JP2021182820A - Power conversion device - Google Patents

Abstract

To provide a power conversion device in which the cooling performance for a circuit board included in a current sensor unit can be improved.SOLUTION: A power conversion device 1 includes: a power module unit 5 including a plurality of semiconductor modules 2 and a cooler 6 that are formed integrally; and a current sensor unit 4. The current sensor unit 4 is provided adjacent to the cooler 6 and measures the current in a current route connecting a power source and an electric load. The current sensor unit 4 incorporates a current sensor component 43 and a circuit board 42 on which the current sensor component 43 is mounted. The circuit board 42 is provided closer to the cooler 6 inside the current sensor unit 4.SELECTED DRAWING: Figure 3

Description

The disclosure herein relates to a power converter.

Patent Document 1 describes a power conversion device in which a current sensor is arranged next to a laminated body in which a semiconductor module and a cooling tube are laminated, and the current sensor is cooled by the cooling tube.

Japanese Unexamined Patent Publication No. 2019-37049

The heat resistance of the current sensor is low, and it is necessary to lower the heat resistance temperature of the circuit board having parts such as the sensor IC in order to improve the reliability and productability of the power conversion device. Patent Document 1 does not specifically disclose a technique for effectively cooling a circuit board included in a current sensor. The device of Patent Document 1 has room for improvement in this respect.

One of the purposes disclosed in this specification is to provide a power conversion device capable of improving the cooling performance of the circuit board included in the current sensor unit.

The plurality of embodiments disclosed herein employ different technical means to achieve their respective objectives. Further, the scope of claims and the reference numerals in parentheses described in this section are examples showing the correspondence with the specific means described in the embodiment described later as one embodiment, and limit the technical scope. is not it.

One of the disclosed power conversion devices is a power conversion unit (2) that converts the power input from the power supply (300) and supplies a current to the electric load (310), and a cooling fluid flowing inside. A cooler (6; 106) that cools the power conversion unit by means of a current sensor unit (4; 104; 204) that measures the current in the current path that is provided adjacent to the cooler and connects the power supply and the electric load. And a case (11) for accommodating a power conversion unit, a cooler, and a current sensor unit.
The current sensor unit has a built-in current sensor component (43) and a circuit board (42) on which the current sensor component is mounted.
The circuit board is provided at a position closer to the cooler inside the current sensor unit.

According to this power converter, the circuit board is located closer to the cooler inside the current sensor unit. Therefore, among the components included in the current sensor unit, the circuit board can be cooled more positively than the others. By promoting the cooling of the circuit board in the current sensor unit, the heat resistant temperature of the board-mounted component including the current sensor component can be lowered. This makes it possible to improve the reliability of the power conversion device that can handle a large current. According to such a disclosure technique, it is possible to provide a power conversion device capable of improving the cooling performance of the circuit board included in the current sensor unit.

It is a circuit diagram which concerns on the power conversion apparatus of 1st Embodiment. It is the figure which looked at the power conversion device inside a case from the bottom. It is a partial sectional view of the power conversion device inside a case as seen from the side. The second embodiment is a partial cross-sectional view of the power conversion device inside the case as viewed from below. The third embodiment is a partial cross-sectional view of the power conversion device inside the case as viewed from the side. The fourth embodiment is a partial cross-sectional view of the power conversion device inside the case as viewed from the side.

Hereinafter, a plurality of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each form, the same reference numerals may be given to the parts corresponding to the matters described in the preceding forms, and duplicate explanations may be omitted. When only a part of the configuration is described in each form, other forms described above can be applied to the other parts of the configuration. Not only the combinations of the parts that clearly indicate that they can be combined in each embodiment, but also the parts of the embodiments that are not explicitly combined if there is no problem in the combination. It is also possible.

<First Embodiment>
A first embodiment that discloses an example of a vehicle drive system and a power conversion device will be described with reference to FIGS. 1 to 3. The power conversion device can be applied to an in-vehicle power conversion device mounted on a vehicle such as an electric vehicle or a fuel cell vehicle. Vehicles include passenger cars, buses, construction work vehicles, agricultural machinery vehicles and the like. A power conversion device capable of achieving the object specified in the specification can be applied to, for example, an inverter device, a converter device, or the like. This converter device includes a power supply device for AC input / DC output, a power supply device for DC input / DC output, and a power supply device for AC input / AC output. In this embodiment, the device applied to the inverter device as an example of the power conversion device will be described below.

As shown in FIG. 1, the vehicle drive system 10 is mounted on the vehicle and includes a DC power supply 300, a motor generator 310, and a power conversion device 1.

