Power Conversion Device

Abstract

The power conversion device (1) includes a first converter valve tower (2), a second converter valve tower (3), and a vibration damping member (40). The vibration damping member (40) connects the first converter valve tower (2) and the second converter valve tower (3) to each other. The first converter valve tower (2) and the second converter valve tower (3) have different vibration modes.

Description

[Technical Field]

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

[0002] International Publication No. 2016 / 162915 (Patent Document 1) discloses a modular multilevel converter (MMC) type high-voltage direct current (HVDC) converter. The MMC includes a number of unit converters, each of which includes a storage element (e.g., a capacitor) and a number of semiconductor switching elements. These unit converters are connected in cascade. Hereinafter, the unit converters are also referred to as "unit cells," "converter cells," or "submodules" (SMs).

[0003] The power conversion device described in Patent Document 1 includes a first rack and a second rack. The first rack and the second rack each include a plurality of stages, a first support pillar, and a second support pillar. The first support pillar supports the lowest stage of the plurality of stages. The second support pillar connects two adjacent stages of the plurality of stages. Each of the plurality of stages includes a substrate on which a plurality of unit cells are mounted, an insulator, and a shield. The first support pillar or the second support pillar is fitted into the insulator. The shield is arranged around the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 162915 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a power conversion device with improved earthquake resistance. [Means for solving the problem]

[0006] The power conversion device of the present disclosure includes a first converter valve tower, a second converter valve tower, and a vibration damping member. The vibration damping member connects the first converter valve tower and the second converter valve tower to each other. The first converter valve tower and the second converter valve tower have different vibration modes. [Effects of the Invention]

[0007] According to the power conversion device of the present disclosure, it is possible to provide a power conversion device with improved earthquake resistance. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a circuit diagram showing the overall configuration of a power conversion device. [Figure 2] FIG. 2 is a schematic circuit diagram of a submodule. [Figure 3] 1 is a schematic front view of a power conversion device according to a first embodiment. [Figure 4] 1 is a schematic side view of a power conversion device according to a first embodiment. [Figure 5A] FIG. 2 is a schematic plan view of a top shield of a first example of the first embodiment. [Figure 5B] FIG. 10 is a schematic plan view of a top shield of a second example of the first embodiment. [Figure 5C] FIG. 10 is a schematic plan view of a top shield according to a third example of the first embodiment. [Figure 6] FIG. 4 is a schematic side view of a power converter according to a modified example of the first embodiment. [Figure 7] FIG. 10 is a schematic side view of a power converter according to a second embodiment. [Figure 8] FIG. 10 is a schematic side view of a power conversion device according to a third embodiment. [Figure 9] FIG. 11 is a schematic side view of a power converter according to a first modified example of the third embodiment. [Figure 10] FIG. 11 is a schematic side view of a power converter according to a second modified example of the third embodiment. [Figure 11] FIG. 10 is a schematic side view of a power converter according to a fourth embodiment. [Figure 12]FIG. 10 is a schematic front view of a power conversion device according to a fourth embodiment. [Figure 13] FIG. 10 is a schematic rear view of the power conversion device of the fourth embodiment. [Figure 14] FIG. 13 is a schematic side view of a power converter according to a modified example of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described. Note that the same reference numerals are used to designate the same components, and the description thereof will not be repeated.

[0010] Embodiment 1 The circuit configuration of a power conversion device 1 according to the first embodiment will be described with reference to Figures 1 and 2. The power conversion device 1 according to the present embodiment is not particularly limited, but is, for example, a modular multilevel converter (MMC) type high voltage direct current (HVDC) converter.

[0011] Referring to FIG. 1, a power conversion device 1 is connected to an AC power system 100 via a transformer 101. The power conversion device 1 is connected to a DC power system 102. The power converter converts AC power input to the AC power system 100 into high-voltage DC power and outputs it to the DC power system 102. The power conversion device 1 includes multiple pairs of arms 103 and 104. The arms 103 and 104 are connected in series with each other. The multiple pairs of arms 103 and 104 are connected in parallel with each other. A transformer 101 is connected between the arms 103 and 104. Each of the arms 103 and 104 includes multiple submodules 10 connected in series.

[0012] Referring to FIG. 2, each of the sub-modules 10 includes, for example, switching elements 105a and 105b, diodes 106a and 106b, a capacitor 107, and connecting lines 108a and 108b.

[0013] The switching elements 105a and 105b are, for example, IGBTs (Insulated Gate Bipolar Transistors). The switching elements 105a and 105b are connected in series to each other.

[0014] The diode 106a is connected in anti-parallel to the switching element 105a. The diode 106b is connected in anti-parallel to the switching element 105b. The capacitor 107 is connected in parallel to the switching elements 105a and 105b.

[0015] The connection line 108a is connected to the emitter terminal of the switching element 105a and the collector terminal of the switching element 105b. The connection line 108b is connected to the emitter terminal of the switching element 105b. The connection line 108a of a submodule 10 is connected to the connection line 108b of another submodule 10 adjacent to the submodule 10. In this way, the submodules 10 form a half-bridge converter cell.

[0016] 3 to 5C, the configuration of the power conversion device 1 of the first embodiment will be described. The power conversion device 1 includes a first converter valve tower 2, a second converter valve tower 3, and a vibration damping member 40.

