[0017] The electrical power conversion device according to the present invention can be used in electric vehicles and hybrid vehicles. Exemplary implementation

[0018] A description of the structure and behavior of the electrical power conversion device 1 according to an exemplary embodiment is given with reference to Fig. 1 to Fig. 6 is given.

[0019] Fig. Figure 1 shows a schematic cross-section of the electrical power conversion device 1 according to the exemplary embodiment. The electrical power conversion device 1 converts direct current (DC) power into alternating current (AC) power. As shown in Fig. As shown in Figure 1, the electrical power conversion device 1 comprises a plurality of semiconductor modules 10, a control circuit board 20, a main P-power rail 30p, a main N-power rail 30n, a capacitor module 40, an input P-power rail 5p and an input N-power rail 5n.

[0020] Each of the semiconductor modules 10 has a built-in semiconductor element 11. For example, each of the semiconductor elements 10 that are in Fig. Figure 6 shows a pair of semiconductor elements 11. A control circuit is arranged on the control circuit board 20. The control circuit is connected to a control terminal 13 of each of the semiconductor modules 10 and performs a control and regulation of the behavior of each embedded semiconductor element 11.

[0021] As it is in Fig. As shown in Figure 1, the main P-bus 30 is connected to a positive electrode terminal of each of the semiconductor modules 10. The main N-bus 30n is connected to a negative electrode terminal of each of the semiconductor modules 10. The capacitor module 40, a capacitor P-bus 42p, and a capacitor N-bus 42n are jointly molded or encased using a capacitor molding resin or a capacitor molding plastic 46. The capacitor P-bus 42p is connected to a positive electrode terminal 41p of a filter capacitor 41. The capacitor N-bus 42n is connected to a negative electrode terminal 41n of the filter capacitor 41.

[0022] The input P-bus 5p is connected to a positive electrode terminal 2p (see Fig. 6) a direct current power source (DC power source) 2. The input N-rail 5n is connected to a negative electrode terminal 2n (see Fig. 6) connected to the DC power source 2.

[0023] The input N busbar 5n has a first N connection section 51n and a second N connection section 52n. The first N connection section 51n is connected to the capacitor N busbar 42n. The second N connection section 52n is connected to the main N busbar 30n. The main N busbar 30n is arranged to protrude from the capacitor resin 46.

[0024] The following is a detailed description of the structure and behavior of the electrical power conversion device 1 according to the exemplary embodiment.

[0025] Fig. Figure 6 shows a schematic diagram of the electrical power conversion device 1 according to the exemplary embodiment shown in Fig. Figure 1 shows the electrical power conversion device 1. The electrical power conversion device 1 has the following features shown in Figure 1. Fig. The circuit shown in Figure 6 is described. The electrical power conversion device 1 converts DC power supplied by the DC power source 2 into three-phase AC power. An alternating current load (AC load) is driven or controlled by the converted three-phase AC power.

[0026] As it is in Fig. As shown in Figure 1, the electrical power conversion device 1 comprises a top housing 81, a bottom side housing 82, and a cover 83. The top housing 81 has a rectangular top plate 81a and four side wall plates 81b. The side wall plates are arranged perpendicular to the top plate 81a. The top housing 81 has an open section opposite the top plate 81a. A first housing section 8a is enclosed by the top plate 81a and the side wall plates 81b.

[0027] In the construction of the electrical power conversion device 1 according to the exemplary embodiment shown in Fig. As shown in Figure 1, the upper plate 81a is arranged in a direction X and a direction Y. The direction X is perpendicular to the direction Y, with the side wall plates 81b being arranged in a direction Z.

[0028] As it is in Fig. As shown in Figure 1, the bottom side housing 82 is arranged in the open section of the top housing 81. The bottom side housing 82 has a partition plate 82a and four side wall plates 82b. The partition plate 82a is arranged parallel to the top plate 81a. The side wall plates 82b are arranged perpendicular to the partition plate 82a. A second housing section 8b is enclosed by the partition plate 82a and the side wall plates 82b.

