JPWO2018211580A1 - Power converter - Google Patents

Abstract

To reduce the size of the power converter. The inverter device (3A) includes a power module (4), a smoothing capacitor (5), and a discharge resistor (6A). The power module (4) includes a switching element (4a) constituting each of the U, V, and W phase arm circuits (40U, 40V, 40W). The smoothing capacitor (5) suppresses voltage fluctuation. The resistor body (6Aa) serving as a discharge resistor is electrically connected to the smoothing capacitor (5), and discharges the charge of the smoothing capacitor (5) when the operation is stopped. In this inverter device (3A), the power module (4) has a high-current terminal (front high-current terminal 43). The resistor main body (6Aa) is disposed at the high-current terminal (front high-current terminal 43).

Description

  The present disclosure relates to a power conversion device.

  2. Description of the Related Art Conventionally, a semiconductor module, a smoothing capacitor, and a discharge resistor are attached to an inverter device as a power conversion device (for example, see Patent Document 1).

JP 2010-124523 A

  However, the conventional inverter device requires an area for providing a discharge resistor in addition to an area for providing a semiconductor module and a smoothing capacitor. Therefore, there is a problem that the size of the inverter device is increased in at least one direction in plan view of the inverter device.

  The present disclosure has been made in view of the above problem, and has as its object to reduce the size of a power conversion device.

In order to achieve the above object, a power conversion device according to the present disclosure includes a power conversion module, a smoothing capacitor, and a discharge resistor.
The power conversion module includes a switching element forming a power conversion circuit.
The smoothing capacitor suppresses voltage fluctuation.
The discharge resistor is electrically connected to the smoothing capacitor, and discharges the charge of the smoothing capacitor when operation is stopped.
In addition, the power conversion module has a high-power terminal portion. The discharge resistor is arranged at a high-current terminal of the power conversion module.

  In this way, the size of the power converter can be reduced by connecting the discharge resistor to the high-current terminal.

FIG. 3 is a circuit diagram of a drive system of an electric vehicle to which the inverter devices according to the first to third embodiments are applied. FIG. 2 is a plan view of the inverter device according to the first embodiment. FIG. 2 is a schematic sectional view of the inverter device according to the first embodiment. FIG. 4 is an explanatory diagram illustrating fastening of the discharge resistance unit in the first embodiment. It is a top view of the inverter apparatus in a conventional example. FIG. 8 is a diagram illustrating a relationship between a terminal temperature and a discharge resistance temperature in an operation scene of a DC power supply according to the first to third embodiments. FIG. 9 is an explanatory diagram illustrating fastening of a discharge resistance unit in Embodiment 2. FIG. 8 is a schematic end view when the discharge resistance unit according to the second embodiment is fastened, and is a schematic end view taken along line II-II of FIG. 7. FIG. 13 is an explanatory diagram illustrating fastening of a discharge resistance unit in Embodiment 3. FIG. 10 is a schematic end view when the discharge resistance unit according to the third embodiment is fastened, and is a schematic end view taken along line III-III in FIG. 9.

  Hereinafter, the best mode for realizing the power converter of the present invention will be described based on Embodiments 1 to 3 shown in the drawings.

First, the configuration will be described.
The power conversion device according to the first embodiment is applied to an inverter device (an example of a power conversion device) of a motor generator mounted on an electric vehicle (an example of an electric vehicle) as a driving source for traveling or the like. Hereinafter, the configuration of the first embodiment will be described by dividing into “the circuit configuration of the drive system”, “the configuration of the inverter device”, and “the detailed configuration of the discharge resistance unit”.

[Circuit configuration of drive system]
FIG. 1 is a circuit diagram of a drive system for an electric vehicle to which the inverter device according to the first embodiment is applied. Hereinafter, a circuit configuration of the drive system according to the first embodiment will be described with reference to FIG.

  The drive system 1 includes a DC power supply 2 (high-power battery), an inverter device 3A, and a motor generator 11.

  The DC power supply 2 is a high-voltage battery for driving an electric vehicle, and includes a battery (not shown) in which a plurality of secondary batteries are connected in series or in parallel. DC power supply 2 outputs a DC voltage between P bus bar 12 (plus, positive) and N bus bar 13 (minus, negative).

  Inverter device 3A converts DC power supplied from DC power supply 2 to AC power, and outputs the converted power to motor generator 11. Inverter device 3A converts AC power generated by motor generator 11 into DC power, and outputs the converted power to DC power supply 2. The inverter device 3A includes a power module 4 (power conversion module), a smoothing capacitor 5, a discharge resistance unit 6A, and a three-phase line 7.

  The power module 4 has a plurality of switch groups each including a plurality of modularized switching elements 4a such as an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET). Then, based on a control signal from a controller (not shown), the switching element is turned on and off to convert DC power from DC power supply 2 and output AC power to motor generator 11 through three-phase line 7. The power module 4 converts the regenerative power (AC power) of the motor generator 11 into DC power by the regenerative operation of the motor generator 11 and supplies the DC power to the DC power supply 2. Will be charged by.

  A motor generator 11 is electrically connected to the AC side of the power module 4 through a three-phase line 7. A smoothing capacitor 5 is electrically connected to the DC side of the power module 4. The power module 4 has a plurality of switching elements 4a and a plurality of diodes 4b. A transistor such as an IGBT or a MOSFET is used as the switching element 4a. The diode 4b is a reflux diode. The switching element 4a and the diode 4b are connected in parallel while reversing the current conduction direction. A circuit in which a plurality of parallel circuits of the switching element 4a and the diode 4b are connected in series becomes the U, V, and W phase arm circuits 40U, 40V, 40W (power conversion circuits). The plurality of arm circuits 40U, 40V, 40W are connected in parallel between the P bus bar 12 and the N bus bar 13.

  The smoothing capacitor 5 smoothes voltage fluctuations. The smoothing capacitor 5 stores electricity when the voltage is high, and discharges when the voltage is low to suppress the fluctuation of the voltage. That is, the smoothing capacitor 5 smoothes the input / output voltage on the DC side of each of the U, V, and W phase arm circuits 40U, 40V, and 40W. Smoothing capacitor 5 is connected between P bus bar 12 and N bus bar 13.

  The discharge resistance unit 6A discharges the electric charge stored in the smoothing capacitor 5 when the operation of the inverter device 3A is stopped. The discharge resistance unit 6A is connected between the P bus bar 12 and the N bus bar 13.