The power conversion device 1 includes at least an inverter circuit 200, a control circuit 210, and a smoothing capacitor 3. As shown in FIG. 1, the inverter circuit 200 includes a plurality of semiconductor modules 2 to form a power conversion unit. The power conversion unit converts the power input from the power source and supplies the current to the electric load. The smoothing capacitor 3 is connected in parallel to the semiconductor module 2. The power conversion unit converts the DC power supplied from the DC power supply 300 into AC power by turning on / off the semiconductor element 20 included in the semiconductor module 2. The DC power supply 300 is, for example, a plurality of secondary batteries. As the secondary battery, a lithium ion secondary battery, a nickel hydrogen secondary battery, an organic radical battery, or the like can be adopted.

The motor generator 310 includes a three-phase AC rotary electric machine, that is, a three-phase AC motor. The motor generator 310 functions as an electric motor that is a traveling drive source of the vehicle. The motor generator 310 functions as a generator during regeneration. The power conversion device 1 performs power conversion between the DC power supply 300 and the motor generator 310.

The power conversion device 1 converts the DC voltage into a three-phase AC voltage and outputs the DC voltage to the motor generator 310 according to the switching control by the control circuit 210. As a result, the vehicle runs by driving the motor generator 310 using the AC power converted from the DC power by the power conversion unit. The power conversion device 1 converts the AC power generated by the power generation of the motor generator 310 into DC power and outputs it to the power line on the high potential side in the circuit. The power conversion device 1 performs bidirectional power conversion between the DC power supply 300 and the motor generator 310.

The motor generator 310 is connected to the axle of an electric vehicle. The rotational energy of the motor generator 310 is transmitted to the traveling wheels of the electric vehicle via the axle. The rotational energy of the traveling wheel is transmitted to the motor generator 310 via the axle. The motor generator 310 is powered by AC power supplied from the power conversion device 1. As a result, propulsive force is applied to the traveling wheels. The motor generator 310 is regenerated by the rotational energy transmitted from the traveling wheels. The AC power generated by this regeneration is converted into DC power by the power conversion device 1. This DC power is supplied to the DC power supply 300. This DC power is also supplied to various electric loads mounted on the vehicle.

In the inverter circuit 200, a smoothing capacitor 3 is connected to the input side of the power conversion unit, and a motor generator 310, which is an example of an electric load, is connected to the output side. The smoothing capacitor 3 mainly smoothes the DC voltage supplied from the DC power supply 300. The smoothing capacitor 3 is connected between the power line on the high potential side and the power line on the low potential side. The power line on the high potential side is connected to the positive electrode of the DC power supply 300. The power line on the low potential side is connected to the negative electrode of the DC power supply 300. The positive electrode of the smoothing capacitor 3 is connected to the power line on the high potential side between the DC power supply 300 and the semiconductor module 2. The negative electrode of the smoothing capacitor 3 is connected to the power line on the low potential side between the DC power supply 300 and the semiconductor module 2.

A P bus bar is provided on the power line on the high potential side. An N bus bar is provided on the power line on the low potential side. The P bus bar and the N bus bar are provided on the power line on the input side with respect to the power conversion unit. At the end of the P bus bar and the end of the N bus bar, a connection terminal 151 provided on the power line on the input side with respect to the power conversion unit is provided. An output terminal provided at the end of a power supply line for supplying power from the DC power supply 300 is connected to the connection terminal 151.

The power conversion device 1 includes a three-phase leg connected in parallel between a P bus bar connected to the positive electrode of the DC power supply 300 and an N bus bar connected to the negative electrode of the DC power supply 300. The leg of each phase includes a plurality of semiconductor elements 20 connected in series between the P bus bar and the N bus bar. It can be said that the inverter circuit 200 includes three upper and lower arm circuits including two arms connected in series. The three upper and lower arm circuits are, for example, U-phase, V-phase, and W-phase from the smoothing capacitor 3 side. The arm on the high potential side of each upper and lower arm circuit can be said to be an upper arm. The arm on the low potential side can also be said to be the lower arm.

Each arm has an IGBT as a switching element and a diode. The IGBT is an insulated gate bipolar transistor which is a kind of transistor. The IGBT and the diode are provided on the semiconductor substrate. The semiconductor chip provided with the IGBT and the diode corresponds to the semiconductor element 20. In the upper arm, the collector is connected to the power line on the high potential side. In the lower arm, the emitter is connected to the power line on the low potential side. The emitter on the upper arm side and the collector on the lower arm side are connected to each other. The anode of the diode is connected to the emitter of the corresponding IGBT and the cathode is connected to the collector of the corresponding IGBT.

The control circuit 210 generates a drive command for operating the IGBT and outputs the drive command to the drive circuit. The control circuit 210 generates a drive command based on, for example, a torque request input from a higher-level ECU and signals detected by various sensors. Various sensors include a current sensor unit 4, a rotation angle sensor, and a voltage sensor. The control circuit 210 outputs, for example, a PWM signal as a drive command. The control circuit 210 includes a microcomputer.

