WO2025126315A1 - Motor drive device having dc link connection - Google Patents

Abstract

This motor drive device comprises: a housing that houses a power conversion device including at least one among a converter that converts AC power supplied from an AC power supply 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; a busbar that is for electrically connecting the power conversion device to the DC link; and a connector that is for electrically connecting the busbar with the power conversion device when the busbar is inserted in said connector. The connector is mounted to the housing such that the insertion/removal direction of the busbar with respect to the connector is substantially perpendicular to the mounting surface of the connector onto the housing.

Description

MOTOR DRIVE WITH DC LINK CONNECTION - Patent application

This disclosure relates to a motor drive device having a DC link connection.

A converter and an inverter are provided as power conversion devices within a motor drive device that drives an AC motor. 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.

Since a relatively large current flows through the DC link between the converter and the inverter, a bus bar made of metal such as copper, brass, or aluminum is often used to connect the DC link.

JP 2014-207803 A JP 2002-237341 A

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 to develop a motor drive device with an easy-to-assemble DC link connection.

According to one aspect of the present disclosure, the motor drive device includes a housing that houses a power conversion device, which is either a converter that converts AC power supplied from an AC power source into DC power or an inverter that converts DC power supplied from the converter via a DC link into AC power for driving the motor, a bus bar for electrically connecting the power conversion device to the DC link, and a connector for conducting the bus bar with the power conversion device when the bus bar is inserted, and the connector is mounted on the housing so that the insertion and removal direction of the bus bar with respect to the connector is approximately perpendicular to the mounting surface of the connector on the housing.

FIG. 1 is a front view showing a motor drive device according to an embodiment of the present disclosure. FIG. 2 is a circuit diagram of the motor drive device shown in FIG. FIG. 1 is a side view illustrating a motor drive device according to an embodiment of the present disclosure. 1 is a front view illustrating a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. FIG. FIG. 5 is an enlarged view of the connector shown in FIG. 4 . FIG. 1 is a first perspective view of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. 1 is a front view of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. FIG. FIG. 2 is a second perspective view of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. FIG. 3 is a third perspective view of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. FIG. 4 is a perspective view (part 4) of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. 1 is a side view of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. FIG. FIG. 2 is a perspective view of a bus bar used for DC link connection of a motor drive device according to an embodiment of the present disclosure. FIG. 1 is a perspective view (part 1) of a bus bar and a support base used for DC link connection of a motor drive device according to an embodiment of the present disclosure. FIG. 2 is a perspective view of a support base that supports a bus bar used for DC link connection of a motor drive device according to an embodiment of the present disclosure. FIG. 2 is a second perspective view of a bus bar and a support base used for DC link connection of a motor drive device according to an embodiment of the present disclosure. 1 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. 1 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. 1 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. 1 is a front view illustrating a state in which a bus bar with a support base attached thereto is inserted into a connector in a motor drive device according to an embodiment of the present disclosure. FIG. 1 is a front view showing the size relationship between a housing and a bus bar in a motor drive device according to an embodiment of the present disclosure. FIG.

Below, a motor drive device having a DC link connection according to an embodiment will be described with reference to the drawings. In the following description, components having the same or similar functions will be given the same reference numerals. Furthermore, duplicate descriptions of those components may be omitted. The scale of the drawings has been appropriately changed to facilitate understanding.

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 "inverse converter." As both converters and inverters are devices that perform power conversion operations, they are collectively referred to as a "power conversion device." In other words, a power conversion device means either a converter alone, an inverter alone, or an integrated converter and inverter. A "DC link" refers to a circuit portion that electrically connects the DC output terminal of the converter and the DC input terminal of the inverter, and is also referred to as a "DC link portion," "DC link," "DC link portion," "DC bus," or "DC intermediate circuit." A "DC link connection" refers to forming a DC link between the DC output terminal of the converter and the DC input terminal of the 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 "shorting bar". "Sheet metal" refers to metal formed into a thin, flat shape. "Electrically connect" means "connect so that electricity can flow". "Parallel installation" means to align and arrange in a line close to each other. "Parallel installation direction" refers to the direction in which the housings are lined up when multiple housings are arranged in a line.

