Bus bar-connected motor drive device

Abstract

This motor drive device comprises a connector which is provided in correspondence with a power conversion device that is for generating electric power for driving a motor. The connector has: a first terminal that is used for electric power transfer between a power conversion device to which the connector is provided and one of two other power conversion devices which are adjacent to the power conversion device; a second terminal that is used for electric power transfer between the power conversion device to which the connector is provided and the other one of the two other power conversion devices, and that is electrically connected to the first terminal; and a third terminal that is for electrically connecting, to an external circuit, a circuit provided inside the power conversion device to which the connector is provided.

Description

Busbar-connected motor drive device

[0001] The present disclosure relates to a bus bar-connected motor drive device.

[0002] A motor drive device that drives an AC motor includes a converter and an inverter as power conversion devices. The converter and inverter are connected via a DC link. The converter converts AC power supplied from an AC power source into DC power and outputs it. The inverter converts DC power into AC power for driving the motor and outputs it.

[0003] Since a relatively large current flows in the DC link between the converter and the inverter, bus bars made of metal, for example copper, brass or aluminum, are often used for the DC link connections.

[0004] JP 2014-207803 A JP 2000-164042 A

[0005] When assembling a motor drive device, the DC output terminal of the converter and the DC input terminal of the inverter are electrically connected using a bus bar. There is a need for a motor drive device that can be easily assembled and that uses a bus bar connection.

[0006] According to one aspect of the present disclosure, a motor drive device includes a connector provided in correspondence with a power conversion device for generating power to drive a motor, the connector having a first terminal used for power exchange between the power conversion device in which the connector is provided and one of two other power conversion devices adjacent to the power conversion device, a second terminal used for power exchange between the power conversion device in which the connector is provided and the other of the other two power conversion devices, the second terminal being electrically connected to the first terminal, and a third terminal for electrically connecting a circuit provided inside the power conversion device in which the connector is provided to an external circuit.

[0007] FIG. 1 is a front view showing a connector in a motor drive device according to an embodiment of the present disclosure; FIG. 2 is a side view showing a connector in a motor drive device according to an embodiment of the present disclosure; FIG. 3 is a perspective view (part 1) showing a connector in a motor drive device according to an embodiment of the present disclosure; FIG. 4 is a perspective view (part 3) showing a connector in a motor drive device according to an embodiment of the present disclosure; FIG. 5 is a perspective view (part 5) showing a connector in a motor drive device according to an embodiment of the present disclosure; FIG. 6 is an exploded view showing a connection relationship between a first terminal and a second terminal of a connector in a motor drive device according to an embodiment of the present disclosure; FIG. 7 is a front view showing an implementation example when a connector in a motor drive device according to an embodiment of the present disclosure is used for DC link connection; FIG. 8 is a front view of a housing in which a positive side connector and a negative side connector in a motor drive device according to an embodiment of the present disclosure are mounted; FIG. 9 is a side view of a housing in which a positive side connector and a negative side connector in a motor drive device according to an embodiment of the present disclosure are mounted; FIG. 10 is a perspective view of a bus bar in a motor drive device according to an embodiment of the present disclosure; Fig. 17 is a front view of a connector into which a bus bar is inserted in a motor drive device according to an embodiment of the present disclosure; Fig. 18 is a side view of a connector into which a bus bar is inserted in a motor drive device according to an embodiment of the present disclosure; Fig. 19 is a perspective view of a connector into which a bus bar is inserted in a motor drive device according to an embodiment of the present disclosure; Fig. 20 is a front view of a motor drive device according to an embodiment of the present disclosure; Fig. 21 is a diagram illustrating a configuration in which a plurality of power conversion devices are connected via a DC link in a motor drive device according to an embodiment of the present disclosure; Fig. 22 is a circuit diagram of a motor drive device having the configuration shown in Fig. 17;

[0008] A busbar-connected motor drive device according to an embodiment will be described below with reference to the drawings. In the following description, components having the same or similar functions will be assigned the same reference numerals. Duplicate descriptions of those components may be omitted. The scale of the drawings has been appropriately changed to facilitate understanding.

[0009] In the following description, a converter that converts AC power supplied from an AC power source into DC power and outputs it is also referred to as a “rectifier device,” “rectifier circuit,” “rectifier,” or “forward converter.” An inverter that converts DC power into AC power and outputs it is also referred to as an “inverter.” Because converters and inverters are both devices that perform power conversion operations, they are collectively referred to as a “power conversion device.” That is, a power conversion device refers to any of a converter alone, an inverter alone, and a converter and inverter integrated together. A “DC link” refers to a circuit portion that electrically connects the DC output terminal of a converter and the DC input terminal of an inverter, and is also referred to as a “DC link unit,” “DC link,” “DC link unit,” “DC bus,” or “DC intermediate circuit.” A “DC link connection” refers to the formation of a DC link between the DC output terminal of a converter and the DC input terminal of an inverter. A “DC output terminal” includes a “positive DC output terminal” and a “negative DC output terminal.” "DC input terminal" includes "positive DC input terminal" and "negative DC input terminal". Bus bar is also called "bus bar" or "short bar". "Bus bar connection" refers to electrically connecting power conversion devices using a bus bar. "Sheet metal" refers to metal formed into a thin, flat shape. "Electrically connecting" means "connecting so that electricity can flow". "Parallel installation" means aligning and arranging adjacent housings in a line. "Parallel installation direction" refers to the direction in which housings are lined up when multiple housings are arranged in a line.

