Electric power conversion device

An object of the present invention is to achieve reduction in height of an electric power conversion device while maintaining high performance of the electric power conversion device. An electric power conversion device according to the present invention includes: a first power semiconductor module, a second power semiconductor module, a third power semiconductor module, and an AC circuit body that transmits and detects U-phase, V-phase, and W-phase AC currents, and when a direction along an arrangement direction of the first power semiconductor module and the second power semiconductor module is defined as a first column, the third power semiconductor module and the AC circuit body are disposed along a second column being in a direction parallel to the first column, and the AC circuit body is disposed in a space that is in a direction orthogonal to the first column and faces the second power semiconductor module, and is in a direction parallel to the second column and faces the third power semiconductor module.

TECHNICAL FIELD

The present invention relates to an electric power conversion device for converting DC power to AC power or converting AC power to DC power, and in particular relates to an electric power conversion device suitable for being mounted on a vehicle.

BACKGROUND ART

A hybrid car and an electric car are each provided with an electric power conversion device for driving and controlling a drive motor. The electric power conversion device is disposed at various positions of a vehicle, and depending on the disposed position, it is required to be made smaller in the height direction of the electric power conversion device, or it is required to be made smaller in the width direction of the electric power conversion device. A typical case of the former is that the electric power conversion device is disposed directly below the driver's seat or the assistant driver's seat.

In JP 2013-027218 A (PTL 1), three power semiconductor modules are arranged in a line, whereby reduction in height of the electric power conversion device is achieved.

In an electric power conversion device described in JP 2013-233052 A (PTL 2), two power semiconductor modules are arranged in a line and a remaining one power semiconductor module is disposed above the two power semiconductor modules.

In the electric power conversion devices described in PTL 1 and PTL 2, achieving reduction in height of the electric power conversion device while maintaining high performance of the electric power conversion device has not been sufficiently considered.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

An electric power conversion device according to the present invention is to achieve reduction in height of the electric power conversion device while maintaining high performance of the electric power conversion device.

Solution to Problem

The electric power conversion device according to the present invention includes: a first power semiconductor module that outputs a U-phase AC current; a second power semiconductor module that outputs a V-phase AC current; a third power semiconductor module that outputs a W-phase AC current; and an AC circuit body that transmits and detects the U-phase AC current, the V-phase AC current, and the W-phase AC current, and when a direction along an arrangement direction of the first power semiconductor module and the second power semiconductor module is defined as a first column, the third power semiconductor module and the AC circuit body are disposed along a second column being in a direction parallel to the first column, and the AC circuit body is disposed in a space that is in a direction orthogonal to the first column and faces the second power semiconductor module, and is in a direction parallel to the second column and faces the third power semiconductor module.

Advantageous Effects of Invention

With the present invention, reduction in height of the electric power conversion device can be achieved while maintaining high performance of the electric power conversion device.

DESCRIPTION OF EMBODIMENT

FIG. 1is an exploded perspective view related to an AC circuit body150, a first AC relay bus bar104, a second AC relay bus bar105, a third AC relay bus bar106, and other components among internal components of an electric power conversion device according to a present embodiment.FIG. 2is a perspective view of the internal components of the electric power conversion device illustrated inFIG. 1.FIG. 3is an exploded perspective view of the internal components of the electric power conversion device according to the present embodiment.FIG. 4is a perspective view of the internal components of the electric power conversion device illustrated inFIG. 3.

As illustrated inFIG. 3, as an inverter circuit, a first power semiconductor module101, a second power semiconductor module102, and a third power semiconductor module103are provided. For example, the first power semiconductor module101includes multiple switching devices configuring the upper arm and the lower arm of the U-phase of the inverter circuit, for outputting the U-phase AC current. Similarly, the second power semiconductor module102includes multiple switching devices configuring the upper arm and the lower arm of the V-phase of the inverter circuit, for outputting the V-phase AC current. The third power semiconductor module103includes multiple switching devices configuring the upper arm and the lower arm of the W-phase of the inverter circuit, for outputting the W-phase AC current.

FIG. 5is an exterior perspective view of the first power semiconductor module101. The first power semiconductor module101inputs and outputs DC power through a positive electrode terminal311and a negative electrode terminal312. An AC terminal313outputs AC power. Signal terminals314and315receive control signals from a driver circuit.