[0017] The first converter valve tower 2 includes a plurality of first units 22a, 22b, 22c, and 22d and a first support insulator 21. The first converter valve tower 2 may further include a first base 20. The first converter valve tower 2 may further include a first top shield 28 and a first side shield 29.

[0018] The first converter valve tower 2 is fixed to the installation surface 5. For example, a first base 20 is fixed to the installation surface 5. The first base 20 is made of, for example, steel. A first support insulator 21 is fixed to the first base 20. The first support insulator 21 extends in the vertical direction. The first support insulator 21 supports a plurality of first units 22a, 22b, 22c, and 22d. The first support insulator 21 is made of, for example, an insulating material such as fiber reinforced plastic (FRP) or ceramic.

[0019] The first units 22a, 22b, 22c, and 22d are stacked. Each of the first units 22a, 22b, 22c, and 22d includes a plurality of first submodules 11, a first mounting plate 27, and a first frame 23. The first frame 23 includes a first support column 24 and a first connection insulator 25.

[0020] The plurality of submodules 10 includes a plurality of first submodules 11 and a plurality of second submodules 12. The plurality of first submodules 11 are part of the plurality of submodules 10. The plurality of first submodules 11 are mounted on a first mounting plate 27.

[0021] The first mounting plate 27 is fixed to the first frame 23. The first mounting plate 27 is fixed to the first support column 24 using, for example, bolts. The first mounting plate 27 is made of an insulating material such as glass epoxy resin.

[0022] The first support 24 is formed of a material such as steel. The first support 24 of the first unit 22a in the lowest row (first row) of the multiple first units 22a, 22b, 22c, and 22d is fixed to the first support insulator 21 using bolts or the like. In this specification, the nth row unit refers to the nth unit counting from the installation surface 5, where n is a natural number. Therefore, for example, the first row first unit refers to the first unit closest to the installation surface 5 among the multiple first units 22a, 22b, 22c, and 22d, i.e., the lowest row first unit.

[0023] The first connection insulators 25 connect the first struts 24 included in adjacent first units among the plurality of first units 22a, 22b, 22c, and 22d to each other. The first connection insulators 25 included in the uppermost first unit 22d among the plurality of first units 22a, 22b, 22c, and 22d connect the first struts 24 and the first top shield 28 included in the uppermost first unit 22d to each other. The first connection insulators 25 are fixed to the first struts 24 and the first top shield 28 using, for example, bolts. The first connection insulators 25 are made of an insulating material such as fiber-reinforced plastic (FRP) or ceramic. The first connection insulators 25 may be made of the same material as the first support insulators 21.

[0024] The first top shield 28 is disposed at the top of the first converter valve tower 2. The first top shield 28 is fixed, for example, with bolts, to the first connection insulator 25 included in the uppermost first unit 22d among the plurality of first units 22a, 22b, 22c, and 22d. In this embodiment, the first top shield 28 has the shape of a single rectangular ring as shown in FIG. 5A. The first top shield 28 may have the shape of two combined half-rectangular rings as shown in FIG. 5B, or may have the shape of two combined rectangular rings as shown in FIG. 5C.

[0025] The first side shield 29 is disposed on the side of the first converter valve tower 2. The first side shield 29 is fixed to the first support 24, for example, using bolts. The first top shield 28 and the first side shield 29 are formed of a metal such as aluminum. The first top shield 28 and the first side shield 29 attenuate the electric field incident on the plurality of first sub-modules 11 from the periphery of the first converter valve tower 2, thereby protecting the plurality of first sub-modules 11 from the electric field. The first top shield 28 and the first side shield 29 attenuate the electric field emitted from the plurality of first sub-modules 11 to the periphery of the first converter valve tower 2.

[0026] The second converter valve tower 3 is disposed adjacent to the first converter valve tower 2 in the depth direction of the power converter 1. The second converter valve tower 3 includes a plurality of second units 32a, 32b, 32c and a second support insulator 31. The second converter valve tower 3 may further include a second base 30. The second converter valve tower 3 may further include a second top shield 38 and a second side shield 39.

[0027] The second converter valve tower 3 is fixed to the installation surface 5. For example, a second base 30 is fixed to the installation surface 5. The second base 30 is made of, for example, steel. A second support insulator 31 is fixed to the second base 30. The second support insulator 31 extends in the vertical direction. The second support insulator 31 supports a plurality of second units 32a, 32b, 32c. The second support insulator 31 is made of, for example, an insulating material such as fiber reinforced plastic (FRP) or ceramic.

[0028] The second units 32a, 32b, and 32c are stacked. Each of the second units 32a, 32b, and 32c includes a plurality of second submodules 12, a second mounting plate 37, and a second frame 33. The second frame 33 includes second supports 34 and second connection insulators 35.

[0029] The plurality of second submodules 12 are part of the plurality of submodules 10. The number of the plurality of second submodules 12 may be equal to the number of the plurality of first submodules 11, or may be different from the number of the plurality of first submodules 11. The plurality of second submodules 12 are mounted on a second mounting plate 37.

[0030] The second mounting plate 37 is fixed to the second frame 33. The second mounting plate 37 is fixed to the second support columns 34 using, for example, bolts. The second mounting plate 37 is formed of an insulating material such as glass epoxy resin.

[0031] The second support 34 is formed of a material such as steel. The second support 34 of the second unit 32a in the lowest (first) stage among the plurality of second units 32a, 32b, 32c is fixed to the second support insulator 31 using bolts or the like.

