JP6780583B2 - Power converter - Google Patents

Description

The technology disclosed herein relates to a power converter comprising a laminate in which a plurality of coolers and a plurality of semiconductor modules are laminated.

In a power conversion device, a semiconductor module in which a circuit (switching circuit) including a switching element for power conversion is sealed is often used. On the other hand, in a power conversion device, a snubber circuit is used in order to reduce noise associated with switching operation of a switching element or to reduce current / voltage vibration called ringing. Patent Document 1 describes snubbers for high-potential side terminals and low-potential side terminals (terminals conducting to the high-potential side and terminals conducting to the low-potential side of the internal switching circuit) extending from the semiconductor module. A power converter in which a board on which a circuit is mounted is screwed is disclosed.

Japanese Unexamined Patent Publication No. 2014-128066

Power converters often use multiple semiconductor modules. Further, since the switching element for power conversion has a large amount of heat generation, the power conversion device is often accompanied by a cooler for cooling the semiconductor module. One type of power conversion device includes a laminate in which a plurality of semiconductor modules and a plurality of coolers are laminated so that the semiconductor modules and the coolers are alternately arranged. In such a power conversion device, the gap between adjacent semiconductor modules is narrow, and screwing the board of the snubber circuit to the high potential side terminal and the low potential side terminal of each semiconductor module is poor in assembly workability.

The applicant of the present application has proposed a structure having good workability for assembling a snubber circuit with respect to a power conversion device of a type including a laminate in which a plurality of semiconductor modules and a plurality of coolers are laminated (Japanese Patent Application No. 2016-001776, 2016). Filed on January 7, 2014, unpublished at the time of filing this application). The power converter includes a laminate in which a plurality of semiconductor modules and a plurality of coolers are laminated so that the semiconductor modules and the coolers are arranged alternately, and a socket component attached to at least one semiconductor module. There is. The semiconductor module to which the socket component is attached seals the switching circuit including the switching element, and extends in the direction in which the high-potential side terminal and the low-potential side terminal of the switching circuit intersect the stacking direction of the laminate. There is. The socket component houses a snubber circuit connected between the high-potential side terminal and the low-potential side terminal inside the insulating main body into which the high-potential side terminal and the low-potential side terminal can be inserted. There is. Since the socket component can be inserted into the high potential side terminal and the low potential side terminal from the direction orthogonal to the stacking direction of the semiconductor modules, it can be assembled to a laminated body in which a plurality of semiconductor modules are laminated. Good sex.

However, with a structure in which the socket component is simply inserted into the terminal of the semiconductor module, the socket component may come off from the terminal in an environment with large vibration such as a power converter mounted on an automobile. The present specification provides a technique for improving the vibration resistance of a component that houses a snubber circuit and is attached to a terminal of a semiconductor module, with respect to the improvement of the power conversion device with a socket component presented by the applicant of the present application.

The power conversion device disclosed in the present specification is attached to a laminate in which a plurality of semiconductor modules and a plurality of coolers are laminated so that semiconductor modules and coolers are alternately arranged, and at least one semiconductor module. Equipped with an attachment. The semiconductor module to which the attachment is attached encloses a switching circuit including a switching element inside. Further, in the semiconductor module, the high potential side terminal and the low potential side terminal of the switching circuit extend in a direction intersecting the stacking direction of the laminated body. At least one of the high-potential side terminal and the low-potential side terminal can be inserted into the attachment along the above-mentioned "direction intersecting the stacking direction". Further, the attachment houses a snubber circuit connected between the high potential side terminal and the low potential side terminal inside the main body. A notch is provided in at least one of the high-potential side terminal and the low-potential side terminal . The attachment is located on the side of the main body, is connected to the snubber circuit inside the main body, and has a locking claw that is locked to the notch and a high potential side terminal that has a notch between the main body. It is provided with a metal fitting having a holding claw that sandwiches at least one of the low potential side terminals. In this power conversion device, since the attachment can be inserted into the terminals along the direction intersecting the stacking direction, the attachment can be easily assembled even if the distance between adjacent terminals in the stacking direction is narrow. Further, in this power conversion device, the attachment accommodating the snubber circuit is provided with a claw, and the claw is locked to a notch provided in the terminal. The claws are locked in the notch of the terminal, which makes it difficult for the attachment to come off the terminal even in a violent vibration environment. Attachments with a built-in snubber circuit may be attached to all the semiconductor modules stacked, or attachments may be attached to some semiconductor modules in the laminated body. Details of the techniques disclosed herein and further improvements will be described in the "Modes for Carrying Out the Invention" below.