[0010] <Configuration of Connector According to an Embodiment of the Present Disclosure> Fig. 1 is a front view showing a connector in a motor drive device according to an embodiment of the present disclosure. Fig. 2 is a side view showing a connector in a motor drive device according to an embodiment of the present disclosure. Figs. 3 to 7 are perspective views showing a connector in a motor drive device according to an embodiment of the present disclosure. Fig. 8 is an exploded view showing the connection relationship between a first terminal and a second terminal of a connector in a motor drive device according to an embodiment of the present disclosure.

[0011] In a motor drive device, multiple power conversion devices are arranged side by side to generate power for driving a motor. Examples of power conversion devices include a converter that converts AC power from an AC power source into DC power, an inverter that converts DC power supplied from the converter via a DC link into AC power for driving the motor, and a combination of a converter and an inverter. Each of the multiple power conversion devices is housed in a separate housing. A motor drive device according to an embodiment of the present disclosure includes a connector 13 for electrically connecting the adjacently arranged power conversion devices. The connector 13 is provided corresponding to the power conversion device that generates power for driving the motor in the motor drive device. The connector 13 is mounted on one of six surfaces of the housing. More specifically, the connector 13 is mounted on a printed circuit board, and the printed circuit board on which the connector 13 is mounted is installed in the housing. In the motor drive device, multiple housings each equipped with the connector 13 are arranged side by side adjacent to each other along a substantially same direction.

[0012] In this disclosure, for the sake of simplicity, of the six faces of the housing that houses the power conversion device of the motor drive device, the face of the housing on which the connector 13 to which the bus bar is attached is mounted is referred to as the "front face" of the motor drive device. In the examples shown in Figures 1 to 7 and 9 to 16, for example, the face viewed from the negative Y-axis side to the positive Y-axis side on the XYZ coordinate axes is referred to as the "front face." For example, the front face of the motor drive device is preferably the face that allows workers performing maintenance work and various operations to most easily and efficiently access the motor drive device.

[0013] The connector 13 includes a first terminal 20A, a second terminal 20B, and a third terminal 20C. The first terminal 20A, the second terminal 20B, and the third terminal 20C are made of conductive materials. The connector 13 also includes a contact protection unit 32 and a printed circuit board 21.

[0014] As described above, the plurality of power conversion devices are arranged in parallel in approximately one direction, and therefore, two power conversion devices can be arranged adjacent to each other on both sides of one power conversion device.

[0015] The first terminal 20A of the connector 13 is used for transferring DC power between the power conversion device in which the connector 13 is provided and one of two other power conversion devices adjacent to the power conversion device. In other words, the first terminal 20A of the connector 13 is used for transferring DC power between the power conversion device in which the connector 13 is provided and the other power conversion device provided on the first side of the power conversion device.

[0016] The second terminal 20B of the connector 13 is used for transferring DC power between the power conversion device in which the connector 13 is provided and the other of the other two power conversion devices adjacent to the power conversion device. In other words, the second terminal 20B of the connector 13 is used for transferring DC power between the power conversion device in which the connector 13 is provided and the other power conversion device provided on the second side of the power conversion device.

[0017] Also, as shown in FIG. 8, in one connector 13, the first terminal 20A and the second terminal 20B are electrically connected, and these first terminal 20A and second terminal 20B are integrally molded.

[0018] Each of the first terminal 20A and the second terminal 20B has a structure that allows a bus bar to be inserted and removed. The first terminal 20A has a floating structure that allows the bus bar to move relative to the first terminal 20A due to elastic deformation that occurs when the bus bar is inserted. The second terminal 20B has the same structure as the first terminal 20A, i.e., a floating structure that allows the bus bar to move relative to the second terminal 20B due to elastic deformation that occurs when the bus bar is inserted.

[0019] Each of the first terminal 20A and the second terminal 20B, which have a floating structure, has a plurality of contacts 31 that elastically deform when the bus bar 12 is inserted, making physical and electrical contact with the bus bar 12. These contacts 31 are arranged in a row along substantially the same direction as the longitudinal direction of the inserted bus bar 12. When the motor drive device is viewed from the front (i.e., from the negative Y-axis direction), the contacts 31 are exposed for each of the first terminal 20A and the second terminal 20B. Two rows of the juxtaposed contacts 31 are provided, and these two rows face each other. When the bus bar is inserted into each of the first terminal 20A and the second terminal 20B, the bus bar is sandwiched between the two rows of the elastically deformed contacts 31, making physical and electrical contact with the bus bar. As shown in FIG. 8, the contacts 31 of the first terminal 20A and the second terminal 20B are further electrically connected to DC terminals of the power conversion device (i.e., DC output terminals of the converter and / or DC input terminals of the inverter) within the housing in which the connector 13 is mounted.

[0020] The connector 13 is provided with a contact protection part 32 to prevent electric shock caused by a human finger touching the contact 31 or to prevent current leakage caused by another conductive member touching the contact 31. The contact protection part 32 is made of a highly insulating material. Examples of insulating materials include plastic, urethane, glass, porcelain, fine ceramics, vinyl, rubber, wood, and paper.

