JP2010115089A - Power conversion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and low-noise power conversion apparatus that reduces the noise generated by a smoothing capacitor. <P>SOLUTION: The power conversion apparatus includes a power conversion section that performs power conversion between the direct current and alternating current using a switching operation of switching elements, a control circuit for controlling the switching operation of the switching elements, a smoothing capacitor for suppressing variations in a supply voltage to be supplied to the switching elements, a case for fixing the smoothing capacitor and housing the switching elements and the smoothing capacitor, and a cooling member fixed to the case for cooling the switching elements. A vibration-proof member is inserted between the cooling member and the case to reduce the noise generated due to the ripple of the direct current voltage or the direct current to be supplied to the power conversion section. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an on-vehicle power conversion device mounted on an automobile or the like, and more particularly to a structure of a power conversion device including a semiconductor switching element that constitutes a power conversion unit such as an inverter.

  Conventionally, in a vehicle such as an electric vehicle, DC power from a battery is converted into predetermined AC power by a power conversion unit such as an inverter and supplied to a motor, and electric power is supplied according to an accelerator operation by a driver of the vehicle. The output torque of the motor is controlled by controlling the switching operation of the semiconductor switching element constituting the conversion unit. The switching operation of the power return unit is controlled by controlling the generation timing of the gate signal applied to the semiconductor switching element by the control circuit unit.

  In order to control the switching operation described above, it is necessary to suppress the pulsation of the DC voltage or DC current supplied to the power conversion unit such as an inverter. Usually, the pulsation is suppressed using a large-capacity smoothing capacitor. Suppressed. As the large-capacity smoothing capacitor, an aluminum electrolytic capacitor or a film capacitor that can easily obtain a large capacitance is generally used. Conventionally, as a large-capacity smoothing capacitor, a cylindrically wound film capacitor formed by winding a film with a strong tension is used, and noise or vibration due to pulsation of DC voltage or DC current supplied to the power conversion unit is There has been proposed a technique for further reducing the characteristics of the wound film capacitor (see, for example, Patent Document 1).

  Since the conventional power converter uses a smoothing capacitor having a large capacitance as the smoothing capacitor as described above, noise or vibration from the smoothing capacitor due to the pulsation of the DC voltage or DC current supplied to the power conversion unit. Is reduced.

JP 2006-304410 A

In the case of the conventional apparatus shown in Patent Document 1, a plurality of cylindrically wound film capacitors are connected in parallel so as to ensure a necessary capacitance, and a DC voltage or a DC current supplied to the power conversion unit. However, there is a problem that a dead space between a plurality of cylindrically wound film capacitors connected in parallel is large, and the size cannot be reduced.

  In addition, when a flat wound film capacitor is used instead of a cylindrical wound film capacitor, the dead space between a plurality of flat wound film capacitors can be reduced, so that the size can be reduced. There is a problem that the noise or vibration caused by the pulsation of the DC voltage or DC current supplied to the capacitor is larger than that of a cylindrical film capacitor.

  The present invention has been made to solve the above-described problems in the conventional power conversion device, and an object thereof is to provide a small-sized power conversion device with low noise or vibration.

The power conversion device according to the present invention is supplied to a power conversion unit that performs power conversion between direct current and alternating current by a switching operation of the switching element, a control circuit unit that controls the switching operation of the switching element, and the switching element. A smoothing capacitor that suppresses fluctuations in the power supply voltage, a case that fixes the smoothing capacitor and houses the switching element and the smoothing capacitor, and a cooling member that is fixed to the case and cools the switching element. In the power conversion apparatus provided, a vibration isolating member is inserted between the cooling member and the case.

  The power conversion device according to the present invention includes a power conversion unit that performs power conversion between direct current and alternating current by a switching operation of the switching element, a control circuit unit that controls the switching operation of the switching element, and the switching element. A smoothing capacitor that suppresses fluctuations in the supplied power supply voltage, a case that fixes the smoothing capacitor and houses the switching element and the smoothing capacitor, and a cooling member that is fixed to the case and cools the switching element Is provided with a hollow portion between the cooling member and the case.

  According to the power conversion device of the present invention, since the vibration isolating member is inserted between the cooling member and the case, by using, for example, a flat wound film capacitor as a smoothing capacitor, low noise and low vibration and a small size are achieved. The power conversion device can be obtained.

  Further, according to the power conversion device of the present invention, since the cavity is provided between the cooling member and the case, by using, for example, a flat wound film capacitor as a smoothing capacitor, low noise or low vibration, and A small power converter can be obtained.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a power conversion apparatus according to Embodiment 1 of the present invention. In FIG. 1, six switching power modules 8 in which switching elements and free wheel diodes are modularized by resin sealing are provided, and a power conversion unit (such as an inverter) configured by a three-phase bridge circuit ( A positive-side arm and a negative-side arm of each phase (not shown) are configured.