The current sensor unit 4 measures the current in the current path connecting the power supply and the electric load. The current sensor unit 4 includes a current sensor that detects the output current of the arm, that is, the phase current flowing through the winding of each phase. The current sensor outputs an electric signal corresponding to the output current of the arm to the control circuit 210. This electrical signal is a feedback signal. The feedback signal is a signal corresponding to the output current. The rotation angle sensor detects the rotation angle of the rotor of the motor generator 310 and outputs it to the control circuit 210. The voltage sensor detects the voltage across the smoothing capacitor 3 and outputs it to the control circuit 210.

The drive circuit is a driver that supplies a drive voltage to the gate of the IGBT of the corresponding arm based on the drive command of the control circuit 210. The drive circuit drives the corresponding IGBT, that is, on drive and off drive by applying a drive voltage. The power conversion device 1 of this embodiment includes one drive circuit for one arm.

The power conversion device 1 includes an input side bus bar and an output side bus bar. Since such a bus bar forms one of the electric power paths and generates heat, it dissipates heat to surrounding parts. The input side bus bar is a conductive member to which electric power is supplied from the DC power supply 300. The input side bus bars are, for example, P bus bars and N bus bars.

The output-side bus bar includes, for example, a bus bar 44 provided in a power path through which the output current of the arm flows to the motor generator 310. The current sensor detects the output current flowing through the output side bus bar. The output-side bus bar is provided in the power path connecting the connection portion between the upper arm and the lower arm in the U phase and the winding of the motor generator 310. The output-side bus bar is provided in a power path connecting the connection portion between the upper arm and the lower arm in the V phase and the winding of the motor generator 310. The output-side bus bar is provided in the power path connecting the connection portion between the upper arm and the lower arm in the W phase and the winding of the motor generator 310. The output side bus bar includes a U-phase bus bar, a V-phase bus bar, and a W-phase bus bar.

The U-phase bus bar, the V-phase bus bar, and the W-phase bus bar are provided on the power line on the output side with respect to the power conversion unit. At each end of the U-phase bus bar, the V-phase bus bar, and the W-phase bus bar, a connection terminal 141 provided on the power line on the output side with respect to the power conversion unit is provided. An input terminal provided at the end of a power supply line that supplies power to the windings of each phase of the motor generator 310 is connected to the connection terminal 141.

The internal configuration of the power conversion device 1 will be described with reference to FIGS. 2 to 3. The power conversion device 1 includes a case 11 for accommodating a plurality of electric components. The case 11 forms one container. The case 11 houses a capacitor unit, a power module unit 5, a current sensor unit 4, and the like.

The capacitor unit contains at least a smoothing capacitor 3. The capacitor unit contains a resin-sealed smoothing capacitor 3 with the terminals connected to other electrical components exposed. The smoothing capacitor 3 has a built-in resin-sealed capacitor element. The resin to be sealed is made of a thermosetting resin such as an epoxy resin. The sealing resin portion is filled in the gap between the capacitor element and the terminal and the accommodating portion of the smoothing capacitor 3. A part of the terminal and the like of the smoothing capacitor 3 protrudes from the sealing resin portion. The capacitor unit is fixed to the bottom wall of the case 11, for example, by a fixing tool such as a bolt, a screw, or a rivet, or a connecting means such as a welded bond or a brazed bond.

The case 11 is a housing formed by combining a plurality of case members. The case 11 includes, for example, at least a first case member and a second case member. The second case member is a member attached to the first case member so as to cover the internal space of the lower case, which is the first case member. FIG. 2 shows a state in which the member covering the internal space is removed in the case 11 for explaining the configuration of the power conversion device 1. The case 11 is made of a metal material. The case 11 includes, for example, a molded body made of die-cast aluminum. The X direction and the Y direction in the drawing are the horizontal direction and the vertical direction of the power conversion device 1. The Z direction in the drawing is the height direction of the power conversion device 1.

The case 11 includes, for example, a bottom wall and a plurality of side walls erected from the peripheral edge of the bottom wall. The plurality of side walls include a first side wall 11b and a second side wall 11c facing in the X direction, and a third side wall 11d and a fourth side wall 11e facing in the Y direction. The first side wall 11b is adjacent to the third side wall 11d and the fourth side wall 11e. The second side wall 11c is adjacent to the third side wall 11d and the fourth side wall 11e.

The semiconductor module 2 includes a main body portion in which the semiconductor element 20 is built, and a power terminal and a signal terminal protruding from the main body portion. The semiconductor module 2 is also called a power module. The power terminal and the signal terminal project in opposite directions in the semiconductor module 2. The power terminal includes an input terminal to which a DC voltage is applied and an output terminal connected to an output side bus bar on the motor generator 310 side. The input terminal is connected to the terminal of the smoothing capacitor 3 and is electrically connected to the output unit of the DC power supply 300 via the input side bus bar. The signal terminal is connected to a control circuit mounted on the control board. The control circuit constitutes a circuit in which electronic components such as arithmetic elements that control the operation of the semiconductor element 20 are mounted.