[0032] The second connection insulators 35 connect the second struts 34 included in adjacent second units among the plurality of second units 32a, 32b, and 32c to each other. The second connection insulators 35 included in the uppermost second unit 32c among the plurality of second units 32a, 32b, and 32c connect the second struts 34 and the second top shield 38 included in the uppermost second unit 32c to each other. The second connection insulators 35 are fixed to the second struts 34 and the second top shield 38 using, for example, bolts. The second connection insulators 35 are made of an insulating material such as fiber-reinforced plastic (FRP) or ceramic. The second connection insulators 35 may be made of the same material as the second support insulators 31.

[0033] The second top shield 38 is disposed on the top of the second converter valve tower 3. The second top shield 38 is fixed, for example, with bolts, to the second connection insulator 35 included in the uppermost second unit 32c among the plurality of second units 32a, 32b, and 32c. In this embodiment, the second top shield 38 has a single rectangular ring shape as shown in FIG. 5A. The second top shield 38 may have a shape combining two half-rectangular rings as shown in FIG. 5B, or a shape combining two rectangular rings as shown in FIG. 5C.

[0034] The second side shield 39 is disposed on the side of the second converter valve tower 3. The second side shield 39 is fixed to the second support 34, for example, using bolts. The second top shield 38 and the second side shield 39 are formed of a metal such as aluminum. The second top shield 38 and the second side shield 39 attenuate the electric field incident on the plurality of second submodules 12 from the periphery of the second converter valve tower 3, thereby protecting the plurality of second submodules 12 from the electric field. The second top shield 38 and the second side shield 39 attenuate the electric field emitted from the plurality of second submodules 12 to the periphery of the second converter valve tower 3.

[0035] The first converter valve tower 2 and the second converter valve tower 3 have different vibration modes. For example, by making the structure of the first converter valve tower 2 different from the structure of the second converter valve tower 3, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In this embodiment, by making the height of the first converter valve tower 2 different from the height of the second converter valve tower 3, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3.

[0036] For example, the first height of the n-th first unit among the plurality of first units 22a, 22b, 22c, and 22d from the installation surface 5 is equal to the second height of the n-th second unit among the plurality of second units 32a, 32b, and 32c from the installation surface 5, where n is a natural number. The number of stages of the plurality of first units 22a, 22b, 22c, and 22d is different from the number of stages of the plurality of second units 32a, 32b, and 32c. In this embodiment, the number of stages of the plurality of first units 22a, 22b, 22c, and 22d is greater than the number of stages of the plurality of second units 32a, 32b, and 32c. For example, the first converter valve tower 2 includes four stages of the plurality of first units 22a, 22b, 22c, and 22d, and the second converter valve tower 3 includes three stages of the plurality of second units 32a, 32b, and 32c. Therefore, the first converter valve tower 2 and the second converter valve tower 3 have different heights.

[0037] 4, the length of the second strut 34 included in each of the plurality of second units 32a, 32b, 32c is equal to the length of the first strut 24 included in each of the plurality of first units 22a, 22b, 22c, 22d. The length of the second connection insulator 35 included in each of the second units 32a, 32b is equal to the length of the first connection insulator 25 included in each of the first units 22a, 22b, 22c. The length of the second connection insulator 35 included in the third-stage (top-most) second unit 32c is equal to the length of the first connection insulator 25 included in the fourth-stage (top-most) first unit 22d.

[0038] Therefore, the height of the first unit 22a in the first tier is equal to the height of the second unit 32a in the first tier. The height of the first unit 22b in the second tier is equal to the height of the second unit 32b in the second tier. The height of the first unit 22c in the third tier is equal to the height of the second unit 32c in the third tier. The first converter valve tower 2 is higher than the second converter valve tower 3 by the height of the first unit 22d in the fourth tier. The first shield height of the first top shield 28 from the installation surface 5 is higher than the second shield height of the second top shield 38 from the installation surface 5.

[0039] The vibration-damping member 40 connects the first converter valve tower 2 and the second converter valve tower 3. The vibration-damping member 40 is, for example, a viscous damper or a vibration-damping sheet in which a metal layer and a vibration-damping resin layer are laminated.

[0040] The vibration-damping member 40 connects one of the multiple first units 22a, 22b, 22c, and 22d to one of the multiple second units 32a, 32b, and 32c. A first height of one of the multiple first units 22a, 22b, 22c, and 22d from the installation surface 5 is equal to a second height of one of the multiple second units 32a, 32b, and 32c from the installation surface 5. Specifically, the vibration-damping member 40 connects the first-tier first unit 22a to the first-tier second unit 32a. The vibration-damping member 40 connects the second-tier first unit 22b to the second-tier second unit 32b. The vibration-damping member 40 connects the third-tier first unit 22c to the third-tier second unit 32c.