Overall configuration of a motor drive device according to an embodiment of the present disclosure
Fig. 1 is a front view showing a motor drive device according to an embodiment of the present disclosure. Fig. 3 is a side view showing a motor drive device according to an embodiment of the present disclosure. Fig. 4 is a front view illustrating a connector provided on a housing of the motor drive device according to an embodiment of the present disclosure. Fig. 5 is an enlarged view of the connector shown in Fig. 4.

A motor drive device 1 according to one embodiment of the present disclosure includes a housing 11, a bus bar 12, and a connector 13. The motor drive device 1 also includes a converter, an inverter, a control board, a sensor, communication equipment, a backup power supply, and other circuits. The motor drive device 1 may also include a display device and/or an input device.

In this disclosure, for the sake of simplicity, of the six faces of the housing 11, the face of the housing 11 on which the bus bar 12 is attached is referred to as the "front" of the motor drive device 1. In the examples shown in Figs. 1 and 3 to 20, 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". For example, it is preferable that the front of the motor drive device 1 is the face from which workers performing maintenance work and various operations can most easily and efficiently access the motor drive device 1.

The housing 11 houses a power conversion device, which may be a converter alone, an inverter alone, or an integrated converter and inverter. The housing 11 is made of a material with high insulating (non-conductive) properties. Examples of insulating materials include plastic, urethane, glass, porcelain, fine ceramics, vinyl, rubber, wood, and paper. The housing 11 may be provided with openings for passing electrical wiring, terminals, etc.

Generally, in the motor drive device 1, an inverter is provided corresponding to the drive shaft. In addition, in order to reduce the cost and the space occupied by the motor drive device 1, one converter is often connected to multiple inverters via a DC link. In the illustrated example, as an example, two housings 11 are provided adjacent to each other along the X-axis direction. Hereinafter, the reference numbers of the two adjacent housings 11 may be separately written as 11-1 and 11-2, and the housings 11-1 and 11-2 may be collectively written 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, but the type of power conversion device housed in the housing 11-1 and the housing 11-2 does not limit this embodiment. For example, the housing 11-1 may house an inverter, and the housing 11-2 may house a converter. In addition, the number of adjacent housings 11 is not limited to two, and may be three or more.

The bus bar 12 is used to electrically connect the DC terminals of the power conversion devices provided in adjacent housings 11 (housings 11-1 and 11-2 in FIG. 1) to the 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, rod-shaped, approximately straight metal sheet. The bus bar 12 is manufactured, for example, by sheet metal processing.

The DC power line constituting the DC link has a positive power line and a negative power line. The bus bar 12 constituting the positive power line of the DC link is referred to as the positive bus bar 12P. The bus bar 12 constituting the negative power line of the DC link is referred to as the negative bus bar 12N. Hereinafter, the positive bus bar 12P and the negative bus bar 12N may be collectively referred to as the bus bar 12. Therefore, the bus bar 12 means the positive bus bar 12P, or the negative bus bar 12N, or both the positive bus bar 12P and the negative bus bar 12N. The positive bus bar 12P is used to electrically connect the 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 the positive power line of the DC link. The negative bus bar 12N is used to electrically connect the 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 the negative power line of the DC link. The positive bus bar 12P and the negative bus bar 12N have the same shape and structure.

A connector 13 is provided on the surface of the housing 11 that corresponds to the "front" of the motor drive device 1 for connecting the power conversion device in the housing 11 to a DC link using a bus bar 12. The connector 13 has a structure that allows the bus bar 12 to be inserted and removed. FIG. 1 shows a state in which the bus bar 12 has already been inserted (attached) into the connector 13. The connector 13 is mounted on a printed circuit board, and the printed circuit board on which the connector 13 is mounted is placed in the housing 11. At that time, the connector 13 is mounted on the housing 11 via the printed circuit board so that the insertion and removal direction (Y-axis direction) of the bus bar 12 relative to the connector 13 is approximately perpendicular to the mounting surface of the connector 13 relative to the housing 11.