[0021] The contact protection part 32 opens in the direction (Y-axis direction) in which the bus bar is inserted into or removed from the connector 13, and covers the contact 31 so that the contact 31 is exposed in the direction (Y-axis direction) in which the bus bar is inserted into or removed from the connector 13. Therefore, the contact 31 is provided at a position recessed in the positive direction of the Y-axis from the end face of the opening of the contact protection part 32 that faces the direction (Y-axis direction) in which the bus bar is inserted into or removed from the connector 13.

[0022] The contact protection section 32 has a structure that prevents a human finger from touching the contacts 31 even if the human finger is inserted into the connector 13 from the bus bar insertion direction (Y-axis direction). For example, the width in the Z-axis direction (the short side direction of the bus bar 12) of the opening of the contact protection section 32 facing the bus bar 12 insertion / removal direction (Y-axis direction) is set to be smaller than the thickness of a human finger and larger than the width of the bus bar 12 in the Z-axis direction.

[0023] The third terminal 20C is used to electrically connect a circuit (e.g., a control circuit, a sensor, a communication circuit, a control terminal of a switching element of the power conversion device, etc.) provided inside the power conversion device in which the connector 13 is provided to an external circuit. The third terminal 20C is installed on a printed circuit board 21. Electrical wiring and electronic components may be mounted on the printed circuit board 21. The printed circuit board 21 is physically connected to the connector 13. In the examples shown in FIGS. 1 to 6 , the printed circuit board 21 is connected to the surface on the positive side in the X-axis direction of the connector 13, but is not limited thereto. For example, as shown in FIG. 7 , the printed circuit board 21 may be connected to the surface on the negative side in the X-axis direction of the connector 13.

[0024] The third terminal 20C is, for example, a land in a through-hole that penetrates the printed circuit board 21. The land is a conductor pattern used for physical attachment and electrical connection of components. The shape of the land hole is not particularly limited to this embodiment and may be, for example, a round hole, an elongated hole, or a rectangular hole. In the examples shown in Figures 1 to 7 and Figures 9 to 16, the third terminal 20C is depicted as a rectangular parallelepiped for clarity. The through-hole is electrically connected to a control circuit, a sensor, a communication circuit, a control terminal of a switching element of the power conversion device, and the like, which are provided in the power conversion device within the housing in which the connector 13 is mounted. Electrical connection between these circuits provided in the power conversion device and an external circuit is achieved by soldering the land, which is the third terminal 20C, to electrical wiring electrically connected to the external circuit.

[0025] FIG. 9 is a front view showing an example of implementation in which a connector in a motor drive device according to an embodiment of the present disclosure is used for DC link connection.

[0026] In general, in a motor drive device, a DC output terminal of a converter and a DC input terminal of an inverter are connected via a DC link, and the DC power lines that make up the DC link include a positive power line and a negative power line.

[0027] By inserting two bus bars into each of the two connectors 13, a positive power line and a negative power line of the DC link can be configured. The connector 13 into which the bus bar used to connect the positive power line of the DC link can be inserted and removed is referred to as the positive connector 13P. The connector 13 into which the bus bar used to connect the negative power line of the DC link can be inserted and removed is referred to as the negative connector 13N. Hereinafter, the positive connector 13P and the negative connector 13N may be collectively referred to as the connector 13. Therefore, the connector 13 may refer to the positive connector 13P, the negative connector 13N, or both the positive connector 13P and the negative connector 13N. The positive connector 13P and the negative connector 13N have the same shape and structure. The positive connector 13P and the negative connector 13N are mounted via a printed circuit board 21 in a housing that accommodates the power conversion device. The positive connector 13P is used to electrically connect a positive DC terminal of the power conversion device (i.e., the positive DC output terminal of the converter and / or the positive DC input terminal of the inverter) to a positive power line of the DC link using a bus bar. The negative connector 13N is used to electrically connect a negative DC terminal of the power conversion device (i.e., the negative DC output terminal of the converter and / or the negative DC input terminal of the inverter) to a negative power line of the DC link using a bus bar.

[0028] <Configuration of Housing According to Embodiment of the Present Disclosure> Fig. 10 is a front view of a housing in which a positive connector and a negative connector of a motor drive device according to an embodiment of the present disclosure are mounted. Fig. 11 is a side view of the housing in which a positive connector and a negative connector of a motor drive device according to an embodiment of the present disclosure are mounted.

[0029] The housing 11 houses a power conversion device, which is either a converter or an inverter. In a motor drive device, multiple power conversion devices are arranged side by side, and therefore multiple housings 11 are arranged side by side adjacent to each other in approximately one direction.

[0030] The housing 11 is made of a highly insulating (non-conductive) material. Examples of insulating materials include plastic, urethane, glass, porcelain, fine ceramics, vinyl, rubber, wood, and paper. The housing 11 may have openings for passing electrical wiring, terminals, and the like.

[0031] A positive connector 13P and a negative connector 13N are mounted on a surface of the housing 11 corresponding to the "front" of the motor drive device 1. More specifically, the positive connector 13P and the negative connector 13N are mounted on a printed circuit board 21, and the printed circuit board 21 on which the positive connector 13P and the negative connector 13N are mounted is installed in the housing 11. In this case, the positive connector 13P is mounted on the surface of the housing 11 via the above-mentioned electronic components so that the insertion and removal direction of the bus bar with respect to the first terminal 20A and the second terminal 20B of the positive connector 13P is approximately perpendicular to the mounting surface of the positive connector 13P on the housing 11. Similarly, the negative connector 13N is mounted on the surface of the housing 11 via the above-mentioned electronic components so that the insertion and removal direction of the bus bar with respect to the first terminal 20A and the second terminal 20B of the negative connector 13N is approximately perpendicular to the mounting surface of the negative connector 13N on the housing 11. In the examples shown in FIGS. 10 and 11, the bus bar insertion / removal direction is the Y-axis direction.