  The three-phase line 7 includes U, V, and W-phase bus bars 7U, 7V, and 7W having conductivity. The bus bars 7U, 7V, 7W of the U, V, W phases electrically connect between the terminals of the arm circuits 40U, 40V, 40W of the U, V, W phases and the terminals of each phase of the motor generator 11. Connecting.

  The motor generator 11 is, for example, a synchronous motor in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. The motor generator 11 is connected to the axle of the vehicle, and operates by an electromagnetic action by the electric power supplied from the inverter device 3A to generate a rotational force.

[Configuration of inverter device]
FIG. 2 is a plan view of the inverter device according to the first embodiment, and FIG. 3 is a schematic cross-sectional view of the inverter device according to the first embodiment. In FIG. 3, illustration of the drive substrate and the like is omitted. Hereinafter, the configuration of the inverter device 3A according to the first embodiment will be described with reference to FIGS.

  The inverter device 3A has a case 30 for housing the power module 4 and the like. FIG. 2 shows only the bottom surface of the case 30. Case 30 is arranged, for example, at a position above motor generator 11. Inside the case 30, a power module 4, a smoothing capacitor 5, a discharge resistor unit 6A, a P bus bar 12, an N bus bar 13, a three-phase line 7, a cooler 8, a drive board 9 (circuit Substrate). The case 30 is made of, for example, metal.

  The power module 4 is obtained by integrating a switching element and the like by resin molding. As shown in FIG. 2, the power module 4 is disposed ahead of the smoothing capacitor 5 and is fixed to the case 30 by PM fixing bolts 101. A cooler 8 is provided below the power module 4 as shown in FIG. The cooler 8 has a coolant channel 8a. A coolant (for example, cooling water) flows through the coolant channel 8a. The power module 4 is cooled by heat exchange between the refrigerant and heat generated when the power module 4 is driven. That is, the cooling method of the power module 4 is a direct cooling type (direct water cooling structure). The cooling method of the power module 4 may be an indirect cooling type (indirect water cooling structure) or a cooler integrated type. Here, the power module 4 has a PM main body 41 at the center in the front-rear direction, and has a PM strong electric terminal 42 at the front and rear. The front side of the PM high-voltage terminal 42 in the front-rear direction is referred to as a front high-voltage terminal 43, and the rear side is referred to as a rear high-voltage terminal 44.

  The drive board 9 is disposed above the PM main body 41 (in a direction perpendicular to the plane of FIG. 2). The drive substrate 9 is one in which electric circuit wiring is formed on the surface or inside of an integrated plate made of an insulator. The drive substrate 9 is, for example, a multilayer substrate in which a plurality of substrates are stacked. The drive board 9 is arranged with a space from the power module 4.

  A U-phase terminal 4U, a V-phase terminal 4V, and a W-phase terminal 4W are arranged in the front high-current terminal 43 in order from the left. That is, the front high-current terminal section 43 is an area where terminals are provided. The terminals 4U, 4V, and 4W of the U, V, and W phases are connected to the power module 4. One end of each of the U, V, W phase terminals 4U, 4V, 4W and one end of each of the U, V, W phase bus bars 7U, 7V, 7W is fastened by bolts 102. At this time, the U-phase terminal 4U, one end of the U-phase bus bar 7U and the second bracket 6Ae of the discharge resistance unit 6A are fastened together by the bolt 102. Also, the V-phase terminal 4V, one end of the V-phase bus bar 7V, and the first bracket 6Ad of the discharge resistance unit 6A are fastened together by bolts 102. Thus, the discharge resistance unit 6A is disposed in the front high-current terminal section 43. The other end of each of the U, V, and W phase busbars 7U, 7V, and 7W is connected to each of the U, V, and W phases of the stator coil of motor generator 11 (not shown). Thereby, power module 4 and motor generator 11 are connected.

  PN terminals 4P, 4N corresponding to the U, V, and W phases, respectively, are arranged in the rear high-voltage terminal section 44 in order from the left. That is, the rear high-voltage terminal section 44 is an area where terminals are provided. These PN terminals 4P and 4N are connected to the power module 4.

  The smoothing capacitor 5 is disposed behind the power module 4 as shown in FIG. The smoothing capacitor 5 is provided between the power module 4 and the DC power supply 2 (not shown). The smoothing capacitor 5 has a DC P bus bar 121, a DC N bus bar 131, a power P bus bar 122, and a power N bus bar 132. DC P bus bar 121 and DC N bus bar 131 are fastened to PN terminals 4P, 4N corresponding to the U, V, and W phases by bolts 102. Thereby, the power module 4 and the smoothing capacitor 5 are connected. At this time, the direct current P bus bar 121, the U-phase P terminal 4P, and the first harness 6Ab extending from the discharge resistance unit 6A are fastened together by the bolt 102. In addition, the DC N bus bar 131, the U-phase N terminal 4N, and the second harness 6Ac extending from the discharge resistance unit 6A are fastened together by bolts 102. The power supply P bus bar 122 and the power supply N bus bar 132 are connected to the DC power supply 2. Note that the DC P bus bar 121 and the power supply P bus bar 122 constitute the P bus bar 12, and the DC N bus bar 131 and the power supply N bus bar 132 constitute the N bus bar 13.

[Detailed configuration of discharge resistance unit]
FIG. 4 is an explanatory diagram illustrating fastening of the discharge resistance unit in the first embodiment. In FIG. 4, illustration of a smoothing capacitor and the like is omitted. Hereinafter, a detailed configuration of the discharge resistance unit 6A in the first embodiment will be described with reference to FIG.

  The discharge resistance unit 6A includes a resistance main body 6Aa (discharge resistance), a first harness 6Ab, a second harness 6Ac, a first bracket 6Ad, and a second bracket 6Ae. A resistor (not shown) (for example, a wound resistance element) is built in the resistor main body 6Aa. The periphery of the resistor is molded with a sealing material (for example, cement). The first harness 6Ab and the second harness 6Ac are electrically connected to terminals of a resistor built in the resistor main body 6Aa. The first bracket 6Ad and the second bracket 6Ae hold the resistance main body 6Aa. The first bracket 6Ad and the second bracket 6Ae are formed of resin. Each of the first bracket 6Ad and the second bracket 6Ae has an insertion hole 6Af through which the bolt 102 is inserted.