The connector 13 is configured as a floating connector in which the bus bar 12 moves relative to the connector 13 due to elastic deformation caused when the bus bar 12 is inserted. That is, the connector 13 has a plurality of contacts 31 that elastically deform when the bus bar 12 is inserted and come into physical and electrical contact with the bus bar 12. These plurality of contacts 31 are arranged in parallel so as to be aligned in substantially the same direction as the longitudinal direction of the bus bar 12 to be inserted. When the motor drive device 1 is viewed from the front (i.e., viewed from the negative Y-axis direction), the contacts 31 of the connector 13 are exposed. The contacts 31 of the connector 13 are further electrically connected to a DC terminal (not shown) of the power conversion device in the housing 11 in which the connector 13 is installed. The connector 13 also has an insulating contact protection part 32 that covers the contacts 31 so that the contacts 31 are exposed in the direction in which the bus bar 12 is inserted into and removed from the connector 13 (Y-axis direction). Details of the contact protection part 32 will be described later.

The connector 13 into which the positive bus bar 12P 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 negative bus bar 12N 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 means the positive connector 13P, or 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 is used to electrically connect the 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 the positive bus bar 12P. The negative connector 13N is used to electrically connect the 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 the negative bus bar 12N.

On the surface of the housing 11-1, which corresponds to the "front" of the motor drive device 1, there are provided a positive connector 13P and a negative connector 13N for connecting the DC output terminal of the converter in said housing 11-1 to a DC link using a positive bus bar 12P and a negative bus bar 12N. Similarly, on the surface of the housing 11-2, which corresponds to the "front" of the motor drive device 1, there are provided a positive connector 13P and a negative connector 13N for connecting the DC input terminal of the inverter in said housing 11-2 to a DC link using a positive bus bar 12P and a negative bus bar 12N.

Multiple housings 11 (in the example shown in FIG. 1, housings 11-1 and 11-2) are arranged side by side in one direction adjacent to each other. The connectors 13 are provided on each of the multiple housings 11 so that the rod-shaped bus bar 12 can be simultaneously inserted into each of the connectors 13 provided on the multiple housings 11. The connectors 13 provided 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 these housings 11 are arranged side by side adjacent to each other. 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 bar 12 into each of the connectors 13 provided on the multiple housings 11. In the example shown in FIG. 1, the connectors 13 are mounted on the housings 11 so that the Y coordinate values of the connectors 13 provided on each of the adjacent housings 11 are approximately the same in the XYZ coordinate system. Here, an example is described in which there are two adjacent housings 11, but the same applies when there are three or more adjacent housings 11.

FIG. 2 is a circuit diagram of the motor drive device shown in FIG. 1.

In FIG. 1, the positive bus bar 12P is inserted into the positive connector 13P provided in the housing 11-1 housing the converter and the positive connector 13P provided in the housing 11-2 housing the inverter. Also, the negative bus bar 12N is inserted into the negative connector 13N provided in the housing 11-1 housing the converter and the negative connector 13N provided in the housing 11-2 housing the inverter. The converter housed in the housing 11-1 shown in FIG. 1 is indicated by reference number 200 in FIG. 2. Also, the inverter housed in the housing 11-2 shown in FIG. 1 is indicated by reference number 300 in FIG. 2. By inserting the positive bus bar 12P and the negative bus bar 12N into the positive connector 13P and the negative connector 13N as shown in FIG. 1, the DC output terminal of the converter 200 and the DC input terminal of the inverter 300 are connected via a DC link as shown in FIG. 2.

The converter 200 converts the AC power supplied from the AC power source 100 into DC power and outputs it to the DC link. The converter 200 is configured as a three-phase bridge circuit when three-phase AC power is supplied from the AC power source 100, and is configured as a single-phase bridge circuit when single-phase AC power is supplied from the AC power source 100. Examples of the converter 200 include a diode rectifier, a 120-degree conduction rectifier, and a PWM switching control rectifier. For example, when the converter 200 is configured as a 120-degree conduction rectifier or a PWM switching control rectifier, it is configured as a bridge circuit of switching elements and diodes connected in reverse parallel to the switching elements, and each switching element is controlled to be turned on and off according to a drive command received from a higher-level control device (not shown) to perform power conversion in both directions. In this case, examples of the switching elements include FETs, IGBTs, thyristors, GTOs, transistors, etc., but other semiconductor elements may also be used. An AC reactor, AC line filter, etc. may be provided on the AC input side of the converter 200, but these are not shown here.

