JP2005161940A - Air-conditioner for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-conditioner capable of suppressing and preventing electric noise generated in a compressor driving device even when a DC power supply forming a driving source of an air-conditioning equipment also drives a three-phase AC motor for traveling. <P>SOLUTION: The air-conditioner for automobile comprises a DC power supply 10 stored in a first metallic casing 12, an electric compressor 32, a compressor driving device 20 which is stored in a second metallic casing 30 to drive the electric compressor by the DC power, a filter 25 to reduce electric noise generated in the compressor driving device, and first shield parts 14 and 16 to shield a first positive electrode wire 13 and a first negative electrode wire 15. The filter includes a positive electrode side normal mode coil 26 arranged on the first positive electrode wire, a negative electrode side normal mode coil 27 arranged on the first negative electrode wire, and a common mode coil 28 arranged between the first positive electrode wire, the first negative electrode wire and the GND. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air conditioner for automobiles, and more particularly to an apparatus that suppresses electric noise generated by a compressor driving device that drives an electric compressor.

  There is a case where an electric compressor is driven by a compressor driving device that is operated by a DC power source as one type of air conditioner for automobiles. For example, it is employed in an air conditioner of an electric vehicle or a hybrid vehicle (hereinafter referred to as “hybrid vehicle etc.”) that drives an electric motor with a DC power source. During driving, a large current flows from the compressor driving device to the electric compressor, and electrical noise may be generated, which may be noise of the in-vehicle radio.

  In order to prevent this, in a conventional automobile air conditioner (see Patent Document 1), a filter 105 is disposed between the DC power supply 100 and the compressor driving device 102 as shown in FIG. As shown in FIG. 6B, the filter 105 includes a coil 107 disposed in the positive electrode side wiring 106, a capacitor 108 disposed between the positive electrode side wiring 106 and the ground 110, and a negative electrode side wiring 111. It includes a coil 112 disposed and a capacitor 113 disposed between the negative electrode side wiring 111 and the ground 110.

The compressor driving device 102 is covered with a metal casing. Further, the wiring 121 between the filter 105 and the compressor driving device 102 and the wiring 122 between the compressor driving device 102 and the electric compressor 115 are shielded by shield members 123 and 124, respectively.
Japanese Patent No. 3266026

  In the conventional example, the noise is removed by the filter 105 arranged between the DC power supply 100 and the compressor driving device 102 (low frequency components are allowed to pass), thereby shielding the wiring 126 between the DC power supply 100 and the filter 105. Will be abolished. However, it cannot be said that there is no doubt as to whether or not this can be done in an actual hybrid vehicle.

  That is, in a hybrid vehicle or the like, in addition to the electric compressor 115, a three-phase AC motor (not shown) and a motor driving inverter are driven by the DC power of the DC power source 100. In particular, the output of the inverter for driving the motor is much larger than the output of the compressor driving device 102 (may be several tens of times), and the risk of generating electrical noise is high accordingly. In addition, there is a possibility that electrical noise is radiated from a wiring (not shown) between the DC power supply 110 and the motor driving inverter, from the wiring 126 between the DC power supply 110 and the compressor driving device 102. Higher than fear.

  Therefore, in the conventional example, even if the electrical noise radiated from the wiring 126 is prevented, if the electrical noise radiated from the wiring between the DC power supply 100 and the motor driving inverter is not prevented, an actual hybrid vehicle is used. However, noise countermeasures are not enough.

  Since the motor in the electric compressor is immersed in the air conditioner refrigerant, the motor and the metal casing are coupled with a large capacitance in the electric compressor. In a vehicle such as a hybrid vehicle, the GND potential is not stable, and in order to prevent radio noise, reduction of common mode noise is a greater issue than normal mode noise.