  The first bracket 6Ad and the second bracket 6Ae are fastened (connected) to the front high-current terminal 43. That is, the bolt 102 is inserted into the insertion hole 6Af of the first bracket 6Ad, and the first bracket 6Ad is fastened together with one end of the V-phase terminal 4V and one end of the V-phase bus bar 7V by the bolt 102. The bolt 102 is inserted into the insertion hole 6Af of the second bracket 6Ae, and the second bracket 6Ae is fastened together with one end of the U-phase terminal 4U and one end of the U-phase bus bar 7U by the bolt 102. For this reason, the resistor built in the resistor main body 6Aa by the first bracket 6Ad and the second bracket 6Ae made of resin allows the power module 4, the U, V, and W-phase terminals 4U, 4V, 4W, U, It is not electrically connected to the bus bars 7U, 7V, 7W of the V and W phases.

  The first harness 6Ab and the second harness 6Ac are connected to the smoothing capacitor 5 as described above. That is, the first harness 6Ab is fastened together with the DC P bus bar 121 and the U-phase P terminal 4P by the bolt 102. The second harness 6Ac is fastened together with the DC N bus bar 131 and the U-phase N terminal 4N with the bolt 102. For this reason, the resistor incorporated in the resistor main body 6Aa is electrically connected to the smoothing capacitor 5 through the terminal of the resistor (not shown) and the first harness 6Ab and the second harness 6Ac. Thereby, the resistor discharges the electric charge accumulated in the smoothing capacitor 5 when the operation of the inverter device 3A is stopped. That is, the resistor consumes the electric charge stored in the smoothing capacitor 5 by heat. Therefore, the resistor main body 6Aa generates heat.

Next, the operation will be described.
The operation of the inverter device 3A according to the first embodiment will be described by dividing the operation into a “problem generating operation”, a “relation operation between a terminal portion temperature and a discharge resistance temperature”, and a “characteristic operation of the inverter device”.

[Problem generating action]
FIG. 5 is a plan view of a conventional inverter device. Hereinafter, the problem generating operation will be described with reference to FIG.

  Conventionally, a semiconductor module, a smoothing capacitor, and a discharge resistor have been attached to an inverter device as a power conversion device. That is, in the conventional inverter device, an area for providing a discharge resistor is required in addition to an area for providing a semiconductor module and a smoothing capacitor. Therefore, there is a problem that the size of the case is increased in at least one direction in plan view of the inverter device. For example, in FIG. 5, the size (size Y1) of the inverter device is enlarged in the Y direction in plan view of the inverter device. In addition, in FIG. 5, even if the arrangement of the discharge resistors is changed, the size of the inverter device is enlarged in the X direction or both the X direction and the Y direction in plan view of the inverter device. Actually, it is necessary to secure a tool space for mounting the discharge resistor, and thus a space is required in the Z direction (a direction orthogonal to the plane of FIG. 5).

  On the other hand, if the discharge resistor is mounted as a chip component on a circuit board separate from the semiconductor module and the smoothing capacitor, the size of the inverter device does not need to be increased. However, if the chip resistor is used as the discharge resistor, the discharge resistor becomes smaller, and the temperature of the chip component itself becomes higher than the conventional discharge resistor. In addition, when a plurality of chip components are used as a measure against the high temperature, the chip components occupy the board area. In addition, there is a problem that the heat of the chip component may harm other semiconductor components of the inverter device, an electrolytic capacitor weak to heat, a substrate element having low heat resistance, and the like.

  By taking such measures, another problem occurs even if the size of the inverter device can be reduced. Therefore, it is necessary to reduce the size of the inverter device by another configuration.

[Relationship between terminal temperature and discharge resistance temperature]
FIG. 6 shows the relationship between the terminal temperature and the discharge resistance temperature in the operation scene of the DC power supply according to the first embodiment. Hereinafter, the relationship between the terminal temperature and the discharge resistance temperature will be described with reference to FIG.

  When the same DC power is output from the DC power supply 2, the magnitudes of the voltage and the current differ depending on the remaining amount of the DC power supply 2.

  For example, when the remaining amount of the DC power supply 2 is small (for example, when the remaining amount is less than half of the maximum amount), DC power is output with a large current and a low voltage. At this time, the temperatures of the PN terminals 4P, 4N and the U, V, W phase terminals 4U, 4V, 4W rise, and the terminal temperature of the PM strong electric terminal 42 rises. On the other hand, the temperature of the discharge resistor 6A hardly rises, and the discharge resistance temperature of the resistor main body 6Aa as a discharge resistor becomes lower than the terminal temperature of the PM strong electric terminal 42.

  Further, for example, when the remaining amount of the DC power supply 2 is large (for example, when the remaining amount is almost the maximum amount), DC power is output with a low current and a high voltage. At this time, the temperature of the resistor main body 6Aa rises, and the discharge resistance temperature rises. On the other hand, the temperatures of the PN terminals 4P, 4N and the terminals 4U, 4V, 4W of the U, V, W phases hardly rise, and the terminal temperature of the PM strong electric terminal 42 becomes lower than the discharge resistance temperature.

  As described above, when the same DC power is output, the terminal temperature of the PM high-voltage terminal 42 becomes higher than the discharge resistance 6 A temperature when the current is large, and the terminal temperature of the PM high-voltage terminal 42 when the voltage is high. The discharge resistance temperature becomes higher than that. For this reason, when the same DC power is output, since the heat generation scene is different between the PM strong electric terminal 42 and the resistor main body 6Aa as a discharge resistor, the mutual heat resistance reserve can be utilized. Thus, the cooling function of the inverter device 3A does not need to be enhanced using the cooler 8 or the like. Such a temperature relationship is the reason why the resistor main body 6Aa serving as a discharge resistor is disposed in the PM high-current terminal 42 (the front high-current terminal 43).

[Features of inverter device]
As described above, since an area for providing a discharge resistor is required, the size of the inverter device is increased in at least one direction in plan view of the inverter device. On the other hand, in the first embodiment, the resistor main body 6Aa is arranged at the front high-current terminal 43 of the power module 4. That is, the resistor main body 6Aa is disposed in an empty space above the front high-current terminal 43. Therefore, the size of the inverter device 3A is reduced because the resistor main body 6Aa is not provided in the vertical and horizontal directions in plan view of the inverter device 3A. As a result, the size of the inverter device 3A can be reduced. In addition, the resistor main body 6Aa is separated from a substrate element having low heat resistance by the first bracket 6Ad and the second bracket 6Ae. Therefore, the components around the discharge resistance unit 6A are less likely to be harmed by the heat of the resistance main body 6Aa.