[0041] The vibration damping member 40 includes a first vibration damping member 41 and a second vibration damping member 42. The first vibration damping member 41 and the second vibration damping member 42 intersect with each other. For example, the first vibration damping member 41 and the second vibration damping member 42 connect one of the plurality of first units 22a, 22b, 22c, and 22d to one of the plurality of second units 32a, 32b, and 32c. A first height of one of the plurality of first units 22a, 22b, 22c, and 22d from the installation surface 5 is equal to a second height of one of the plurality of second units 32a, 32b, and 32c from the installation surface 5. Specifically, the first vibration damping member 41 and the second vibration damping member 42 connect the first-tier first unit 22a to the first-tier second unit 32a. The first vibration damping member 41 and the second vibration damping member 42 connect the second-stage first unit 22b and the second-stage second unit 32b to each other. The first vibration damping member 41 and the second vibration damping member 42 connect the third-stage first unit 22c and the third-stage second unit 32c to each other.

[0042] Referring to FIG. 6 , in a modification of the present embodiment, the vibration damping member 40 includes a first vibration damping member 41 but does not include a second vibration damping member 42. For example, the first vibration damping member 41 connects one of the plurality of first units 22a, 22b, 22c, and 22d to one of the plurality of second units 32a, 32b, and 32c. A first height of one of the plurality of first units 22a, 22b, 22c, and 22d from the installation surface 5 is equal to a second height of one of the plurality of second units 32a, 32b, and 32c from the installation surface 5. The first vibration damping member 41 extends parallel to the installation surface 5. Specifically, the first vibration damping member 41 connects the first unit 22a of the first stage to the second unit 32a of the first stage. The first vibration damping member 41 connects the first unit 22b of the second stage to the second unit 32b. The first vibration damping member 41 connects the third-stage first unit 22c and the third-stage second unit 32c to each other.

[0043] The effects of the power conversion device 1 of this embodiment will be described.

[0044] The power conversion device 1 of this embodiment includes a first converter valve tower 2, a second converter valve tower 3, and a vibration damping member 40. The vibration damping member 40 connects the first converter valve tower 2 and the second converter valve tower 3 to each other. The first converter valve tower 2 and the second converter valve tower 3 have different vibration modes.

[0045] Because the first converter valve tower 2 and the second converter valve tower 3 have different vibration modes, even if one of the first converter valve tower 2 and the second converter valve tower 3 shakes significantly during an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 shakes only slightly. Furthermore, because the first converter valve tower 2 and the second converter valve tower 3 are connected by a vibration damping member 40, any significant vibration of one of the first converter valve tower 2 and the second converter valve tower 3 is damped by the vibration damping member 40 and transmitted to the other of the first converter valve tower 2 and the second converter valve tower 3. Therefore, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for the one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0046] Furthermore, since the earthquake resistance of the power conversion device 1 is improved, the structures of the first converter valve tower 2 and the second converter valve tower 3 can be simplified by reducing the numbers and diameters of the first support insulators 21, the second support insulators 31, the first support columns 24, the second support columns 34, the first connection insulators 25, and the second connection insulators 35. This allows the power conversion device 1 to be made smaller.

[0047] Furthermore, since the earthquake resistance of the power conversion device 1 is improved, a larger number of first units can be stacked, and a larger number of second units can be stacked. The number of the plurality of first sub-modules 11 included in the first converter valve tower 2 and the number of the plurality of second sub-modules 12 included in the second converter valve tower 3 can be increased. The capacity of the power conversion device 1 can be increased, and the power that the power conversion device 1 can handle can be increased.

[0048] In the power converter 1 of this embodiment, the first converter valve tower 2 and the second converter valve tower 3 have different heights.

[0049] Therefore, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0050] In the power conversion device 1 of this embodiment, the first converter valve tower 2 includes a plurality of stacked first units 22a, 22b, 22c, and 22d. The plurality of first units 22a, 22b, 22c, and 22d each include a plurality of first sub-modules 11. The second converter valve tower 3 includes a plurality of stacked second units 32a, 32b, and 32c. The number of stages of the plurality of first units 22a, 22b, 22c, and 22d is different from the number of stages of the plurality of second units 32a, 32b, and 32c.

[0051] Therefore, the height of the first converter valve tower 2 can be made different from the height of the second converter valve tower 3. The vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0052] In the power converter 1 of this embodiment, the vibration damping member 40 includes a first vibration damping member 41 and a second vibration damping member 42. The first vibration damping member 41 and the second vibration damping member 42 intersect with each other.

[0053] Therefore, the first vibration damping member 41 and the second vibration damping member 42 are longer than the vibration damping member 40 (see FIG. 6) that extends parallel to the installation surface 5. The second converter valve tower 3 can be disposed closer to the first converter valve tower 2 while suppressing electrical coupling between the first converter valve tower 2 and the second converter valve tower 3 via the first vibration damping member 41 and the second vibration damping member 42. The power conversion device 1 can operate more stably and can be made smaller.

[0054] Embodiment 2 The power conversion device 1 of the second embodiment will be described with reference to Fig. 7. The power conversion device 1 of the present embodiment has the same configuration as the power conversion device 1 of the first embodiment and achieves the same effects, but differs mainly in the following points.

[0055] In the power conversion device 1 of the present embodiment, the first height of the n-th first unit among the plurality of first units 22a, 22b, 22c, and 22d from the installation surface 5 is different from the second height of the n-th second unit among the plurality of second units 32a, 32b, and 32c from the installation surface 5, where n is a natural number. The third height of the (n+1)th first unit among the plurality of first units 22a, 22b, 22c, and 22d from the installation surface 5 is different from the first height and the second height. In this way, by making the structure of the first converter valve tower 2 different from the structure of the second converter valve tower 3, the vibration mode of the first converter valve tower 2 is made different from the vibration mode of the second converter valve tower 3.