The inverter 300 converts the DC power in the DC link into AC power for driving the motor and outputs it to the motor 400. The inverter 300 may have any configuration capable of converting DC power into AC current, such as a PWM control type inverter with a switching element inside. The inverter 300 is configured as a three-phase bridge circuit when the motor 400 is a three-phase AC motor, and is configured as a single-phase bridge circuit when the motor 400 is a single-phase motor. In the illustrated example, the motor 400 is a three-phase AC motor, so the inverter 300 is configured as a three-phase bridge circuit. When the inverter 300 is configured as a PWM control type inverter, it is configured as a bridge circuit of a diode and a switching element connected in reverse parallel to the diode. In this case, examples of the switching element include FET, IGBT, thyristor, GTO, transistor, etc., but other semiconductor elements may also be used. The inverter 300 converts the DC power in the DC link into AC power for driving the motor and outputs it by PWM-controlling the on/off operation of the internal switching elements based on commands from a higher-level control device (not shown). The speed, torque, or rotor position of the motor 400 is controlled based on the AC power supplied from the inverter 300. Note that the inverter 300 can also convert the AC power regenerated by the motor 400 into DC power and return it to the DC link on the DC side by appropriately PWM-controlling the on/off operation of the switching elements.

A DC link capacitor is provided in the DC link connecting the DC output terminal of converter 200 and the DC input terminal of inverter 300, but is not shown in FIG. 2. The DC link capacitor has the function of storing DC power used by inverter 300 to generate AC power and the function of suppressing pulsation in the DC output of converter 200. Examples of DC link capacitors include electrolytic capacitors and film capacitors. The DC link capacitor is provided either inside housing 11-1, inside housing 11-2, or outside housings 11-1 and 11-2.

<Configuration of Connector According to an Embodiment of the Present Disclosure>
6 and 8 to 10 are perspective views of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. Fig. 7 is a front view of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure. Fig. 11 is a side view of a connector provided in a housing of a motor drive device according to an embodiment of the present disclosure.

The connector 13 is a floating connector in which the bus bar 12 moves relative to the connector 13 due to elastic deformation that occurs when the bus bar 12 is inserted. That is, the connector 13 has a plurality of elastically deformable contacts 31. When the motor drive device 1 is viewed from the front (i.e., viewed from the negative Y-axis direction), the plurality of contacts 31 are exposed. When the bus bar 12 is inserted, each of the plurality of contacts 31 elastically deforms and comes into physical and electrical contact with the bus bar 12. The plurality of contacts 31 are arranged in parallel so as to extend in approximately the same direction as the longitudinal direction of the bus bar 12 to be inserted. Two rows of the juxtaposed contacts 31 are provided, and these two rows face each other. When the bus bar 12 is inserted into the connector 13, the bus bar 12 is sandwiched between the two rows of the elastically deformed plurality of contacts 31 while making physical and electrical contact with the bus bar 12.

The connector 13 is provided with a contact protection section 32 to prevent a human finger from touching the contact 31 and getting an electric shock, or another conductive member from touching the contact 31 and causing a current leak. The contact protection section 32 opens in the direction in which the bus bar 12 is inserted into or removed from the connector 13 (the negative Y-axis direction), and covers the contact 31 so that the contact 31 is exposed in the direction in which the bus bar 12 is inserted into or removed from the connector 13 (the negative Y-axis direction). The contact 31 is provided at a position recessed in the positive Y-axis direction from the end face of the opening of the contact protection section 32 facing the insertion/removal direction of the bus bar 12 (the negative Y-axis direction). The contact protection section 32 has a structure that prevents a human finger from touching the contact 31 even if the human finger is inserted into the connector 13 from the insertion direction side of the bus bar 12 (the negative Y-axis direction). For example, the width in the Z-axis direction (short direction of the bus bar 12) of the opening of the contact protection part 32 facing the insertion/removal direction of the bus bar 12 (negative 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. The contact protection part 32 is also made of a material with high insulating properties. Examples of insulating materials include plastic, urethane, glass, porcelain, fine ceramics, vinyl, rubber, wood, and paper.

