JP2023018359A - power converter - Google Patents

Abstract

To provide a power converter capable of improving current balance.SOLUTION: A power converter comprises: a power conversion component that includes a capacitor and a semiconductor switch; and a multilayer laminated conductor that alternately laminates a plurality of plate-shaped conductors electrically connected to the power conversion component and a plurality of plate-shaped insulators with respect to the plurality of plate-shaped conductors. The multilayer insulation conductor includes: a first sub-multilayer laminated conductor connected to the semiconductor switch; and a second sub-multilayer laminated conductor connected to the capacitor, each provided corresponding to each phase. The power converter further comprises: a plurality of first fuses provided corresponding to a positive side; and a plurality of second fuses provided corresponding to a negative side, connected between the first sub-multilayer laminated conductor and the second sub-multilayer laminated conductor, each corresponding to each phase. The plurality of first and second fuses are arranged in a first direction. One fuses of the plurality of first and second fuses arranged between the first sub-multilayer laminated conductor and the second sub-multilayer laminated conductor are arranged so as not to be adjacent to each other.SELECTED DRAWING: Figure 9

Description

The present disclosure relates to power converters.

A conventional power converter is configured by mounting a plurality of switching elements and electrolytic capacitors on a multilayer laminated conductor.

A multilayer laminated conductor is configured by laminating a positive conductor plate and a negative conductor plate via an insulating plate (Patent Documents 1 and 2). A positive terminal and a negative terminal of each switching element are connected to a positive conductor plate and a negative conductor plate of the multilayer laminated conductor, respectively. The positive terminal and the negative terminal of the electrolytic capacitor are connected to the positive conductor plate and the negative conductor plate of the multilayer laminated conductor, respectively.

By using a multilayer laminated conductor in a power conversion device, it is possible to reduce the inductance, and it is possible to reduce the surge voltage of circuit elements.

Patent No. 5609298 Patent No. 6824840

On the other hand, it is important to improve the current balance of the circuit elements when arranging the circuit elements on the multi-layer laminated conductor of the power converter. This is because, in the case of arrangement of circuit elements with poor current balance, the amount of heat generated increases and may exceed the allowable temperature value of the power converter. In this respect, it is necessary to devise further in terms of improving the current balance in the power converter.

The present disclosure has been made to solve the above problems, and provides a power conversion device capable of improving current balance.

A power conversion device according to one aspect includes a power conversion component including a capacitor and a semiconductor switch, a plurality of plate-shaped conductors electrically connected to the power conversion component, and a plurality of plate-shaped conductors for the plurality of plate-shaped conductors. and a multilayer laminated conductor in which insulators are alternately laminated. The multilayer laminated conductor includes a first sub-multilayer laminated conductor connected to the semiconductor switch and a second sub-multilayer laminated conductor connected to the capacitor, which are provided corresponding to each phase. A plurality of first fuses connected between the first sub-multilayer laminated conductor and the second sub-multilayer laminated conductor corresponding to each phase and provided corresponding to the positive electrode side, and a plurality of first fuses provided corresponding to the negative electrode side. and a plurality of second fuses that are connected to each other. A plurality of first and second fuses are arranged along a first direction. One fuse of the plurality of first and second fuses arranged between the first sub-multilayer laminated conductor and the second sub-multilayer laminated conductor is arranged so as not to be adjacent to each other.

Preferably, one of the plurality of first fuses and the plurality of second fuses forming the current path is arranged so as not to be adjacent to each other.

Preferably, each of the plurality of first and second fuses are arranged in alternating order.
Preferably, the capacitor and the semiconductor switch are provided on one side of the multilayer laminated conductor. A plurality of first and second fuses are provided on the other side of the multilayer laminated conductor.

Preferably, the first sub-multilayer laminated conductor provided corresponding to each phase has an open area between the semiconductor switch and the plurality of first and second fuses.

The power conversion device of the present disclosure can improve current balance.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the structure of the power conversion system 1 based on embodiment. It is a figure explaining circuit composition of bidirectional converter 2 based on an embodiment. It is a figure explaining the structure of the bidirectional converter 2 based on embodiment. It is a figure explaining the multilayer laminated conductor based on embodiment. It is a figure explaining the schematic structure of the multilayer laminated conductor based on embodiment. FIG. 10 is a diagram illustrating the arrangement of fuses 20 in a power conversion device based on a comparative example; FIG. 5 is a diagram illustrating current paths according to the arrangement of fuses 20 in a power conversion device based on a comparative example; FIG. 11 is a diagram illustrating the arrangement of fuses 20 in a power conversion device based on another comparative example; It is a figure explaining arrangement|positioning of the fuse 20 of the power converter device based on embodiment. FIG. 5 is a diagram for explaining analysis results of current variations based on the embodiment and a comparative example; It is a figure explaining the multilayer laminated conductor of the power converter device according to the modification of embodiment.