[0056] 7, the length of the second support pillar 34 included in the first-stage second unit 32a is longer than the length of the first support pillar 24 included in the first-stage first unit 22a. The length of the second support pillar 34 included in each of the second units 32b, 32c is equal to the length of the first support pillar 24 included in each of the plurality of first units 22a, 22b, 22c, 22d. The length of the second connection insulator 35 included in each of the second units 32a, 32b is equal to the length of the first connection insulator 25 included in each of the first units 22a, 22b, 22c. The length of the second connection insulator 35 included in the third-stage (top) second unit 32c is equal to the length of the first connection insulator 25 included in the fourth-stage (top) first unit 22d.

[0057] Therefore, the height of the first-tier second unit 32a is higher than the height of the first-tier first unit 22a and lower than the height of the second-tier first unit 22b. The height of the second-tier second unit 32b is higher than the height of the second-tier first unit 22b and lower than the height of the third-tier first unit 22c. The height of the third-tier second unit 32c is higher than the height of the third-tier first unit 22c and lower than the height of the fourth-tier first unit 22d. The first converter valve tower 2 is higher than the second converter valve tower 3. The first shield height of the first top shield 28 from the installation surface 5 is higher than the second shield height of the second top shield 38 from the installation surface 5.

[0058] The second side shield 39 is also disposed between the second mounting plate 37 and the second support insulator 31 included in the second unit 32a in the first stage (lowest stage).

[0059] The vibration damping member 40 includes a first vibration damping member 41. The first vibration damping member 41 connects the nth stage first unit and the nth stage second unit to each other. The vibration damping member 40 may further include a second vibration damping member 42. The second vibration damping member 42 connects the n+1th stage first unit and the nth stage second unit to each other. The first vibration damping member 41 and the second vibration damping member 42 have, for example, a zigzag shape.

[0060] Specifically, the first vibration damping member 41 connects the first-stage first unit 22a to the first-stage second unit 32a. The second vibration damping member 42 connects the second-stage first unit 22b to the first-stage second unit 32a. The first vibration damping member 41 connects the second-stage first unit 22b to the second-stage second unit 32b. The second vibration damping member 42 connects the third-stage first unit 22c to the second-stage second unit 32b. The first vibration damping member 41 connects the third-stage first unit 22c to the third-stage second unit 32c. The second vibration damping member 42 connects the fourth-stage first unit 22d to the third-stage second unit 32c.

[0061] The power conversion device 1 of this embodiment has the following effects in addition to the effects of the power conversion device 1 of the first embodiment.

[0062] In the power conversion device 1 of this embodiment, the first converter valve tower 2 includes a plurality of stacked first units 22a, 22b, 22c, and 22d. Each of the plurality of first units 22a, 22b, 22c, and 22d includes a plurality of first submodules 11. The second converter valve tower 3 includes a plurality of stacked second units 32a, 32b, and 32c. Each of the plurality of second units 32a, 32b, and 32c includes a plurality of second submodules 12. The first converter valve tower 2 and the second converter valve tower 3 are fixed to an installation surface 5. A first height of an n-th first unit among the plurality of first units 22a, 22b, 22c, and 22d from the installation surface 5 is different from a second height of an n-th second unit among the plurality of second units 32a, 32b, and 32c from the installation surface 5, where n is a natural number. The vibration damping member 40 includes a first vibration damping member 41. The first vibration damping member 41 connects the n-th stage first unit and the n-th stage second unit to each other.

[0063] Therefore, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0064] Furthermore, the first vibration damping member 41 is longer than the vibration damping member 40 (see FIG. 6) that extends parallel to the installation surface 5. The second converter valve tower 3 can be disposed closer to the first converter valve tower 2 while suppressing electrical coupling between the first converter valve tower 2 and the second converter valve tower 3 via the first vibration damping member 41. The power conversion device 1 operates more stably and can be made smaller.

[0065] In the power conversion device 1 of the present embodiment, the vibration damping member 40 further includes a second vibration damping member 42. The third height of the first unit in the (n+1)th row among the plurality of first units 22a, 22b, 22c, 22d from the installation surface 5 is different from the first height and the second height. The second vibration damping member 42 connects the first unit in the (n+1)th row and the second unit in the nth row to each other.

[0066] Therefore, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0067] Furthermore, the first vibration damping member 41 and the second vibration damping member 42 are longer than the vibration damping member 40 (see FIG. 6) that extends parallel to the installation surface 5. The second converter valve tower 3 can be disposed closer to the first converter valve tower 2 while suppressing electrical coupling between the first converter valve tower 2 and the second converter valve tower 3 via the first vibration damping member 41 and the second vibration damping member 42. The power conversion device 1 operates more stably and can be made smaller.

[0068] Embodiment 3 The power conversion device 1 of the third embodiment will be described with reference to Fig. 8. The power conversion device 1 of the present embodiment has the same configuration as the power conversion device 1 of the first embodiment and achieves the same effects, but differs mainly in the following points.

[0069] In this embodiment, the first converter valve tower 2 does not include the first unit 22d, and the first converter valve tower 2 and the second converter valve tower 3 have the same height. Therefore, the first shield height of the first top shield 28 from the installation surface 5 is equal to the second shield height of the second top shield 38 from the installation surface 5. However, the first converter valve tower 2 and the second converter valve tower 3 differ from each other in at least one of the number of support insulators, the structure of the support insulators, and the structure of the frame. Therefore, the vibration mode of the first converter valve tower 2 is different from the vibration mode of the second converter valve tower 3.