The power conversion device 1 includes a cooler 6 that cools the semiconductor module 2 by the endothermic action of the cooling fluid flowing inside. The power module unit 5 includes a plurality of semiconductor modules 2 integrally formed and a cooler 6. The cooler 6 is fixed to the case 11 by, for example, a fixture such as a bolt, a screw, or a rivet, or a connecting means such as a welded bond or a brazed bond.

The cooler 6 includes an inflow pipe 61, an upstream side connecting pipe 62, a plurality of passage pipe portions 63 alternately stacked and installed on the semiconductor module 2, a downstream side connecting pipe 64, an outflow pipe 65, and the like. Each part of the cooler 6 forming a passage is made of a material having good thermal conductivity, and is made of aluminum as an example.

The inflow pipe 61 is a fluid introduction portion in the cooler 6. The downstream portion of the inflow pipe 61 communicates with the passage pipe portion 63 and the upstream connecting pipe 62. The upstream portion of the inflow pipe 61 communicates with the external introduction pipe 71. The external introduction pipe 71 is an external pipe that forms a passage that communicates with the inflow pipe 61, and extends to the outside of the case 11. The external introduction pipe 71 is connected to the power conversion device 1 in order to form a passage for introducing the cooling fluid into the cooler 6. A seal portion is provided between the outer surface of the external introduction pipe 71 and the inner surface of the through hole formed in the case 11. This seal portion is in close contact with the external introduction pipe 71 and the case 11 to prevent water from entering the case 11 from the outside.

The passage pipe portion 63 is a square tubular body that is flat in the stacking direction. The stacking direction corresponds to the X direction in the drawing. The inside of the square cylinder is a rectangular parallelepiped cooling passage. The cooling passage is an internal passage of the passage pipe portion 63. The cooling fluid absorbs heat generated by the semiconductor module 2 when flowing through the cooling passage. The passage pipe portion 63 is in contact with the semiconductor module 2 on both end faces orthogonal to the stacking direction. The semiconductor module 2 is cooled on both end faces by the passage pipe portions 63 adjacent to each other in the stacking direction.

The passage pipe portion 63 is formed with an upstream side through hole portion and a downstream side through hole portion that penetrate in the stacking direction on both end sides in the longitudinal direction. The longitudinal direction of the passage pipe portion 63 corresponds to the Y direction in the drawing. The inner peripheral edge of the upstream side through hole portion located on the upstream side is joined to the upstream side connecting pipe 62. The inner peripheral edge of the downstream side through hole portion located on the downstream side is joined to the downstream side connecting pipe 64.

The upstream side connecting pipe 62 connects the upstream side through hole portions in the passage pipe portions 63 adjacent to each other in the stacking direction. The upstream side connecting pipe 62 provides a communication passage that communicates the internal passage of the passage pipe portion 63 adjacent to each other in the stacking direction and the internal passage of the passage pipe portion 63 on the upstream side of the cooler 6. The downstream side connecting pipe 64 connects the downstream side through hole portions in the passage pipe portions 63 adjacent to each other in the stacking direction. The downstream connecting pipe 64 provides a connecting passage that connects the internal passage of the passage pipe portion 63 adjacent to each other in the stacking direction and the internal passage of the passage pipe portion 63 on the downstream side of the cooler 6.

The outflow pipe 65 is a fluid discharge portion in the cooler 6. The upstream portion of the outflow pipe 65 is joined to the inner peripheral edge of the downstream through hole portion in the passage pipe portion 63 located closest to the outflow pipe 65 and is connected to the passage pipe portion 63. The downstream portion of the outflow pipe 65 is connected to the external discharge pipe 72. The external discharge pipe 72 is an external pipe that forms a passage that communicates with the outflow pipe 65, and extends to the outside of the case 11. The external discharge pipe 72 is connected to the power conversion device 1 in order to form a passage for discharging the cooling fluid from the cooler 6.

The external discharge pipe 72 is inscribed and connected to the outflow pipe 65. Alternatively, the external discharge pipe 72 may be configured to be externally connected to the outflow pipe 65. The external discharge pipe 72 and the outflow pipe 65 are connected by fitting each other. A seal portion is provided between the outer surface of the external discharge pipe 72 and the inner surface of the through hole formed in the case 11. This seal portion is in close contact with the external discharge pipe 72 and the case 11 to prevent water from entering the case 11 from the outside.

The passage pipe portion 63 is in contact with the adjacent semiconductor module 2. The cooling fluid flowing through each passage pipe portion 63 absorbs heat from the adjacent semiconductor module 2 and cools the cooling fluid. The internal passage of each passage pipe portion 63 communicates with the internal passage of the inflow pipe 61 on the upstream side and communicates with the internal passage of the outflow pipe 65 on the downstream side. The cooling fluid flowing inside the cooler 6 is preferably an antifreeze liquid having a large heat capacity such as LLC. Further, a gas such as air may be adopted as the cooling fluid.

