JP2019198167A - Power control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for a power control device including a plurality of heat-generating components to cope with an increase in size of a capacitor housed in a case while suppressing an increase in size of the entire case. A power control device (10) includes a case (20) having a bottom portion (21) provided with a refrigerant flow path (22), a reactor (4a) housed in the case (20), a voltage converter, and a smoothing capacitor (7). The reactor 4a and the voltage converter are fixed on the bottom so as to face the refrigerant passage. The smoothing capacitor 7 is arranged next to the reactor 4a in a direction intersecting with the arrangement direction of the reactor 4a and the voltage converter. In the power control device 10, the smoothing capacitor 7 does not overlap the refrigerant flow path 22 when the case 20 is viewed from above, and the case 20 has a lower portion of the smoothing capacitor 7 protruding below the refrigerant flow path 22. In addition, the space Sp is secured below the smoothing capacitor 7. [Selection diagram] Figure 2

Description

  The technology disclosed in this specification relates to a power control apparatus. In particular, the present invention relates to a power control apparatus in which a cooler is incorporated in a case.

  Patent Documents 1-3 disclose a power control device that controls driving power of a traveling motor. Since the power control device handles a large amount of power, the amount of heat generated by the components inside the case is large. As for the electric power control apparatus of patent documents 1-3, the cooler is incorporated in the case. In the power control device of Patent Document 1, a refrigerant flow path (cooler) is provided at the bottom of the case. A voltage converter and a reactor are fixed on the bottom so as to face the refrigerant flow path. A stacked unit of a plurality of semiconductor modules and a plurality of flat coolers is disposed above the voltage converter. Two capacitors are arranged on the side of the multilayer unit.

  In the power control device of Patent Document 2, a partition wall that extends in the horizontal direction is provided in the middle of the case in the vertical direction, and a refrigerant flow path is provided in the partition wall. That is, the partition wall corresponds to a cooler. A power converter and a transformer are fixed to the lower surface of the partition wall. A stacked unit of a plurality of semiconductor modules and a plurality of flat coolers is disposed above the partition wall. A capacitor is arranged on the side of the multilayer unit.

  In the power control device of Patent Document 3, a refrigerant flow path (cooler) is provided at the bottom of the case. A voltage converter is fixed to the lower surface of the bottom so as to face the refrigerant flow path. An inverter is fixed on the upper surface of the bottom so as to face the refrigerant flow path. A portion of the bottom where no refrigerant flow path is provided is recessed downward, and a capacitor is disposed in the recess.

Japanese Patent Laid-Open No. 2016-10093 Japanese Patent Laying-Open No. 2015-073401 JP 2005-341893 A

  As described above, the power control device that controls the driving power of the traveling motor includes a plurality of relatively large heat generating components, and a cooler is incorporated in the case that stores the heat generating components. The capacitor incorporated in the power control device is connected between the positive electrode and the negative electrode of the power line, and suppresses current pulsation in the power line. As the power handled by the power control device increases, the capacitor also increases in size. On the other hand, a power control device mounted on an electric vehicle (including a hybrid vehicle and a fuel cell vehicle) desirably has a small overall case size due to restrictions on the mounting space of the vehicle. The present specification relates to a power control apparatus including a plurality of heat-generating components, and provides a technique corresponding to an increase in the size of a capacitor accommodated in a case while suppressing an increase in the size of the entire case.

  The power control device disclosed in the present specification includes a case in which a refrigerant flow path is provided at the bottom, and a reactor, a voltage converter, and a capacitor accommodated in the case. The reactor and the voltage converter are fixed on the bottom so as to face the refrigerant flow path. The capacitor is arranged next to the reactor in a direction that intersects the direction in which the reactor and the voltage converter are arranged. In the power control device disclosed in the present specification, when the case is viewed from above, the capacitor does not overlap the refrigerant flow path, and the case has a lower portion of the capacitor protruding downward from the refrigerant flow path. A space is secured below the capacitor.

  The power control device disclosed in the present specification is provided with a refrigerant flow path at the bottom of the case in a range that does not overlap with the capacitor in the vertical direction, and only a portion below the capacitor protrudes downward from the refrigerant flow path. Ensure space underneath. By providing a space below the capacitor, a larger capacitor can be accommodated as necessary. The bottom part of the case can be accommodated to an increase in the size of the capacitor while suppressing the increase in the size of the entire case by projecting only the lower portion of the capacitor while keeping the portion where the refrigerant flow path is provided at the conventional position. .