[0070] 8, the number of the first support insulators 21 and the number of the second support insulators 31 are different from each other. For example, the number of the first support insulators 21 is greater than the number of the second support insulators 31. Therefore, the vibration mode of the first converter valve tower 2 is different from the vibration mode of the second converter valve tower 3.

[0071] Furthermore, the structure of the first frame 23 and the structure of the second frame 33 are different from each other. For example, the number of first supports 24 and the number of second supports 34 are different from each other. The number of first connection insulators 25 and the number of second connection insulators 35 are different from each other. Specifically, the number of first supports 24 is greater than the number of second supports 34. The number of first connection insulators 25 is greater than the number of second connection insulators 35. Therefore, the vibration mode of the first converter valve tower 2 is different from the vibration mode of the second converter valve tower 3.

[0072] 9, in a first modification of the present embodiment, the diameter of the first support insulator 21 is larger than the diameter of the second support insulator 31. Therefore, the vibration mode of the first converter valve tower 2 is different from the vibration mode of the second converter valve tower 3.

[0073] Furthermore, the structure of the first frame 23 and the structure of the second frame 33 are different from each other. For example, the diameter of the first support column 24 is larger than the diameter of the second support column 34. The diameter of the first connection insulator 25 is larger than the diameter of the second connection insulator 35. Therefore, the vibration mode of the first converter valve tower 2 is different from the vibration mode of the second converter valve tower 3.

[0074] 10 , in a second modification of the present embodiment, the structure of the first frame 23 and the structure of the second frame 33 are different from each other. For example, the first frame 23 includes reinforcing frames that reinforce more columns than the second frame 33. Specifically, the first frame 23 includes reinforcing frames 26 that reinforce the first columns 24. The reinforcing frames 26 of the first frame 23 are fixed to the first columns 24 to reinforce the first columns 24. In contrast, the second frame 33 does not include reinforcing frames that reinforce the second columns 34.

[0075] The power conversion device 1 of this embodiment has the following effects in addition to the effects of the power conversion device 1 of the first embodiment.

[0076] In the power converter 1 of this embodiment, the first converter valve tower 2 includes a plurality of stacked first units 22a, 22b, and 22c and a first support insulator 21 that supports the plurality of first units 22a, 22b, and 22c. The plurality of first units 22a, 22b, and 22c each include a plurality of first sub-modules 11. The second converter valve tower 3 includes a plurality of stacked second units 32a, 32b, and 32c and a second support insulator 31 that supports the plurality of second units 32a, 32b, and 32c. The plurality of second units 32a, 32b, and 32c each include a plurality of second sub-modules 12. The number of first support insulators 21 and the number of second support insulators 31 are different from each other, or the diameters of the first support insulators 21 and the second support insulators 31 are different from each other.

[0077] Therefore, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0078] In the power conversion device 1 of this embodiment, the first converter valve tower 2 includes a plurality of stacked first units 22a, 22b, and 22c. Each of the plurality of first units 22a, 22b, and 22c includes a plurality of first submodules 11, a first mounting plate 27 on which the plurality of first submodules 11 are mounted, and a first frame 23 to which the first mounting plate 27 is fixed. The second converter valve tower 3 includes a plurality of stacked second units 32a, 32b, and 32c. Each of the plurality of second units 32a, 32b, and 32c includes a plurality of second submodules 12, a second mounting plate 37 on which the plurality of second submodules 12 are mounted, and a second frame 33 to which the second mounting plate 37 is fixed. The structure of the first frame 23 and the structure of the second frame 33 are different from each other.

[0079] Therefore, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0080] In the power conversion device 1 of this embodiment, the first frame 23 includes first supports 24 to which a first mounting plate 27 is fixed, and first connection insulators 25 connected to the first supports 24. The second frame 33 includes second supports 34 to which a second mounting plate 37 is fixed, and second connection insulators 35 connected to the second supports 34. The number of first supports 24 and the number of second supports 34 are different from each other, or the diameters of the first supports 24 and the second supports 34 are different from each other, or the number of first connection insulators 25 and the number of second connection insulators 35 are different from each other, or the diameters of the first connection insulators 25 and the second connection insulators 35 are different from each other.

[0081] Therefore, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0082] In the power conversion device 1 of this embodiment, the first frame 23 includes a reinforcing frame that reinforces more columns than the second frame 33 does.

[0083] Therefore, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0084] In the power converter 1 of this embodiment, the first converter valve tower 2 and the second converter valve tower 3 have the same height.

[0085] In this embodiment, even if the first converter valve tower 2 and the second converter valve tower 3 have the same height, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0086] In the power conversion device 1 of this embodiment, the first converter valve tower 2 includes a first top shield 28 at the top of the first converter valve tower 2. The second converter valve tower 3 includes a second top shield 38 at the top of the second converter valve tower 3. The first converter valve tower 2 and the second converter valve tower 3 are fixed to the installation surface 5. The first shield height of the first top shield 28 from the installation surface 5 is equal to the second shield height of the second top shield 38 from the installation surface 5. Note that if the first shield height of the first top shield 28 and the second shield height of the second top shield 38 are equal, the first top shield 28 and the second top shield 38 may be integrated to form the configuration shown in FIG. 5B.