The external introduction pipe 71 and the external discharge pipe 72 communicate with a heat dissipation device installed outside the power conversion device 1. The heat radiating device is a device such as a heat exchanger that dissipates heat from the cooling fluid to the outside. The radiator is, for example, a radiator. The cooling fluid is introduced into the passage pipe portion 63 from the heat radiating device via the external introduction pipe 71. The cooling fluid is diverted from the inflow pipe 61 into the plurality of passage pipe portions 63, absorbs heat, and joins in the outflow pipe 65. The cooling fluid flows out of the cooler 6 and returns to the heat radiating device via the inside of the external discharge pipe 72.

The current sensor unit 104 includes a current sensor component 43 and a circuit board 42 on which the current sensor component 43 is mounted.

The current sensor included in the current sensor unit 4 includes a resistance detection type sensor or a magnetic field detection type sensor. Current sensors that perform current detection using resistance detection include shunt resistors and high speed amplifiers. The resistance detection type current sensor component 43 includes an electronic component having a circuit that converts a voltage drop due to a shunt resistance into a current and detects a current value.

The current sensor that performs current detection using magnetic field detection includes a Hall IC that is a current sensor component 43. The Hall IC detects a current value by converting a magnetic field generated around a current into a voltage by the Hall effect and measuring the voltage. The magnetic field detection type current sensor component 43 includes an electronic component having a Hall element and an amplifier circuit, and is mounted on the second surface 42b of the circuit board 42. Further, the magnetic field detection type current sensor component 43 may be a current sensor that non-contactly detects a magnetic field by an MI (Magneto Impedance) element.

The current sensor unit 4 is provided below the cooler 6 adjacent to the cooler 6. The circuit board 42 is provided inside the current sensor unit 4 at a position closer to the cooler 6 and in a posture along the cooler 6. The circuit board 42 is provided below the cooler 6 adjacent to the cooler 6.

The circuit board 42 is provided below the upstream side portion of the passage pipe portion 63 and adjacent to the upstream side portion of the passage pipe portion 63. The upstream side portion of the passage pipe portion 63 is a portion corresponding to the flow path closer to the inflow pipe 61 than the outflow pipe 65 in the flow path of the passage pipe portion 63. The circuit board 42 is provided so as to have a portion that overlaps with the upstream connecting pipe 62 and the passage pipe portion 63 in the height direction. Alternatively, the circuit board 42 is provided so that the current sensor component 43 overlaps the upstream connecting pipe 62 and the passage pipe portion 63 in the height direction. It is preferable that the circuit board 42 is provided so as to be entirely overlapped with the upstream connecting pipe 62 and the passage pipe portion 63 in the height direction.

As shown in FIG. 3, the current sensor unit 4 has a built-in circuit board 42, a bus bar 44, and the like sealed with a resin in a state where terminals and the like connected to other electric components are exposed. The bus bar 44 and the current sensor component 43 are provided at positions where they overlap each other. The sealing resin portion made of a thermosetting resin such as an epoxy resin is filled around the circuit board 42, the current sensor component 43, and the bus bar 44 to cover these portions. The sealing resin portion forms the outer surface of the current sensor unit 4. The sealing resin portion contains a current sensor component 43 and a circuit board 42.

The current sensor unit 4 has a first outer wall surface 4a and a second outer wall surface 4b located on the side opposite to the first outer wall surface 4a. The first outer wall surface 4a and the second outer wall surface 4b are outer surfaces facing each other in the stacking direction in which the circuit board 42 and the bus bar 44 are laminated. The first outer wall surface 4a is an outer surface close to the circuit board 42. The second outer wall surface 4b is an outer surface that is closer to the bus bar 44 than the circuit board 42.

The circuit board 42 has a first surface 42a and a second surface 42b located on the side opposite to the first surface 42a. The first surface 42a and the second surface 42b are a pair of outer surfaces facing each other in the thickness direction of the circuit board 42. The first surface 42a is a surface on which the current sensor component 43 is not mounted, and is located on the cooler 6 side and is provided along the cooler 6. The second surface 42b is a surface on which the current sensor component 43 is mounted, and is located on the side opposite to the cooler 6. The circuit board 42 is provided so that the first surface 42a is located on the upstream side connecting pipe 62 and the passage pipe portion 63 side and is in a posture along the upstream side portion of the upstream side connecting pipe 62 and the passage pipe portion 63.

The current sensor unit 4 is fixed to the case 11 by a fixture such as a bolt, a screw, a rivet, or a coupling means such as a welded coupling or a brazed coupling. The current sensor unit 4 may have a configuration in which the first outer wall surface 4a along the first surface 42a is fixed in contact with the cooler 6.