It is a block diagram of the electric power system of the electric vehicle including the electric power conversion device of an Example. It is a top view of the power conversion device. It is a perspective view of a semiconductor module. It is a perspective view of an attachment. It is a perspective view of the semiconductor module which attached the attachment. It is a perspective view of the semiconductor module which attaches the attachment of the modification. It is a perspective view of the attachment of a modification. It is a perspective view of the semiconductor module which attached the attachment of the modification. It is sectional drawing of the attachment attached to the semiconductor module.

The power conversion device 2 of the embodiment will be described with reference to the drawings. The power conversion device 2 of the embodiment is mounted on the electric vehicle 100. FIG. 1 shows a block diagram of a power system of an electric vehicle 100 including a power conversion device 2. The power conversion device 2 boosts the DC power of the battery 11 and then converts it into AC power to supply AC power to the two traveling motors 19a and 19b. The power conversion device 2 includes a bidirectional voltage converter circuit 17 and two inverter circuits 18a and 18b. The bidirectional voltage converter circuit 17 includes a filter capacitor 12, a reactor 13, two switching elements 14a and 14b, two diodes 15a and 15b, a snubber capacitor 5, and a snubber resistor 6. The bidirectional voltage converter circuit 17 has a boosting function that boosts the voltage of the power supplied from the battery 11 side and outputs it to the inverter circuits 18a and 18b, and the power supplied from the inverter circuits 18a and 18b ( It has a step-down function that steps down the voltage of the motors 19a and 19b (regenerated power generated by the power generated by the motors 19a and 19b) and outputs the voltage to the battery 11. Since the circuit configuration and operation of the bidirectional voltage converter circuit 17 shown in FIG. 1 are well known, detailed description thereof will be omitted.

In the bidirectional voltage converter circuit 17, two switching elements 14a and 14b are connected in series, and a snubber capacitor 5 and a snubber resistor 6 are connected in series between the high potential side and the low potential side of the series circuit. Has been done. The series circuit of the snubber capacitor 5 and the snubber resistor 6 is the snubber circuit 9. The snubber circuit 9 is provided for reducing noise associated with the switching operation of the switching elements 14a and 14b and for reducing ringing. The broken line rectangle indicated by reference numeral 3a shown in FIG. 1 means a semiconductor module described later. The semiconductor module 3a is a package in which two switching elements 14a and 14b are connected in series and diodes 15a and 15b connected in antiparallel to each of the switching elements 14a and 14b are sealed. Further, the broken line rectangle indicated by reference numeral 4 in FIG. 1 means the attachment 4 described later. The attachment 4 is a package containing the snubber circuit 9.

The inverter circuit 18a has a circuit structure in which three sets of two switching elements connected in series are connected in parallel. By appropriately controlling each switching element, alternating current is output from the midpoint of each series connection. Since the circuit configuration and operation of the inverter circuit 18a shown in FIG. 1 are well known, detailed description thereof will be omitted.

A diode is connected in antiparallel to each switching element of the inverter circuit 18a. As is clear from FIG. 1, the three sets of series connections included in the inverter circuit 18a are the same as the circuit configurations of the switching elements 14a and 14b and the diodes 15a and 15b included in the bidirectional voltage converter circuit 17. In FIG. 1, the broken line rectangle indicated by reference numeral 3b-3d represents a semiconductor module, and the semiconductor module 3b-3d has the same physical structure as the semiconductor module 3a of the bidirectional voltage converter circuit 17.

In the inverter circuit 18a, the same snubber circuit as the snubber circuit 9 of the bidirectional voltage converter circuit 17 is connected between the high potential side and the low potential side of the series connection of the two switching elements. Attachments 4 incorporating a snubber circuit 9 are connected in parallel to each of the semiconductor modules 3b-3d of the inverter circuit 18a.

