Power conversion device

Abstract

To provide a power conversion device that reduces burden of fuse installation.SOLUTION: A power conversion device 1 that converts three-phase AC power into multi-phase AC power using a multi-phase transformer 3 which is a 12-phase transformer and converts the converted multi-phase AC power into DC power using a full-wave rectifier circuit 4, in which fuses H1, H2, and H3 are provided on a current path between main windings R1, S1, and T1 on a secondary side of the multi-phase transformer 3 and the full-wave rectifier circuit 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 describes a power conversion device that uses a six-phase transformer having a star-connected winding and a delta-connected winding on the secondary side to generate DC power from three-phase AC power using a multi-phase transformer, and full-wave rectifies the generated six-phase voltage to generate DC power. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-295155 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the power conversion device described in Patent Document 1, in order to prevent secondary failures caused by failure of the diodes used in the full-wave rectifier circuit, it is necessary to provide fuses for all phases of the star-connected windings and delta-connected windings on the secondary side, which results in a large burden on fuse installation, such as the installation space and costs.

[0005] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to reduce the burden involved in installing fuses. [Means for solving the problem]

[0006] One aspect of the present invention is a power conversion device that converts three-phase AC power into polyphase AC power using a polyphase transformer and converts the converted polyphase AC power into DC power using a full-wave rectifier circuit, in which a fuse is provided in a current path of a main winding on the secondary side of the polyphase transformer. One aspect of the present invention is the power conversion device, wherein the fuse is provided in a current path between a main winding on a secondary side of the multi-phase transformer and the full-wave rectifier circuit. One aspect of the present invention is the power conversion device, wherein the multi-phase transformer is a 12-phase transformer, and the fuse is provided in each of three phases of a main winding on the secondary side of the 12-phase transformer. One aspect of the present invention is a power conversion device as described above, comprising a fuse blowout detection unit that detects the blowing of the fuse, and an alarm unit that outputs a predetermined signal when the blowing of the fuse is detected. One aspect of the present invention is the power conversion device, wherein the predetermined signal is a notification signal. One aspect of the present invention is a power conversion device, further comprising a cut-off unit that cuts off the input of the three-phase AC power to the multi-phase transformer when the specified signal is output. Effect of the Invention

[0007] According to the present invention, it is possible to obtain an effect that the burden imposed on fuse installation can be reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a configuration example of a power conversion device according to an embodiment; [Diagram 2] FIG. 2 is an explanatory diagram showing a specific configuration of a 12-phase transformer according to one embodiment. [Diagram 3] FIG. 2 is an explanatory diagram showing a specific configuration of a 12-phase transformer according to one embodiment. [Figure 4] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Diagram 5] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 6] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 7] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 8] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 9] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 10] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 11] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 12] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 13] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 14] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 15] FIG. 2 is a diagram showing a current path of a power conversion device according to an embodiment. [Figure 16] FIG. 13 is a block diagram showing a modified example of a power conversion device according to an embodiment. [Figure 17] FIG. 13 is a block diagram showing a modified example of a power conversion device according to an embodiment. [Figure 18] FIG. 13 is a diagram illustrating another modified example of the power conversion device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram showing an example of the configuration of a power conversion device according to an embodiment. The power conversion device 1 shown in Fig. 1 converts three-phase AC power supplied from a three-phase power source 10 into multi-phase AC power using a multi-phase transformer 3, and converts the converted multi-phase AC power into DC power using a full-wave rectifier circuit. Specifically, the power conversion device 1 uses a 12-phase transformer 3a as the multi-phase transformer 3 to output a 12-phase voltage, and generates a set of DC outputs by a 12-phase 24-wave rectifier circuit 4 having four three-phase full-wave rectifier circuits. In the example of FIG. 1, the DC outputs are connected to a load 6.

[0010] Three fuses H1, H2, and H3 are provided between the 12-phase transformer 3a and the 12-phase 24-wave rectifier circuit 4. The fuses H1, H2, and H3 are provided in the current path of the main windings R1, S1, and T1 on the secondary side of the 12-phase transformer 3a. In the example of Fig. 1, the fuses H1, H2, and H3 are provided in the current path between the main windings R1, S1, and T1 on the secondary side of the 12-phase transformer 3a and the 12-phase 24-wave rectifier circuit 4.