The operation and effect brought about by the power conversion device 1 of the first embodiment will be described. The power conversion device 1 is provided adjacent to the cooler 6 and includes a current sensor unit 4 that measures a current in a current path connecting a power supply and an electric load. The current sensor unit 4 includes a current sensor component 43 and a circuit board 42 on which the current sensor component 43 is mounted. The circuit board 42 is provided at a position closer to the cooler inside the current sensor unit 4.

According to the power conversion device 1, the circuit board 42 is located closer to the cooler. Therefore, among the components included in the current sensor unit 4, the circuit board 42 can be cooled more positively than the others. Due to the cooling promotion effect of the circuit board 42, the heat resistant temperature of the board-mounted component including the current sensor component 43 can be lowered, the reliability of the mounted component can be improved, and the cost of the mounted component can be reduced. Further, the reliability of the power conversion device 1 that can handle a large current can be improved. The power conversion device 1 contributes to the improvement of the cooling performance of the circuit board 42 included in the current sensor unit 4.

The current sensor unit 4 incorporates at least a part of the output side bus bar. The output-side bus bar is provided inside the current sensor unit 4 at a position separated from the circuit board 42 with respect to the cooler 6. According to this configuration, since the output side bus bar is separated from the cooler 6 from the circuit board 42, it is possible to suppress the reduction of the cooling effect of the circuit board 42 due to the heat dissipation of the bus bar.

The outer surface of the current sensor unit 4 is formed by a resin mold portion containing the current sensor component 43, the circuit board 42, and the output side bus bar. According to this power conversion device 1, it is possible to improve the cooling performance of the circuit board 42 and the board-mounted components while improving the insulation between the electric components.

The circuit board 42 includes a first surface 42a on which the current sensor component 43 is not mounted, and a second surface 42b located on the opposite side of the first surface 42a and on which the current sensor component 43 is mounted. The first surface 42a faces the cooler 6 side. The second surface 42b faces the side opposite to the cooler 6. According to this configuration, since the current sensor component 43 is not mounted on the first surface 42a, the first surface 42a can be arranged so as to be close to the cooler 6. Thereby, the effect of cooling the circuit board 42 by the cooler 6 can be further enhanced.

The circuit board 42 is provided at a position closer to the fluid introduction portion located on the upstream side of the cooler 6 than the fluid discharge portion located on the downstream side of the cooler 6. According to this configuration, the circuit board 42 can be cooled by the fluid before the heat is absorbed from the power conversion unit. Thereby, it is possible to provide the power conversion device 1 having further improved the cooling performance of the circuit board 42.

Further, the circuit board 42 is provided below the fluid introduction section and adjacent to the fluid introduction section. According to this configuration, the heat dissipation of the circuit board 42, which tends to rise, can be effectively absorbed by the fluid introduction portion adjacent above the circuit board 42. Thereby, it is possible to provide the power conversion device 1 capable of more efficiently cooling the circuit board 42 by the fluid before the heat is absorbed from the power conversion unit.

The circuit board 42 is provided adjacent to the upstream side portion of the passage pipe portion 63 below the upstream side portion of the passage pipe portion 63 into which the cooling fluid flows from the inflow pipe 61. According to this configuration, the circuit board 42 can be cooled by the fluid flowing through the upstream side portion of the passage pipe portion 63 whose heat absorption amount is not so large. Further, it is possible to provide a power conversion device 1 capable of effectively absorbing heat from the circuit board 42, which tends to rise, by the upstream side portion of the passage tube portion 63 adjacent above the circuit board 42.

<Second Embodiment>
The power conversion device 101 of the second embodiment will be described with reference to FIG. The power conversion device 101 of the second embodiment has a different arrangement of the current sensor unit 104 from the first embodiment. The configurations, actions, and effects that are not particularly described in the second embodiment are the same as those in the first embodiment, and the differences from the first embodiment will be described below.

As shown in FIG. 4, the current sensor unit 104 is provided adjacent to the downstream side portion of the cooler 6. The downstream side portion of the cooler 6 is a portion corresponding to the flow path closer to the outflow pipe 65 than the inflow pipe 61 in the flow path of the cooler 6. It is adjacent to the current sensor unit 104, for example, the downstream connecting pipe 64 located on the upstream side of the outflow pipe 65. At least a part of the current sensor unit 104 is at the same height as the downstream connecting pipe 64 and the passage pipe portion 63. The current sensor unit 104 has a portion that horizontally overlaps with the downstream connecting pipe 64 and the passage pipe portion 63.

The current sensor unit 104 includes a current sensor component 43 and a circuit board 142 on which the current sensor component 43 is mounted. The circuit board 142 is provided adjacent to the side portion of the cooler 6.

The circuit board 142 is provided adjacent to the downstream side portion of the passage pipe portion 63 on the side of the downstream side portion of the passage pipe portion 63 where the cooling fluid flows out toward the outflow pipe 65. The downstream side portion of the passage pipe portion 63 is a portion corresponding to the flow path closer to the outflow pipe 65 than the inflow pipe 61 in the flow path of the passage pipe portion 63. At least a part of the circuit board 142 is at the same height as the downstream connecting pipe 64 and the passage pipe portion 63. The circuit board 142 has a portion that horizontally overlaps with the downstream connecting pipe 64 and the passage pipe portion 63.

