Power conversion device

Abstract

To provide a power conversion device capable of further increasing an electrification current.SOLUTION: A power conversion device comprises: a single-phase full-bridge circuit including a high potential side DC terminal, a low potential side DC terminal, a pair of connection terminals, four switching elements and four rectification elements; and a batch RDC snubber circuit which is provided between the high potential side DC terminal and the low potential side DC terminal. The batch RDC snubber circuit includes a first diode, a second diode, a capacitor and a resistance element. The first diode is provided between the rectification elements, which are connected in reverse parallel to the high-side switching elements of one leg and one end of the capacitor. The second diode is provided between the rectification elements, which are connected in reverse parallel to the high-side switching elements of the other leg, and one end of the capacitor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a power conversion device.

Background Art

[0002] There is a power conversion device including a single-phase full-bridge circuit and a lump-sum RDC snubber circuit. The single-phase full-bridge circuit has four switching elements that are full-bridge connected between a pair of DC terminals, and four rectifier elements that are connected in anti-parallel to each of the four switching elements.

[0003] The lump-sum RDC snubber circuit is provided between the DC terminals of the single-phase full-bridge circuit. In other words, the lump-sum RDC snubber circuit is provided collectively for the four switching elements of the single-phase full-bridge circuit. The lump-sum RDC snubber circuit suppresses the surge voltage generated during the switching of each switching element. The lump-sum RDC snubber circuit can suppress an increase in the number of components compared to individual snubber circuits provided for each of the switching elements. For example, it is possible to suppress an increase in the size of the power conversion device and an increase in manufacturing cost.

[0004] The lump-sum RDC snubber circuit has a diode, a capacitor, and a resistive element. The anode of the diode is connected to the DC terminal on the high potential side. The cathode of the diode is connected to one end of the capacitor. The other end of the capacitor is connected to the DC terminal on the low potential side. The resistive element is connected in parallel with the diode.

[0005] As described above, when a lump-sum RDC snubber circuit is provided for the single-phase full-bridge circuit, the length of the path around the lump-sum RDC snubber circuit may be different between the two switching elements on one leg side of the single-phase full-bridge circuit and the two switching elements on the other leg side of the single-phase full-bridge circuit. When the length of the path around increases, the magnitude of the parasitic inductance in the path around increases, and the magnitude of the surge voltage generated during current interruption also increases.

[0006] The magnitude of the energizing current constantly flowing through each switching element needs to be set according to the switching element that generates the largest surge voltage during current interruption. For this reason, if the one-round path for the two switching elements on one leg side becomes long and the magnitude of the surge voltage increases, these two switching elements will become a constraint, and it will be impossible to increase the energizing current for each switching element. For example, it becomes difficult to increase the capacity of the power conversion device.

[0007] Therefore, in a power conversion device including a single-phase full-bridge circuit and a collective RDC snubber circuit, it is desirable to be able to further increase the energizing current for the four switching elements of the single-phase full-bridge circuit.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] Embodiments of the present invention provide a power conversion device capable of further increasing the energizing current.

Means for Solving the Problems

[0010] According to an embodiment of the present invention, there is provided a power conversion device including: a single-phase full-bridge circuit having a DC terminal on the high potential side, a DC terminal on the low potential side, a pair of connection terminals, four switching elements, and four rectifying elements; and a lump RDC snubber circuit provided between the DC terminal on the high potential side and the DC terminal on the low potential side. The four switching elements are full-bridge connected between the DC terminal on the high potential side and the DC terminal on the low potential side. The four rectifying elements are connected in anti-parallel to each of the four switching elements. One of the pair of connection terminals is electrically connected to a connection point of two of the switching elements connected in series that constitute one leg of the single-phase full-bridge circuit. The other of the pair of connection terminals is electrically connected to a connection point of another two of the switching elements connected in series that constitute the other leg of the single-phase full-bridge circuit. The lump RDC snubber circuit includes a first diode, a second diode, a capacitor, and a resistive element. An anode of the first diode is connected to the DC terminal on the high potential side. A cathode of the first diode is connected to one end of the capacitor. The second diode is connected in parallel with the first diode. The other end of the capacitor is connected to the DC terminal on the low potential side. The resistive element is connected in parallel with the first diode and the second diode. The first diode is provided between a rectifying element connected in anti-parallel to the switching element on the high side of the one leg and one end of the capacitor. The second diode is provided between a rectifying element connected in anti-parallel to the switching element on the high side of the other leg and one end of the capacitor.