  Note that the power control device disclosed in this specification may include a plurality of capacitors. In that case, it is sufficient that at least one capacitor is arranged next to the reactor, and the periphery of the capacitor has the above-described characteristics. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a block diagram of the electric power control apparatus of an Example. It is a front view of an electric power control apparatus (cutting the side plate of a case front part). It is a side view of a power control device (cutting a case side plate). It is a top view of a power control device (parts above the case are not shown). It is a top view of the power control device of a modification (parts above the case are not shown).

  A power control apparatus 10 according to an embodiment will be described with reference to the drawings. The power control apparatus 10 according to the embodiment is mounted on an electric vehicle 100. FIG. 1 shows a block diagram of a power system of an electric vehicle 100 including a power control device 10. The electric vehicle 100 includes traveling motors 92a and 92b. The power control device 10 boosts the DC power of the main battery 91 and then converts it into AC power. The power control apparatus 10 includes two voltage converter circuits 11a and 11b, two inverter circuits 12a and 12b, and a voltage converter 8.

  The voltage converter circuits 11a and 11b are connected in parallel. The voltage converter circuit 11a is a non-insulating type, and includes two switching elements 5a and 5b, a reactor 4a, a filter capacitor 3, and two diodes. The two switching elements 5a and 5b are connected in series between the high voltage ends 19a and 19b. A diode is connected in antiparallel to each of the switching elements 5a and 5b. One end of the reactor 4a is connected to the midpoint of the series connection of the two switching elements 5a and 5b, and the other end is connected to the positive electrode 18a at the low voltage end. The filter capacitor 3 is connected between the positive electrode 18a and the negative electrode 18b at the low voltage end. The negative electrode 18b at the low voltage end and the negative electrode 19b at the high voltage end are directly connected.

  The voltage converter circuit 11a of FIG. 1 boosts the voltage applied to the low voltage terminals 18a and 18b and outputs the boosted voltage from the high voltage terminals 19a and 19b, and steps down the voltage applied to the high voltage terminals 19a and 19b. Thus, a boosting function for outputting from the low voltage ends 18a and 18b is provided. The voltage converter circuit 11a is a so-called bidirectional DC-DC converter. The switching element 5a is mainly involved in the step-down operation, and the switching element 5b is mainly involved in the step-up operation.

  The voltage applied to the high voltage ends 19a and 19b is a voltage of regenerative power generated by the motors 92a and 92b. The switching elements 5 a and 5 b are controlled by the control circuit 17. The control circuit 17 supplies complementary PWM signals to the switching elements 5a and 5b. By supplying a complementary PWM signal, the voltage converter circuit 11a can perform a step-up operation and a step-down operation depending on the balance between the voltage applied to the low voltage ends 18a and 18b and the voltage applied to the high voltage ends 19a and 19b. Switch passively. Since the circuit configuration and operation of the voltage converter circuit 11a of FIG. 1 are well known, detailed description thereof is omitted.

  The voltage converter circuit 11b has the same circuit structure as the voltage converter circuit 11a. The voltage converter circuit 11b is a non-insulating type, and includes two switching elements 5c and 5d, a reactor 4b, a filter capacitor 3, and two diodes. The two switching elements 5c and 5d are connected in series between the high voltage ends 19a and 19b. A diode is connected in antiparallel to each of the switching elements 5c and 5d. One end of the reactor 4b is connected to the midpoint of the series connection of the two switching elements 5c and 5d, and the other end is connected to the positive electrode 18a at the low voltage end. The filter capacitor 3 is shared with the voltage converter circuit 11a. The voltage converter circuit 11b is also a bidirectional DC-DC converter, boosts the voltage applied to the low voltage terminals 18a and 18b and outputs the boosted voltage from the high voltage terminals 19a and 19b, and applies to the high voltage terminals 19a and 19b. A step-down function for stepping down the output voltage and outputting it from the low voltage ends 18a, 18b is provided.

  The control circuit 17 turns on and off the switching element 5a of the voltage converter circuit 11a and the switching element 5c of the voltage converter circuit 11b at the same timing. In the control circuit 17, the switching element 5b and the switching element 5d are turned on and off at the same timing. Since the two voltage converter circuits 11a and 11b that have the same circuit structure and are connected in parallel operate at the same timing, the two voltage converter circuits 11a and 11b are as if one voltage converter circuit. To work. Since the load is distributed to the two voltage converter circuits 11a and 11b connected in parallel, the power control apparatus 10 can handle a large amount of power.