This embodiment will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are given the same reference numerals, and the description thereof will not be repeated.

Drawing 1 is a figure explaining the composition of power conversion system 1 based on an embodiment. Referring to FIG. 1 , power conversion system 1 includes voltage sag compensator 10 that is connected to commercial power source 5 and supplies power to AC load 15 . The voltage sag compensator 10 includes a compensating power supply circuit 11, a high speed switch (hereinafter also referred to as HSS) 8, an input circuit breaker 6, output circuit breakers 7 and 9, and a bypass circuit breaker 12 provided in a bypass circuit. including. Compensating power supply circuit 11 includes bidirectional converter 2 , power storage device 3 , and transformer 4 .

In this example, the bidirectional converter 2, which is a power conversion device, will be mainly described, but other power conversion devices can be similarly applied.

The bidirectional converter 2 is provided between the power storage device 3 and the transformer 4, supplies a DC voltage to charge the power storage device 3, and converts the DC voltage discharged from the power storage device 3 into an AC voltage. and output.

FIG. 2 is a diagram illustrating the circuit configuration of the bidirectional converter 2 based on the embodiment. Referring to FIG. 2 , bidirectional converter 2 includes a plurality of semiconductor switch IGBTs, which are semiconductor switches, and a plurality of capacitors 40 .

A plurality of semiconductor switch IGBTs are provided corresponding to each phase of U-phase, V-phase and W-phase. A snubber circuit 30 is provided as a protection circuit for each phase. The snubber circuit 30 absorbs a transient high voltage that occurs when the semiconductor switch IGBT is cut off.

In this example, snubber circuits 30 to 32 (hereinafter also collectively referred to as snubber circuit 30) are provided.

Further, fuses are provided in the current paths of the positive electrode side (P side) and the negative electrode side (N side) corresponding to each phase. As an example, a fuse 20 is provided on the positive side (P side) of the U phase, and a fuse 21 is provided on the negative side (N side) of the U phase. A fuse 22 is provided on the positive side (P side) of the V phase, and a fuse 23 is provided on the negative side (N side) of the U phase. A fuse 24 is provided on the positive side (P side) of the W phase, and a fuse 25 is provided on the negative side (N side) of the U phase. In this example, they are also collectively referred to as fuses 20 .

A plurality of capacitors 40 are provided in parallel with each other. It is connected between the positive electrode PB and the neutral electrode MB and between the negative electrode NB and the neutral electrode MB.

FIG. 3 is a diagram illustrating the configuration of the bidirectional converter 2 based on the embodiment.
Referring to FIG. 3, bidirectional converter 2 is configured by mounting a semiconductor switch IGBT, a capacitor 40, a fuse 20, and a snubber circuit 30 on a multilayer laminated conductor, which will be described later.

Bidirectional converter 2 includes a plurality of semiconductor switches IGBTs, nine snubber circuits 30 , twelve fuses 20 and twelve capacitors 40 .

Each component of the bidirectional transducer 2 is connected using multilayer laminated conductors.
In this example, each component is appropriately connected to the stacked positive electrode PB, neutral electrode MB, and negative electrode NB.

As an example, a snubber circuit 30 and a fuse 20 are arranged on the top (surface) side of the multilayer laminated conductor. A capacitor 40 and a semiconductor switch IGBT are arranged on the lower surface (back surface) side of the multilayer laminated conductor.

U-phase, V-phase, and W-phase AC lines are connected to end regions of the multilayer conductor.
FIG. 4 is a diagram illustrating a multilayer laminated conductor based on the embodiment.

Referring to FIG. 4, this example shows a case where components other than the fuse 20 mounted on the multilayer laminated conductor are excluded.

The multilayer laminated conductor includes first sub-multilayer laminated conductors SB0 to SB2 connected to semiconductor switches IGBTs and the like, and second sub-layered conductors SB0 to SB2 connected to the capacitor 40, which are provided corresponding to the respective (U, V, W) phases. and a multilayer laminated conductor SB3.

The fuses 20 are connected between the first sub-multilayer laminated conductors SB0 to SB2 and the second sub-multilayer laminated conductor SB3 corresponding to each phase to form current paths.