Effect of the Invention

[0011] A power conversion device capable of further increasing the energization current is provided.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

[0013] Hereinafter, each embodiment will be described with reference to the drawings. Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes between parts, etc. are not necessarily the same as the actual ones. Also, even when representing the same part, the dimensions and ratios may be represented differently in the drawings. In the present specification and each drawing, the same reference numerals are given to the same elements as those described above with respect to the already shown drawings, and detailed descriptions are appropriately omitted.

[0014] FIG. 1 is a block diagram schematically showing a power conversion device according to an embodiment. As shown in FIG. 1, the power conversion device 10 includes a single-phase full-bridge circuit 12 and a lump RDC snubber circuit 14.

[0015] The single-phase full-bridge circuit 12 has a high-potential-side DC terminal 20a, a low-potential-side DC terminal 20b, a pair of connection terminals 22a and 22b, four switching elements 31 to 34, and four rectifying elements 41 to 44.

[0016] The four switching elements 31 to 34 are full-bridge connected between the DC terminals 20a and 20b. Each of the switching elements 31 to 34 has a pair of main terminals and a control terminal.

[0017] Each of the switching elements 31 to 34 has an on state in which current can flow between a pair of main terminals and an off state in which the current flowing between the pair of main terminals is cut off. The off state is not limited to a state where no current flows completely between the pair of main terminals. For example, a weak current that does not affect the operation of the single-phase full-bridge circuit 12 may flow between the pair of main terminals. In other words, the off state is a state where the current flowing between the pair of main terminals is made sufficiently small. Each of the switching elements 31 to 34 switches between the on state and the off state according to the magnitude of the voltage applied between the pair of main terminals and the magnitude of the voltage applied to the control terminal.

[0018] One main terminal of the switching element 31 is electrically connected to the DC terminal 20a. The other main terminal of the switching element 31 is electrically connected to one main terminal of the switching element 32. The other main terminal of the switching element 32 is electrically connected to the DC terminal 20b. One main terminal of the switching element 33 is electrically connected to the DC terminal 20a. The other main terminal of the switching element 33 is electrically connected to one main terminal of the switching element 34. The other main terminal of the switching element 34 is electrically connected to the DC terminal 20b.

[0019] In other words, the switching elements 31 and 32 are connected in series between the DC terminals 20a and 20b. The switching elements 33 and 34 are connected in series between the DC terminals 20a and 20b and are connected in parallel with the switching elements 31 and 32. As a result, each of the switching elements 31 to 34 is full-bridge connected between the DC terminals 20a and 20b.

[0020] The single-phase full-bridge circuit 12 has two legs LG1 and LG2. The switching elements 31 and 32 constitute one leg LG1. The switching elements 33 and 34 constitute the other leg LG2.

[0021] For each of the switching elements 31 to 34, semiconductor elements such as, for example, IEGT (Injection Enhanced Gate Transistor), IGBT (Insulated Gate Bipolar Transistor), and MOSFET (Metal - Oxide - Semiconductor Field - Effect Transistor) are used.

[0022] For each of the switching elements 31 to 34, for example, a pressure - contact type (press - pack type) semiconductor element in which electrodes of a pair of main terminals are arranged on both sides of the package is used. However, each of the switching elements 31 to 34 is not limited to the pressure - contact type semiconductor element, and for example, a module - type semiconductor element in which electrodes of a pair of main terminals are arranged on one side of the package may also be used.

[0023] The four rectifier elements 41 to 44 are connected in anti - parallel to each of the four switching elements 31 to 34. Each of the rectifier elements 41 to 44 is, for example, a free - wheeling diode. For each of the rectifier elements 41 to 44, for example, a pressure - contact type semiconductor element is used in the same manner as each of the switching elements 31 to 34.