In FIG. 1, since the configuration of the switching element, the diode, and the snubber circuit included in the inverter circuit 18a is the same as the circuit configuration of the bidirectional voltage converter circuit 17, the reference numerals to the individual electronic components are omitted in the inverter circuit 18a. ing.

The inverter circuit 18b has the same structure as the inverter circuit 18a, and the detailed circuit configuration of the inverter circuit 18b is not shown in FIG. The inverter circuit 18b consists of a semiconductor module 3e-3g in which two switching elements are connected in series and diodes connected in antiparallel to each switching element, and an attachment 4 connected in parallel to each semiconductor module 3e-3g. It is composed of. The snubber circuits 9 of the inverter circuits 18a and 18b are also provided in order to reduce the noise generated by each switching element and to reduce the ringing.

A smoothing capacitor 16 is connected between the bidirectional voltage converter circuit 17 and the two inverter circuits 18a and 18b. The smoothing capacitor 16 is inserted to suppress the pulsation of the current output by the bidirectional voltage converter circuit 17.

The hardware structure of the power conversion device 2 will be described with reference to FIG. FIG. 2 is a top view of the power conversion device 2. The power conversion device 2 includes seven semiconductor modules 3a-3g. In the following, when any one of the seven semiconductor modules 3a-3g is shown without distinction, it is referred to as the semiconductor module 3.

The seven semiconductor modules 3 are laminated with a plurality of coolers 22, and they form a stacking unit 10. The plurality of semiconductor modules 3 and the plurality of coolers 22 are alternately laminated one by one. The X direction of the coordinate system in the figure corresponds to the stacking direction of the semiconductor module 3 and the cooler 22. In FIG. 2, reference numerals 22 are given only to the coolers at both ends in the stacking direction, and the reference numerals are omitted for the other coolers. The stacking unit 10 is housed in the housing 23 of the power conversion device 2, and is subjected to pressure in the stacking direction by the leaf spring 28.

The stacking unit 10 includes two pipes 58 and 59 that penetrate a plurality of coolers 22 in the stacking direction, and the pipes 58 and 59 are used as a refrigerant circulation device (not shown) outside the power conversion device 2. It is connected. The refrigerant is distributed to each cooler 22 through one of the pipes 58. The refrigerant absorbs heat from the adjacent semiconductor module 3 while flowing through each cooler 22, and is discharged from the power converter 2 through the other pipe 59. Due to the pressure of the leaf spring 28, the adjacent cooler 22 and the semiconductor module 3 are brought into close contact with each other, and heat transfer from the semiconductor module 3 to the cooler 22 is promoted.

Here, the semiconductor module 3 will be described with reference to FIG. FIG. 3 is a perspective view of the semiconductor module 3. Semiconductor chips 35a and 35b are sealed inside the main body 30 of the semiconductor module 3. The main body 30 is made by injection molding of resin. That is, the semiconductor chips 35a and 35b are sealed in the resin main body 30. The semiconductor chips 35a and 35b are reverse-conducting IGBT chips in which one switching element (IGBT element) and one diode are connected in antiparallel, respectively. The semiconductor chips 35a and 35b are connected in series inside the semiconductor module 3 and form a circuit in a range surrounded by a broken line rectangle indicated by reference numerals 3a to 3g in FIG. That is, the semiconductor module 3 has a switching circuit including a switching element sealed therein.

Three power terminals extend from the main body 30 of the semiconductor module 3. The three power terminals extend in a direction (Z direction in the figure) intersecting the stacking direction (X direction in the figure) of the plurality of semiconductor modules 3. The three power terminals are a positive electrode terminal 31 conducting with the high potential side of the series connection (switching circuit) of the switching element, a negative electrode terminal 32 conducting with the low potential side of the series connection, and a series connection. The midpoint terminal 33 is conductive with the point. In FIG. 2, the reference numerals of the terminals are attached only to the rightmost semiconductor module 3a, and the reference numerals indicating the terminals are omitted from the other semiconductor modules 3b-3g. The positive electrode terminal 31 is provided with a notch 31a, and the negative electrode terminal 32 is provided with a notch 32a (see FIG. 3). The notches 31a and 32a will be described later.