[0087] Therefore, the first top shield 28 can attenuate the electric field incident on the second converter valve tower 3 from above the first converter valve tower 2, in addition to the electric field incident on the first converter valve tower 2 from above the first converter valve tower 2. The first top shield 28 attenuates the electric field emitted from the plurality of second sub-modules 12 to above the first converter valve tower 2. The second top shield 38 can attenuate the electric field incident on the first converter valve tower 2 from above the second converter valve tower 3, in addition to the electric field incident on the second converter valve tower 3 from above the second converter valve tower 3. The second top shield 38 attenuates the electric field emitted from the plurality of first sub-modules 11 to above the second converter valve tower 3. The power conversion device 1 can operate more stably.

[0088] Embodiment 4 The power conversion device 1 of the fourth embodiment will be described with reference to Figures 11 to 14. The power conversion device 1 of the present embodiment has the same configuration as the power conversion device 1 of the first embodiment and achieves the same effects, but differs mainly in the following points.

[0089] In the power conversion device 1 of this embodiment, the first converter valve tower 2 and the second converter valve tower 3 have the same height. Therefore, the first shield height of the first top shield 28 from the installation surface 5 is equal to the second shield height of the second top shield 38 from the installation surface 5. However, as shown in FIGS. 11 to 13 , the number of the plurality of first sub-modules 11 and the number of the plurality of second sub-modules 12 are different from each other. Therefore, the vibration mode of the first converter valve tower 2 is different from the vibration mode of the second converter valve tower 3.

[0090] For example, the number of the second submodules 12 is smaller than the number of the first submodules 11. The number of second submodules 12 included in the n-th second units 32a and 32b excluding the uppermost second unit 32c is equal to the number of first submodules 11 included in the n-th first units 22a and 22b excluding the uppermost first unit 22c, but the number of second submodules 12 included in the uppermost second unit 32c is smaller than the number of first submodules 11 included in the uppermost first unit 22c. As shown in FIGS. 11 and 13, the number of second submodules 12 included in the uppermost second unit 32c may be zero as shown in FIGS. 11 and 13, or may be one or more as shown in FIG. 14.

[0091] The power conversion device 1 of this embodiment has the following effects in addition to the effects of the power conversion device 1 of the first embodiment.

[0092] In the power conversion device 1 of this embodiment, the first converter valve tower 2 includes a plurality of stacked first units 22a, 22b, and 22c. Each of the plurality of first units 22a, 22b, and 22c includes a plurality of first submodules 11. The second converter valve tower 3 includes a plurality of stacked second units 32a, 32b, and 32c. Each of the plurality of second units 32a, 32b, and 32c includes a plurality of second submodules 12. The number of the plurality of first submodules 11 and the number of the plurality of second submodules 12 are different from each other.

[0093] Therefore, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0094] The number of second submodules 12 included in the uppermost second unit 32c among the multiple second units 32a, 32b, 32c is smaller than the number of first submodules 11 included in the uppermost first unit 22c among the multiple first units 22a, 22b, 22c.

[0095] Therefore, the weight of the uppermost second unit 32c is reduced, and the earthquake resistance of the power conversion device 1 is improved.

[0096] In the power converter 1 of this embodiment, the first converter valve tower 2 and the second converter valve tower 3 have the same height.

[0097] In this embodiment, even if the first converter valve tower 2 and the second converter valve tower 3 have the same height, the vibration mode of the first converter valve tower 2 can be made different from the vibration mode of the second converter valve tower 3. In the event of an earthquake, the other of the first converter valve tower 2 and the second converter valve tower 3 functions as a support for one of the first converter valve tower 2 and the second converter valve tower 3. This improves the earthquake resistance of the power conversion device 1.

[0098] In the power conversion device 1 of this embodiment, the first converter valve tower 2 includes a first top shield 28 at the top of the first converter valve tower 2. The second converter valve tower 3 includes a second top shield 38 at the top of the second converter valve tower 3. The first converter valve tower 2 and the second converter valve tower 3 are fixed to the installation surface 5. The first shield height of the first top shield 28 from the installation surface 5 is equal to the second shield height of the second top shield 38 from the installation surface 5.

[0099] Therefore, the first top shield 28 can attenuate the electric field incident on the second converter valve tower 3 from above the first converter valve tower 2, in addition to the electric field incident on the first converter valve tower 2 from above the first converter valve tower 2. The first top shield 28 attenuates the electric field emitted from the plurality of second sub-modules 12 to above the first converter valve tower 2. The second top shield 38 can attenuate the electric field incident on the first converter valve tower 2 from above the second converter valve tower 3, in addition to the electric field incident on the second converter valve tower 3 from above the second converter valve tower 3. The second top shield 38 attenuates the electric field emitted from the plurality of first sub-modules 11 to above the second converter valve tower 3. The power conversion device 1 can operate more stably.