[0024] One connection terminal 22a is electrically connected to the connection point between the switching element 31 and the switching element 32. In other words, one connection terminal 22a is electrically connected to the connection point of the two switching elements 31 and 32 connected in series that constitute one leg LG1 of the single - phase full - bridge circuit 12. The other connection terminal 22b is electrically connected to the connection point between the switching element 33 and the switching element 34. In other words, the other connection terminal 22b is electrically connected to the connection point of the two switching elements 33 and 34 connected in series that constitute the other leg LG2 of the single - phase full - bridge circuit 12.

[0025] The single-phase full-bridge circuit 12 is connected to a DC power supply via DC terminals 20a and 20b. Also, the single-phase full-bridge circuit 12 is connected to a load via connection terminals 22a and 22b. The single-phase full-bridge circuit 12 converts the DC power supplied from the DC power supply into another power by switching of each of the switching elements 31 to 34, and supplies the converted power to the load. The single-phase full-bridge circuit 12, for example, converts the DC power supplied from the DC power supply into AC power by switching of each of the switching elements 31 to 34, and supplies the converted AC power to the load. The connection terminals 22a and 22b are, in other words, AC terminals. The single-phase full-bridge circuit 12 may, for example, change the direction of the DC current of the DC power supplied from the DC power supply by switching of each of the switching elements 31 to 34, and supply a DC current in an arbitrary direction to the load. Also, the single-phase full-bridge circuit 12 may further have a function of supplying the power supplied from the load side to the DC power supply side, for example.

[0026] The batch RDC snubber circuit 14 is provided between the DC terminals 20a and 20b of the single-phase full-bridge circuit 12. The batch RDC snubber circuit 14 is provided collectively for the four switching elements 31 to 34 of the single-phase full-bridge circuit 12. The batch RDC snubber circuit 14 suppresses the surge voltage generated during the switching of each of the switching elements 31 to 34. The batch RDC snubber circuit 14, for example, absorbs the surge voltage generated during the switching of each of the switching elements 31 to 34.

[0027] The integrated RDC snubber circuit 14 includes a first diode 51, a second diode 52, a capacitor 53, and a resistive element 54. The anode of the first diode 51 is connected to the high-potential DC terminal 20a. The cathode of the first diode 51 is connected to one end of the capacitor 53. The second diode 52 is connected in parallel with the first diode 51. In other words, similar to the first diode 51, the anode of the second diode 52 is connected to the high-potential DC terminal 20a, and the cathode is connected to one end of the capacitor 53. The other end of the capacitor 53 is connected to the low-potential DC terminal 20b. The resistive element 54 is connected in parallel with the first diode 51 and the second diode 52.

[0028] For the first diode 51 and the second diode 52, a pressure-contact type semiconductor element is used, for example, in the same manner as each of the switching elements 31 to 34 and each of the rectifying elements 41 to 44.

[0029] FIG. 2 is an explanatory diagram schematically showing a power conversion device according to an embodiment. As described above, each of the switching elements 31 to 34, each of the rectifying elements 41 to 44, the first diode 51, and the second diode 52 is a pressure-contact type semiconductor element. In this case, as shown in FIG. 2, the switching elements 31 to 34 are stacked and provided.

[0030] The four switching elements 31 to 34 are stacked and connected in series by stacking the two switching elements 31 and 32 on one leg LG1, and stacking and connecting the two switching elements 33 and 34 on the other leg LG2, and connecting the connection points to the low-potential DC terminal 20b to each other. The first stacked body SB1 of the two switching elements 31 and 32 on one leg LG1 and the second stacked body SB2 of the two switching elements 33 and 34 on the other leg LG2 are stacked and provided. In other words, the first stacked body SB1 and the second stacked body SB2 are stacked so as to connect the low-potential main terminal of the low-side switching element 32 on one leg LG1 and the low-potential main terminal of the low-side switching element 34 on the other leg LG2.

[0031] Each of the switching elements 31 to 34 is electrically connected to the high-potential-side DC terminal 20a at both ends of the laminate of the first laminate SB1 and the second laminate SB2 in the lamination direction, and is electrically connected to the low-potential-side DC terminal 20b at the connection point of the first laminate SB1 and the second laminate SB2.