[0011] 2 and 3 are explanatory diagrams showing a specific configuration of the 12-phase transformer 3a. The 12-phase transformer 3a will be specifically described with reference to FIGS. Fig. 2 is a configuration diagram of the 12-phase transformer 3a. As shown in Fig. 2, the 12-phase transformer 3a includes a first winding 11 constituting a primary winding L1, and four windings (a second winding 12, a third winding 13, a fourth winding 14, and a fifth winding 15) constituting a secondary winding L2. Each winding has three winding portions (11a to 11c, 12a to 12c, 13a to 13c, 14a to 14c, and 15a to 15c) corresponding to the input three-phase AC power.

[0012] The first winding 11 may be either delta-connected or star-connected, but is shown in the present embodiment as being star-connected. Three-phase AC power supplied from a three-phase power source 10 is connected to three terminals (Rin, Sin, Tin). The second to fifth windings 12, 13, 14, and 15 are all star-connected (however, as described later, the fourth winding 14 and the fifth winding 15 are not completely star-connected). In the following description, the three phases are referred to as an R phase, an S phase, and a T phase.

[0013] The secondary side of the 12-phase transformer 3a has output terminals R1, S1, T1 of the second winding 12, output terminals R2, S2, T2 of the third winding 13, output terminals R3, S3, T3 of the fourth winding 14, and output terminals R4, S4, T4 of the fifth winding 15, for a total of 12 terminals. The star-connected neutral points Q of the second winding 12 and the third winding 13 are connected to each other, and the third winding 13 is wound around the iron core 8 so that its polarity is opposite to that of the second winding 12, and is formed with 0.73 times the number of turns of the second winding. The fourth winding 14 and the fifth winding 15 are formed by branching off from the same point in the middle of the second winding 12, and the fourth winding 14 and the fifth winding 15 share the neutral point Q of the second winding 12.

[0014] Specifically, the fourth winding 14 and the fifth winding 15 are wound around the iron core 8 as follows. The fourth winding is formed by branching off a T-phase winding 14a from the middle of the R-phase winding 12a of the second winding 12 and pulling it out, and winding it around a leg core 8c shared with the primary side T-phase winding. The tip of the T-phase winding is the output terminal T3. The R-phase winding 14b is branched off from the middle of the S-phase winding 12b of the second winding 12 and wound around the leg core 8a common to the R-phase winding 11. The tip of the R-phase winding 14b is the output terminal R3. The S-phase winding 14c is branched off from the middle of the T-phase winding 12c of the second winding 12 and wound around the leg core 8b common to the primary S-phase winding 12. The tip of the S-phase winding 14c is the output terminal S3.

[0015] The fifth winding 15 has an S-phase winding 15a branched off from the middle of the R-phase winding 12a of the second winding 12, which is the same portion as the fourth winding 14, and is wound around the leg core 8c shared with the S-phase winding of the first winding 11. The tip of the S-phase winding 15a is the output terminal S4. The T-phase winding 15b is branched off from the middle of the S-phase winding 12b of the second winding 12, which is the same portion as the fourth winding 14, and is wound around the leg core 8c shared with the T-phase winding of the first winding 11. The tip of the T-phase winding 15b is the output terminal T4. The R-phase winding 15c is branched off from the middle of the T-phase winding 12c of the second winding 12, which is the same portion as the fourth winding 14, and is wound around the leg core 8a shared with the R-phase winding of the first winding 11. The tip of the R-phase winding 15c is the output terminal R4.

[0016] Fig. 3 is a vector diagram of each winding of the secondary winding L2 of the 12-phase transformer 3a, and each phase is shown based on the R1 phase of the second winding 12. As shown in Fig. 3, the three-phase windings 12a, 12b, and 12c of the second winding 12 output voltages having a phase difference of 120 degrees from output terminals R1, S1, and T1, similar to the input three-phase AC power. As described above, the phases of the windings 13a, 13b, and 13c of the third winding 13 are opposite to the phase of the second winding 12, and the phases of the output terminals R2, S2, and T2 have a phase difference of 180 degrees with respect to the phases of R1, S1, and T1 of the second winding 12. The number of turns of the third winding 13 is 0.73 times (√3-1 times) the number of turns of the second winding 12.

[0017] The phases of output terminals R3, S3, T3 of windings 14a, 14b, 14c extended from the second winding 12 of the fourth winding 14 generate voltages in phase with the respective phases of the third winding 13. Furthermore, the phases of output terminals R4, S4, T4 of windings 15a, 15b, 15c extended from the second winding 12 of the fifth winding 15 generate voltages in phase with the respective output terminals R2, S2, T2 of the corresponding phases of the third winding 13, similar to the fourth winding 14.