Next, effects will be described.
In the inverter device 3A according to the first embodiment, the following effects can be obtained.

(1) The power conversion device (inverter device 3A) includes a power conversion module (power module 4), a smoothing capacitor 5, and a discharge resistor (resistance main body 6Aa).
The power conversion module (power module 4) includes a switching element 4a that forms a power conversion circuit (U, V, and W phase arm circuits 40U, 40V, and 40W).
The smoothing capacitor 5 suppresses voltage fluctuation.
The discharge resistor (resistance main body 6Aa) is electrically connected to the smoothing capacitor, and discharges the charge of the smoothing capacitor 5 when the operation is stopped.
The power conversion module (power module 4) has a high-current terminal (front high-current terminal 43).
The discharge resistor (the resistor main body 6Aa) is arranged at the high-current terminal (front high-current terminal 43).
Therefore, it is possible to provide a power conversion device (the inverter device 3A) that reduces the size of the power conversion device (the inverter device 3A).

  The second embodiment is an example in which a bracket having conductivity is formed and the bracket is fastened to a PN terminal together.

First, the configuration will be described.
As in the first embodiment, the power converter in the second embodiment is applied to an inverter device (an example of a power converter) of a motor generator mounted on an electric vehicle (an example of an electric vehicle) as a driving source for traveling or the like. It is. Hereinafter, the configuration of the second embodiment will be described by dividing into “the configuration of the inverter device” and “the detailed configuration of the discharge resistance unit”. Note that the “circuit configuration of the drive system” of the second embodiment is the same as that of the first embodiment, and thus illustration and description are omitted.

[Configuration of inverter device]
FIG. 7 is an explanatory diagram illustrating fastening of the discharge resistance unit in the second embodiment. In FIG. 7, illustration of a smoothing capacitor and the like is omitted. Hereinafter, the configuration of the inverter device 3B according to the second embodiment will be described with reference to FIG.

  The discharge resistance unit 6B is housed inside the case 30 of the inverter device 3B.

  One end of each of the U, V, and W phase terminals 4U, 4V, and 4W and one end of each of the U, V, and W phase bus bars 7U, 7V, and 7W are fastened by bolts 102. At this time, the first bracket 6Bd (first holding portion) and the second bracket 6Be (second holding portion) of the discharge resistance unit 6B are not fastened together by the bolt 102.

  DC P bus bar 121 and DC N bus bar 131 are fastened to PN terminals 4P, 4N corresponding to the U, V, and W phases by bolts 102. Thereby, the power module 4 and the smoothing capacitor 5 are connected. At this time, the DC P bus bar 121, the W-phase P terminal 4P (positive positive terminal), and the first bracket 6Bd of the discharge resistance unit 6B are fastened together by the bolt 102. Further, the DC N bus bar 131, the V-phase N terminal 4N (negative pole strong terminal), and the second bracket 6Be of the discharge resistance unit 6B are fastened together by the bolt 102. As a result, the discharge resistance unit 6B is disposed at the rear high-current terminal section 44.

  Other configurations are the same as those of the first embodiment, and the corresponding components are denoted by the same reference numerals and description thereof is omitted. In addition, illustration and description of components not illustrated in FIG. 7 are omitted.

[Detailed configuration of discharge resistance unit]
FIG. 8 is a schematic end view when the discharge resistance unit according to the second embodiment is fastened. Hereinafter, a detailed configuration of the discharge resistance unit according to the second embodiment will be described with reference to FIGS. 7 and 8.

  The discharge resistance unit 6B includes a resistance main body 6Ba, a first resistance terminal 6Bb, a second resistance terminal 6Bc, a first bracket 6Bd, and a second bracket 6Be. A resistor (not shown) (for example, a wire-wound resistance element) is built in the resistor main body 6Ba. The periphery of the resistor is molded with a sealing material (for example, cement). The first resistance terminal 6Bb and the second resistance terminal 6Bc are formed integrally with a resistor built in the resistance main body 6Ba. The first resistance terminal 6Bb and the second resistance terminal 6Bc are electrically connected to a resistor built in the resistance main body 6Ba, and are exposed outside the resistance main body 6Ba. Here, the resistor body 6Ba, the first resistor terminal 6Bb, and the second resistor terminal 6Bc are discharge resistors. Note that, unlike the first embodiment, the discharge resistance unit 6B of the second embodiment does not include the first harness 6Ab and the second harness 6Ac.

  The first bracket 6Bd and the second bracket 6Be are formed of a conductive material (for example, copper). That is, the first bracket 6Bd and the second bracket 6Be have conductivity. As shown in FIG. 8, each of the first bracket 6Bd and the second bracket 6Be is integrally formed from one end 6Bg, an intermediate portion 6Bh, and the other end 6Bj. The intermediate portion 6Bh extends in the up-down direction. The one end 6Bg and the other end 6Bj are bent in the left-right direction about the middle 6Bh. One end 6Bg is bent to the opposite side to the other end 6Bj. Therefore, the one end 6Bg and the intermediate portion 6Bh are separated from the PN terminals 4P, 4N, etc., and do not contact the PN terminals 4P, 4N, etc. Thereby, unintended transmission of an electric signal can be suppressed. One end 6Bg of the first bracket 6Bd is fixed to the first resistance terminal 6Bb, and one end 6Bg of the second bracket 6Be is fixed to the second resistance terminal 6Bc. As a result, the first bracket 6Bd and the second bracket 6Be hold the resistance main body 6Ba. As shown in FIG. 7, an insertion hole 6Bf for inserting the bolt 102 is formed in each of the other end portions 6Bj of the first bracket 6Bd and the second bracket 6Be.