[0032] In FIG. 2, for example, an example is shown in which the switching elements 33, 34, 32, and 31 are laminated in this order from the lower side of the paper surface. As a result, as described above, each of the switching elements 31 to 34 can be laminated so as to be electrically connected to the high-potential-side DC terminal 20a at both ends of the laminate of the first laminate SB1 and the second laminate SB2 in the lamination direction, and to be electrically connected to the low-potential-side DC terminal 20b at the connection point of the first laminate SB1 and the second laminate SB2.

[0033] Each of the rectifying elements 41 to 44 is provided by being laminated side by side with the laminate of the first laminate SB1 and the second laminate SB2, and is connected in anti-parallel to each of the four switching elements 31 to 34.

[0034] The first diode 51 is provided by being laminated on one end side of the laminate of the rectifying elements 41 to 44 in the lamination direction. The first diode 51 is provided between the rectifying element 41 connected in anti-parallel to the switching element 31 on the high side of one leg LG1 and one end of the capacitor 53.

[0035] The second diode 52 is provided by being laminated on the other end side of the laminate of the rectifying elements 41 to 44 in the lamination direction. The second diode 52 is provided between the rectifying element 43 connected in anti-parallel to the switching element 33 on the high side of the other leg LG2 and one end of the capacitor 53.

[0036] The capacitor 53 and the resistor element 54 are provided separately from the laminate of each of the switching elements 31 to 34 and the laminate of each of the rectifier elements 41 to 44. The resistor element 54 is connected in parallel to each of the first diode 51 and the second diode 52 laminated together with each of the rectifier elements 41 to 44, for example. However, as described above, when the first diode 51 and the second diode 52 are provided by being laminated together with each of the rectifier elements 41 to 44, the resistor element 54 may be provided so as to be connected in parallel only to the first diode 51, or may be provided so as to be connected in parallel only to the second diode 52.

[0037] FIGS. 3(a) and 3(b) are explanatory diagrams schematically showing a reference power conversion device. As shown in FIGS. 3(a) and 3(b), in the reference power conversion device 10a, the integrated RDC snubber circuit 14a has one diode 55 instead of the two diodes of the first diode 51 and the second diode 52. Note that components that are substantially the same in function and configuration as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0038] The diode 55 is, for example, a pressure-contact type semiconductor element, and is provided by being laminated on the laminate of each of the rectifier elements 41 to 44 in the same manner as the second diode 52 in the example shown in FIG. 2. The diode 55 is provided, for example, between the rectifier element 43 connected in anti-parallel to the switching element 33 on the high side of the other leg LG2 and one end of the capacitor 53.

[0039] FIG. 3(a) schematically shows an example of a path CP21 of one round of the current flowing through the single-phase full-bridge circuit 12 and the integrated RDC snubber circuit 14a when the current flowing through the switching element 32 is cut off.

[0040] As shown in FIG. 3(a), when the current flowing through the switching element 32 is cut off, due to the influence of the parasitic inductance of the circuit, a current flows in the path CP21 that returns from the main terminal on the high potential side of the switching element 32, through the rectifier element 41, the diode 55, and the capacitor 53, to the main terminal on the low potential side of the switching element 32.

[0041] Figure 3(b) schematically shows an example of the path CP22 of one cycle of the current flowing through the single-phase full-bridge circuit 12 and the batch RDC snubber circuit 14a when the current flowing through the switching element 34 is interrupted.

[0042] As shown in Figure 3(b), when the current flowing through the switching element 34 is interrupted, due to the influence of the parasitic inductance of the circuit, in the path CP22 that returns from the main terminal on the high-potential side of the switching element 34 to the main terminal on the low-potential side of the switching element 34 via the rectifying element 43, the diode 55, and the capacitor 53, a current flows.

[0043] As shown in FIGS. 3(a) and 3(b), when the number of diodes 55 provided in the batch RDC snubber circuit 14a is only one, the length of the path around the batch RDC snubber circuit 14a may be different from that of the two switching elements 31 and 32 on one leg LG1 side of the single-phase full-bridge circuit 12 and the two switching elements 33 and 34 on the other leg LG2 side of the single-phase full-bridge circuit 12.