[0018] 4 to 15 are diagrams showing current paths in the power conversion device of this embodiment. The current paths in the power conversion device 1 according to this embodiment will be described with reference to Figs. 4 to 15.

[0019] [Operation mode 1: R1-T1 phase] Fig. 4 shows a current path R1T1 between the power conversion device 1 and the load 6 in the operation mode 1 "R1-T1 phase". As shown in Fig. 4, the current path R1T1 can be interrupted by a fuse H1 (R1-phase fuse) connected to the main winding R1.

[0020] [Operation mode 2: R1-R4 phase] Fig. 5 shows a current path R1R4 between the power conversion device 1 and the load 6 in the operation mode 2 "R1-R4 phase". As shown in Fig. 5, the current path R1R4 can be interrupted by a fuse H1 (R1 phase fuse) connected to the main winding R1.

[0021] [Operation mode 3: R1-R2 phase] Fig. 6 shows a current path R1R2 between the power conversion device 1 and the load 6 in the operation mode 3 "R1-R2 phase". As shown in Fig. 6, the current path R1R2 can be interrupted by a fuse H1 (R1 phase fuse) connected to the main winding R1.

[0022] [Operation mode 4: R1-R3 phase] 7 shows a current path R1R3 between the power conversion device 1 and the load 6 in the operation mode 4 "R1-R3 phase". As shown in Fig. 7, the current path R1R3 can be interrupted by a fuse H1 (R1 phase fuse) connected to the main winding R1.

[0023] [Operation mode 5: S1-R1 phase] Fig. 8 shows a current path S1R1 between the power conversion device 1 and the load 6 in the operation mode 5 "S1-R1 phase". As shown in Fig. 8, the current path S1R1 can be interrupted by a fuse H2 (S1 phase fuse) connected to the main winding S1.

[0024] [Operation mode 6: S1-S4 phase] Fig. 9 shows a current path S1S4 between the power conversion device 1 and the load 6 in the operation mode 6 "S1-S4 phase". As shown in Fig. 9, the current path S1S4 can be interrupted by a fuse H2 (S1 phase fuse) connected to the main winding S1.

[0025] [Operation mode 7: S1-S2 phase] Fig. 10 shows a current path S1S2 between the power conversion device 1 and the load 6 in the operation mode 7 "S1-S2 phase". As shown in Fig. 10, the current path S1S2 can be interrupted by a fuse H2 (S1 phase fuse) connected to the main winding S1.

[0026] [Operation mode 8: S1-S3 phase] Fig. 11 shows a current path S1S3 between the power conversion device 1 and the load 6 in the operation mode 8 "S1-S3 phase". As shown in Fig. 11, the current path S1S3 can be interrupted by a fuse H2 (S1 phase fuse) connected to the main winding S1.

[0027] [Operation mode 9: T1-S1 phase] Fig. 12 shows a current path T1S1 between the power conversion device 1 and the load 6 in the operation mode 9 "T1-S1 phase". As shown in Fig. 12, the current path T1S1 can be interrupted by a fuse H3 (T1-phase fuse) connected to the main winding T1.

[0028] [Operation mode 10: T1-T4 phase] Fig. 13 shows a current path T1T4 between the power conversion device 1 and the load 6 in the operation mode 10 "T1-T4 phase". As shown in Fig. 13, the current path T1T4 can be interrupted by a fuse H3 (T1-phase fuse) connected to the main winding T1.

[0029] [Operation mode 11: T1-T2 phase] Fig. 14 shows a current path T1T2 between the power conversion device 1 and the load 6 in the operation mode 11 "T1-T2 phase". As shown in Fig. 14, the current path T1T2 can be interrupted by a fuse H3 (T1-phase fuse) connected to the main winding T1.

[0030] [Operation mode 12: T1-T3 phase] Fig. 15 shows a current path T1T3 between the power conversion device 1 and the load 6 in the operation mode 12 "T1-T3 phase". As shown in Fig. 15, the current path T1T3 can be interrupted by a fuse H3 (T1-phase fuse) connected to the main winding T1.

[0031] According to this embodiment, as described above with reference to Figures 4 to 15, all current paths between the power conversion device 1 and the load 6 can be cut off by the R1-phase fuse H1, the S1-phase fuse H2, and the T1-phase fuse H3. Therefore, it is not necessary to provide fuses for all phases (12 phases) of the 12-phase transformer 3a, and only three fuses H1, H2, and H3 are required. This provides the effect of reducing the burden of installing fuses.