  The switching elements 5a and 5b are accommodated in one package (power module 6a), and the switching elements 5c and 5d are also accommodated in another package (power module 6b).

  The inverter circuits 12a and 12b will be described. The inverter circuit 12a has a structure in which three sets of two switching elements are connected in parallel. When the control circuit 17 appropriately turns on and off the six switching elements, alternating current is output from the midpoint of each series connection. The structure and operation of the inverter circuit 12a are well known and will not be described in detail. Two switching elements connected in series are accommodated in one package. Six switching elements included in the inverter circuit 12a are housed in three power modules 6c-6e, two by two.

  The inverter circuit 12b has the same structure as the inverter circuit 12a. The inverter circuit 12b also includes three power module modules 6f-6h, and each of the power modules 6f-6h accommodates a series connection of two switching elements.

  A smoothing capacitor 7 is connected between the voltage converter circuits 11a and 11b and the inverter circuits 12a and 12b.

  The voltage converter 8 is connected to the common low voltage terminals 18a and 18b of the voltage converter circuits 11a and 11b. The voltage converter 8 is a step-down converter that steps down the voltage of the main battery 91 and supplies it to the sub battery 93. The output voltage of the main battery 91 is 200 volts, for example, and the voltage of the sub battery 93 is 12 volts, for example. The voltage converter 8 is an insulation type converter using a transformer. Illustration and description of the circuit configuration of the voltage converter 8 are omitted.

  The sub-battery 93 supplies electric power to various auxiliary machines 95 via a power line 94 that is stretched around the vehicle body. Auxiliary equipment is a general term for electric components driven by the power of the sub-battery 93, such as car audio and room lamps. In FIG. 1, only one auxiliary machine 95 is depicted, but the vehicle is equipped with a large number of auxiliary machines.

  A hardware configuration of the power control apparatus 10 will be described. FIG. 2 shows a front view of the case 20 of the power control apparatus 10. FIG. 2 is a front view of the front side plate cut so that the structure inside the case can be understood. In FIG. 3, the side view of the electric power control apparatus 10 which cut the near side plate is shown. For convenience of explanation, the + X direction of the coordinate system in the figure is defined as “front”, and the + Z direction is defined as “up”. The power control device 10 is fixed on a transaxle of the electric vehicle 100, for example. Motors 92a and 92b are accommodated in the housing of the transaxle. The power control device 10 that controls the drive power of the motors 92a and 92b is fixed on the housing of the transaxle that houses the motors 92a and 92b, thereby shortening the power cable to the motors 92a and 92b.

  The power modules 6a-6h described above are stacked together with a plurality of flat coolers 31. The inside of the cooler 31 is a refrigerant flow path. A laminated body of the power modules 6 a-6 h and the cooler 31 is expressed as a laminated unit 30. In FIG. 3, reference numerals 6a and 6h are attached to the power modules at both ends, and the reference numerals are omitted for the power modules between them. Hereinafter, when any one of the plurality of power modules 6a-6h is shown without distinction, it is referred to as a power module 6. The laminated unit 30 is sandwiched between the inner surface of the case 20 and the partition plate 25 inside the case. A leaf spring (not shown) is sandwiched between the laminated unit 30 and the partition plate 25. The plurality of power modules 6 and the plurality of coolers 31 are pressurized in the stacking direction by the leaf springs.

  The plurality of flat coolers 31 are arranged in a row so that the wide surfaces face each other. The power module 6 is sandwiched between the adjacent coolers 31. Adjacent coolers 31 are connected by two connecting pipes. A refrigerant supply pipe 32a and a refrigerant discharge pipe 32b are connected to the cooler 31 at one end in the stacking direction. One connecting pipe between the adjacent coolers 31 is positioned so as to overlap the refrigerant supply pipe 32a when viewed from the X direction in the figure. The other connecting pipe is positioned so as to overlap with the refrigerant discharge pipe 32b when viewed from the X direction. The refrigerant supply pipe 32a is connected to a refrigerant circulation device (not shown). The refrigerant discharge pipe 32b is connected to a refrigerant supply / discharge pipe 23a (described later) via a connection pipe (not shown) disposed outside the case 20. The refrigerant supply / discharge pipe 23b described later is connected to a refrigerant circulation device (not shown).