Sealing resin331seals a portion of the positive electrode terminal311, a portion of the negative electrode terminal312, a portion of each of the signal terminals314and315, and the switching devices. A case341accommodates a portion of the sealing resin331.

The case341includes: a first heat radiation base portion344aon which a first fin343ais formed; a second heat radiation base portion344bthat is disposed to face the first heat radiation base portion344aand on which a second fin343bis formed; and a frame342connecting the first heat radiation base portion344aand the second heat radiation base portion344btogether. The frame342is connected to the first heat radiation base portion344avia a bonding portion305. The second heat radiation base portion344bis connected to the frame342similarly.

The first fin343aand the second fin343b, and the first heat radiation base portion344aand the second heat radiation base portion344bare preferably formed of material with good heat conduction, and are formed of pure aluminum material, pure copper, copper alloy, or the like. The frame342is preferably formed of material that is easily produced and has rigidity, and is formed of aluminum die-casting material, duralumin, or the like. The bonding portion305is bonded with FSW or brazing, and seals the frame342and the first heat radiation base portion344a, and seals the frame342and the second heat radiation base portion344b. Incidentally, the seal here may be an O-ring or an adhesive.

FIG. 6is an exploded perspective view of a circuit body330excluding the sealing resin331. The circuit body330configures the upper arm and the lower arm of the inverter circuit, and includes an upper arm side semiconductor device323and a lower arm side semiconductor device324.

The upper arm side semiconductor device323is configured with an IGBT321U and a diode322U. The IGBT321U and the diode322U are connected to a positive electrode side conductive plate334and a first intermediate conductive plate335via solder360.

The IGBT321U is connected to the signal terminals314via bonding wires363, and receives the control signals from the driver circuit via the signal terminals314.

The lower arm side semiconductor device324is configured with an IGBT321L and a diode322L. The IGBT321L and the diode322L are connected to a second intermediate conductive plate336and a negative electrode side conductive plate337via the solder360.

The IGBT321L is connected to the signal terminals315via the bonding wires363, and receives the control signals from the driver circuit via the signal terminals315.

For the IGBT321U and the IGBT321L, a metal oxide semiconductor field effect transistor (hereinafter referred to as a MOSFET for short) may be used.

The first intermediate conductive plate335is connected to the second intermediate conductive plate336via the solder361. The negative electrode side conductive plate337includes an intermediate DC negative electrode terminal316. The intermediate DC negative electrode terminal316is connected to the negative electrode terminal312via the solder362.

The positive electrode side conductive plate334is connected to the positive electrode terminal311. The second intermediate conductive plate336is connected to the AC terminal313. The AC terminal313may be formed on the first intermediate conductive plate335. The positive electrode side conductive plate334, the first intermediate conductive plate335, the second intermediate conductive plate336, and the negative electrode side conductive plate337are formed of copper or the like.

As illustrated inFIG. 3, the AC circuit body150is configured with an AC bus bar107, a current sensor109, and a terminal block110. The AC bus bar107is connected to each of the first AC relay bus bar104, the second AC relay bus bar105, and the third AC relay bus bar106. The terminal block110is disposed at a position facing a bonding portion of the AC bus bar107with the first AC relay bus bar104and the like, and receives stress at the time of connection and transmits heat of the bonding portion to a flow path forming body100described later. The current sensor109is configured to penetrate the AC bus bar107.

The flow path forming body100forms a first accommodation portion112for accommodating the first power semiconductor module101, a second accommodation portion113for accommodating the second power semiconductor module102, and a third accommodation portion114for accommodating the third power semiconductor module103. In the present embodiment, the first accommodation portion112, the second accommodation portion113, and the third accommodation portion114also serves as a flow path space through which a refrigerant flows; however, piping through which the refrigerant flows may be brought into contact with the first accommodation portion112.

A first pressing plate117presses the first power semiconductor module101and the second power semiconductor module102against the flow path forming body100. A second pressing plate118presses the third power semiconductor module103against the flow path forming body100.

An insulating member119is disposed between a space in which the first pressing plate117and the second pressing plate118are disposed and a space in which the first AC relay bus bar104, the second AC relay bus bar105, and the third AC relay bus bar106are disposed. The insulating member119has a function of insulating the first pressing plate117and the like from the first AC relay bus bar104and the like, and has a function of transmitting heat generated in the first AC relay bus bar104and the like to the flow path forming body100via the first pressing plate117and the like.