[0032] <Configuration of Bus Bar According to an Embodiment of the Present Disclosure> FIG. 12 is a perspective view of a bus bar in a motor drive device according to an embodiment of the present disclosure.

[0033] A conductive bus bar 12 is used to electrically connect a DC terminal of a power conversion device provided in an adjacent housing 11 to a DC link. The bus bar 12 is made of a metal such as copper, brass, or aluminum. The bus bar 12 is, for example, a thin, substantially straight, rod-shaped metal sheet, and has a substantially rectangular parallelepiped shape. The bus bar 12 is manufactured, for example, by sheet metal processing.

[0034] The bus bar 12 is insertable into and removable from a first terminal 20A of a connector 13 provided on one of two adjacent power conversion devices and a second terminal 20B of a connector 13 provided on the other of the two adjacent power conversion devices. In other words, the bus bar 12 is insertable into and removable from a first terminal 20A of a connector 13 mounted on a housing 11 accommodating a certain power conversion device and a second terminal 20B of another connector 13 mounted on a housing 11 accommodating a power conversion device adjacent to the certain power conversion device. By determining the number of bus bars 12 according to the number of housings 11 accommodating adjacent power conversion devices, scalability can be achieved to accommodate various numbers of housings 11 using bus bars 12 of the same standard. Furthermore, the standardization of the bus bar 12 standard reduces the number of bus bar 12 varieties in stock, thereby reducing the manufacturing cost of the motor drive device.

[0035] The longitudinal direction (X-axis direction) of the bus bar 12 substantially coincides with the direction in which the multiple contacts 31 are arranged in the connector 13 shown in Figures 1 to 7, 9, and 10. The lateral direction (Y-axis direction) of the bus bar 12 substantially coincides with the direction in which the bus bar 12 is inserted into and removed from the connector 13 shown in Figures 1 to 7, 9, and 10. The length of the bus bar 12 in the Z-axis direction is shorter than the length of the bus bar 12 in the Y-axis direction. The length of the bus bar 12 in the Z-axis direction is, for example, approximately 3 mm. Note that the values ​​given here are merely examples, and other values ​​may be used.

[0036] <Attachment of bus bar and connector according to an embodiment of the present disclosure>

[0037] Fig. 13 is a front view of a connector into which a bus bar is inserted in a motor drive device according to an embodiment of the present disclosure. Fig. 14 is a side view of a connector into which a bus bar is inserted in a motor drive device according to an embodiment of the present disclosure. Fig. 15 is a perspective view of a connector into which a bus bar is inserted in a motor drive device according to an embodiment of the present disclosure. Figs. 13 to 15 show, as an example, a case in which a bus bar 12 is inserted into the second terminal 20B of connector 13, but the following description is equally applicable to a case in which a bus bar 12 is inserted into the first terminal 20A of connector 13.

[0038] When bus bar 12 is inserted into second terminal 20B of connector 13 from the negative direction of the Y-axis toward the positive direction of the Y-axis, the plurality of contacts 31 of second terminal 20B, which has a floating structure, elastically deforms, and bus bar 12 is sandwiched, while maintaining physical and electrical contact, between two rows of the plurality of contacts 31. Even if the insertion direction or position of bus bar 12 is slightly misaligned with respect to second terminal 20B, the elastic deformation of contacts 31 ensures stable physical and electrical contact between bus bar 12 and contacts 31.

[0039] 16 is a front view showing a motor drive device according to an embodiment of the present disclosure, in which the third terminal 20C is not shown.

[0040] Generally, a motor drive device 1 is provided with an inverter corresponding to each drive shaft. Furthermore, in order to reduce the cost and space occupied by the motor drive device 1, one converter is often connected to multiple inverters. In FIG. 16 , as an example, two housings 11 are provided adjacent to each other along the X-axis direction. Hereinafter, the reference numerals for the two adjacent housings 11 may be separately designated 11-1 and 11-2, and the housings 11-1 and 11-2 may be collectively referred to as the housing 11. In the following description, as an example, the housing 11-1 houses a converter and the housing 11-2 houses an inverter. However, the types of power conversion devices housed in the housings 11-1 and 11-2 are not intended to limit this embodiment. For example, the housing 11-1 may house an inverter, and the housing 11-2 may house a converter. Furthermore, the number of housings 11 arranged side by side is not limited to two and may be three or more.

[0041] A positive connector 13P and a negative connector 13N are mounted on the surface of housing 11-1, which corresponds to the "front" of motor drive device 1, for connecting the DC output terminal of the converter in housing 11-1 to a DC link using bus bars 12. Similarly, a positive connector 13P and a negative connector 13N are mounted on the surface of housing 11-2, which corresponds to the "front" of motor drive device 1, for connecting the DC input terminal of the inverter in housing 11-2 to a DC link using bus bars 12.