The current sensor unit 104 has a built-in circuit board 142 or the like sealed with a resin in a state where terminals or the like connected to other electric components are exposed. The sealing resin portion made of a thermosetting resin such as an epoxy resin is filled around the circuit board 142, the current sensor component 43, and the bus bar 44 to cover these portions. The sealing resin portion contains a current sensor component 43 and a circuit board 142. The sealing resin portion forms the outer surface of the current sensor unit 104. The current sensor unit 104 has a first outer wall surface 104a and a second outer wall surface 104b located on the side opposite to the first outer wall surface 104a. The first outer wall surface 104a and the second outer wall surface 104b are outer surfaces facing each other in the stacking direction of the circuit board 142 and the bus bar 44. The first outer wall surface 104a is an outer surface close to the circuit board 142. The second outer wall surface 104b is an outer surface that is closer to the bus bar 44 than the circuit board 142.

The circuit board 142 has a first surface 142a and a second surface 142b located on the side opposite to the first surface 142a. The first surface 142a and the second surface 142b are in a relationship of facing each other in the thickness direction of the circuit board 142. The first surface 142a is a surface on which the current sensor component 43 is not mounted, is located on the cooler 6 side and is along the cooler 6. The second surface 142b is a surface on which the current sensor component 43 is mounted, and is located on the side opposite to the cooler 6. The circuit board 142 is provided with the first surface 142a located on the upstream side connecting pipe 62 and the passage pipe portion 63 side and along the upstream side portion of the upstream side connecting pipe 62 and the passage pipe portion 63.

The current sensor unit 104 is fixed to the case 11 by a fixing tool such as a bolt, a screw, a rivet, or a coupling means such as a welding coupling or a brazing coupling. The current sensor unit 104 is fixed in a state where the first outer wall surface 104a along the first surface 142a is in contact with the cooler 6.

According to the power converter 101, the circuit board 142 is adjacent to the cooler 6 on the side of the cooler 6. According to this, the cooling performance of the circuit board 142 can be improved, and the physique of the device in the horizontal direction or the vertical direction can be suppressed.

<Third Embodiment>
The power conversion device 201 of the third embodiment will be described with reference to FIG. The power conversion device 201 of the third embodiment has a different configuration of the current sensor unit 204 from the first embodiment. The configurations, actions, and effects that are not particularly described in the third embodiment are the same as those in the first embodiment, and the differences from the first embodiment will be described below.

As shown in FIG. 5, the current sensor unit 204 has a circuit board 42, a bus bar 44, and the like built in the outer case 45. The outer case 45 is a housing made of metal or resin. The outer case 45 forms the outer surface of the current sensor unit 204.

The current sensor unit 204 has a first outer wall surface 45a and a second outer wall surface 45b located on the side opposite to the first outer wall surface 45a. The first outer wall surface 45a and the second outer wall surface 45b are outer surfaces facing each other in the stacking direction in which the circuit board 42 and the bus bar 44 are laminated. The first outer wall surface 45a is an outer surface close to the circuit board 42. The second outer wall surface 45b is an outer surface that is closer to the bus bar 44 than the circuit board 42. The first outer wall surface 45a is located on the upstream side connecting pipe 62 and the passage pipe portion 63 side, and is provided in a posture along the upstream side portion of the upstream side connecting pipe 62 and the passage pipe portion 63.

The outer case 45 of the current sensor unit 204 is fixed to the case 11 by a fixing tool such as a bolt, a screw, or a rivet, or a connecting means such as a welded bond or a brazed bond. The current sensor unit 204 may be fixed so that the first outer wall surface 45a along the first surface 42a is in contact with the cooler 6.

<Fourth Embodiment>
The power conversion device 301 of the fourth embodiment will be described with reference to FIG. The power conversion device 301 of the fourth embodiment has a different configuration of the current sensor unit 204 from the first embodiment. The configurations, actions, and effects that are not particularly described in the fourth embodiment are the same as those in the first embodiment, and the differences from the first embodiment will be described below.

As shown in FIG. 5, the power module unit 5 included in the power conversion device 301 includes a plurality of semiconductor modules 2 and a cooler 106 for cooling the semiconductor modules 2. The cooler 106 has a first outer wall surface 106a that is in contact with or is close to the first outer wall surface 4a of the current sensor unit 4. The cooler 106 has a second outer wall surface 106b that contacts one side of the semiconductor module. The first outer wall surface 106a and the second outer wall surface 106b are outer surfaces facing the semiconductor module 2, the cooler 106, and the current sensor unit 4 in the stacking direction. The cooler 106 includes a cooling passage 106p through which a cooling fluid flows between the first outer wall surface 106a and the second outer wall surface 106b.