  The first bracket 6Bd and the second bracket 6Be are fastened (connected) to the rear high-voltage terminal section 44 as shown in FIGS. That is, the bolt 102 is inserted into the insertion hole 6Bf of the first bracket 6Bd, and the first bracket 6Bd is fastened together with the W-phase P terminal 4P and the DC P bus bar 121 by the bolt 102. Thereby, the first bracket 6Bd and the W-phase P terminal 4P are fastened. The bolt 102 is inserted through the insertion hole 6Bf of the second bracket 6Be, and the second bracket 6Be is fastened together with the V-phase N terminal 4N and the DC N bus bar 131 by the bolt 102. As a result, the second bracket 6Be and the V-phase N terminal 4N are fastened. Therefore, the resistor built in the resistor body 6Ba is electrically connected to the smoothing capacitor 5 through the first resistor terminal 6Bb, the second resistor terminal 6Bc, the first bracket 6Bd, and the second bracket 6Be. Thereby, the resistor discharges the electric charge accumulated in the smoothing capacitor 5 when the operation of the inverter device 3B is stopped. That is, the resistor consumes the electric charge stored in the smoothing capacitor 5 by heat. Therefore, the resistor body 6Ba generates heat, and the first resistor terminal 6Bb and the second resistor terminal 6Bc connected to the resistor body 6Ba also generate heat.

Next, the operation will be described.
As in the first embodiment, the operation of the inverter device 3 </ b> B in the second embodiment indicates a “problem generating operation”, a “relation operation between a terminal portion temperature and a discharge resistance temperature”, and a “characteristic operation of the inverter device”. In both operations, the discharge resistance becomes the resistance main body 6Ba, the first resistance terminal 6Bb, and the second resistance terminal 6Bc. Therefore, illustration and description are omitted. Further, the inverter device 3B according to the second embodiment exhibits the following characteristic operation of the second embodiment.

  In the second embodiment, a first bracket 6Bd and a second bracket 6Be having conductivity are provided on the resistor body 6Ba as the discharge resistor, the first resistor terminal 6Bb, and the second resistor terminal 6Bc. The first bracket 6Bd is fastened to the W-phase P terminal 4P, and the second bracket 6Be is fastened to the V-phase N terminal 4N. That is, the first bracket 6Bd and the second bracket 6Be have a holding function of holding the resistor body 6Ba, the first resistor terminal 6Bb, and the second resistor terminal 6Bc. Further, since the first bracket 6Bd and the second bracket 6Be have conductivity, they have a conductive function of transmitting an electric signal to the resistance main body 6Ba, the first resistance terminal 6Bb, and the second resistance terminal 6Bc. Therefore, the first bracket 6Bd and the second bracket 6Be have two functions of a holding function and a conduction function. Accordingly, it is possible to reduce the harness for connecting the discharge resistor (the resistor body 6Ba, the first resistor terminal 6Bb, and the second resistor terminal 6Bc) and the smoothing capacitor 5. Further, since it is possible to reduce the number of harnesses, the space for managing the harness and the work of connecting the harness are not required. Therefore, since the first bracket 6Bd and the second bracket 6Be have the holding function and the conduction function, the cost can be reduced.

Next, effects will be described.
In the inverter device 3B according to the second embodiment, the effects described in (1) of the first embodiment can be obtained. In the inverter device 3B of the second embodiment, the following effect (2) can be obtained.

(2) The high-voltage terminals (PN terminals 4P and 4N corresponding to the U, V, and W phases) of the high-voltage terminal section (rear high-voltage terminal section 44) include a positive high-voltage terminal (P terminal 4P) and a negative high-voltage terminal. (N terminal 4N).
Discharge resistors (the resistor body 6Ba, the first resistor terminal 6Bb, and the second resistor terminal 6Bc) are provided with a first holding portion (first bracket 6Bd) and a second holding portion (second bracket 6Be) having conductivity. .
The first holding portion (the first bracket 6Bd) is fastened to the positive electrode terminal (the W-phase P terminal 4P).
The second holding portion (second bracket 6Be) is fastened to the negative high-voltage terminal (V-phase N terminal 4N).
For this reason, the cost can be reduced because the first holding portion (the first bracket 6Bd) and the second holding portion (the second bracket 6Be) have the holding function and the conduction function.

  Third Embodiment A third embodiment is an example in which a bracket having conductivity is provided, and the bracket is jointly fastened to a PN terminal.

First, the configuration will be described.
Similar to the first embodiment, the power converter in the third embodiment is applied to an inverter device (an example of a power converter) of a motor generator mounted on an electric vehicle (an example of an electric vehicle) as a driving source for traveling or the like. It is. Hereinafter, the configuration of the third embodiment will be described by dividing into “the configuration of the inverter device” and “the detailed configuration of the discharge resistance unit”. The “circuit configuration of the drive system” of the third embodiment is the same as that of the first embodiment, and thus illustration and description are omitted.

[Configuration of inverter device]
FIG. 9 is an explanatory diagram illustrating fastening of the discharge resistance unit according to the third embodiment. In FIG. 9, illustration of a smoothing capacitor and the like is omitted. Hereinafter, the configuration of the inverter device 3C according to the third embodiment will be described with reference to FIG.

  The discharge resistance unit 6C is housed inside the case 30 of the inverter device 3C.

  One end of each of the U, V, and W phase terminals 4U, 4V, and 4W and one end of each of the U, V, and W phase bus bars 7U, 7V, and 7W are fastened by bolts 102. At this time, the first bracket 6Cd (first holding portion) and the second bracket 6Ce (second holding portion) of the discharge resistance unit 6B are not fastened together by the bolt 102.

  DC P bus bar 121 and DC N bus bar 131 are fastened to PN terminals 4P and 4N (positive / negative terminals) corresponding to the U, V and W phases by bolts 102. Thereby, the power module 4 and the smoothing capacitor 5 are connected. At this time, the DC P bus bar 121, the W-phase P terminal 4P (positive positive terminal, positive terminal) and the first bracket 6Cd of the discharge resistance unit 6C are fastened together by the bolt 102. The DC N bus bar 131, the U-phase N terminal 4N (negative terminal, negative terminal) and the second bracket 6Ce of the discharge resistance unit 6C are fastened together by the bolt 102. As a result, the discharge resistance unit 6C is disposed in the rear high-current terminal section 44.

  Other configurations are the same as those of the first embodiment, and the corresponding components are denoted by the same reference numerals and description thereof is omitted. The illustration and description of the components not shown in FIG. 9 are omitted.