FIG. 5 is a diagram illustrating a schematic structure of a multilayer laminated conductor based on the embodiment.
As shown in FIG. 5, the multilayer laminated conductor includes a plurality of plate-shaped conductors electrically connected to the power conversion component, and a plurality of plate-shaped insulators alternately laminated on the plurality of plate-shaped conductors. It is a laminated conductor. Specifically, the multilayer laminated conductor includes a first conductor plate 122 having a first electrode (negative electrode NB) formed thereon, a second conductor plate 123 having a second electrode (neutral electrode MB) formed thereon, and a second conductor plate 123 having a second electrode (neutral electrode MB) formed thereon. It has a third conductor plate 124 on which three electrodes (positive electrode PB) are formed, and four insulating plates 126-129.

These are laminated in the order of insulating plate 126, negative electrode conductor plate 122, insulating plate 127, neutral electrode conductor plate 123, insulating plate 128, positive electrode conductor plate 124, and insulating plate 129 from below. The multilayer laminated conductor is plate-shaped, and the shape of the plate surface is formed in a substantially rectangular shape. Note that the insulating plates 126 to 129 are omitted for simplification of explanation.

A plurality of connection holes are formed by drilling at predetermined positions of the first conductor plate 122 to third conductor plate 124 and the insulating plates 126 to 129, and connection bolts (not shown) are inserted into the plurality of connection holes. ) is inserted. These connecting bolts are provided so as to electrically connect each component with the positive electrode PB, the neutral electrode MB, and the negative electrode NB at predetermined positions.

FIG. 6 is a diagram illustrating the arrangement of fuses 20 in a power converter based on a comparative example. FIG. 6 shows the case where the surface side of the multilayer laminated conductor is viewed from above. The fuses 20 are connected between the first sub-multilayer laminated conductors SB0 to SB2 and the second sub-multilayer laminated conductor SB3 corresponding to each phase to form current paths.

A plurality of fuses 20 are arranged along the horizontal direction. Each fuse 20 is arranged to be connected to the first sub-multilayer laminated conductors SB0 to SB2 arranged in the vertical direction perpendicular to the horizontal direction with respect to the second sub-multilayer laminated conductor SB3.

Here, two fuses 20 are provided on the P side and two on the N side. The order of arrangement shows the case where the fuses 20 are arranged in the order of N, N, P, P side from the left corresponding to each phase.

FIG. 7 is a diagram illustrating current paths according to the arrangement of fuses 20 in a power conversion device based on a comparative example. FIG. 7 shows current paths between the V-phase AC line and the U-phase AC line.

In this example, eight current analysis patterns (1) to (8) flowing through a plurality of semiconductor switches IGBTs provided corresponding to the U phase will be described.

The current analysis pattern (1) is a case where the U-phase negative (N) side semiconductor switch IGBT switches and the V-phase positive (P) side semiconductor switch IGBTs are all always turned on.

The current path is V-phase AC line→V-phase positive electrode (P) side semiconductor switch IGBT→P-side fuse→P-side capacitor→N-side capacitor→N-side fuse→U-phase negative electrode (N) side Semiconductor switch IGBT→AC line of U phase.

Current analysis pattern (2) is a case where the semiconductor switch IGBT on the U-phase negative (N) side switches and all the semiconductor switches IGBT on the W-phase positive (P) side are always on.

The current path is: W-phase AC line → W-phase positive (P) side semiconductor switch IGBT → P-side fuse → P-side capacitor → N-side capacitor → N-side fuse → U-phase negative (N) side Semiconductor switch IGBT→AC line of U phase.

The current analysis pattern (3) is a case where the U-phase positive (P) side semiconductor switch IGBT switches and the V-phase negative (N) side semiconductor switch IGBTs are all always turned on.

The current path is: U-phase AC line → U-phase positive (P) side semiconductor switch IGBT → P-side fuse → P-side capacitor → N-side capacitor → N-side fuse → V-phase negative (N) side Semiconductor switch IGBT→V-phase AC line.

Current analysis pattern (4) is a case where the semiconductor switch IGBT on the positive (P) side of the U phase switches and all the semiconductor switches IGBT on the negative (N) side of the W phase are always on.

The current path is: U-phase AC line → U-phase positive (P) side semiconductor switch IGBT → P-side fuse → P-side capacitor → N-side capacitor → N-side fuse → W-phase negative (N) side Semiconductor switch IGBT→V-phase AC line.

Current analysis pattern (5) is a case where the semiconductor switch IGBT on the positive (P) side of the V phase is switched, and the semiconductor switch IGBT on the negative (N) side of the U phase is always on.