<Configuration of bus bar according to embodiment of the present disclosure>
FIG. 12 is a perspective view of a bus bar used for DC link connection of a motor drive device according to an embodiment of the present disclosure.

The busbar 12 is made of a metal such as copper, brass, or aluminum. The busbar 12 is, for example, a thin, straight, rod-like metal sheet, and has a substantially rectangular parallelepiped shape. The longitudinal direction (X-axis direction) of the busbar 12 is substantially the same as the direction in which the multiple contacts 31 are arranged in the connector 13. The transverse direction (Y-axis direction) of the busbar 12 is substantially the same as the direction in which the busbar 12 is inserted into and removed from the connector 13. The length of the busbar 12 in the Z-axis direction is shorter than the length of the busbar 12 in the Y-axis direction. The length of the busbar 12 in the Z-axis direction is, for example, about 3 mm. Note that the values given here are merely examples, and other values may be used. As will be described later, the length of the busbar 12 in the longitudinal direction (X-axis direction) is set to be shorter than the width of one housing 11 in the X-axis direction when multiple housings 11 are arranged adjacent to each other along the X-axis direction.

Configuration of the support base according to the embodiment of the present disclosure
Fig. 14 is a perspective view of a support base supporting a bus bar used in a DC link connection of a motor drive device according to an embodiment of the present disclosure. Fig. 13 and Fig. 15 are perspective views of a bus bar and a support base used in a DC link connection of a motor drive device according to an embodiment of the present disclosure.

The larger the exposed area of the busbar 12 through which a large current flows, the greater the possibility of a person receiving an electric shock when touching the busbar 12, or of another conductive member contacting the busbar 12 causing a current leak. In addition, the busbar 12 inserted into the connector 13 may become dislodged due to vibration of the housing 11. In addition, the busbar 12 is a thin, rod-shaped, approximately straight metal sheet, which makes it somewhat inconvenient to handle. In order to eliminate these problems, it is preferable to attach a support stand 14 to the busbar 12.

The support base 14 supports the bus bar 12. The support base 14 has a latch mechanism 21 and a bus bar protective cover 22. The latch mechanism 21 and the bus bar protective cover 22 are integrally molded. The latch mechanism 21 and the bus bar protective cover 22 are made of an insulating material (non-conductive material). Examples of insulating materials include plastic, urethane, glass, porcelain, fine ceramics, vinyl, rubber, wood, and paper.

The latch mechanism 21 holds the bus bar 12 so that the bus bar 12 is exposed in the direction in which the bus bar 12 is inserted into the connector 13 (the positive direction of the Y axis). In consideration of the ease of attaching the bus bar 12 to the latch mechanism 21, it is preferable that the latch mechanism 21 be made of a flexible material.

The busbar protective cover 22 opens in the direction in which the busbar 12 is inserted into the connector 13 (positive direction on the Y axis), and covers the busbar 12 so that the busbar 12 is not exposed in the direction in which the busbar 12 is removed from the connector 13 (negative direction on the Y axis). The busbar protective cover 22 may have a surface parallel to the direction in which the busbar 12 is inserted and removed. The busbar protective cover 22 can prevent electric shock caused by a person touching the busbar 12, and electric leakage caused by another conductive member touching the busbar 12. In order to improve the insertion and removal of the busbar 12 into and from the connector 13, a recess may be provided in the busbar protective cover 22 so that the busbar protective cover 22 can be gripped by a person's fingers by fitting into the recess.

<Attachment of busbars and connectors according to an embodiment of the present disclosure>

FIG. 16 is a front view of a connector with a bus bar inserted in a motor drive device according to an embodiment of the present disclosure. FIG. 17 is a side view of a connector with a bus bar inserted in a motor drive device according to an embodiment of the present disclosure. FIG. 18 is a perspective view of a connector with a bus bar inserted in a motor drive device according to an embodiment of the present disclosure. In FIGS. 16 to 18, the support base 14 is not shown to make it easier to see the attachment state of the bus bar 12 and the connector 13, but the support base 14 may be attached to the bus bar 12.