[0044] In the example shown in FIGS. 3(a) and 3(b), the length of the path for the two switching elements 31 and 32 on one leg LG1 side is longer than the length of the path for the two switching elements 33 and 34 on the other leg LG2 side.

[0045] Thus, the difference in the length of the path around the batch RDC snubber circuit 14a becomes significant, for example, when pressure-contact type semiconductor elements are used for each element of the single-phase full-bridge circuit 12 and the batch RDC snubber circuit 14a, and the diode 55 of the batch RDC snubber circuit 14a is laminated on the stack of the rectifying elements 41 to 44 of the single-phase full-bridge circuit 12. For example, when the diode 55 is laminated on one end side of the stack of the rectifying elements 41 to 44, the length of the path connecting the other end side of the stack of the rectifying elements 41 to 44 and the diode 55 becomes long.

[0046] When the length of the one-cycle path increases, the magnitude of the parasitic inductance in the one-cycle path increases, and the magnitude of the surge voltage generated when the current is interrupted also increases. For example, when the one-cycle path for the two switching elements 31 and 32 on one leg LG1 side becomes longer and the magnitude of the surge voltage increases, the switching elements 31 and 32 become a constraint, and the energizing current for each of the switching elements 31 to 34 cannot be increased. For example, it becomes difficult to increase the capacity of the power conversion device.

[0047] On the other hand, in the power conversion device 10 according to the present embodiment, the integrated RDC snubber circuit 14 has two diodes, a first diode 51 and a second diode 52. FIG. 2 schematically shows an example of a one-cycle path CP11 of the current flowing through the single-phase full-bridge circuit 12 and the integrated RDC snubber circuit 14 when the current flowing through the switching element 32 is interrupted, and an example of a one-cycle path CP12 of the current flowing through the single-phase full-bridge circuit 12 and the integrated RDC snubber circuit 14 when the current flowing through the switching element 34 is interrupted.

[0048] As shown in FIG. 2, when the current flowing through the switching element 32 in the power conversion device 10 is interrupted, a current flows in a path CP11 that returns from the high-potential side main terminal of the switching element 32, through the rectifying element 41, the first diode 51, and the capacitor 53, to the low-potential side main terminal of the switching element 32.

[0049] When the current flowing through the switching element 34 in the power conversion device 10 is interrupted, a current flows in a path CP12 that returns from the high-potential side main terminal of the switching element 34, through the rectifying element 43, the second diode 52, and the capacitor 53, to the low-potential side main terminal of the switching element 34.

[0050] Thus, in the power conversion device 10 according to this embodiment, since the collective RDC snubber circuit 14 has two diodes, namely the first diode 51 and the second diode 52, the path lengths for the two switching elements 31 and 32 on one leg LG1 side and the path lengths for the two switching elements 33 and 34 on the other leg LG2 side can be equalized.

[0051] In the power conversion device 10 according to this embodiment, even when pressure-contact type semiconductor elements are used for the elements of the single-phase full-bridge circuit 12 and the collective RDC snubber circuit 14, and the first diode 51 and the second diode 52 are provided by being laminated on the laminate of the rectifier elements 41 to 44, the path lengths for the two switching elements 31 and 32 on one leg LG1 side and the path lengths for the two switching elements 33 and 34 on the other leg LG2 side can be equalized.

[0052] For example, the length of the wiring connecting the cathode of the second diode 52 and one end of the capacitor 53 is 0.6 times or more and 1.4 times or less the length of the wiring connecting the cathode of the first diode 51 and one end of the capacitor 53. Thereby, the path lengths for the two switching elements 31 and 32 on one leg LG1 side and the path lengths for the two switching elements 33 and 34 on the other leg LG2 side can be more appropriately equalized. It is possible to more appropriately suppress the difference in the magnitude of the parasitic inductance from becoming large in each path on the leg LG1 side and the leg LG2 side.