  The present invention has been made in view of the above circumstances, and in an automotive air conditioner, even if a DC power source that drives a compressor drive device also drives a traveling three-phase AC motor or inverter, the compressor drive An object of the present invention is to provide an automotive air conditioner capable of suppressing electrical noise generated in the apparatus and preventing radiation of electrical noise from a DC power source, a compressor driving device, and wiring between the DC power source and the compressor driving device. And

  The present invention is a basic technique for preventing the radiation of electric noise from a DC power source, a compressor driving device, and wiring between the DC power source and the compressor driving device, and further suppressing the electric noise generated in the compressor driving device. It is thought.

The automotive air conditioner according to the present invention includes a DC power source 10 housed in the first metal housing 12, an electric compressor 32, and a second metal housing 30 housed in the DC power source. A compressor driving device 20 that drives an electric compressor with supplied DC power; a filter 25 that is disposed between the DC power source and the compressor driving device to reduce electrical noise generated in the compressor driving device; and a DC power source and a filter. An automotive air conditioner comprising first shield portions 14 and 16 that shield the first positive electrode wiring 13 and the first negative electrode wiring 15 therebetween,
The filter includes a positive-side normal mode coil 26 arranged in a positive electrode wiring extending from the positive electrode of the DC power source to the compressor driving device, and a negative-side normal mode coil arranged in a negative electrode wiring extending from the negative electrode of the DC power source to the compressor driving device. 27, and a common mode coil 28 disposed between the positive and negative wirings and GND.

  According to a second aspect of the present invention, the positive air-side normal mode coil and the negative-side normal mode coil have the same inductance. According to a third aspect of the present invention, there is provided an automotive air conditioner according to the second aspect, wherein the electric compressor and the compressor driving device are structurally integrated. According to a fourth aspect of the present invention, there is provided the air conditioner for automobiles according to the third aspect, wherein the filter is housed in the second metal casing. According to a fifth aspect of the present invention, there is provided an automotive air conditioner according to the fourth aspect, wherein the electric compressor is housed in the third metal casing 31 and the AC wiring 33 between the compressor driving device and the electric compressor is shielded by the second shield part 34. ing.

  According to a sixth aspect of the present invention, the positive air-side normal mode coil and the negative-side normal mode coil are located closer to the DC power source than the common mode coil. According to a seventh aspect of the present invention, there is provided a vehicle air conditioner according to the sixth aspect, wherein a positive common mode capacitor and a negative common mode capacitor are disposed closer to the compressor driving device than the common mode coil.

  According to an eighth aspect of the present invention, there is provided an automotive air conditioner according to the first aspect, wherein the automobile is a hybrid vehicle or the like, and the traveling three-phase AC motor 45 is driven by a motor driving device 35 to which DC power is supplied from a DC power source. According to a ninth aspect of the present invention, there is provided an automotive air conditioner according to the eighth aspect, wherein the motor driving device is accommodated in the fourth metal casing 38, and the positive electrode wiring 41 and the negative electrode wiring 43 between the DC power source and the motor driving device are third. The shield members 42 and 44 are shielded.

  According to the automotive air conditioner of the present invention, even when a DC power source is a driving source for a traveling system, electric noise generated in the compressor driving device is effectively suppressed and prevented by the normal mode coil and the common mode coil. . In addition, radiation of electrical noise from the DC power source and the compressor driving device is prevented by the metal casing.

  According to the automotive air conditioner of the second aspect, a remarkable noise reduction effect of the filter can be obtained by the equal inductance of both normal mode coils. According to the automobile air conditioner of the third aspect, the grounding of the compressor driving device and the electric compressor is simplified, and the wiring shield between the compressor driving device and the electric compressor becomes unnecessary. According to the automotive air conditioner of the fifth aspect, radiation of electric noise from the electric compressor or the wiring between the compressor driving device and the electric compressor is prevented.

  According to the automotive air conditioner of the sixth aspect, the normal mode noise and the common mode noise are effectively reduced, and the automotive air conditioner of the seventh aspect is further effectively reduced. According to the automotive air conditioner of the eighth aspect, a single DC power source can be used for the traveling system in addition to the air conditioning system, and the accommodation space is halved. According to the automobile air conditioner of the ninth aspect, radiation of electrical noise from the motor drive device or the wiring between the DC power source and the motor drive device is prevented.