  The refrigerant is distributed to each cooler 31 through the refrigerant supply pipe 32a and one of the connection pipes. The refrigerant absorbs heat from the adjacent power module 6 while passing through the cooler 31. The refrigerant that has absorbed heat is sent to the refrigerant flow path 22 (described later) through the other connecting pipe and the refrigerant discharge pipe 32b. The refrigerant cools another heating element (reactors 4 a and 4 b and voltage converter 8) while flowing through the refrigerant flow path 22. The refrigerant discharged from the refrigerant flow path 22 is returned to the refrigerant circulation device. The refrigerant is a liquid, water or antifreeze.

  Three power terminals 33a, 33b, and 33c extend from the lower surface of each power module 6 (see FIG. 2). As described above, the power module 6 accommodates a series connection of two switching elements. The power terminal 33a is electrically connected to the positive electrode connected in series, and the power terminal 33b is electrically connected to the negative electrode connected in series. The power terminal 33c is connected to the midpoint of series connection. As shown in FIG. 2, the power terminal 33a is connected to the smoothing capacitor 7 via the positive electrode bus bar 34a. The power terminal 33b is connected to the smoothing capacitor 7 through the negative electrode bus bar 34b. The connection destination of the power terminal 33c is not shown. As shown in FIG. 1, all power modules 6 a-6 h are connected to a smoothing capacitor 7. All the power modules 6a-6h are connected to the smoothing capacitor 7 via the positive bus bar 34a and the negative bus bar 34b.

  Control terminals 33 d and 33 e extend upward from the upper surface of the power module 6, and the control terminals 33 e and 33 d are connected to the control board 35. The control terminals 33d and 33e are terminals connected to the gate electrodes of the two switching elements in the power module 6, and terminals of a temperature sensor built in the power module 6. The control circuit 17 shown in FIG. 1 is mounted on the control board 35.

  A refrigerant flow path 22 is provided at the bottom 21 of the case 20. The refrigerant flow path 22 is provided with a plurality of fins. Reactors 4 a and 4 b and voltage converter 8 are fixed to the upper surface of bottom 21 so as to face refrigerant flow path 22. Refrigerant supply / discharge pipes 23 a and 23 b communicating with the refrigerant flow path 22 are provided on the front surface of the case 20. As described above, the refrigerant supply / discharge pipe 23 a is connected to the refrigerant discharge pipe 32 b of the stacked unit 30 via a connection pipe (not shown) located outside the case 20. The refrigerant supply / discharge pipe 23b is connected to a refrigerant circulation device (not shown). The refrigerant flowing into the refrigerant flow path 22 from the cooler 31 of the stacked unit 30 through the refrigerant supply / discharge pipe 23 a absorbs heat from the reactors 4 a and 4 b and the voltage converter 8 while flowing through the refrigerant flow path 22. That is, the reactors 4 a and 4 b and the voltage converter 8 are cooled by a cooler (refrigerant flow path 22) incorporated in the case 20. The refrigerant that has absorbed the heat of the reactors 4a and 4b and the voltage converter 8 is returned from the refrigerant supply / discharge pipe 23b to a refrigerant circulation device (not shown).

  FIG. 4 is a top view of the power control apparatus 10. In FIG. 4, the parts from the middle to the upper side (specifically, the laminated unit 30 and the control board 35) are not displayed. Moreover, in FIG. 4, the refrigerant | coolant flow path 22 is drawn with the broken line.

  The smoothing capacitor 7 is arranged next to the reactors 4a and 4b in a direction (Y direction in the figure) intersecting the arrangement direction (X direction in the figure) of the two reactors 4a and 4b and the voltage converter 8. Further, the filter capacitor 3 is disposed so as to be adjacent to both the smoothing capacitor 7 and the voltage converter 8. The smoothing capacitor 7 and the filter capacitor 3 are fixed to a protruding portion (not shown) protruding from the inner surface of the case 20.