[0053] The length of the wiring connecting the cathode of the second diode 52 and one end of the capacitor 53 is more preferably 0.7 times or more and 1.3 times or less, more preferably 0.8 times or more and 1.2 times or less, and even more preferably 0.9 times or more and 1.1 times or less, of the length of the wiring connecting the cathode of the first diode 51 and one end of the capacitor 53. And it is most preferable that the length of the wiring connecting the cathode of the second diode 52 and one end of the capacitor 53 is substantially equal to the length of the wiring connecting the cathode of the first diode 51 and one end of the capacitor 53. Thereby, the difference in parasitic inductance of each path can be more appropriately suppressed. Also, the length of the wiring connecting the cathode of the first diode 51 and one end of the capacitor 53, and the length of the wiring connecting the cathode of the second diode 52 and one end of the capacitor 53 are preferably set to the shortest possible length. In other words, it is preferable that the length of each of the above wirings is as short as possible.

[0054] Also, in the power conversion device 10 according to the present embodiment, for example, compared with the configuration of the power conversion device 10a having only one diode 55, while equalizing the lengths of the paths on the leg LG1 side and the leg LG2 side, it is possible to suppress the length of one of the paths from becoming long. For example, the path CP11 for the switching element 32 shown in FIG. 2 can be made shorter than the path CP21 for the switching element 32 shown in FIG. 3(a).

[0055] Thus, in the power conversion device 10 according to the present embodiment, while equalizing the lengths of the paths on the leg LG1 side and the leg LG2 side, it is possible to suppress one of the paths from becoming long and suppress the surge voltage generated during current interruption from becoming large.

[0056] In other words, in the power conversion device 10, the second diode 52 (clamp snubber diode) is added and configured in a two-parallel configuration, and the terminal structure is made symmetric with respect to the capacitor 53 (clamp snubber capacitor), so that the parasitic inductance of the integrated RDC snubber circuit 14 is equalized among the switching elements 31 to 34, and it is possible to implement with a structure that minimizes the parasitic inductance.

[0057] Therefore, in the power conversion device 10 according to the present embodiment, the energizing current for each of the switching elements 31 to 34 can be increased as compared with the configuration of the power conversion device 10a. In the power conversion device 10 according to the present embodiment, by increasing the energizing current of each of the switching elements 31 to 34, it is possible to realize an increase in the capacity of the device while suppressing an increase in the size of the device.

[0058] Note that, without being limited to the pressure-contact type semiconductor element, for example, when module-type semiconductor elements are used for the elements of the single-phase full-bridge circuit 12 and the integrated RDC snubber circuit 14, and a plurality of module-type semiconductor elements are arranged side by side, there may be a difference in the length of each path on the leg LG1 side and the leg LG2 side. Therefore, even when module-type semiconductor elements are used for each element, the lengths of the paths on the leg LG1 side and the leg LG2 side may be equalized by providing the first diode 51 and the second diode 52.

[0059] The present embodiment includes the following aspects. (Appendix 1) A single-phase full-bridge circuit having a high-potential-side DC terminal, a low-potential-side DC terminal, a pair of connection terminals, four switching elements, and four rectifying elements; An integrated RDC snubber circuit provided between the high-potential-side DC terminal and the low-potential-side DC terminal; Comprising: The four switching elements are full-bridge connected between the high-potential-side DC terminal and the low-potential-side DC terminal; The four rectifying elements are connected in anti-parallel to each of the four switching elements; One of the pair of connection terminals is electrically connected to the connection point of two switching elements connected in series that constitute one leg of the single-phase full-bridge circuit. The other connection terminal of the pair of connection terminals is electrically connected to the connection point of another two switching elements connected in series that constitute the other leg of the single-phase full-bridge circuit. The batch RDC snubber circuit has a first diode, a second diode, a capacitor, and a resistive element. The anode of the first diode is connected to the DC terminal on the high potential side. The cathode of the first diode is connected to one end of the capacitor. The second diode is connected in parallel with the first diode. The other end of the capacitor is connected to the DC terminal on the low potential side. The resistive element is connected in parallel with the first diode and the second diode. The first diode is provided between the rectifying element connected in anti-parallel with the switching element on the high side of the one leg and one end of the capacitor. The second diode is provided between the rectifying element connected in anti-parallel with the switching element on the high side of the other leg and one end of the capacitor, a power conversion device.