[Detailed configuration of discharge resistance unit]
FIG. 10 is a schematic end view when the discharge resistance unit according to the third embodiment is fastened. Hereinafter, a detailed configuration of the discharge resistor according to the third embodiment will be described with reference to FIGS. 9 and 10.

  The discharge resistance unit 6C includes a resistance main body 6Ca, a first resistance terminal 6Cb, a second resistance terminal 6Cc, a first bracket 6Cd, and a second bracket 6Ce. A resistor (not shown) (for example, a wound resistance element) is built in the resistor main body 6Ca. The periphery of the resistor is molded with a sealing material (for example, cement). The first resistance terminal 6Cb and the second resistance terminal 6Cc are formed integrally with a resistor built in the resistance main body 6Ca. The first resistance terminal 6Cb and the second resistance terminal 6Cc are electrically connected to a resistor built in the resistance main body 6Ca, and are exposed outside the resistance main body 6Ca. Here, the resistor body 6Ca, the first resistor terminal 6Cb, and the second resistor terminal 6Cc are discharge resistors. Note that the discharge resistance unit 6C of the third embodiment does not include the first harness 6Ab and the second harness 6Ac, unlike the first embodiment.

  The first bracket 6Cd and the second bracket 6Ce are formed of a conductive material (for example, copper). That is, the first bracket 6Cd and the second bracket 6Ce have conductivity. As shown in FIG. 10, each of the first bracket 6Cd and the second bracket 6Ce is integrally formed from one end 6Cg, an intermediate portion 6Ch, and the other end 6Cj. The middle portion 6Ch extends in the up-down direction. The one end 6Cg and the other end 6Cj are bent in the left-right direction about the middle 6Ch. One end 6Cg is bent to the opposite side to the other end 6Cj. Therefore, the one end 6Cg and the intermediate portion 6Ch are separated from the PN terminals 4P, 4N and the like, and do not contact the PN terminals 4P and 4N. Thereby, unintended transmission of an electric signal can be suppressed. One end 6Cg of the first bracket 6Cd is fixed to the first resistance terminal 6Cb, and one end 6Cg of the second bracket 6Ce is fixed to the second resistance terminal 6Cc. Thus, the first bracket 6Cd and the second bracket 6Ce hold the resistance main body 6Ca. Each of the other end portions 6Cj of the first bracket 6Cd and the second bracket 6Ce has an insertion hole 6Cf through which the bolt 102 is inserted, as shown in FIG.

  The first bracket 6Cd and the second bracket 6Ce are fastened (connected) to the rear high-current terminal section 44 as shown in FIGS. That is, the bolt 102 is inserted into the insertion hole 6Cf of the first bracket 6Cd, and the first bracket 6Cd is fastened together with the W-phase P terminal 4P and the DC P bus bar 121 by the bolt 102. As a result, the first bracket 6Cd and the W-phase P terminal 4P are fastened. The bolt 102 is inserted into the insertion hole 6Cf of the second bracket 6Ce, and the second bracket 6Ce is fastened together with the U-phase N terminal 4N and the DC N bus bar 131 by the bolt 102. As a result, the second bracket 6Ce and the U-phase N terminal 4N are fastened. Therefore, the resistor built in the resistor body 6Ca is electrically connected to the smoothing capacitor 5 through the first resistor terminal 6Cb, the second resistor terminal 6Cc, the first bracket 6Cd, and the second bracket 6Ce. Thereby, the resistor discharges the charge stored in the smoothing capacitor 5 when the operation of the inverter device 3C is stopped. That is, the resistor consumes the electric charge stored in the smoothing capacitor 5 by heat. Therefore, the resistance main body 6Ca generates heat, and the first resistance terminal 6Cb and the second resistance terminal 6Cc connected to the resistance main body 6Ca also generate heat.

Next, the operation will be described.
As in the first embodiment, the operation of the inverter device 3 </ b> C in the third embodiment indicates a “problem generating operation”, a “relation operation between a terminal portion temperature and a discharge resistance temperature”, and a “characteristic operation of the inverter device”. In both operations, the discharge resistance becomes the resistance main body 6Ca, the first resistance terminal 6Cb, and the second resistance terminal 6Cc. Therefore, illustration and description are omitted. Further, the operation of the third embodiment shows the characteristic operation of the second embodiment, similarly to the second embodiment. Therefore, the description is omitted. Further, the inverter device 3C according to the third embodiment exhibits the following characteristic operation of the third embodiment.

  In the third embodiment, the first bracket 6Cd and the second bracket 6Ce having conductivity are provided on the resistor main body 6Ca as the discharge resistor, the first resistor terminal 6Cb, and the second resistor terminal 6Cc. The power module 4 has PN terminals 4P and 4N for each of the three phases. The first bracket 6Cd and the second bracket 6Ce are fastened to the W-phase P terminal 4P and the U-phase N terminal 4N in the outer two phases of the three phases, respectively.

  For example, in general, a phase arranged at the center of a semiconductor module receives thermal interference from both adjacent phases. For this reason, the phase arranged at the center of the semiconductor module has a higher temperature than the adjacent phases.

On the other hand, in the third embodiment, the first bracket 6Cd is fastened to the outer W-phase P terminal 4P of the three phases, and the second bracket 6Ce is fastened to the outer U-phase N terminal 4N of the three phases. You.
That is, the first bracket 6Cd and the second bracket 6Ce are fastened to the P terminal 4P and the N terminal 4N of the outer phases of the three phases, respectively, avoiding the V phase disposed at the center of the power module 4.
Therefore, it is possible to reduce the influence of heat interference from the two adjacent phases.

  In addition, the first bracket 6Cd and the second bracket 6Ce straddle the V-phase disposed at the center of the power module 4 and extend outward among the three phases. For this reason, when the operation scene of the DC power supply 2 is a large current and a low voltage, the heat of the PM strong electric terminal 42 is transmitted through the first bracket 6Cd and the second bracket 6Ce to the resistance main body 6Ca and the first resistance terminal 6Cb. Conducted to the second resistance terminal 6Cc. However, the first bracket 6Cd and the second bracket 6Ce dissipate the heat of the PM strong electric terminal 42. On the other hand, when the operation scene of the DC power supply 2 is a low current and a high voltage, heat of the resistor main body 6Ca, the first resistor terminal 6Cb, and the second resistor terminal 6Cc is transmitted through the first bracket 6Cd and the second bracket 6Ce to the PM. The electric power is transmitted to the high-power terminal section 42. However, the first bracket 6Cd and the second bracket 6Ce dissipate the heat of the resistor body 6Ca, the first resistor terminal 6Cb, and the second resistor terminal 6Cc. As described above, since the first bracket 6Cd and the second bracket 6Ce have a heat radiation function, heat management can be easily performed.