A plurality of control terminals 34 extend from the opposite side surface of the main body of the semiconductor module 3. The plurality of control terminals 34 are gate terminals conducting with the gate electrodes of the respective switching elements (semiconductor chips 35a, 35b), control lines connected to temperature sensors and current sensors inside the semiconductor chips 35a, 35b, and the like. is there. The control terminal 34 is connected to a control board (not shown). A circuit for driving the switching elements (semiconductor chips 35a, 35b) of each semiconductor module 3 is mounted on the control board.

The three power terminals 31, 32, and 33 are each connected to other components through a bus bar. As is clear from the block diagram of FIG. 1, the high potential side (that is, the positive electrode terminal 31) and the low potential side (that is, the negative electrode terminal 32) of all the semiconductor modules 3 are connected to the smoothing capacitor 16. A capacitor element corresponding to the smoothing capacitor 16 and the filter capacitor 12 of FIG. 1 is housed in the capacitor unit 21 shown in FIG. The positive electrode terminals 31 of all the semiconductor modules 3 are connected to the capacitor unit 21 through the positive electrode bus bar 51, and the negative electrode terminals 32 are connected to the capacitor unit 21 through the negative electrode bus bar 52. The positive electrode bus bar 51 is a large metal plate on the side close to the capacitor unit 21, and the same number of branches as the number of semiconductor modules 3 extends toward the positive electrode terminals 31 of each semiconductor module 3. Each branch is joined to each positive electrode terminal 31. The same applies to the negative electrode bus bar 52, which is a large metal plate on the side close to the capacitor unit 21, and the same number of branches as the number of semiconductor modules 3 extends toward the negative electrode terminal 32. Each branch is joined to each negative electrode terminal 32.

The midpoint terminal 33 of the semiconductor module 3a of the bidirectional voltage converter circuit 17 is connected to the reactor unit 29 via an intermediate bus bar 53. A part corresponding to the reactor 13 of FIG. 1 is housed in the reactor unit 29. The midpoint terminal 33 of the other semiconductor module 3b-3g is connected to one end of the output bus bar 25, and the other end of the output bus bar 25 is the power of the terminal block 26 that leads to the motors 19a and 19b (see FIG. 1). The cable connection terminal 27 is formed.

The attachment 4 described above is attached to the positive electrode terminal 31 and the negative electrode terminal 32 of each semiconductor module 3. In FIG. 2, the attachment 4 is painted in gray to aid understanding.

FIG. 4 shows a perspective view of the attachment 4, and FIG. 5 shows a perspective view of the semiconductor module 3 to which the attachment 4 is attached. The main body 41 of the attachment 4 is made of resin, and the capacitor element 45 and the resistance element 46 are housed inside the main body 41. The capacitor element 45 and the resistance element 46 are connected in series. The capacitor element 45 corresponds to the snubber capacitor 5 shown in FIG. The resistance element 46 corresponds to the snubber resistance 6 shown in FIG. That is, the snubber circuit 9 shown in FIG. 1 is housed in the main body 41.

Metal fittings 42 and 43 having conductivity and elasticity are attached to the side surface of the main body 41 of the attachment 4. The metal fitting 42 and the metal fitting 43 are connected to a snubber circuit inside the main body 41. The metal fitting 42 includes a holding claw 42a and a locking claw 42b, and the metal fitting 43 includes a holding claw 43a and a locking claw 43b. The attachment 4 moves toward the semiconductor module 3 along the extending direction (that is, the Z direction in the figure) of the power terminals (positive electrode terminal 31 and negative electrode terminal 32), and thus is between the main body 41 and the holding claw 42a. The positive electrode terminal 31 can be inserted, and the negative electrode terminal 32 can be inserted between the main body 41 and the holding claw 43a. When the attachment 4 is moved to the roots of the positive electrode terminal 31 and the negative electrode terminal 32, the locking claw 42b is locked in the notch 31a of the positive electrode terminal 31, and the locking claw 43b is locked in the notch 32a of the negative electrode terminal 32. The positive electrode terminal 31 is sandwiched between the main body 41 and the holding claw 42a of the metal fitting 42, and the locking claw 42b is locked in the notch 31a. Further, the negative electrode terminal 32 is sandwiched between the main body 41 and the holding claw 43a of the metal fitting 43, and the locking claw 43b is locked in the notch 32a. In this way, the attachment 4 is fixed to the positive electrode terminal 31 and the negative electrode terminal 32. Since the locking claws 42b and 43b of the attachment 4 are locked to the notches 31a and 32a of the semiconductor module 3, the attachment 4 is hard to come off even if the semiconductor module 3 vibrates.