[0029] The partition plate 82a has a vertical wall 82c, a first through-hole 82d, and a second through-hole 82e. The vertical wall 82c is oriented in one direction toward the top housing 81. The first through-hole 82d and the second through-hole 82e are formed in the partition plate 82a to penetrate in the direction Z.

[0030] As it is in Fig. As shown in Figure 1, each of the side wall panels 82b projects in the direction opposite to the side facing the top housing 81 when compared with the partition panel 82a. The projecting end section of each side wall panel 82b is covered by the cover 83. A third housing section 8c is enclosed by the partition panel 82a and the side wall panels 82b.

[0031] As it is in Fig. As shown in Figure 1, the capacitor module 40 and an inductor 60 are arranged and housed in the first housing section 8a. The capacitor module 40 has a capacitor housing 40a. The filter capacitor 41, a capacitor P-type busbar 42p, and a capacitor N-type busbar 42n are arranged inside the capacitor housing 40a and are formed or cast together in the capacitor housing 40a using a capacitor casting resin 46. A smoothing capacitor 44, a positive electrode busbar 45p, and a negative electrode busbar 45n are arranged in the capacitor module 40a and are formed or cast together using the capacitor casting resin 46.

[0032] As it is in Fig. As shown in Figure 1, a large number of the semiconductor modules 10 are housed in the second accommodation section 8b.

[0033] Fig. Figure 5 shows a front view of the semiconductor modules 10 in the electrical power conversion device 1 according to the exemplary embodiment described in Figure 5. Fig. Figure 1 shows that the semiconductor module 10 has a structure in which two devices, i.e., two embedded semiconductor elements 11, are arranged. Furthermore, the semiconductor module 10 has a positive electrode terminal 11p, a negative electrode terminal 11n, an output terminal 12, and a control terminal 13. As shown in Figure 1, the semiconductor module 10 has a positive electrode terminal 11p, a negative electrode terminal 11n, an output terminal 12, and a control terminal 13. Fig. Figure 1 shows an exemplary embodiment with a plurality of semiconductor modules 10. The semiconductor modules 10 and a plurality of cooling tubes 15 are arranged alternately in the X direction. That is, the semiconductor module 10 and the cooling tubes 15 are stacked alternately to form a layered body 18. The layered body 18 is pressed by a pressing element 19 such that the semiconductor modules 10 and the cooling tubes 15 adhere to each other alternately in the X direction.

[0034] A coolant supply section 16 supplies a coolant to the cooling tubes in sequence. The coolant is expelled from the cooling tubes 15 to the outside of the electrical power conversion device 1 through a coolant outlet section 16. The coolant supply section 16 and the coolant outlet section 17 are arranged in the Y direction. As described above, this Y direction is perpendicular to the X and Z directions, respectively. The Y direction is in Fig. 1 omitted.

[0035] Fig. Figure 3 shows a top view showing the busbars electrically connected to an input busbar module 5 in the electrical power conversion device 1 according to the exemplary embodiment, which is located in Fig. 1 is shown. As it is in Fig. 1 and Fig. As shown in Figure 3, the electrical power conversion device 1 according to the exemplary embodiment has the capacitor P-bus 42p, the capacitor N-bus 42n, the input P-bus 5p, the input N-bus 5n, a sensing bus 70, the main P-bus 30p, the main N-bus 30n, the positive electrode bus 45p and the negative electrode bus 45n.

[0036] As it is in Fig. As shown in Figure 1, the capacitor P-rail 42p is connected to a positive electrode terminal 41p of the filter capacitor 41. The capacitor P-rail 42p has a capacitor P-connection section 43p. The capacitor N-rail 42n is connected to a negative electrode terminal 41n of the filter capacitor 41. The capacitor N-rail 42n has a capacitor N-connection section 43n.