Next, effects will be described.
In the inverter device 3C according to the third embodiment, the effects described in (1) of the first embodiment and (2) of the second embodiment can be obtained. In the inverter device 3C according to the third embodiment, the following effect (3) can be obtained.

(3) Discharge resistors (resistor body 6Ca, first resistor terminal 6Cb, and second resistor terminal 6Cc) have a first holding portion (first bracket 6Cd) and a second holding portion (second bracket 6Ce) having conductivity. Is provided.
The power conversion module (power module 4) has positive and negative terminals (PN terminals 4P, 4N) in each of three or more phases (three phases of U, V, and W phases).
The first holding portion (first bracket 6Cd) and the second holding portion (second bracket 6Ce) are two outer phases (U, W phases) of three or more phases (three phases of U, V, W phases). At the positive terminal (W-phase P terminal 4P) and the negative terminal (U-phase N terminal 4N).
For this reason, it is possible to reduce the influence of heat interference from both adjacent phases.

  As described above, the power converter according to the present disclosure has been described based on the first to third embodiments. However, the specific configuration is not limited to these embodiments, and according to each claim of the claims. Changes and additions to the design are permitted without departing from the spirit of the invention.

  In the first embodiment, the first bracket 6Ad is fastened to the V-phase terminal 4V, and the second bracket 6Ae is fastened to the U-phase terminal 4U. However, it is not limited to this. For example, the first bracket may be fastened to the V-phase P terminal and the second bracket may be fastened to the W-phase N terminal. Further, the first bracket may be fastened to a PM fixing bolt, and the second bracket may be fastened to another PM fixing bolt. In short, it suffices that the discharge resistor is arranged at the high-voltage terminal (PM high-voltage terminal).

  In the first embodiment, the first harness 6Ab is fastened to the U-phase P terminal 4P, and the second harness 6Ac is fastened to the U-phase N terminal 4N. However, it is not limited to this. For example, the first harness may be fastened to the W-phase P terminal and the second harness may be fastened to the V-phase N terminal. In short, it is only necessary that the discharge resistor is electrically connected to the smoothing capacitor.

  In the second embodiment, the first bracket 6Bd is fastened to the W-phase P terminal 4P, and the second bracket 6Be is fastened to the V-phase N terminal 4N. However, it is not limited to this. For example, the first bracket may be fastened to the V-phase P terminal and the second bracket may be fastened to the W-phase N terminal. Further, the first bracket may be fastened to the U-phase P terminal, and the second bracket may be fastened to the V-phase N terminal. In short, it is only necessary that the first bracket is fastened to the positive electrode and the second bracket is fastened to the negative electrode.

  In the third embodiment, an example is shown in which the first bracket 6Cd is fastened to the W-phase P terminal 4P and the second bracket 6Ce is fastened to the U-phase N terminal 4N. However, the first bracket may be fastened to the U-phase P terminal and the second bracket may be fastened to the W-phase N terminal. In short, the first bracket and the second bracket only need to be fastened to the positive terminal and the negative terminal in the two outer phases of the three phases.

  In the second and third embodiments, an example has been described in which the first holding unit and the second holding unit are the first bracket and the second bracket. However, the first holding portion and the second holding portion are not limited to the brackets, and may have at least two functions of a holding function and a conduction function.

  In the first to third embodiments, the example has been described in which the discharge resistance units 6A to 6C are arranged on the PM strong electric terminal 42 via the bracket. However, it is not limited to this. That is, the discharge resistor does not need to have a harness or a bracket, and the discharge resistor only needs to be arranged at the high-current terminal portion (PM high-current terminal portion). However, the discharge resistor is electrically connected to the smoothing capacitor, and discharges the charge of the smoothing capacitor when the operation is stopped.

  Embodiments 1 to 3 show an example in which the power module 4 has three phases (U, V, and W phases). However, five or seven phases may be used. In other words, three or more phases are sufficient. For example, when the power module has positive and negative terminals in each of the five phases, in the third embodiment, the first bracket and the second bracket are respectively connected to the positive and negative terminals in the outer two phases of the five phases. It should be done.

  In the first to third embodiments, the example in which the power conversion module is the power module 4 has been described. However, the present invention is not limited to this, and the power conversion module only needs to include a switching element that forms a power conversion circuit.

Embodiments 1 to 3 show examples in which the power converter according to the present disclosure is applied to inverter devices 3A to 3C used as AC / DC converters of motor generator 11. However, the power conversion device according to the present disclosure can be applied to various power conversion devices other than the inverter device as long as the power conversion device includes at least the power conversion module, the smoothing capacitor, and the discharge resistor. Further, the present invention is not limited to an inverter device mounted on an electric vehicle such as an electric vehicle (an example of an electric vehicle).

[0001]
Technical field [0001]
The present disclosure relates to a power conversion device.
BACKGROUND ART [0002]
2. Description of the Related Art Conventionally, a semiconductor module, a smoothing capacitor, and a discharge resistor are attached to an inverter device as a power conversion device (for example, see Patent Document 1).
Prior art document Patent document [0003]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2010-124523 Summary of the Invention Problems to be Solved by the Invention [0004]
However, the conventional inverter device requires an area for providing a discharge resistor in addition to an area for providing a semiconductor module and a smoothing capacitor. Therefore, there is a problem that the size of the inverter device is increased in at least one direction in plan view of the inverter device.
[0005]
The present disclosure has been made in view of the above problem, and has as its object to reduce the size of a power conversion device.
Means for solving the problem [0006]
In order to achieve the above object, a power conversion device according to the present disclosure includes a case, a power conversion module, a cooler, a smoothing capacitor, and a discharge resistor.
The power conversion module includes a switching element housed in a case and configuring a power conversion circuit.
The cooler is housed in the case and cools the power conversion module.
The smoothing capacitor is housed in the case and suppresses voltage fluctuation.
The discharge resistor is housed in the case, is electrically connected to the smoothing capacitor, and discharges the charge of the smoothing capacitor when the operation is stopped.
In addition, the power conversion module has a high-power terminal portion. The discharge resistor is a power converter located above the cooler