[0060] (Appendix 2) The four switching elements, the four rectifying elements, the first diode, and the second diode are pressure-contact type semiconductor elements. The four switching elements are provided by stacking and connecting in series the two switching elements on one leg, stacking and connecting in series the two switching elements on the other leg, and stacking a first stack of the two switching elements on one leg and a second stack of the two switching elements on the other leg so that connection points with the DC terminal on the low potential side are connected to each other. The first stack and the second stack are electrically connected to the DC terminal on the high potential side at both ends in the stacking direction of the stack, and are electrically connected to the DC terminal on the low potential side at the connection point of the first stack and the second stack. The four rectifying elements are provided by being stacked side by side with the stack of the first stack and the second stack, and are connected in anti-parallel to each of the four switching elements. The first diode is provided by being stacked on one end side in the stacking direction of the stack of the four rectifying elements. The second diode is provided by being stacked on the other end side in the stacking direction of the stack of the four rectifying elements. The power conversion device according to Additional Note 1.

[0061] (Additional Note 3) The length of the wiring connecting the cathode of the second diode and one end of the capacitor is 0.6 times or more and 1.4 times or less the length of the wiring connecting the cathode of the first diode and one end of the capacitor. The power conversion device according to Additional Note 1 or 2.

[0062] Although some embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0063] 10, 10a... Power conversion device, 12... Single-phase full-bridge circuit, 14, 14a... Integrated RDC snubber circuit, 20a... DC terminal on the high potential side, 20b... DC terminal on the low potential side, 22a, 22b... Connection terminals, 31 - 34... Switching elements, 41 - 44... Rectifying elements, 51... First diode, 52... Second diode, 53... Capacitor, 54... Resistive element, 55... Diode

Claims

1. A single-phase full-bridge circuit having a DC terminal on the high potential side, a DC terminal on the low potential side, a pair of connection terminals, four switching elements, and four rectifying elements; A lump RDC snubber circuit provided between the DC terminal on the high potential side and the DC terminal on the low potential side; Comprising: The four switching elements are full-bridge connected between the DC terminal on the high potential side and the DC terminal on the low potential side; The four rectifying elements are connected in anti-parallel to each of the four switching elements; One of the pair of connection terminals is electrically connected to the connection point of two of the switching elements connected in series that constitute one leg of the single-phase full-bridge circuit; The other of the pair of connection terminals is electrically connected to the connection point of another two of the switching elements connected in series that constitute the other leg of the single-phase full-bridge circuit; The lump RDC snubber circuit has a first diode, a second diode, a capacitor, and a resistive element; The anode of the first diode is connected to the DC terminal on the high potential side; The cathode of the first diode is connected to one end of the capacitor; The second diode is connected in parallel with the first diode; The other end of the capacitor is connected to the DC terminal on the low potential side; The resistive element is connected in parallel with the first diode and the second diode; The first diode is provided between the rectifying element connected in anti-parallel to the switching element on the high side of the one leg and one end of the capacitor; The second diode is provided between the rectifying element connected in anti-parallel to the switching element on the high side of the other leg and one end of the capacitor, a power conversion device.

2. The four switching elements, the four rectifying elements, the first diode, and the second diode are press-contact type semiconductor elements. The four switching elements are provided by stacking the two switching elements of the one leg in series connection, stacking the two switching elements of the other leg in series connection, and stacking a first stack body of the two switching elements of the one leg and a second stack body of the two switching elements of the other leg so that connection points with the DC terminal on the low potential side are connected to each other. The first stack body and the second stack body are electrically connected to the DC terminal on the high potential side at both ends in the stacking direction of the stack body, and are electrically connected to the DC terminal on the low potential side at the connection point of the first stack body and the second stack body. The four rectifying elements are provided by being stacked side by side with the stack body of the first stack body and the second stack body, and are connected in anti-parallel to each of the four switching elements. The first diode is provided by being stacked on one end side in the stacking direction of the stack body of the four rectifying elements. The second diode is provided by being stacked on the other end side in the stacking direction of the stack body of the four rectifying elements. The power conversion device according to claim 1.

3. The length of the wiring connecting the cathode of the second diode and one end of the capacitor is 0.6 times or more and 1.4 times or less the length of the wiring connecting the cathode of the first diode and one end of the capacitor. The power conversion device according to claim 1.

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