  A part (protrusion 24) of the bottom 21 of the case 20 protrudes downward. The protrusion 24 is located below the smoothing capacitor 7. In other words, the smoothing capacitor 7 is disposed above the protruding portion 24. As shown in FIGS. 2 and 3, the inside of the protrusion 24 is hollow, and a space Sp is secured below the smoothing capacitor 7. As shown in FIGS. 2 and 3, the projecting portion 24 projects downward from the refrigerant flow path 22 provided in the bottom portion 21. On the other hand, as shown in FIG. 4, the smoothing capacitor 7 does not overlap the refrigerant flow path 22 when the case 20 is viewed from above.

  The advantages of the above structure will be described. A space Sp is secured below the smoothing capacitor 7. Using this space Sp, a larger capacitor can be accommodated in the case 20 as the smoothing capacitor 7. On the other hand, in order to accommodate a large-sized capacitor, the entire case 20 is not extended vertically, but is protruded downward only under the smoothing capacitor 7. Since the entire case 20 is not increased in size, the increase in the size of the capacitor can be accommodated while suppressing the increase in size of the entire case. As described above, the power control apparatus 10 is fixed on the transaxle housing in the electric vehicle 100. There are many irregularities in the housing, and the protrusion 24 of the case 20 is limited to a size that fits into a recess in the upper part of the housing. Therefore, the case 20 having the protrusion 24 can be disposed at the same height (height from the ground) as the case having no protrusion.

  FIG. 5 shows a top view of a modified power control apparatus 10a. In FIG. 5 as well, the components (stacked unit and control board) arranged on the upper side of the case 20a are not shown. A refrigerant flow path 22a is provided at the bottom of the case 20a of the power control apparatus 10a. The refrigerant flow path 22 a includes a curved portion 22 b that does not overlap with the smoothing capacitor 7 in a top view but goes around the filter capacitor 3. In the power control device disclosed in this specification, the smoothing capacitor 7 does not have to overlap the refrigerant flow path when viewed from above, and the filter capacitor 3 and the refrigerant flow path 22a may overlap. As understood from FIG. 1, the filter capacitor 3 is connected to the low voltage terminals 18a and 18b of the voltage converter circuits 11a and 11b, and the smoothing capacitor 7 is connected to the high voltage terminals 19a and 19b of the voltage converter circuits 11a and 11b. The That is, the applied voltage of the smoothing capacitor 7 can be higher than that of the filter capacitor 3. Therefore, the smoothing capacitor 7 has a larger capacity than the filter capacitor 3 and is larger in size than the filter capacitor 3. By providing the space Sp below the smoothing capacitor 7 that is larger than the filter capacitor 3, the case 20 can accommodate a larger smoothing capacitor.

  Points to be noted regarding the technology described in the embodiments will be described. The smoothing capacitor 7 is arranged next to the reactors 4a and 4b in the case 20 (20a) in a direction (Y direction in the drawing) intersecting the alignment direction of the reactors 4a and 4b and the voltage converter 8. When the case 20 (20a) is viewed from above, the smoothing capacitor 7 does not overlap the refrigerant flow path 22 (22a). Further, in the case 20 (20a), the lower portion of the smoothing capacitor 7 projects downward from the refrigerant flow path 22 (22a), and a space Sp is secured below the smoothing capacitor 7.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

3: Filter capacitor 4a, 4b: Reactor 5a-5d: Switching element 6, 6a-6h: Power module 7: Smoothing capacitor 8: Voltage converter 10, 10a: Power control device 11a, 11b: Voltage converter circuit 12a, 12b: Inverter Circuit 17: Control circuit 18a, 18b: Low voltage end 19a, 19b: High voltage end 20, 20a: Case 21: Bottom part 22, 22a: Refrigerant flow path 22b: Curved part 23a, 23b: Refrigerant supply / exhaust pipe 24: Projection part 30: Laminate unit 31: Cooler 32a: Refrigerant supply pipe 32b: Refrigerant discharge pipes 33a, 32b, 32c: Power terminal 35: Control board 91: Main battery 92a, 92b: Motor 93: Sub battery 94: Power line 95: Auxiliary equipment 100: Electric car

Claims (1)

A case in which a refrigerant channel is provided at the bottom;
A reactor and a voltage converter fixed on the bottom so as to face the refrigerant flow path;
A capacitor disposed next to the reactor in a direction that intersects the direction in which the reactor and the voltage converter are arranged in the case;
With
The capacitor does not overlap the refrigerant flow path when the case is viewed from above,
The case is a power control device in which a lower portion of the capacitor protrudes downward from the refrigerant flow path and a space is secured below the capacitor.

Images