[0042] In the motor drive device 1, multiple power conversion devices are arranged side by side adjacent to each other, and therefore multiple housings 11 (housings 11-1 and 11-2 in the example shown in FIG. 16) are arranged side by side adjacent to each other in approximately one direction. The mounting surfaces of the connectors 13 on each of the housings 11-1 and 11-2 form approximately the same plane when these housings 11-1 and 11-2 are arranged side by side adjacent to each other. The connectors 13 are mounted on each of the two adjacent housings 11-1 and 11-2 so that the approximately linear bus bar 12 is simultaneously inserted into the first terminal 20A of the connector 13 on housing 11-1 and the second terminal 20B mounted on housing 11-2.

[0043] Here, two adjacent housings 11-1 and 11-2 are illustrated, but the same applies to the case where there are three or more adjacent housings 11. For example, if an additional housing (not shown) is installed next to the housing 11-2 on the side opposite to the side on which the housing 11-1 is installed (the right side of the housing 11-2 in the drawing), the connector 13 is mounted on each of the two adjacent housings 11-2 and the additional housing so that the substantially straight bus bar 12 is simultaneously inserted into the second terminal 20B of the connector 13 of the housing 11-2 and the first terminal 20A of the connector 13 mounted on the additional housing. Furthermore, for example, if an additional housing (not shown) is installed next to housing 11-1 on the side opposite to the side on which housing 11-2 is installed (the left side of housing 11-1 in the figure), connectors 13 are mounted on each of the two adjacent housings 11-1 and the additional housing so that the approximately straight bus bar 12 is simultaneously inserted into the first terminal 20A of the connector 13 of housing 11-1 and the second terminal 20B of the connector 13 mounted on the additional housing.

[0044] As described above, the connectors 13 mounted on each of the multiple housings 11 have the same shape and structure. The mounting surfaces of the connectors 13 for each of the multiple housings 11 form approximately the same plane when the housings 11 are adjacently arranged side by side. By setting the mounting surfaces of the connectors 13 for each of the multiple housings 11 to be positioned approximately on the same plane, it becomes possible to simultaneously insert the bus bars 12 into each of the connectors 13 mounted on the multiple housings 11. In the example shown in FIG. 16 , the connectors 13 are mounted on the housings 11 so that the Y coordinate values ​​of the connectors 13 mounted on adjacent housings 11 are approximately the same in the XYZ coordinate system. Here, an example in which there are two adjacent housings 11 has been described, but the same applies when there are three or more adjacent housings 11.

[0045] 16, for example, a bus bar 12 is inserted between the second terminal 20B of the positive connector 13P mounted on the housing 11-1 and the first terminal 20A of the positive connector 13P mounted on the housing 11-2. In addition, a bus bar 12 is inserted between the second terminal 20B of the negative connector 13N mounted on the housing 11-1 and the first terminal 20A of the negative connector 13N mounted on the housing 11-2. As a result, the DC output terminal of the converter in the housing 11-1 and the DC input terminal of the inverter in the housing 11-2 are connected via a DC link.

[0046] Fig. 17 is a diagram illustrating a configuration in which a plurality of power electronics devices are connected via a DC link in a motor drive device according to an embodiment of the present disclosure. Fig. 18 is a circuit diagram of the motor drive device having the configuration shown in Fig. 17.

[0047] 17, motor drive device 1 includes two converters 200-1 and 200-2 and two inverters 300-1 and 300-2. Each of converters 200-1 and 200-2 and inverters 300-1 and 300-2 includes a control circuit, a sensor, a communication circuit, and the like, all of which are not shown.

[0048] An AC power supply 100 is electrically connected to each of the AC input terminals of the converters 200-1 and 200-2.

[0049] Each of the converters 200-1 and 200-2 converts AC power supplied from the AC power source 100 into DC power and outputs the DC power to the DC link 500. In the examples shown in FIGS. 17 and 18 , the AC power source 100 is a three-phase AC power source, and therefore each of the converters 200-1 and 200-2 is configured as a three-phase bridge circuit. If the AC power source 100 is configured as a single-phase AC power source, each of the converters 200-1 and 200-2 is configured as a single-phase bridge circuit. Examples of the converters 200-1 and 200-2 include diode rectifiers, 120-degree conduction rectifiers, and PWM switching control rectifiers. For example, if the converters 200-1 and 200-2 are configured as 120-degree conduction rectifiers or PWM switching control rectifiers, they are configured as a bridge circuit of switching elements and diodes connected in antiparallel to the switching elements, and each switching element is controlled on and off in response to a drive command received from a higher-level control device (not shown), thereby performing power conversion in both directions, AC and DC. In this case, examples of the switching elements include FETs, IGBTs, thyristors, GTOs, transistors, etc., but other semiconductor elements may also be used. Note that an AC reactor, an AC line filter, etc. may be provided on the AC input side of converters 200-1 and 200-2, but these are not shown here.

[0050] An AC motor 400-1 is electrically connected to an AC output terminal of the inverter 300-1, and an AC motor 400-2 is electrically connected to an AC output terminal of the inverter 300-2.