[0037] As it is in Fig. As shown in Figure 1, the input P-bus 5p has an input P-connection section 50p, a choke connection section 51p, a second P-connection section 52p, and a control circuit P-connection section 53p. As shown in Figure 1, the input P-bus 5p has an input P-connection section 50p, a choke connection section 51p, a second P-connection section 52p, and a control circuit P-connection section 53p. Fig. As shown in Figure 6, the input P-connection section 50p of the input P-rail 5p is connected to a positive electrode 2p of the DC power source 2. The choke connection section 51p is connected to the choke 60. The second P-connection section 52p is connected to the capacitor P-connection section 43p. The control circuit P-connection section 53p is connected to the control circuit board 20.

[0038] Furthermore, the input N busbar 5n has a power source N connection section 50n, a first N connection section 51n, a second N connection section 52n, and a control circuit N connection section 53n. As shown in Fig. As shown in Figure 6, the power source N-connection section 50n of the input N-bus 5n is connected to the negative electrode terminal 2n of the DC power source 2. The first N-connection section 51n is connected to the capacitor N-connection section 53n. The second N-connection section 52n is connected to a main N-bus 31n connection section located in the main bus 30n. The control circuit N-connection section 53n is connected to the control circuit board 20.

[0039] The detection busbar 70 has a first P-connection section 71p and a control circuit connection section 72. The first P-connection section 71p is connected to a main P-busbar connection section 31p of the main P-busbar 30p. The control circuit connection section 72 is connected to the control circuit board 20.

[0040] As it is in Fig. As shown in Figure 1, the main N busbar is 30n with each of the negative electrode terminals 11n (see Figure 1). Fig. 5) the semiconductor modules 11 are connected. Furthermore, the main N-busbar 30n is connected to the input N-busbar 5n at the main N-busbar connection section 31n. The entire main N-busbar 30n is not formed or encased in the capacitor resin 46.

[0041] As it is in Fig. As shown in Figure 1, the main P-bus is 30p with the positive electrode terminal 11p (see Figure 1). Fig. 5) Each of the semiconductor modules 10 is connected and is also connected to the input P-bus 5p at the main P-bus connection section 31p of the main P-bus 30. The main N-bus 30n and the main P-bus connection section 31p of the main P-bus 30p are located outside the capacitor form resin 46.

[0042] As it is in Fig. As shown in Figure 1, the positive electrode busbar 45p is connected to a positive electrode terminal 44p of the smoothing capacitor 44. The positive electrode busbar 45p has a positive electrode busbar connection section 46p. The positive electrode busbar connection section 46p and the main P-busbar connection section 31p are connected to the input N-busbar 5n.

[0043] The negative electrode busbar 45n is connected to a negative electrode terminal 44n of the smoothing capacitor 44. The negative electrode busbar 45n has a negative electrode busbar connection section 46n. The negative electrode busbar connection section 46n and the main N busbar connection section 31n are connected to the input N busbar 5n.

[0044] As it is in Fig. As shown in Figure 1, the third housing section 8c contains the control board 20. The control circuit controls each of the semiconductor modules 10. The control circuit is located on the control board 20. The control circuit P-connection section 53p, the control circuit N-connection section 53n, the control circuit connection section 72, and a plurality of the control terminals 13 are connected to the control board 20.

[0045] The control circuit P connection section 53p, the control circuit N connection section 53n, and the control circuit connection section 72 protrude through the first through-hole 82d to the inside of the third housing section 8c. The control terminals 13 protrude through the second through-hole 82e to the inside of the third housing section 8c.

[0046] Fig. Figure 2 shows a top view of the input busbar module 5 in the electrical power conversion device 1 according to the exemplary embodiment shown in Fig. 1 is shown.

[0047] As it is in Fig. 1 and Fig. As shown in Figure 2, the input P-bus 5p, the input N-bus 5n, and the detection bus 70 are formed or cast in an input busbar molding resin 54. That is, the input P-bus 5p, the input N-bus 5n, and the detection bus 70, which are formed or cast together, constitute the input busbar module 5. Fig. Figure 1 shows a schematic assembly of the input bus module 5, in which the first N-connection section 51n, the second N-connection section 52n, the first P-connection section 71p, and the second P-connection section 52p are aligned in the Z direction. However, in an actual assembly of the input bus module 5, the first N-connection section 51n, the second N-connection section 52n, the first P-connection section 71p, and the second P-connection section 52p are arranged in the Y direction, as shown in Figure 1. Fig. 2 is shown.