When the bus bar 12 is inserted into the connector 13 from the negative Y-axis direction toward the positive Y-axis direction, the multiple contacts 31 of the connector 13, which is a floating connector, elastically deform, and the bus bar 12 is sandwiched between the two rows of the multiple contacts 31 while maintaining physical and electrical contact. Even if the insertion direction or insertion position of the bus bar 12 is slightly misaligned with respect to the connector 13, the elastic deformation of the contacts 31 ensures stable physical and electrical contact between the bus bar 12 and the contacts 31.

FIG. 19 is a front view showing a bus bar with a support base attached inserted into a connector in a motor drive device according to an embodiment of the present disclosure.

Figure 19 shows the "front" of the motor drive device 1 as viewed from the negative side in the Y-axis direction. The bus bar protective cover 22 of the support base 14 covers the bus bar 12 so that it is not exposed in the direction in which the bus bar 12 is removed from the connector 13 (the negative Y-axis direction), and therefore the bus bar 12 cannot be seen from the negative Y-axis direction. The bus bar protective cover 22 of the support base 14 prevents electric shock caused by a person touching the bus bar 12 and electric leakage caused by other conductive members coming into contact with the bus bar 12.

<Size Relationship Between Bus Bar and Housing According to the Embodiment of the Present Disclosure>
FIG. 20 is a front view showing the size relationship between the housing and the bus bars in the motor drive device according to the embodiment of the present disclosure.

The length of the bus bar 12 in the longitudinal direction (X-axis direction) is LB, and the length of each of the housings 11-1 and 11-2 in the X-axis direction is LH. The longitudinal direction of the bus bar 12 roughly coincides with the direction in which the housings 11-1 and 11-2 are arranged side by side. The length LB of the bus bar 12 in the longitudinal direction (X-axis direction) is set to be shorter than the length LH of the housing 11 in the X-axis direction. Note that if the lengths of the housings 11-1 and 11-2 in the X-axis direction differ, the length of the housing 11 in the X-axis direction that is the shorter length is used as LH.

By inserting the bus bar 12 so as to straddle the connectors 13 provided on each of the adjacent housings 11-1 and 11-2, it is possible to connect each of the power conversion devices in the housings 11-1 and 11-2 to the DC link. In the example shown in FIG. 20, there are two housings 11, but even if there are three or more housings 11, it is possible to connect the power conversion devices in the housings 11 to the DC link by connecting the bus bars 12 in the same manner. If there are housings 11 with different lengths in the X-axis direction among the three or more housings 11, the length in the X-axis direction of the housing 11 with the shortest length in the X-axis direction is used as LH.

By setting the size relationship between the busbars 12 and the housings 11 as described above, it is possible to achieve scalability that can accommodate various numbers of housings 11 with busbars 12 of the same standard. In addition, because the standard of the busbars 12 can be unified, it is possible to reduce the number of types of busbars 12 in stock, and as a result, the manufacturing cost of the motor drive device 1 can be reduced.

Advantages of the embodiments of the present disclosure
According to the embodiments of the present disclosure, a motor drive device having an easy-to-assemble DC link connection can be realized.

Because a relatively large current flows through the power elements of the power conversion devices (converters and inverters) in the motor drive device, bus bars are often used to electrically connect the power conversion devices to a DC link. Conventionally, a DC link was formed by providing a terminal block for each power conversion device and fastening the bus bar to the terminal block by screwing. However, there was a problem that the time-consuming and laborious work of tightening and loosening the screws increased the assembly time and assembly costs of the motor drive device. In addition, considering the ease of tightening and loosening the screws, the terminal block had to be made large, resulting in a problem of an increased size of the motor drive device.