The current path is V-phase AC line→V-phase positive electrode (P) side semiconductor switch IGBT→P-side fuse→P-side capacitor→N-side capacitor→N-side fuse→U-phase negative electrode (N) side Semiconductor switch IGBT→AC line of U phase.

Current analysis pattern (6) is a case where the semiconductor switch IGBT on the W-phase positive (P) side switches and the semiconductor switch IGBT on the U-phase negative (N) side are all always on.

The current path is: W-phase AC line → W-phase positive (P) side semiconductor switch IGBT → P-side fuse → P-side capacitor → N-side capacitor → N-side fuse → U-phase negative (N) side Semiconductor switch IGBT→AC line of U phase.

The current analysis pattern (7) is a case where the V-phase negative (N) side semiconductor switch IGBTs are switched, and the U-phase positive (P) side semiconductor switch IGBTs are all always turned on.

The current path is: U-phase AC line → U-phase positive (P) side semiconductor switch IGBT → P-side fuse → P-side capacitor → N-side capacitor → N-side fuse → V-phase negative (N) side Semiconductor switch IGBT→V-phase AC line.

The current analysis pattern (8) is a case where the W-phase negative (N) side semiconductor switch IGBT switches and the U-phase positive (P) side semiconductor switch IGBTs are all always turned on.

The current path is: U-phase AC line → U-phase positive (P) side semiconductor switch IGBT → P-side fuse → P-side capacitor → N-side capacitor → N-side fuse → W-phase negative (N) side Semiconductor switch IGBT→W-phase AC line.

In the embodiment, the current variation of each current analysis pattern is calculated. Specifically, the current variation rate is calculated.

The current variation rate is calculated by (maximum current value−average current value)/average current value×100. That is, the greater the difference between the maximum current value and the average current value, the greater the current variation rate. The lower the current variation rate, the better the current balance, and the higher the current variation rate, the worse the current balance.

The current paths shown in this example follow the current analysis pattern (7). In this case, a large current variation rate was obtained. The reason for this is that a current path is formed in which the current flows easily when the current flows from the U-phase to the V-phase. Specifically, this is because the P-side fuses are adjacent to each other, and the N-side fuses are also adjacent to each other, so that the current paths are less likely to be cut off.

Also, the current analysis pattern (8) forms a current path through which the current flows easily when the current flows from the U phase to the W phase. This is because the fuses on the P side are adjacent to each other, and the fuses on the N side are also adjacent to each other, so that the current paths are not easily cut off.

In the embodiment, the current balance is improved by devising the arrangement of the fuses 20 serving as current paths.

Specifically, the P-side and N-side fuses 20 serving as a current path when current flows between the U phase and the V phase, which are adjacent phases, are arranged so as not to be adjacent to each other.

One of the P-side and N-side fuses 20 arranged between the first sub-multilayer laminated conductor SB0 and the second sub-multilayer laminated conductor SB3 is arranged so as not to be adjacent to each other.

The arrangement of the P-side and N-side fuses 20 arranged between the first sub-multilayer laminated conductors SB1, SB2 and the second sub-multilayer laminated conductor SB3 also has the same pattern format as above.

FIG. 8 is a diagram illustrating the arrangement of the fuses 20 of the power conversion device based on the embodiment. As shown in FIG. 8, two fuses 20 are provided on the P side and two on the N side. The order of arrangement shows the case where the fuses 20 are arranged in the order of P, N, P, N side from the left corresponding to each phase. P-side and N-side polar fuses 20 are alternately arranged.

In this case, the fuses 20 are not adjacent to each other on both the P-side and the N-side. As a result, a relatively small current variation rate was obtained. The reason is that the arrangement is divided as a current path.

FIG. 9 is a diagram illustrating the arrangement of the fuses 20 of the power converter based on the embodiment. As shown in FIG. 9, two fuses 20 are provided on the P side and two on the N side. The arrangement order shows the case where the fuses 20 are arranged in the order of P, N, N, P side from the left corresponding to each phase.

In this case, the N sides are adjacent to each other, but the fuses 20 are spaced apart on the P side. As a result, a relatively small current variation rate was obtained. The reason is that the arrangement is divided as a current path.