The pinching claws 42a (43a) have elasticity and are strongly pressed against the positive electrode terminal 31 (negative electrode terminal 32). Further, the locking claw 42b (43b) also has elasticity, and when the positive electrode terminal 31 (negative electrode terminal) is inserted, it is curved so as to follow the surface of the positive electrode terminal 31 (negative electrode terminal 32), and the positive electrode terminal 31 (negative electrode terminal) 31 (negative electrode terminal). At the position of the notch 31a (32a) at the base of the terminal 32), it returns to the original state by elasticity and is locked to the notch 31a (32a).

The metal fittings 42 and 43 also serve to electrically connect the snubber circuit 9 between the positive electrode terminal 31 and the negative electrode terminal 32. In other words, when the attachment 4 is attached to the semiconductor module 3, one end of the snubber circuit 9 conducts with the positive electrode terminal 31 via the metal fitting 42, and the other end of the snubber circuit 9 conducts with the negative electrode terminal 32 via the metal fitting 43. To do. That is, the snubber circuit 9 is connected between the high potential side and the low potential side of the series connection of the two switching elements in the semiconductor module 3.

As shown in FIG. 2, attachments 4 are attached to all semiconductor modules 3. As described above, the attachment 4 can be inserted into the terminals (positive electrode terminal 31 and negative electrode terminal 32) of the semiconductor module 3 from the Z direction intersecting the stacking direction (X direction in the drawing) of the plurality of semiconductor modules 3. ing. Therefore, even if the space between the positive electrode terminals 31 (negative electrode terminals 32) of the adjacent semiconductor modules 3 is narrow, the attachment 4 can be easily attached.

On the opposite side of the main body 41 of the attachment 4, the positive electrode bus bar 51 (see FIG. 2) is bonded to the positive electrode terminal 31, and the negative electrode bus bar 52 (see FIG. 2) is bonded to the negative electrode terminal 32.

A modified example of the attachment will be described with reference to FIGS. 6-9. FIG. 6 is a perspective view of the semiconductor module 103 to which the attachment 104 of the modified example is attached. FIG. 7 is a perspective view of the attachment 104 of the modified example. FIG. 8 is a perspective view of the semiconductor module 103 to which the attachment 4 of the modified example is attached. FIG. 9 is a cross-sectional view of the attachment 104 attached to the semiconductor module 103. FIG. 9 is a cross-sectional view of the attachment 104 cut in a plane passing through the metal fitting 142 described later. In FIG. 9, the internal structure of the main body 141 is not shown.

In this modification, notches 31c and 31d are provided at two positions of the positive electrode terminal 31 of the semiconductor module 103, and notches are not provided at the negative electrode terminal 32. Similar to the attachment 4, the main body 141 of the attachment 104 houses the capacitor element 45 and the resistance element 46, and they are connected in series inside the main body 141. The series connection of the capacitor element 45 and the resistance element 46 corresponds to the snubber circuit 9 of FIG. Another conductor 144 is exposed on the main body 141.

Two clip-shaped metal fittings 142 and 143 are attached to the side surfaces of the main body 141 of the attachment 104. The metal fittings 142 and 143 have conductivity and elasticity, and are electrically connected to one end of the snubber circuit inside the main body 141. A conductor 144 is electrically connected to the other end of the snubber circuit.

The metal fitting 142 includes a spring hook 142a and a locking claw 142b, and the metal fitting 143 includes a spring hook 143a and a locking claw 143b. The attachment 104 moves toward the semiconductor module 103 along the extending direction (that is, the Z direction in the figure) of the power terminals (positive electrode terminal 31 and negative electrode terminal 32) between the main body 141 and the spring hooks 142a and 143a. The positive electrode terminal 31 can be inserted into the. When the attachment 104 is moved to the root of the positive electrode terminal 31, the locking claws 142b and 143b are locked in the notches 31c and 31d of the positive electrode terminal 31. The positive electrode terminal 31 is sandwiched between the main body 141 and the spring hooks 142a and 143a of the metal fittings 142 and 143, and the locking claws 142b and 143b are locked in the notches 31c and 31d. FIG. 9 well shows a state in which the locking claw 142b is locked to the notch 31c while the positive electrode terminal 31 is sandwiched between the main body 141 and the spring hook 142a of the metal fitting 142. In this way, the attachment 104 is fixed to the positive electrode terminal 31. Since the locking claws 142b and 143b of the attachment 104 are locked to the notches 31c and 31d of the semiconductor module 103, the attachment 104 is unlikely to come off even if the semiconductor module 103 vibrates.