A capacitor116for smoothing DC power is accommodated in a capacitor accommodation portion140formed in the flow path forming body100.

A first DC bus bar115ais connected to the capacitor116. The first DC bus bar115ain the present embodiment is configured with a positive electrode side bus bar, a negative electrode side bus bar, and an insulating layer disposed between the positive electrode side bus bar and the negative electrode side bus bar.

A second DC bus bar115bis connected to the first DC bus bar115a, the first power semiconductor module101, and the like. Similarly to the first DC bus bar115a, the second DC bus bar115bin the present embodiment is configured with a positive electrode side bus bar, a negative electrode side bus bar, and an insulating layer disposed between the positive electrode side bus bar and the negative electrode side bus bar.

A bonding portion115dis configured with a terminal of the first DC bus bar115aand a terminal of the second DC bus bar115b. This bonding portion115, when viewed from a direction of an arrow A, is formed in a width smaller than a width of the first DC bus bar115aand a width of the second DC bus bar115b. Thus, a return current during switching flowing between the first power semiconductor module101, the second power semiconductor module102, and the third power semiconductor module103easily flows to the second DC bus bar115b. In addition, it is possible to inhibit switching noise of the first power semiconductor module101and the like from mixing into a noise reduction capacitor141for reducing noise from a power supply terminal115c.

In addition, the DC bus bar is divided into the two DC bus bars, the first DC bus bar115aand the second DC bus bar115b, and the two DC bus bars are connected to each other via the bonding portion115d, so that it becomes easier to absorb connection tolerance from the capacitor116to the first power semiconductor module101and the like.

When the three power semiconductor modules are arranged in a line, a longitudinal dimension for the three power semiconductor modules is reflected in a size of a housing of the electric power conversion device, so that a size in a predetermined direction of the electric power conversion device increases and arrangement efficiency decreases, which may lead to a size increase of the electric power conversion device as a result.

Therefore, in the present embodiment, as illustrated inFIG. 1andFIG. 2, in a case where a direction along an arrangement direction of the first power semiconductor module101and the second power semiconductor module102is defined as a first column151, the third power semiconductor module103and the AC circuit body150are disposed along a second column152being in a direction parallel to the first column151. In addition, the AC circuit body150is disposed in a space108that is in a direction orthogonal to the first column151and faces the second power semiconductor module102, and is in a direction parallel to the second column152and faces the third power semiconductor module103.

Thus, miniaturization can be achieved of the longitudinal direction and height direction of the electric power conversion device. In addition, wiring distances to the AC circuit body150from the first power semiconductor module101, the second power semiconductor module102, and the third power semiconductor module103tend to be made uniform, and wiring efficiency of AC wiring is improved, and miniaturization of the electric power conversion device is achieved. In addition, the wiring efficiency of the AC wiring is improved, whereby reduction of an amount of heat of the AC wiring can be achieved.

In addition, the flow path forming body100according to the present embodiment forms the first accommodation portion112for accommodating the first power semiconductor module101such that the first power semiconductor module101is sandwiched by flow paths, the second accommodation portion113for accommodating the second power semiconductor module102such that second power semiconductor module102is sandwiched by flow paths, and the third accommodation portion114for accommodating the third power semiconductor module103such that the third power semiconductor module103is sandwiched by flow paths. Thus, the AC circuit body150is disposed in a position surrounded by the first accommodation portion112, the second accommodation portion113, and the third accommodation portion114, so that cooling performance of the AC circuit body150can be significantly improved.

In particular, the current sensor109among components configuring the AC circuit body150is required to be protected preferentially from a heat source, so that the current sensor109is disposed in the position surrounded by the first accommodation portion112, the second accommodation portion113, and the third accommodation portion114. In addition, to increase thermal contact to the flow path forming body100, the AC bus bar107is bent so as to extend along from a predetermined surface to another surface of the flow path forming body100. A portion of the AC bus bar107protrudes from the position surrounded by the first accommodation portion112, the second accommodation portion113, and the third accommodation portion114to form a terminal.

REFERENCE SIGNS LIST