FIG. 10 is a diagram illustrating analysis results of current variations based on the embodiment and the comparative example. As shown in FIG. 10, the current analysis patterns (1) to (8) show the results of the current variation rate of the fuse arrangement according to the comparative example and the fuse arrangement based on the embodiment. As an example, a current value was measured with a semiconductor switch IGBT through which current passes. In this respect, the measurement was performed when the semiconductor switch IGBT was turned off when the variation in the current value became large. For example, in the current analysis pattern (1), the measurement was performed when the U-phase negative side semiconductor switch IGBT was turned off. In the current analysis pattern (2), the measurement was performed when the semiconductor switch IGBT on the U-phase negative electrode side was turned off. In the current analysis pattern (3), the measurement was performed when the U-phase positive side semiconductor switch IGBT was turned off. In the current analysis pattern (4), the measurement was performed when the semiconductor switch IGBT on the positive side of the U phase was turned off. In the current analysis pattern (5), the measurement was performed when the semiconductor switch IGBT on the V-phase positive electrode side was turned off. In the current analysis pattern (6), the measurement was performed when the semiconductor switch IGBT on the W-phase positive electrode side was turned off. In the current analysis pattern (7), the measurement was performed when the semiconductor switch IGBT on the V-phase negative electrode side was turned off. In the current analysis pattern (8), the measurement was performed when the W-phase negative side semiconductor switch IGBT was turned off.

In this example, analysis of currents flowing through a plurality of semiconductor switches IGBTs provided corresponding to the U-phase has been described, but the same can be applied to other V-phases and W-phases.

As shown in this example, one of the P-side and N-side fuses 20 serving as a current path when current flows between the U-phase and the V-phase is arranged so that the fuses 20 are not adjacent to each other. That is, one polarity of the fuse 20 arranged between the first sub-multilayer laminated conductors SB0, SB1 and the second sub-multilayer laminated conductor SB3, which phases are different from each other, is arranged so as not to be adjacent to each other. Dispersively arranging the fuses 20 of at least one of the P-side and N-side polarities can divide the current path.

In this respect, the fuses corresponding to each phase may be arranged alternately, for example, the P side and the N side, or the plurality of fuses 20 arranged along the horizontal direction may be divided into two. They may be arranged in symmetrical order with respect to the vertical center line.

The configuration of the power converter can improve the current balance.
(Modification)
FIG. 11 is a diagram illustrating the configuration of a multilayer laminated conductor according to a modification of the embodiment; As shown in FIG. 11, compared with the configuration of the multilayered laminated conductor of FIG. ) 200. With this configuration, it is possible to suppress the current path from being formed linearly. Thereby, it is possible to suppress the current variation and improve the current balance. By providing the square hole (open area) 200, the current is divided by the square hole (open area) 200 instead of the straight current path, so that the current balance can be improved.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present disclosure is indicated by the scope of claims rather than the above description, and is intended to include all modifications within the scope and meaning of equivalents of the scope of claims.

1 power conversion system, 2 bidirectional converter, 3 power storage device, 4 transformer, 5 commercial power supply, 6 input circuit breaker, 7, 9 output circuit breaker, 10 voltage sag compensator, 11 compensating feeder circuit, 12 bypass circuit breaker , 15 AC load, 20-25 fuse, 30-32 snubber circuit, 40 capacitor.

Claims (5)

a power conversion component including a capacitor and a semiconductor switch;
A plurality of plate-shaped conductors electrically connected to the power conversion component, and a multilayer laminated conductor in which a plurality of plate-shaped insulators are alternately laminated on the plurality of plate-shaped conductors,
The multilayer laminated conductor is
a first sub-multilayer laminated conductor connected to the semiconductor switch, provided corresponding to each phase;
a second sub-multilayer laminated conductor connected to the capacitor;
A plurality of first fuses connected between the first sub-multilayer laminated conductor and the second sub-multilayer laminated conductor corresponding to each phase and provided corresponding to the positive electrode side, and a plurality of first fuses corresponding to the negative electrode side. further comprising a plurality of second fuses provided in the
the plurality of first and second fuses are arranged along a first direction;
A power conversion device, wherein one fuse of the plurality of first and second fuses arranged between the first sub-multilayer laminated conductor and the second sub-multilayer laminated conductor is arranged so as not to be adjacent to each other. . 2. The power converter according to claim 1, wherein one of said plurality of first fuses and said plurality of second fuses forming a current path is arranged so as not to be adjacent to each other. 2. The power converter of claim 1, wherein each of the plurality of first and second fuses are arranged in alternating order. The capacitor and the semiconductor switch are provided on one side of the multilayer laminated conductor,
2. The power converter according to claim 1, wherein said plurality of first and second fuses are provided on the other side of said multilayer laminated conductor. 2. The power converter according to claim 1, wherein said first sub-multilayer laminated conductor provided corresponding to each phase has a square hole between said semiconductor switch and said plurality of first and second fuses.

Images