In contrast, according to an embodiment of the present disclosure, a connector is mounted on a housing that houses a power conversion device. The mounting surface of the connector on the housing is set so as to be approximately flush with the adjacent housings. This allows a DC link to be configured simply by inserting a bus bar into a connector electrically connected to the power conversion device. This makes it easier to assemble the motor drive device, and reduces assembly time and assembly costs. In addition, since a bulky terminal block is not used in an embodiment of the present disclosure, the motor drive device can be made smaller. In addition, according to an embodiment of the present disclosure, the connector is mounted on the housing so that the insertion and removal direction of the bus bar into and from the connector is approximately perpendicular to the mounting surface of the connector on the housing. By making the mounting surface of the connector on the housing the surface that allows workers performing maintenance work and various operations to most easily and efficiently access the motor drive device, the insertion and removal of the bus bar into and from the connector is made easier.

Furthermore, according to an embodiment of the present disclosure, the connector is configured as a floating connector having contacts that make physical and electrical contact with the bus bar while elastically deforming when the bus bar is inserted. This makes it possible to ensure more reliable physical and electrical contact between the bus bar and the connector contacts, even if the insertion direction or insertion position of the bus bar is slightly misaligned with respect to the connector.

Furthermore, according to an embodiment of the present disclosure, the connector may be provided with a contact protection section. This can prevent a human finger from touching the connector contacts and receiving an electric shock, or prevent another conductive member from touching the connector contacts and causing an electric leak.

Furthermore, according to an embodiment of the present disclosure, the longitudinal length of the bus bar is set to be shorter than the width of one housing when multiple housings are arranged side by side in the same direction. This makes it possible to achieve scalability that can accommodate various numbers of housings with bus bars of the same standard. Furthermore, because the bus bar standards can be unified, the number of bus bar varieties in stock can be reduced, resulting in reduced manufacturing costs for motor drive devices.

Furthermore, according to an embodiment of the present disclosure, a support base may be attached to the bus bar. A bus bar protective cover provided on the support base can prevent electric shock caused by a person touching the bus bar and electric leakage caused by other conductive members touching the bus bar. A latch mechanism provided on the support base can prevent the bus bar inserted into the connector from coming off due to vibration of the housing.

　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 without departing from the gist of the present disclosure, or without departing from the gist of the present disclosure derived from the contents described in the claims and their equivalents. Furthermore, these embodiments and variations can also be implemented in combination. For example, in the above-mentioned 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 formulas are used in the explanation of the above-mentioned embodiments and variations.

<Additional Notes>
The following supplementary notes are further disclosed regarding the above-described embodiment and modified examples.

(Appendix 1)
housings 11, 11-1, and 11-2 that accommodate a power conversion device including at least one of a converter 200 that converts AC power supplied from an AC power source 100 into DC power and an inverter 300 that converts DC power supplied from the converter 200 via a DC link into AC power for driving a motor;
a bus bar 12 for electrically connecting the power converter to a DC link;
a connector 13 for electrically connecting the bus bar 12 to a power conversion device when the bus bar 12 is inserted;
Equipped with
The motor drive device 1 has a connector 13 mounted on the housings 11, 11-1, and 11-2 so that the direction in which the bus bar 12 is inserted into and removed from the connector 13 is substantially perpendicular to the mounting surface of the connector 13 on the housings 11, 11-1, and 11-2.
(Appendix 2)
the bus bar 12 includes a positive bus bar 12P for electrically connecting a positive terminal of the power conversion device to a positive power line of the DC link, and a negative bus bar 12N for electrically connecting a negative terminal of the power conversion device to a negative power line of the DC link;
The motor drive device 1 described in Appendix 1, wherein the connector 13 includes a positive connector 13P into which the positive bus bar 12P can be inserted and removed, and a negative connector 13N into which the negative bus bar 12N can be inserted and removed.
(Appendix 3)
A support base 14 for supporting the bus bar 12 is further provided.
The support base 14 is
a latch mechanism 21 that holds the bus bar 12 so that the bus bar 12 is exposed toward the direction in which the bus bar 12 is inserted into the connector 13;
an insulating bus bar protective cover 22 for covering the bus bar 12 so as to prevent the bus bar 12 from being exposed in a direction in which the bus bar 12 is removed from the connector 13;
The motor drive device 1 according to claim 1,
(Appendix 4)
The motor drive device 1 described in Appendix 1, wherein the longitudinal length LB of the bus bar 12 is shorter than the width LH in one direction of one of the housings 11, 11-1, and 11-2 when the housings 11, 11-1, and 11-2 are arranged adjacent to each other along one direction.
(Appendix 5)
The motor drive device 1 described in Appendix 1, wherein the connector 13 is mounted on each of the multiple housings 11, 11-1, and 11-2 so that the approximately straight bus bar 12 is inserted simultaneously when the multiple housings 11, 11-1, and 11-2 are arranged adjacent to each other along one direction.
(Appendix 6)
2. The motor drive device 1 according to claim 1, wherein the connector 13 is a floating connector in which the bus bar 12 moves relative to the connector 13 due to elastic deformation that occurs when the bus bar 12 is inserted.
(Appendix 7)
7. The motor drive device 1 according to claim 6, wherein the connector 13 has a contact 31 that makes electrical contact with the bus bar 12 while elastically deforming when the bus bar 12 is inserted.
(Appendix 8)
8. The motor drive device 1 according to claim 7, wherein the plurality of contacts 31 are arranged in parallel to the longitudinal direction of the bus bar 12 to be inserted.
(Appendix 9)
8. The motor drive device 1 according to claim 7, wherein the connector 13 has an insulating contact protection portion 32 that covers the contacts 31 so that the contacts are exposed in the direction in which the bus bar 12 is inserted into or removed from the connector 13.