[0048] As it is in Fig. As shown in Figure 2, the first N-connection section 51n, the second N-connection section 52n, the P-connection section 71p, the second P-connection section 52p, the input N-connection section 50n, and the choke connection section 51p are exposed from the input busbar module 5. In the assembly of the electrical power conversion device 1 according to the exemplary embodiment, the first N-connection section 51n and the second N-connection section 52n are arranged adjacent to each other, and the first P-connection section 71p and the second N-connection section 52n are arranged adjacent to each other. Furthermore, the first N-connection section 51n, the second N-connection section 52n, the first P-connection section 71p, and the second P-connection section 52p are arranged in a sequence along the direction Y.

[0049] As it is in Fig. As shown in Figure 2, the first N-compound 51n, the second N-compound 52n, the first P-compound 71p, and the second P-compound 52p form a ribbon-like shape. Similarly, as shown in Figure 2, the first N-compound 51n, the second N-compound 52n, the first P-compound 71p, and the second P-compound 52p form a ribbon-like shape. Fig. Figure 3 shows the capacitor N connection section 43n, the main N busbar connection section 31n, the main P busbar connection section 31p, the capacitor P connection section 43p, the positive electrode busbar connection section 46p and the negative electrode busbar connection section 46n having a ribbon-like shape.

[0050] The first N-connection section 51n is tightly fastened to the capacitor N-connection section 43n by a bolt (not shown). Similarly, the second N-connection section 52p is tightly fastened to the capacitor P-connection section 43p by a bolt (not shown).

[0051] In contrast, the main N busbar connection section 31n and the negative electrode busbar connection section 46n are arranged in a sequence and closely fastened to the second N connection section 52n together by a bolt (not shown).

[0052] Similarly, the P-busbar connection section 31p and the positive electrode busbar connection section 46p are arranged in sequence and closely fastened to the first P-connection section 71p together by a bolt (not shown).

[0053] As it is in Fig. 2 and Fig. As shown in Figure 3, each of the first N-connection section 51n, the second N-connection section 52n, the first P-connection section 71p, and the second P-connection section 52p extends in the X direction. These sections 51n, 52n, 71p, and 52p are arranged in the Y direction, which is perpendicular to the X direction.

[0054] Fig. Figure 4 shows a representation depicting a cross-section of the input busbar module 5 along line IV-IV, which is in Fig. 3 is shown. As it is in Fig. As shown in Figure 4, the electrical power conversion device according to the exemplary embodiment has the improved structure described below in a cross-section that is perpendicular to the direction of extension (i.e., direction X) and parallel to the direction of arrangement (i.e., direction Y).

[0055] The first N-connection section 51n is connected to the capacitor N-busbar 42n at a capacitor N-connection section 43n, wherein a surface 431n of the capacitor N-connection section 43n is arranged on a side opposite to the first N-connection section 51.

[0056] Similarly, the negative electrode busbar connection section 46n, the main N busbar 30n, and the second N connection section 52n are connected at a main N busbar connection section 31n. A surface 461n of the negative electrode busbar connection section 46n is located on a side opposite the second N connection section 52.

[0057] Furthermore, the first P-connection section 71p, the main P-busbar 30p, and the positive electrode busbar 45p are connected at the main P-busbar connection section 31p. A surface 461p of the positive busbar connection section 46p is located on a side opposite the first P-connection section 71p.

[0058] Furthermore, the second P-connection section 52p is connected to the capacitor P-bus 42p at a capacitor P-connection section 43p. A surface 431p of the capacitor P-connection section 43p is arranged opposite the second P-connection section 52p.