[0051] The inverter 300-1 converts the DC power in the DC link 500 into AC power for driving the motor and outputs it to the motor 400-1. The inverter 300-2 converts the DC power in the DC link 500 into AC power for driving the motor and outputs it to the motor 400-2. An example of the inverters 300-1 and 300-2 is a PWM control inverter equipped with internal switching elements. In the example shown in FIGS. 17 and 18, the motors 400-1 and 400-2 are each three-phase AC motors, and therefore the inverters 300-1 and 300-2 are each configured as a three-phase bridge circuit. If the motors 400-1 and 400-2 were configured as single-phase AC motors, the inverters 300-1 and 300-2 would each be configured as a single-phase bridge circuit. Each of the inverters 300-1 and 300-2 is configured as a bridge circuit of a diode and a switching element connected in antiparallel to the diode. In this case, examples of switching elements include FETs, IGBTs, thyristors, GTOs, and transistors, but other semiconductor elements may also be used. The inverters 300-1 and 300-2 convert DC power in the DC link 500 into AC power for driving the motors and output it by PWM-controlling the on / off operation of their internal switching elements based on commands from a higher-level control device (not shown). The speed, torque, or rotor position of the motor 400-1 is controlled based on the AC power supplied from the inverter 300-1. By appropriately PWM-controlling the on / off operation of the switching elements, the inverter 300-1 can also convert AC power regenerated by the motor 400-1 into DC power and return it to the DC link 500 on the DC side. Similarly, the speed, torque, or rotor position of the motor 400-2 is controlled based on the AC power supplied from the inverter 300-2. The inverter 300-2 can also convert AC power regenerated by the motor 400-2 into DC power and return it to the DC link 500 on the DC side by appropriately PWM controlling the on / off operation of the switching elements.

[0052] Converters 200-1 and 200-2 and two inverters 300-1 and 300-2 are each housed in a housing 11. Housing 11 is not shown in Figures 17 and 18. Converters 200-1 and 200-2 and inverters 300-1 and 300-2 are arranged side by side adjacent to each other, and therefore, housings 11 that house converters 200-1 and 200-2 and inverters 300-1 and 300-2 are arranged side by side adjacent to each other and substantially in one direction.

[0053] A positive connector 13P and a negative connector 13N are mounted on each housing 11. The mounting surfaces of the positive connector 13P and the negative connector 13N for each of the multiple housings 11 form approximately the same plane when these housings 11 are arranged side by side adjacent to each other. By setting the mounting surfaces of the positive connector 13P and the negative connector 13N for each of the multiple housings 11 to be positioned on approximately the same plane, it becomes possible to simultaneously insert the bus bar 12 into each of the positive connectors 13P and the negative connectors 13N mounted on the multiple housings 11.

[0054] A bus bar 12 is inserted into a second terminal 20B of a positive connector 13P mounted on a housing 11 that houses converter 200-1 and a first terminal 20A of a positive connector 13P mounted on a housing 11 that houses converter 200-2. A bus bar 12 is inserted into a second terminal 20B of a positive connector 13P mounted on a housing 11 that houses converter 200-2 and a first terminal 20A of a positive connector 13P mounted on a housing 11 that houses inverter 300-1. A bus bar 12 is inserted into a second terminal 20B of a positive connector 13P mounted on a housing 11 that houses inverter 300-1 and a first terminal 20A of a positive connector 13P mounted on a housing 11 that houses inverter 300-2. By inserting the bus bars 12 into the positive connectors 13P in this manner, a positive power line 500P of the DC link 500 as shown in FIG. 18 is formed.

[0055] A bus bar 12 is inserted into a second terminal 20B of a negative connector 13N mounted on the housing 11 that houses converter 200-1 and a first terminal 20A of a negative connector 13N mounted on the housing 11 that houses converter 200-2. A bus bar 12 is inserted into a second terminal 20B of a negative connector 13N mounted on the housing 11 that houses converter 200-2 and a first terminal 20A of a negative connector 13N mounted on the housing 11 that houses inverter 300-1. A bus bar 12 is inserted into a second terminal 20B of a negative connector 13N mounted on the housing 11 that houses inverter 300-1 and a first terminal 20A of a negative connector 13N mounted on the housing 11 that houses inverter 300-2. By inserting the bus bars 12 into the negative connectors 13N in this manner, a negative power line 500N of the DC link 500 as shown in FIG. 18 is formed.

[0056] Although a DC link capacitor is provided in the DC link 500, it is not shown in FIGS. 17 and 18. The DC link capacitor has the function of storing DC power used by the inverters 300-1 and 300-2 to generate AC power and the function of suppressing pulsation in the DC output of the converters 200-1 and 200-2. Examples of the DC link capacitor include an electrolytic capacitor and a film capacitor. The DC link capacitor is provided either inside or outside the housing 11.

[0057] 17 and 18 , the third terminals 20C of the positive connector 13P and the negative connector 13N are not shown. The third terminals 20C are electrically connected to a control circuit, a sensor, a communication circuit, a control terminal of a switching element of the power conversion device, and the like, which are provided in the power conversion device inside the housing 11 in which the positive connector 13P and the negative connector 13N having the third terminals 20C are mounted. The electrical connection between these circuits provided in the power conversion device and an external circuit is realized by connecting the land of the third terminal 20C to electrical wiring leading to the external circuit by soldering.

[0058] As shown in FIG. 17, by inserting the bus bars 12 into the positive side connector 13P and the negative side connector 13N, respectively, the DC output terminals of the converters 200-1 and 200-2 and the DC input terminals of the inverters 300-1 and 300-2 are connected via a DC link 500 consisting of a positive side power line 500P and a negative side power line 500N, as shown in FIG. 18.