The spring hooks 142a and 143a have elasticity and are strongly pressed against the positive electrode terminal 31. Further, the locking claws 142b and 143b also have elasticity, and when the positive electrode terminal 31 is inserted, they are curved so as to follow the surface of the positive electrode terminal 31. At the positions of the notches 31c and 31d at the base of the positive electrode terminal 31, the locking claws 142b and 143b return to their original state by elasticity and are locked to the notches 31c and 31d.

The metal fittings 142, 143, and the conductor 144 also serve to electrically connect the snubber circuit 9 between the positive electrode terminal 31 and the negative electrode terminal 32. In other words, when the attachment 104 is attached to the semiconductor module 103, one end of the snubber circuit 9 conducts with the positive electrode terminal 31 via the metal fittings 142 and 143, and the other end of the snubber circuit 9 conducts with the negative electrode terminal 32 via the conductor 144. Conducts with. That is, the snubber circuit 9 is connected between the high potential side and the low potential side of the series connection of the two switching elements in the semiconductor module 103.

On the opposite side of the main body 141 of the attachment 104, the positive electrode bus bar 51 (see FIG. 2) is bonded to the positive electrode terminal 31, and the negative electrode bus bar 52 (see FIG. 2) is bonded to the negative electrode terminal 32.

The points to be noted regarding the technique described in the examples will be described. The positive electrode terminal 31 of the embodiment corresponds to an example of the high potential side terminal, and the negative electrode terminal 32 corresponds to an example of the low potential side terminal. The stacking unit 10 corresponds to an example of a laminated body. The locking claws 42b, 43b, 142b, 143b correspond to an example of a claw engaged in the notch of the terminal.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

2: Power converter 3, 3a-3g, 103: Semiconductor module 4, 104: Attachment 5: Snubber capacitor 6: Snubber resistor 9: Snubber circuit 10: Stacking unit 11: Battery 12: Filter capacitor 13: Reactor 14a, 14b: Switching elements 15a, 15b: Diode 16: Smoothing capacitor 17: Bidirectional voltage converter circuit 18a, 18b: Inverter circuit 19a, 19b: Traveling motor 21: Capacitor unit 22: Cooler 23: Housing 25: Output bus bar 26: Terminal block 27: Connection terminal 28: Leaf spring 29: Reactor unit 30: Main body 31: Positive electrode terminals 31a, 31c, 31d, 32a: Notch 32: Negative electrode terminal 35a: Capacitor chip 35b: Semiconductor chip 41: Main body 42, 142, 43, 143 : Metal fittings 42a, 43a: Holding claws 42b, 43b, 142b, 143b: Locking claws 45: Capacitor element 46: Resistance element 51: Positive electrode bus bar 52: Negative electrode bus bar 100: Electric vehicle 141: Main body 142: Metal fittings 142a, 143a: Spring hook

Claims (1)

A laminate in which a plurality of semiconductor modules and a plurality of coolers are laminated so that the semiconductor modules and the coolers are arranged alternately,
With the attachment attached to at least one of the semiconductor modules,
Is equipped with
The semiconductor module, together with the seals the switching circuit including a switching element, which extends in the direction the high potential side terminal and the low potential side terminal of the switching circuit crossing the stacking direction of the laminate, the high A notch is provided in at least one of the potential side terminal and the low potential side terminal.
The attachment is
A main body containing a snubber circuit connected between the high potential side terminal and the low potential side terminal, and
The notch, which is arranged on the side surface of the main body, is connected to the snubber circuit inside the main body, and has the notch between the locking claw that is locked to the notch and the main body. A metal fitting having a high-potential side terminal and a holding claw that sandwiches at least one of the low-potential side terminals.
Equipped with a power converter.

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