[0059] That is, each of the surface 431n of the capacitor-N connection section 43n, the surface 461n of the negative electrode bus connection section 46n, the surface 461p of the positive electrode bus connection section 46p, and the surface 431p of the capacitor-P connection section 43p is, as shown in Fig. 4 is shown, arranged on a virtual straight line L, which is indicated by a single long and double short dashed line.

[0060] As described in detail above and in Fig. 1 to Fig. As shown in Figure 5, the electrical power conversion device 1 according to the exemplary embodiment is equivalent to the one shown in Figure 5. Fig. The circuit shown in section 6, i.e., it forms the one shown in Fig. Circuit shown in section 6. Fig. Figure 6 schematically shows the input bus module 5, the capacitor module 40, the main P bus 30p and the main N bus 30n.

[0061] The following is a detailed description of the effects and behavior of the electrical power conversion device 1 according to the exemplary embodiment.

[0062] The electrical power conversion device 1 according to the exemplary embodiment has an improved design in which the main neutral busbar 30n is not connected to the input neutral busbar 5n via the capacitor neutral busbar 42n, which is molded or cast into the capacitor resin 46. That is, the main neutral busbar 30n is not molded or cast into the capacitor resin 46. This improved design prevents the DC current from flowing into the capacitor module 40. As a result, the design prevents the propagation of heat energy generated by the DC power to the filter capacitor 41 (the first capacitor) and the smoothing capacitor 44 (the second capacitor), which are molded or cast into the capacitor module 40 within the capacitor resin 46.This improved design prevents the temperature of capacitors, such as filter capacitor 41 and smoothing capacitor 44, from rising within the capacitor module 40. As a result, this design prevents damage to filter capacitor 41 and smoothing capacitor 44 and ensures the reliable operation of the electrical power conversion device 1 according to the exemplary embodiment.

[0063] Furthermore, the electrical power conversion device 1, according to the exemplary embodiment, has an improved design in which the first N-connection section 51n and the second N-connection section 52n are arranged adjacent to each other. Each of the first N-connection section 51n and the second N-connection section 52n is formed in the input N-busbar 5n and has the same voltage potential. Accordingly, it is not necessary to use and arrange any insulation between them, and it is possible to form the first N-connection section 51n and the second N-connection section 52n with a narrow gap. This design makes it possible to miniaturize the overall size of the electrical power conversion device 1 compared to a conventional design in which the first N-connection section 51n is electrically separated from the second N-connection section 52n by a connecting element.In the construction of the electrical power conversion device 1 according to the exemplary embodiment, the first N-connection section 51n and the second N-connection section 52n are formed and arranged separately from one another. However, the concept of the present invention is not limited by this construction.

[0064] It is equally acceptable to assemble the first N-connection section 51n and the second N-connection section 52n.

[0065] Furthermore, the electrical power conversion device 1 according to the exemplary embodiment has an improved design in which the detection busbar 70, which has the first P-connection section 71p connected to the main P-busbar 30p, is connected to the main P-busbar 30p, wherein the first P-connection section 71p and the second N-connection section 52n are arranged adjacent to each other. This design makes it possible to reduce the inductance generated between the first P-connection section 71p and the second N-connection section 52n. This design can reduce the generation of noise.

[0066] Furthermore, in the assembly of the electrical power conversion device 1 according to the exemplary embodiment, the input P-bus 5p, the input N-bus 5n, and the detection bus 70 are formed or cast in the input bus resin 54, thereby forming the input bus module 5. This assembly makes it possible to handle the individual component formed or cast in the input bus resin 54 and improves work efficiency during the manufacture of the electrical power conversion device 1.

[0067] Furthermore, the electrical power conversion device 1, according to the exemplary embodiment, comprises the smoothing capacitor 44 as the second capacitor, the positive electrode busbar 45p, and the negative electrode busbar 45n. The positive electrode busbar 45p is connected to the smoothing capacitor 44 and the first P-connection section 71p. The negative electrode busbar 45n is connected to the smoothing capacitor 44 and the second N-connection section 52n.