<Automotive air conditioner>
(A) Overall Configuration FIG. 5 shows the basic concept (overall configuration) of the automotive air conditioner of the present invention. A DC power supply 71 is accommodated in the metal casing 70, a compressor driving device 76 and an AM band cutoff filter 82 are accommodated in the metal casing 80, and the electric compressor 87 is accommodated in the metal casing 90. A smoothing capacitor 77 and an inverter bridge circuit 78 arranged in parallel between a positive electrode wiring 72 and a negative electrode wiring 73 extending from the positive electrode and the negative electrode of the DC power source 71 to the compressor driving device 76, are connected to the three-phase AC motor in the electric compressor 87. Arranged to drive and control. The compressor driving device 76 and the electric compressor 87 are connected by three AC wires 88.

Normal mode coils 83 and 84 constituting an AM band cutoff filter are inserted into the positive electrode wiring 72 and the negative electrode wiring 73, respectively, and a common mode coil 85 is inserted between the positive electrode wiring 72 and the negative electrode wiring 73 and the GND 91. These coils 83, 84 and 85 suppress or reduce electrical noise generated in the inverter bridge circuit 78.
(B) AM band cutoff filter a. As described above, a car radio that is one of in-vehicle devices has a built-in tuner that receives a medium wave (AM). Electrical noise generated by the chopping operation or the like of the inverter bridge circuit 78 of the compressor driving device 76 may enter the tuner through the wiring or through the antenna due to radiation, resulting in annoying noise.

Electrical noise includes normal mode noise and common mode noise. The noise component is often transmitted in the common mode, and the common mode coil is effective in separating the signal and the noise.
b. Normal mode noise occurs between power supply lines and signal lines, and the directions of noise currents are opposite to each other. In the case of the common mode coil, the magnetic flux due to the normal mode current cancels each other and no impedance is generated, so the influence is small. In the present invention, normal mode noise is reduced by inserting a pair of normal mode coils in each power line. The inductances of both normal mode coils are preferably equal, but may be different.

  On the other hand, common mode noise is generated between the power supply line or signal line and GND, and the noise current is in the same direction. In the case of a common mode coil, the magnetic flux generated by the common mode current is added to generate impedance, and the common mode noise is reduced by functioning as an inductor with respect to the common mode noise.

Any of the pair of normal mode coils and common mode coils may be arranged on the DC power supply side, and any of them may be arranged on the compressor driving device side. When both normal mode coils are on the DC power supply side and on the compressor driving device side of the common mode coil, a positive common mode capacitor and a negative common mode capacitor can be arranged closer to the compressor driving device than these.
c. Metal casing, shield member The DC power supply 71, the compressor driving device 76, and the electric compressor 87 are covered with the metal casings 70 and 80 and the metal casing 90, respectively, to prevent radiation of electrical noise. Moreover, the positive electrode wiring 72, the negative electrode wiring 73, and the three-phase wiring 88 are shielded by shield members 74, 75, and 89, respectively, so that radiation of electrical noise from the wiring is prevented.
(C) Modified Mode In FIG. 5, the compressor driving device 76 and the electric compressor 87 are structurally separate, but they may be integrated. Moreover, although the electric compressor 76 and the AM band cutoff filter 82 are accommodated in the common metal casing 80, both may be accommodated in separate metal casings. This air conditioner exhibits a remarkable effect when used in a hybrid vehicle or the like, but can also be used in vehicles other than a hybrid vehicle or the like.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
<First embodiment>
(Constitution)
The hybrid vehicle air conditioner shown in FIG. 1 includes an air conditioning system and a drive system. Among these, the air conditioning system includes a DC power supply 10, a filter, a compressor driving device 20, and an electric compressor. A DC power supply 10 is accommodated in a metal casing 11, and a positive electrode and a negative electrode are connected to the compressor driving device 20 by a positive electrode wiring 13 and a negative electrode wiring 15, respectively. The compressor driving device 20 includes a smoothing capacitor 21 and a three-phase inverter bridge circuit 22 connected in parallel between the positive electrode wiring 13 and the negative electrode wiring 15.