  A part of the cooling member 6 is fixed in contact with the bottom surface of the metal case 4. The aforementioned six switching power modules 8 are fixed in contact with the cooling member 6 and are disposed inside the case 4. The heat generated in the switching power module 8 is radiated to the atmosphere via the cooling fins 61 provided on the cooling member 6.

  A smoothing capacitor 1 constituted by a flat wound film capacitor is disposed inside the case 4 and fixed to the case 4 by a main body fixing screw 3 screwed into the case 4. The main body fixing screw 3 may pass through the case 4 and be screwed to the cooling member 6. The smoothing capacitor 1 is provided in order to suppress pulsation of the DC voltage or DC current supplied to the power conversion unit, and a plurality of smoothing capacitors 1 are provided in order to secure necessary capacitance. They are connected in parallel to each other. The plurality of smoothing capacitors 1 connected in parallel are connected between the DC terminals of the power converter. Although not shown, the plurality of smoothing capacitors 1 are juxtaposed adjacently and fixed to the case 4.

The DC-side input terminal 81 of the switching power module 8 is fixed to the case 4 together with one terminal 11 of the smoothing capacitor 1 by a terminal fixing screw 21. The DC input terminal 81 of the switching power module 8, the terminal 11 of the smoothing capacitor 1, and the case 4 are electrically connected to each other and connected to a main power source (not shown) such as a battery. The AC input terminal 82 of the switching power module 8 is fixed to the case 4 by the terminal fixing screw 22 and is electrically connected thereto, and is connected to a vehicle motor (not shown).

  A recess 41 is formed on the back surface of the case 4 corresponding to the vicinity of the position where the smoothing capacitor 1 is fixed. The vibration isolating member 5 is inserted in a state of being pressed between the inner surface of the recess 41 of the case 4 and the surface of the cooling member 6. The recess 41 of the case 4 constitutes a position restricting portion that restricts the position of the vibration isolating member 5. The cover 7 fixed to the case 4 covers the entire power conversion device including the plurality of smoothing capacitors 1 and the plurality of switching power modules 8 and the like. Protect.

  Since the smoothing capacitor 1 uses a flat wound film capacitor, noise is generated due to pulsation of a DC voltage or a DC current supplied to an inverter that constitutes a power conversion unit. In order to prevent foreign matter and condensation, a cover 7 covering the entire power conversion device is attached, and this cover 7 also has a sufficient sound insulation function, so that the noise on the top surface and side surface of the smoothing capacitor 1 is reduced. can do.

  According to the power conversion device according to the first embodiment of the present invention configured as described above, the vibration isolating member 5 is inserted between the case 4 and the cooling member 6, so that it occurs in the smoothing capacitor 1. The vibration or noise is absorbed by the vibration isolating member 5 and the transmission to the case 4 is cut off, so that the noise or vibration generated from the gap between the case 4 and the cooling member 6 and the cooling member 6 can be greatly reduced. .

  In addition, since a flat wound film capacitor is used as the smoothing capacitor 1, there is little dead space due to the juxtaposition of a plurality of smoothing capacitors 1, and a small, low noise or low vibration and small power converter is obtained. Can do.

  Furthermore, when the vibration isolating member 5 is not positioned, there is a possibility that the position of the vibration isolating material 5 is moved due to expansion and contraction such as a heat cycle and the sound insulation performance is reduced. 1 is provided with the recess 41 for inserting the vibration isolating member 5 on the back surface of the case 4, the insertion position of the vibration isolating member 5 is regulated by restricting the insertion position of the vibration isolating member 5. The sound insulation performance can be maintained by preventing the displacement, and the vibration isolation member 5 can be inserted without changing the external size of the power converter.

  Further, the sound insulation performance can be arbitrarily controlled by arbitrarily changing the type and insertion range of the vibration isolating member 5. For example, if it is desired to improve the sound insulation performance, an ethylene-propylene rubber foam may be used as the vibration isolating member 5. When the vibration isolating member 5 and the case 4 and the cooling member 6 are not in close contact with each other, the sound insulation effect is reduced. However, since the ethylene-propylene rubber foam can be compressed even with a very small force, the case 4 is not deformed. Each of them can be easily brought into close contact with each other, and since they are extremely excellent in soundproofing and vibration proofing properties, a great sound insulation performance can be obtained.

Embodiment 2. FIG.
FIG. 2 is a block diagram showing a power conversion apparatus according to Embodiment 2 of the present invention. In FIG. 2, a cavity 9 formed by a recess 41 is provided on the back surface of the case 4 corresponding to the vicinity of the position where the smoothing capacitor 1 is fixed. Further, a recess 42 is formed on the back surface of the case 4 in the vicinity of the cavity 9. The vibration isolation member 51 is inserted in a state of being pressed between the inner surface of the recess 42 of the case 4 and the surface of the cooling member 6. The recess 42 of the case 4 constitutes a position restricting portion that restricts the position of the vibration isolating member 5. Other configurations are the same as those of the power conversion device according to the first embodiment.