[0068] Furthermore, each of the first N-connection section 51n, the second N-connection section 52n, the first P-connection section 71p and the second P-connection section 52p extends along the same direction X, which is perpendicular to the direction Y along which these sections 51n, 52n, 71p and 52p are arranged.

[0069] As it is in Fig.As shown in Figure 4 and described above, in a cross-section that is perpendicular to the direction of extension (in the first direction X) and parallel to the arrangement direction (in the second direction Y), each of the surface 431n of the capacitor-N connection section 43n, the surface 461n of the negative electrode busbar connection section 46n, the surface 461p of the positive electrode busbar connection section 46p and the surface 431p of the capacitor-P connection section 43p is arranged on a virtual straight line L, which is designated by a long dashed double short dashed line.

[0070] The improved design described above makes it possible to improve work efficiency when each busbar is connected to each of the first N connection section 51n, the second N connection section 52n, the first P connection section 71p and the second P connection section 52p in a manufacturing operation.

[0071] The electrical power conversion device 1 according to the exemplary embodiment has the filter capacitor 41 as the first capacitor and the smoothing capacitor 44 as the second capacitor. However, the concept of the present invention is not limited by this configuration. For example, it is acceptable to use only a smoothing capacitor as the first capacitor, without using the second capacitor. In this modified configuration, the negative electrode bus connection section 46n of the negative electrode bus 45n, which is connected to this smoothing capacitor as the first capacitor, is connected to the first N connection section 51n, and the positive electrode bus connection section 46p of the positive electrode bus 45p, which is connected to this smoothing capacitor as the first capacitor, is connected to the second P connection section 52p. This configuration does not require, i.e.,It does not have the choke connection section 51p and the detection busbar 70.

[0072] In this modified configuration, the main neutral busbar 30 is not connected to the input neutral busbar 5n via the negative electrode busbar 45n, which is formed or encased in the capacitor resin 46. Furthermore, since the main neutral busbar 30n is not formed or encased in the capacitor resin 46, the modified configuration can exhibit the same effects and behavior as the configuration of the electrical power conversion device 1 according to the exemplary embodiment described above.

[0073] Furthermore, in the construction of the electrical power conversion device 1 according to the exemplary embodiment, the detection busbar 70 is formed or cast in the input busbar resin 54. However, the concept of the present invention is not limited by this construction. For example, it is acceptable to use a detection busbar 70 that is not formed or cast in the input busbar resin 54.

[0074] As described in detail above, the electrical power conversion device 1, according to the exemplary embodiment and the associated modification, can suppress the temperature increase of each of the capacitors. This makes it possible to provide an electrical power conversion device 1 with high reliability.

[0075] While specific embodiments of the present invention have been described in detail, it is apparent to a person skilled in the art that various modifications and alternatives to these details could be developed in light of the entire teaching of the disclosure. Accordingly, the specific arrangements disclosed are intended merely as illustrations and are not meant to limit the scope of the present invention, which shall be given the full breadth of the following claims and all related equivalents.

[0076] An electrical power conversion device comprises semiconductor modules, a main P-bus, a main N-bus, a capacitor module, an input P-bus, and an input N-bus. The input N-bus is connected to the DC power source. The main N-bus is connected to a negative terminal of the semiconductor module to supply the DC power. A capacitor N-bus, a filter capacitor, and a smoothing capacitor within the capacitor module are formed or encased in a capacitor molding resin. The capacitor N-bus is connected to a negative terminal of the filter capacitor. The input N-bus has a first N-connection section connected to the capacitor N-bus and a second N-connection section connected to the main N-bus. The main N-bus is located outside the capacitor molding resin.