REFERENCE SIGNS LIST 1 motor drive device 11, 11-1, 11-2 housing 12 bus bar 12N negative bus bar 12P positive bus bar 13 connector 13N negative connector 13P positive connector 14 support base 21 latch mechanism 22 bus bar protection cover 31 contact 32 contact protection unit 100 AC power supply 200 converter 300 inverter 400 motor

Claims (9)

a housing that houses a power conversion device including at least one of a converter that converts AC power supplied from an AC power source into DC power and an inverter that converts the DC power supplied from the converter via a DC link into AC power for driving a motor;
a bus bar for electrically connecting the power converter to the DC link;
a connector for electrically connecting the bus bar to the power conversion device when the bus bar is inserted;
Equipped with
a motor drive device in which the connector is mounted on the housing such that a direction in which the bus bar is inserted into and removed from the connector is substantially perpendicular to a mounting surface of the connector on the housing. the bus bar includes a positive-side bus bar for electrically connecting a positive-side DC terminal of the power conversion device to a positive-side power line of the DC link, and a negative-side bus bar for electrically connecting a negative-side DC terminal of the power conversion device to a negative-side power line of the DC link,
2. The motor drive device according to claim 1, wherein the connector includes a positive connector into which the positive bus bar can be inserted and removed, and a negative connector into which the negative bus bar can be inserted and removed. A support base for supporting the bus bar is further provided.
The support base is
a latch mechanism that holds the bus bar so that the bus bar is exposed toward an insertion direction of the bus bar into the connector;
an insulating bus bar protective cover for covering the bus bar so that the bus bar is not exposed in a direction in which the bus bar is removed from the connector;
The motor drive device according to claim 1 . The motor drive device according to claim 1, wherein the longitudinal length of the bus bar is shorter than the width in one direction of one of the housings when the housings are arranged side by side adjacent to each other in one direction. The motor drive device according to claim 1, wherein the connector is mounted to each of the multiple housings so that the substantially linear bus bars are inserted simultaneously when the multiple housings are arranged side by side adjacent to each other in one direction. The motor drive device according to claim 1, wherein the connector is a floating connector in which the bus bar moves relative to the connector due to elastic deformation that occurs when the bus bar is inserted. The motor drive device according to claim 6, wherein the connector has contacts that elastically deform when the bus bar is inserted and electrically contact the bus bar. The motor drive device according to claim 7, in which a plurality of the contacts are arranged in parallel in a direction substantially the same as the longitudinal direction of the bus bar to be inserted. The motor drive device according to claim 7, wherein the connector has an insulating contact protection part that covers the contact so that the contact is exposed in the direction in which the bus bar is inserted into or removed from the connector.

Images