[0100] The presently disclosed embodiments 1-4 and their modifications should be considered to be illustrative in all respects and not restrictive. Unless there is a contradiction, at least two of the presently disclosed embodiments 1-4 and their modifications may be combined. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0101] REFERENCE SIGNS LIST 1 power conversion device, 2 first converter valve tower, 3 second converter valve tower, 5 installation surface, 10 submodule, 11 first submodule, 12 second submodule, 20 first base, 21 first support insulator, 22a, 22b, 22c, 22d first unit, 23 first frame, 24 first support column, 25 first connection insulator, 26 reinforcement frame, 27 first mounting plate, 28 first top shield, 29 first side shield, 30 second base, 31 second support insulator, 32a, 32b, 32c second unit, 33 second frame, 34 second support column, 35 second connection insulator, 37 second mounting plate, 38 second top shield, 39 second side shield, 40 vibration damping member, 41 first vibration damping member, 42 second vibration damping member, 100 AC power system, 101 transformer, 102 DC power system, 103, 104 arms, 105a, 105b switching elements, 106a, 106b diodes, 107 capacitors, 108a, 108b connecting lines.

Claims

1. The first converter valve tower, The second transducer valve tower, The system includes a vibration damping member that connects the first transducer valve tower and the second transducer valve tower to each other. The first transducer valve tower and the second transducer valve tower have different vibration modes. The vibration damping member is a viscous damper, or a vibration damping sheet in which a metal layer and a vibration damping resin layer are laminated, in a power conversion device.

2. The power conversion device according to claim 1, wherein the first converter valve tower and the second converter valve tower have different heights from each other.

3. The first converter valve tower includes a plurality of stacked first units, each of which includes a plurality of first submodules. The second converter valve tower includes a plurality of stacked second units, each of which includes a plurality of second submodules. The power conversion device according to claim 2, wherein the number of stages of the plurality of first units is different from the number of stages of the plurality of second units.

4. The vibration damping member includes a first vibration damping member and a second vibration damping member. The power conversion device according to claim 2 or claim 3, wherein the first vibration damping member and the second vibration damping member intersect each other.

5. The first converter valve tower includes a plurality of stacked first units, each of which includes a plurality of first submodules. The second converter valve tower includes a plurality of stacked second units, each of which includes a plurality of second submodules. The first converter valve tower and the second converter valve tower are fixed to the mounting surface. The first height of the nth-th stage of the plurality of first units from the installation surface is different from the second height of the nth-th stage of the plurality of second units from the installation surface, where n is a natural number. The vibration damping member includes a first vibration damping member, The power conversion device according to claim 1 or claim 2, wherein the first vibration damping member connects the nth stage first unit and the nth stage second unit to each other.

6. The vibration damping member further includes a second vibration damping member, The third height of the (n+1)th first unit among the plurality of first units from the installation surface is different from the first height and the second height. The power conversion device according to claim 5, wherein the second vibration damping member connects the (n+1)th stage first unit and the nth stage second unit to each other.

7. The first converter valve tower includes a plurality of stacked first units and a first support insulator supporting the plurality of first units, Each of the aforementioned plurality of first units includes a plurality of first submodules, The second converter valve tower includes a plurality of stacked second units and a second support insulator supporting the plurality of second units, Each of the aforementioned plurality of second units includes a plurality of second submodules, The number of the first support insulators and the number of the second support insulators are different from each other, or The power conversion device according to claim 1, wherein the diameter of the first support insulator and the diameter of the second support insulator are different from each other.

8. The first converter valve tower includes a plurality of stacked first units, Each of the plurality of first units includes a plurality of first submodules, a first mounting plate on which the plurality of first submodules are mounted, and a first frame to which the first mounting plate is fixed. The second converter valve tower includes a plurality of stacked second units, Each of the aforementioned plurality of second units includes a plurality of second submodules, a second mounting plate on which the plurality of second submodules are mounted, and a second frame to which the second mounting plate is fixed. The power conversion device according to claim 1, wherein the structure of the first frame and the structure of the second frame are different from each other.

9. The first frame includes a first support column to which the first mounting plate is fixed, and a first connecting insulator connected to the first support column. The second frame includes a second support column to which the second mounting plate is fixed, and a second connecting insulator connected to the second support column. The number of the first support and the number of the second support are different from each other, or The diameter of the first support column and the diameter of the second support column are different from each other, or The number of the first connecting insulator and the number of the second connecting insulator are different from each other, or The power conversion device according to claim 8, wherein the diameter of the first connecting insulator and the diameter of the second connecting insulator are different from each other.

10. The power conversion device according to claim 8, wherein the first frame includes a reinforcing frame that reinforces more support columns than the second frame.

11. The first converter valve tower includes a plurality of stacked first units, each of which includes a plurality of first submodules. The second converter valve tower includes a plurality of stacked second units, each of which includes a plurality of second submodules. The power conversion device according to claim 1, wherein the number of the plurality of first submodules and the number of the plurality of second submodules are different from each other.

12. The power conversion device according to claim 11, wherein the number of second submodules included in the uppermost second unit among the plurality of second units is less than the number of first submodules included in the uppermost first unit among the plurality of first units.

13. The power conversion device according to any one of claims 7 to 12, wherein the first converter valve tower and the second converter valve tower are of the same height.

14. The first transducer valve tower includes a first top shield at the top of the first transducer valve tower, The second transducer valve tower includes a second top shield at the top of the second transducer valve tower. The first converter valve tower and the second converter valve tower are fixed to the mounting surface. The power conversion device according to any one of claims 7 to 12, wherein the first shield height of the first top shield from the mounting surface is equal to the second shield height of the second top shield from the mounting surface.

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