[0059] The numbers and combinations of converters and inverters shown in FIGS. 17 and 18 are merely examples, and other numbers and combinations may be used.

[0060] Advantages of the Embodiments of the Present Disclosure According to the embodiments of the present disclosure, it is possible to realize a motor drive device that is bus bar connected and easy to assemble.

[0061] Because relatively large currents flow through the power elements of power conversion devices (converters and inverters) in a motor drive, bus bars are often used to electrically connect the power conversion devices to a DC link. Conventionally, a DC link has been constructed by providing terminal blocks for each power conversion device and fastening bus bars to the terminal blocks with screws. However, the time-consuming and labor-intensive process of tightening and loosening the screws increases the assembly time and cost of the motor drive device. Furthermore, to facilitate the ease of tightening and loosening the screws, the terminal blocks must be enlarged, resulting in a larger motor drive device. Furthermore, connecting parts for connecting control circuits, sensors, communication circuits, and control terminals of switching elements of the power conversion device must be provided in positions separate from the terminal blocks, resulting in a larger motor drive device and increased assembly time and cost.

[0062] In contrast, according to an embodiment of the present disclosure, connectors are mounted on housings that house power conversion devices. The mounting surfaces of the connectors on the housings are configured to be substantially flush with each other between adjacent housings. Each connector has first and second terminals electrically connected to DC terminals of the power conversion devices housed in the housings, and a third terminal for electrically connecting a circuit provided inside the power conversion device housed in the housing to an external circuit. This allows a DC link to be formed simply by inserting a bus bar into the first and second terminals of the connector. Furthermore, the circuit provided inside the power conversion device can be electrically connected to an external circuit via the third terminal. This facilitates assembly of the motor drive device, reducing assembly time and assembly costs. Furthermore, since the embodiment of the present disclosure does not use a bulky terminal block, the motor drive device can be miniaturized. Furthermore, according to the embodiment of the present disclosure, the connector is mounted on the housing so that the insertion and removal direction of the bus bar with respect to the first and second terminals is substantially perpendicular to the mounting surface of the connector on the housing. By designing the connector mounting surface of the housing as the surface that allows the easiest and most efficient access to the motor drive device for workers performing maintenance work and various operations, the insertion and removal of bus bars from the connector becomes easier. Furthermore, according to an embodiment of the present disclosure, by determining the number of bus bars according to the number of housings that house adjacent power conversion devices, scalability can be achieved to accommodate various numbers of housings using bus bars of the same standard. Furthermore, because the bus bar standards can be standardized, the number of bus bar varieties in stock can be reduced, resulting in reduced manufacturing costs for motor drive devices.

[0063] Furthermore, according to an embodiment of the present disclosure, the first and second terminals of the connector have a floating structure with contacts that elastically deform when the bus bar is inserted and make physical and electrical contact with the bus bar, thereby ensuring more reliable physical and electrical contact between the bus bar and the contacts of the first and second terminals even if the insertion direction or position of the bus bar is slightly misaligned with respect to the first and second terminals.

[0064] Furthermore, according to an embodiment of the present disclosure, the connector is provided with a contact protection part, which can prevent a human finger from coming into contact with the connector contacts and causing an electric shock, or prevent other conductive members from coming into contact with the connector contacts and causing a current leak.

[0065] Although the present disclosure has been described in detail above, the present disclosure is not limited to the individual embodiments and individual variations described above. Various additions, substitutions, modifications, partial deletions, etc. are possible for these embodiments and variations within the scope of the gist of the present disclosure, or within the scope of the gist of the present disclosure derived from the content of the claims and their equivalents. These embodiments and variations can also be implemented in combination. For example, in the above-described embodiments and variations, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical formulas are used in the description of the above-described embodiments and variations.

[0066] <Supplementary Notes> The following supplementary notes are further disclosed regarding the above-described embodiment and modifications.