<Other embodiments>
The disclosure of this specification is not limited to the exemplified embodiments. Disclosures include exemplary embodiments and modifications by those skilled in the art based on them. For example, the disclosure is not limited to the combination of parts and elements shown in the embodiment, and can be variously modified and carried out. Disclosure can be carried out in various combinations. Disclosures can have additional parts that can be added to the embodiments. The disclosure includes the parts and elements of the embodiment omitted. Disclosures include replacements or combinations of parts, elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. The technical scope disclosed is indicated by the description of the scope of claims and should be understood to include all modifications within the meaning and scope equivalent to the description of the scope of claims.

The power conversion device that can achieve the object disclosed in the specification may be configured without the control circuit 210. For example, a higher-level ECU or the like may be provided with the same function as the control circuit 210. Further, in the above-described embodiment, an example in which a drive circuit is provided for each arm is shown, but the present invention is not limited to this configuration. For example, one drive circuit may be provided for one upper and lower arm.

The power conversion device that can achieve the object disclosed in the specification may be configured to further include a converter as a power conversion circuit. For example, the converter is provided between the DC power supply 300 and the smoothing capacitor 3. The converter can be configured with a reactor and upper and lower arm circuits. Further, the power conversion device may be configured to include a filter capacitor that removes power supply noise from the DC power supply 300. For example, the filter capacitor is provided between the DC power supply 300 and the converter.

The current sensor unit 104 of the second embodiment may have a configuration in which the first outer wall surface 104a is adjacent to the upstream side portion on the side of the upstream side portion of the cooler 6. In this case, the circuit board 142 is provided adjacent to the upstream side portion of the passage pipe portion 63 on the side of the upstream side portion of the passage pipe portion 63 into which the cooling fluid flows from the inflow pipe 61. At least a part of the circuit board 142 is at the same height as the upstream connecting pipe 62 and the passage pipe portion 63. The circuit board 142 has a portion that horizontally overlaps with the upstream connecting pipe 62 and the passage pipe portion 63.

2 ... Semiconductor module (power conversion unit), 4,104,204 ... Current sensor unit 6,106 ... Cooler, 11 ... Case, 42, 142 ... Circuit board 43 ... Current sensor parts, 44 ... Bus bar (output side bus bar) , 300 ... DC power supply (power supply)
310 ... Motor generator (three-phase AC motor, electric load)

Claims (8)

A power conversion unit (2) that converts the power input from the power supply (300) and supplies the current to the electric load (310).
A cooler (6; 106) that cools the power conversion unit with a cooling fluid flowing inside, and
A current sensor unit (4; 104; 204) provided adjacent to the cooler and measuring a current in a current path connecting the power supply and the electric load, and a current sensor unit (4; 104; 204).
A case (11) accommodating the power conversion unit, the cooler, and the current sensor unit, and
Equipped with
The current sensor unit has a built-in current sensor component (43) and a circuit board (42) on which the current sensor component is mounted.
The circuit board is a power conversion device provided at a position closer to the cooler inside the current sensor unit. An output-side bus bar (44) provided as a power supply line for supplying power to the windings of each phase of the three-phase AC motor (310), which is an electric load, is provided.
The current sensor unit incorporates at least a part of the output side bus bar.
The power conversion device according to claim 1, wherein the output-side bus bar is provided inside the current sensor unit at a position separated from the circuit board with respect to the cooler. The power conversion device according to claim 2, wherein the current sensor unit has an outer surface formed by a resin mold portion incorporating the current sensor component, the circuit board, and the output side bus bar. The circuit board is located on the opposite side of the first surface (42a; 142a) on which the current sensor component is not mounted and the second surface (42b;) on which the current sensor component is mounted. 142b) and
The power conversion device according to any one of claims 1 to 3, wherein the first surface faces the cooler side and the second surface faces the side opposite to the cooler. Any one of claims 1 to 4, wherein the circuit board is provided at a position closer to a fluid introduction portion located on the upstream side of the cooler than a fluid discharge portion located on the downstream side of the cooler. The power conversion device according to one item. The power conversion device according to claim 5, wherein the circuit board is provided below the fluid introduction section and adjacent to the fluid introduction section. The cooler is provided in a plurality of passage pipe portions (63) alternately stacked and installed with the power conversion portion, an inflow pipe (61) communicating with the passage pipe portion on the upstream side, and the passage pipe portion. On the other hand, it is equipped with an outflow pipe (65) that communicates on the downstream side.
The circuit board is provided below the upstream side portion of the passage pipe portion where the cooling fluid flows from the inflow pipe, adjacent to the upstream side portion of the passage pipe portion. The power conversion device according to any one of claims 6. The power conversion device according to claim 1, wherein the circuit board is provided adjacent to the cooler on the side of the cooler.

Images