[0032] Fig. 16 is a block diagram showing a modification of the power conversion device according to the present embodiment. A power conversion device 1A shown in Fig. 16 further includes a fuse blowout detection unit 101, a notification unit 102, and a cutoff unit 103 in addition to the components of the power conversion device 1 in Fig. 1.

[0033] The fuse blowout detection unit 101 detects the blowout of the fuses H1, H2, and H3. As a specific example of a method for detecting the blowout of the fuses H1, H2, and H3, as shown in FIG. 17, alarm fuses H11, H21, and H31 and resistors r11, r21, and r31 are connected in series in parallel with the fuses H1, H2, and H3, respectively. Here, the values ​​of the fuses H1, H2, and H3, the alarm fuses H11, H21, and H31, and the resistors r11, r21, and r31 are determined so that when the fuses H1, H2, and H3 blow, the alarm fuses H11, H21, and H31 also blow and an alarm signal is output from the alarm fuses H11, H21, and H31. The alarm signal output from the alarm fuses H11, H21, and H31 is connected to the fuse blowout detection unit 101. As a result, when the fuses H1, H2, and H3 are blown, an alarm signal is output from the alarm fuses H11, H21, and H31 and input to the fuse blown detection unit 101. The fuse blown detection unit 101 detects the blown fuses H1, H2, and H3 by the alarm signal. Note that, although an alarm fuse is used as a method for detecting the blown fuses H1, H2, and H3 in the example of FIG. 17, this is not limiting.

[0034] The notification unit 102 outputs a predetermined signal when blowing of the fuses H1, H2, and H3 is detected. For example, the notification unit 102 outputs a notification signal for notifying blowing of the fuses H1, H2, and H3. For example, the notification signal may be an alarm sound or a signal that turns on or blinks an alarm lamp. For example, the notification signal may be transmitted to a predetermined destination by communication.

[0035] When a predetermined signal is output from the notification unit 102, the cutoff unit 103 cuts off the input of the three-phase AC power supplied from the three-phase power source 10 to the multi-phase transformer 3. As a result, when the fuse blowout detection unit 101 detects that the fuses H1, H2, and H3 have blown, the three-phase AC power supplied from the three-phase power source 10 is no longer input to the multi-phase transformer 3.

[0036] FIG. 18 is a diagram showing another modified example of the power conversion device according to the present embodiment. In the modified example shown in FIG. 18, the location of the fuse is different. In FIG. 18, the fuse H4 is provided at a location common to all current paths (current paths shown in FIG. 4-FIG. 15) of the main windings R1, S1, T1 on the secondary side of the 12-phase transformer 3a. Therefore, all current paths (current paths shown in FIG. 4-FIG. 15) of the main windings R1, S1, T1 on the secondary side of the 12-phase transformer 3a can be cut off by one fuse H4.

[0037] As described above, according to this embodiment, it is not necessary to provide a fuse for each of the phases (12 phases) of the 12-phase transformer 3a, and the number of fuses can be reduced. This provides the advantage of reducing the burden of fuse installation.

[0038] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not deviate from the gist of the present invention are also included. [Explanation of symbols]

[0039] 1...power conversion device, 3...multi-phase transformer, 3a...12-phase transformer, 4...12-phase 24-wave rectifier circuit, 6...load, H1, H2, H3, H4...fuses, 10...3-phase power supply, 101...fuse blown detection section, 102...alarm section, 103...interrupter, H11, H21, H31...alarm fuse, r11, r21, r31...resistor

Claims

1. A power conversion device that converts three-phase AC power into multi-phase AC power using a multi-phase transformer, and converts the converted multi-phase AC power into DC power using a full-wave rectifier circuit, A fuse is provided in a current path of a main winding on the secondary side of the multi-phase transformer. Power conversion equipment.

2. The fuse is provided in a current path between a main winding on a secondary side of the multi-phase transformer and the full-wave rectifier circuit. The power conversion device according to claim 1 .

3. the multi-phase transformer is a 12-phase transformer; The fuse is provided for each of three phases of the main winding on the secondary side of the 12-phase transformer. The power conversion device according to claim 2 .

4. a fuse blowout detection unit for detecting the blowout of the fuse; a notification unit that outputs a predetermined signal when the blowout of the fuse is detected; The power conversion device according to claim 1 , further comprising:

5. The predetermined signal is a notification signal. The power conversion device according to claim 4.

6. a cutoff unit that cuts off the input of the three-phase AC power to the multi-phase transformer when the predetermined signal is output; The power converter according to claim 4 , further comprising:

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