[0067] (Supplementary Note 1) A motor drive device 1 includes connectors 13, 13P, and 13N provided corresponding to power conversion devices that generate electric power to drive a motor, and the connectors 13, 13P, and 13N have: a first terminal 20A used for power exchange between the power conversion device provided in the connector 13, 13P, or 13N and one of two other power conversion devices adjacent to the power conversion device; a second terminal 20B used for power exchange between the power conversion device provided in the connector 13, 13P, or 13N and the other of the two other power conversion devices, the second terminal 20B being electrically connected to the first terminal 20A; and a third terminal 20C for electrically connecting a circuit provided inside the power conversion device provided in the connector 13, 13P, or 13N to an external circuit. (Supplementary Note 2) The motor drive device 1 described in Supplementary Note 1 comprises: housings 11, 11-1, and 11-2 that house power conversion devices, and housings 11, 11-1, and 11-2 in which connectors 13, 13P, and 13N are mounted; and a conductive bus bar 12 that is insertable into and removable from a first terminal 20A of the connectors 13, 13P, and 13N provided on one of two adjacent power conversion devices and a second terminal 20B of the connectors 13, 13P, and 13N provided on the other of the two adjacent power conversion devices. (Appendix 3) The motor drive device 1 described in Appendix 2, wherein the connectors 13, 13P, and 13N are mounted on the housings 11, 11-1, and 11-2 such that the insertion / removal direction of the bus bar 12 with respect to the first terminal 20A and the second terminal 20B is approximately perpendicular to the mounting surfaces of the connectors 13, 13P, and 13N with respect to the housings 11, 11-1, and 11-2.(Supplementary Note 4) The motor drive device 1 according to Supplementary Note 2, wherein the connectors 13, 13P, and 13N are mounted on each of two adjacent housings 11, 11-1, and 11-2 such that the substantially linear bus bar 12 is simultaneously inserted into a first terminal 20A of one of the connectors 13, 13P, and 13N mounted on each of the two adjacent housings 11, 11-1, and 11-2, and a second terminal 20B of the other of the connectors 13, 13P, and 13N mounted on each of the two adjacent housings 11, 11-1, and 11-2. (Supplementary Note 5) The motor drive device 1 according to Supplementary Note 2, wherein the first terminal 20A and the second terminal 20B have a floating structure in which the bus bar 12 moves relative to the first terminal 20A and the second terminal 20B due to elastic deformation that occurs when the bus bar 12 is inserted. (Supplementary Note 6) The motor drive device 1 according to Supplementary Note 5, wherein the first terminal 20A and the second terminal 20B have contacts 31 that elastically deform when the bus bar 12 is inserted and make electrical contact with the bus bar 12. (Supplementary Note 7) The motor drive device 1 according to Supplementary Note 6, wherein a plurality of contacts are arranged in parallel in approximately the same direction as the longitudinal direction of the inserted bus bar 12. (Supplementary Note 8) The motor drive device 1 according to Supplementary Note 7, wherein the connectors 13, 13P, and 13N have insulating contact protectors 32 that cover the contacts 31 so that the contacts 31 are exposed in the direction of insertion and removal of the bus bar 12 relative to the first terminal 20A and the second terminal 20B. (Supplementary Note 9) The motor drive device 1 according to Supplementary Note 1, wherein the connectors 13, 13P, and 13N have a printed circuit board 21 on which the third terminal 20C is installed. (Supplementary Note 10) The motor drive device 1 according to Supplementary Note 1, wherein the third terminal 20C is formed by a land in a through hole. (Supplementary Note 11) The motor drive device 1 according to any one of Supplementary Notes 1 to 10, wherein the power conversion device includes at least one of converters 200-1 and 200-2 that convert AC power supplied from an AC power source into DC power, and inverters 300-1 and 300-2 that convert DC power supplied from the converters 200-1 and 200-2 via a DC link into AC power for driving the motor.

[0068] REFERENCE SIGNS LIST 1 Motor drive device 13 Connector 13N Negative side connector 13P Positive side connector 20A First terminal 20B Second terminal 20C Third terminal 21 Printed circuit board 31 Contact 32 Contact protection unit 100 AC power supply 200-1, 200-2 Converter 300-1, 300-2 Inverter 400-1, 400-2 Motor 500 DC link 500N Negative side power line 500P Positive side power line

Claims

1. A motor driving device comprising a connector provided corresponding to a power conversion device for generating electric power for driving a motor, the connector having: a first terminal used for power transfer between the power conversion device provided in the connector and one of the other two power conversion devices adjacent to the power conversion device; a second terminal used for power transfer between the power conversion device provided in the connector and the other of the two power conversion devices, the second terminal being electrically connected to the first terminal; and a third terminal for electrically connecting a circuit provided inside the power conversion device provided in the connector to an external circuit.

2. A housing for housing the power conversion device, the housing having: a housing on which the connector is mounted; and a conductive bus bar that is insertable into and removable from the first terminal of the connector provided on one of the two adjacent power conversion devices and the second terminal of the connector provided on the other of the two adjacent power conversion devices. The motor driving device according to claim 1.

3. The motor driving device according to claim 2, wherein the connector is mounted on the housing such that the insertion and removal direction of the bus bar with respect to the first terminal and the second terminal is substantially perpendicular to the mounting surface of the connector with respect to the housing.

4. The motor driving device according to claim 2, wherein the connector is mounted on each of the two adjacent housings such that the substantially linear bus bar is simultaneously inserted into the first terminal of one of the connectors mounted on each of the two adjacent housings and the second terminal of the other of the connectors mounted on each of the two adjacent housings.

5. The motor driving device according to claim 2, wherein the first terminal and the second terminal have a floating structure in which the bus bar is movable with respect to the first terminal and the second terminal due to elastic deformation occurring when the bus bar is inserted.

6. The motor drive device according to claim 5, wherein the first terminal and the second terminal have contacts that electrically contact the bus bar while elastically deforming when the bus bar is inserted.

7. The motor drive device according to claim 6, wherein a plurality of the contacts are arranged in parallel along a direction substantially the same as the longitudinal direction of the inserted bus bar.

8. The motor drive device according to claim 7, wherein the connector has an insulating contact protection portion that covers the contacts so that the contacts are exposed in the insertion and extraction direction of the bus bar with respect to the first terminal and the second terminal.

9. The motor drive device according to claim 1, wherein the connector has a printed circuit board on which the third terminal is installed.

10. The motor drive device according to claim 1, wherein the third terminal consists of a land in a through hole.

11. The motor drive device according to any one of claims 1 to 10, wherein the power conversion device includes at least one of a converter that converts AC power supplied from an AC power source into DC power and an inverter that converts DC power supplied from the converter via a DC link into AC power for driving a motor.

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