  Since the smoothing capacitor 1 uses a flat wound film capacitor, noise is generated due to pulsation of a DC voltage or a DC current supplied to an inverter that constitutes a power conversion unit. In order to prevent foreign matter and condensation, a cover 7 covering the entire power conversion device is attached, and this cover 7 also has a sufficient sound insulation function, so that the noise on the top surface and side surface of the smoothing capacitor 1 is reduced. can do.

  According to the power conversion device according to the second embodiment of the present invention configured as described above, the cavity portion 9 is provided between the case 4 and the cooling member 6 and the vibration isolating member 51 is inserted. The vibration or noise generated in the capacitor 1 is absorbed by the vibration isolating member 5 and the transmission to the case 4 is cut off, and the noise or vibration generated from the gap between the case 4 and the cooling member 6 and the cooling member 6 is greatly increased. Can be reduced. In particular, by combining the vibration isolating member 51 and the cavity 9, the minimum area necessary for the sound insulation performance can be obtained, so that the cost increase due to noise countermeasures can be minimized.

  In addition, since a flat wound film capacitor is used as the smoothing capacitor 1, there is little dead space due to the juxtaposition of a plurality of smoothing capacitors 1, and a small, low noise or low vibration and small power converter is obtained. Can do.

  Furthermore, since the recess 42 for inserting the vibration isolating member 51 is provided on the back surface of the case 4, the vibration isolating member 5 can be inserted without changing the external size of the power conversion device, and the vibration isolating member. By restricting the insertion position of 51, it is possible to prevent the insertion position of the vibration isolation member 51 from shifting.

  Furthermore, when the vibration isolating member 5 is not positioned, the position of the vibration isolating material 51 may move due to expansion and contraction such as a heat cycle, and the sound insulation performance may be reduced. According to the power conversion device 2, the recess 42 for inserting the vibration isolating member 51 is provided on the back surface of the case 4, so that the insertion position of the vibration isolating member 51 is regulated by restricting the insertion position of the vibration isolating member 51. The sound insulation performance can be maintained by preventing the displacement, and the vibration isolation member 51 can be inserted without changing the external size of the power converter.

  Further, the sound insulation performance can be arbitrarily controlled by arbitrarily changing the type and insertion range of the vibration isolating member 5. For example, when it is desired to improve the sound insulation performance, an ethylene-propylene rubber foam may be used as the vibration isolation member 51. When the vibration isolating member 1 and the case 4 and the cooling member 6 are not in close contact with each other, the sound insulation effect is reduced. However, since the ethylene-propylene rubber foam can be compressed even with a very small force, the case 4 is not deformed. Each of them can be easily brought into close contact with each other, and since they are extremely excellent in soundproofing and vibration proofing properties, a great sound insulation performance can be obtained.

It is a block diagram which shows the power converter device by Embodiment 1 of this invention. It is a block diagram which shows the power converter device by Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Smoothing capacitor 2 Terminal fixing screw 3 Main body fixing screw 4 Case 41, 42 Recessed part 5, 51 Anti-vibration member 6 Cooling member 7 Cover 8 Switching power module 9 Cavity part 10 Smoothing capacitor

Claims (10)

  A power conversion unit that performs power conversion between direct current and alternating current by a switching operation of the switching element, a control circuit unit that controls the switching operation of the switching element, and suppresses fluctuations in power supply voltage supplied to the switching element In a power converter comprising a smoothing capacitor, a case for fixing the smoothing capacitor and housing the switching element and the smoothing capacitor, and a cooling member fixed to the case and cooling the switching element. A power conversion device, wherein a vibration isolating member is inserted between the cooling member and the case.   2. The power conversion device according to claim 1, wherein the vibration isolation member is inserted corresponding to a position where the case fixes the smoothing capacitor.   The power conversion device according to claim 1 or 2, wherein a position restricting portion for restricting a position of the vibration isolating member is provided in at least one of the case and the cooling member.   4. The power conversion device according to claim 1, wherein the vibration-proof member is formed of an ethylene-propylene rubber foam. 5.   A power conversion unit that performs power conversion between direct current and alternating current by a switching operation of the switching element, a control circuit unit that controls the switching operation of the switching element, and suppresses fluctuations in power supply voltage supplied to the switching element In a power converter comprising a smoothing capacitor, a case for fixing the smoothing capacitor and housing the switching element and the smoothing capacitor, and a cooling member fixed to the case and cooling the switching element. A power conversion device characterized in that a cavity is provided between the cooling member and the case.   The power conversion device according to claim 5, wherein the hollow portion is formed by a recess provided in the case.   The power converter according to claim 5 or 6, wherein a vibration isolating member is inserted between the cooling member and the case.   The power conversion device according to claim 7, wherein a position restricting portion that restricts a position of the vibration isolating member is provided on at least one of the case and the cooling member.   The power converter according to claim 7 or 8, wherein the vibration-proof member is formed of an ethylene-propylene rubber foam.   The power converter according to any one of claims 1 to 9, wherein the smoothing capacitor is configured by a flat wound film capacitor.

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