Claims

[1] Electrical power conversion device (1) comprising: a semiconductor module (10) or several semiconductor modules (10), each comprising built-in semiconductor elements (11), a positive electrode terminal (11p), a negative electrode terminal (11n) and a control terminal (13); a control circuit board (20) which is connected to the control port (13) of the semiconductor module (10) and is able to control the built-in semiconductor elements (11); a main P-bus (30p) connected to the positive electrode terminal (11p) of the semiconductor module (10), through which DC power is supplied; a main N busbar (30n) which is connected to the negative electrode terminal (11n) of the semiconductor module (10) through which the DC power is supplied; a capacitor module (40) comprising a first capacitor (41), a capacitor P-bus (42p) and a capacitor N-bus (42n), wherein the first capacitor (41), the capacitor P-bus (42p) and the capacitor N-bus (42n) are encased in a capacitor molding resin (46), wherein the capacitor P-bus (42p) is connected to a positive electrode terminal (41p) of the first capacitor (41) and the capacitor N-bus is connected to a negative electrode terminal (41n) of the first capacitor (41); an input P-bus (5p) connected to a positive electrode terminal (2p) of a DC power source (2); and an input N-bus (5n) connected to a negative electrode terminal (2n) of the DC power source (2), the input N-bus (5n) comprising a first N-connection section (51n) and a second N-connection section (52n), the first N-connection section (51n) being connected to the capacitor N-bus (42n) and the second N-connection section (52n) being connected to the main N-bus (30n), the main N-bus (30n) being located outside the capacitor mold resin (46) with which the first capacitor (41), the capacitor P-bus (42p) and the capacitor N-bus (42n) are encapsulated. [2] Electrical power conversion device (1) according to claim 1, with a projection direction (X) and an arrangement direction (Y) which is perpendicular to the projection direction (X), wherein the first N-connection section (51n) and the second N-connection section (52n) are arranged adjacent to each other in the arrangement direction (Y). [3] Electrical power conversion device (1) according to claim 1 or 2, with a projection direction (X) and an arrangement direction (Y) which is perpendicular to the projection direction (X), further comprising a detection busbar (70) which is connected to the main P busbar (30p) and the control board (20), wherein the detection busbar (70) comprises a first P-connection section (71p) which is connected to the main P-busbar (30p), and the first P-connection section (71p) and the second N-connection section (52n) are arranged adjacent to each other in the arrangement direction (Y) and are each connected to a different main busbar. [4] Electrical power conversion device (1) according to claim 3, wherein the input P busbar (5p), the input N busbar (5n) and the sensing busbar (70) are encased by an input busbar molded resin (54) and form an input busbar module (5) as a single assembly. [5] Electrical power conversion device (1) according to claim 4, further comprising: a second capacitor (44); a positive electrode current rail (45p) connected to the second capacitor and the first P-connection section (71p); and a negative electrode current rail (45n) which is connected to the second capacitor and the second N-connection section (52n), wherein the first N-connecting section (51n), the second N-connecting section (52n), the first P-connecting section (71p) and the second P-connecting section (52p) each extend in a first direction (X) and are arranged in a second direction (Y) that is perpendicular to the first direction (X), and the first N-connection section (51n) is connected to the capacitor N-busbar (42n) at a capacitor N-connection section (43n) and a surface (431n) of the capacitor N-connection section (43n) is arranged on a side opposite the first N-connection section (51n), a negative electrode busbar connection section (46n), the main N busbar (30n) and the second N connection section (52n) are connected at a main N busbar connection section (31n) and a surface (461n) of the negative electrode busbar connection section (46n) is arranged on a side opposite the second N connection section (52n), the first P-connection section (71p), the main P-bus (30p) and the positive electrode bus (45p) are connected at a main P-bus connection section (31p) and a surface (461p) of the positive electrode bus connection section (46p) is arranged on a side opposite the first P-connection section (71p), the second P-connection section (52p) is connected to the capacitor P-busbar (42p) at a capacitor P-connection section (43p) and a surface (431p) of the capacitor P-connection section (43p) is arranged opposite to the second P-connection section (52p), where each the surface (431n) of the capacitor-N junction section (43n), the surface (461n) of the negative electrode busbar connection section (46n), the surface (461p) of the positive electrode busbar connection section (46p), and the surface (431p) of the capacitor-P junction section (43p) is arranged on a virtual straight line (L) in a cross-section that is perpendicular to the first direction (X) and parallel to the second direction (Y).

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