[0002]
It is arranged at the high voltage terminal of the module.
Effect of the Invention [0007]
Thus, the size of the power conversion device can be reduced by disposing the discharge resistor at the high-current terminal portion of the power conversion module located above the cooler.
BRIEF DESCRIPTION OF THE DRAWINGS [0008]
FIG. 1 is a circuit diagram of a drive system for an electric vehicle to which the inverter devices according to the first to third embodiments are applied.
FIG. 2 is a plan view of the inverter device according to the first embodiment.
FIG. 3 is a schematic sectional view of the inverter device according to the first embodiment.
FIG. 4 is an explanatory diagram for explaining fastening of a discharge resistance unit in Embodiment 1.
FIG. 5 is a plan view of an inverter device in a conventional example.
FIG. 6 is a diagram showing a relationship between a terminal temperature and a discharge resistance temperature in an operation scene of a DC power supply according to the first to third embodiments.
FIG. 7 is an explanatory view for explaining fastening of a discharge resistance unit in Embodiment 2.
FIG. 8 is a schematic end view when the discharge resistance unit according to the second embodiment is fastened, and is a schematic end view taken along line II-II in FIG. 7;
FIG. 9 is an explanatory view for explaining fastening of a discharge resistance unit in Embodiment 3.
FIG. 10 is a schematic end view when the discharge resistance unit according to the third embodiment is fastened, and is a schematic end view taken along line III-III in FIG. 9;
MODES FOR CARRYING OUT THE INVENTION [0009]
Hereinafter, the best mode for realizing the power converter of the present invention will be described based on Embodiments 1 to 3 shown in the drawings.
Example 1
[0010]
First, the configuration will be described.
The power conversion device according to the first embodiment is applied to an inverter device (an example of a power conversion device) of a motor generator mounted on an electric vehicle (an example of an electric vehicle) as a driving source for traveling or the like. Hereinafter, the configuration of the first embodiment is referred to as a “drive system”.

[0001]
Technical field [0001]
The present disclosure relates to a power conversion device.
BACKGROUND ART [0002]
2. Description of the Related Art Conventionally, a semiconductor module, a smoothing capacitor, and a discharge resistor are attached to an inverter device as a power conversion device (for example, see Patent Document 1).
Prior art document Patent document [0003]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2010-124523 Summary of the Invention Problems to be Solved by the Invention [0004]
However, the conventional inverter device requires an area for providing a discharge resistor in addition to an area for providing a semiconductor module and a smoothing capacitor. Therefore, there is a problem that the size of the inverter device is increased in at least one direction in plan view of the inverter device.
[0005]
The present disclosure has been made in view of the above problem, and has as its object to reduce the size of a power conversion device.
Means for solving the problem [0006]
In order to achieve the above object, a power conversion device according to the present disclosure includes a case, a power conversion module, a cooler, a smoothing capacitor, and a discharge resistor.
The power conversion module includes a switching element housed in a case and configuring a power conversion circuit.
The cooler is housed in the case and cools the power conversion module.
The smoothing capacitor is housed in the case and suppresses voltage fluctuation.
The discharge resistor is housed in the case, is electrically connected to the smoothing capacitor, and discharges the charge of the smoothing capacitor when the operation is stopped.
In addition, the power conversion module has a strong current terminal for connecting to the bus bar. Discharge resistance is power conversion with the bus bar above the cooler

[0002]
Fastened to the strong current terminal of the module.
Effect of the Invention [0007]
As described above, the discharge resistor is fastened to the high-current terminal portion of the power conversion module together with the bus bar above the cooler, so that the size of the power conversion device can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS [0008]
FIG. 1 is a circuit diagram of a drive system for an electric vehicle to which the inverter devices according to the first to third embodiments are applied.
FIG. 2 is a plan view of the inverter device according to the first embodiment.
FIG. 3 is a schematic sectional view of the inverter device according to the first embodiment.
FIG. 4 is an explanatory diagram for explaining fastening of a discharge resistance unit in Embodiment 1.
FIG. 5 is a plan view of an inverter device in a conventional example.
FIG. 6 is a diagram showing a relationship between a terminal temperature and a discharge resistance temperature in an operation scene of a DC power supply according to the first to third embodiments.
FIG. 7 is an explanatory view for explaining fastening of a discharge resistance unit in Embodiment 2.
FIG. 8 is a schematic end view when the discharge resistance unit according to the second embodiment is fastened, and is a schematic end view taken along line II-II in FIG. 7;
FIG. 9 is an explanatory view for explaining fastening of a discharge resistance unit in Embodiment 3.
FIG. 10 is a schematic end view when the discharge resistance unit according to the third embodiment is fastened, and is a schematic end view taken along line III-III in FIG. 9;
MODES FOR CARRYING OUT THE INVENTION [0009]
Hereinafter, the best mode for realizing the power converter of the present invention will be described based on Embodiments 1 to 3 shown in the drawings.
Example 1
[0010]
First, the configuration will be described.
The power conversion device according to the first embodiment is applied to an inverter device (an example of a power conversion device) of a motor generator mounted on an electric vehicle (an example of an electric vehicle) as a driving source for traveling or the like. Hereinafter, the configuration of the first embodiment is referred to as a “drive system”.

Claims (3)

A power conversion module including a switching element forming a power conversion circuit,
A smoothing capacitor that suppresses voltage fluctuations,
A discharge resistor that is electrically connected to the smoothing capacitor and discharges the charge of the smoothing capacitor when operation is stopped,
The power conversion module has a high-power terminal,
The power conversion device, wherein the discharge resistor is arranged at the high-current terminal. The power converter according to claim 1,
The high-power terminal of the high-power terminal portion includes a positive power terminal and a negative power terminal,
A first holding unit and a second holding unit having conductivity are provided on the discharge resistor;
The first holding unit is fastened to the positive high-voltage terminal,
The power conversion device, wherein the second holding unit is fastened to the negative high-voltage terminal. In the power converter according to claim 1 or 2,
A first holding unit and a second holding unit having conductivity are provided on the discharge resistor;
The power conversion module has positive and negative terminals in each of three or more phases,
The power converter, wherein the first holding unit and the second holding unit are fastened to a positive terminal and a negative terminal in two outer phases of the three or more phases, respectively.

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