  An AM band cut-off filter (hereinafter referred to as “filter”) 25 is interposed between the DC power supply 10 and the compressor drive device 20. The filter 25 includes a positive electrode normal mode coil 26 inserted in the positive electrode wiring 13, a negative electrode normal mode coil 27 inserted in the negative electrode wiring 15, and between the positive electrode wiring 13 and the negative electrode wiring 15 and the ground (GND) 57. An inserted common mode coil 28 is included. The inductances of the two normal mode coils 26 and 27 are equal to each other.

  The compressor driving device 20 and the AM band cutoff filter 25 are accommodated in a common (one) metal casing 30. The positive electrode wiring 13 and the negative electrode wiring 15 between the DC power supply 10 and the metal housing 30 are shielded by seal members 14 and 16, respectively. Three AC wirings 33 connecting the three-phase inverter bridge circuit 22 of the compressor driving device 20 and the electric compressor 32 are shielded by shield members 34, respectively.

  The drive system includes a DC power supply 10, a motor drive device 35, and a three-phase AC motor 45. The motor drive device 35 is connected to the DC power supply 10 by a positive electrode wiring 41 branched from the positive electrode wiring 13 and a negative electrode wiring 43 branched from the negative electrode wiring 14, and is arranged in parallel between the positive electrode wiring 41 and the negative electrode wiring 43. The smoothing capacitor 36 and the inverter bridge circuit 37 are housed in a metal casing 38. The positive electrode wiring 41 and the negative electrode wiring 43 are shielded by shield members 42 and 44, respectively. In addition, the three AC wirings 46 that connect the motor driving device 35 and the three-phase AC motor 45 are shielded by shield members 47, respectively.

A metal housing 11 that houses the DC power supply 10, a metal housing 30 that houses the compressor driving device 20 and the filter 25, a metal housing 31 that houses the electric compressor 32, a metal housing 38 that houses the motor driving device 35, and The metal casing 48 that houses the three-phase AC motor 45 is grounded to the vehicle body (GND) 57 by ground wires 51, 52, 53, 54, and 55, respectively.
(Function)
The motor drive device 35 is operated by the DC power supplied from the DC power supply 10 and drives the three-phase AC motor 45 at the time of starting after the idle stop. In addition, the compressor driving device 20 is operated by the DC power supplied from the DC power source 10 to drive the electric compressor 32 at the time of idling stop or the like to air-condition the interior of the vehicle. However, since these actions are known, further detailed explanation is omitted.

  When the compressor driving device 20 and the motor driving device 35 are driven, electrical noise is generated from the three-phase inverter bridge circuits 22 and 37. Since the three-phase inverter bridge circuits 22 and 37 are normally driven at 10 kHz, the generated electrical noise is mainly in the AM band. Noise from the inverter bridge circuit 22 is suppressed and prevented by the pair of normal mode coils 26 and 27 and one common mode coil 28. Here, since the positive-side normal mode coil 26 and the negative-side normal mode coil 27 have the same inductance, both common mode currents cancel each other.

Further, a metal casing 12 in which the DC power supply 10 is accommodated, a metal casing 30 in which the compressor driving apparatus 20 is accommodated, a metal casing 31 in which the electric compressor 32 is accommodated, and a motor driving apparatus are accommodated. The metal casing 38 and the metal casing 48 in which the three-phase AC motor 45 is housed each prevent radiation of electrical noise. Further, the radiation of noise from the positive electrode wiring 13 and the negative electrode wiring 15 between the DC power supply 10 and the compressor driving device 20 is prevented by the shield members 14 and 15. The noise radiation from the AC wiring 33 between the compressor driving device 20 and the electric compressor 32 is radiated from the AC wiring 46 between the motor driving device 35 and the three-phase AC motor 45 by the shield member 34. Is prevented by the shield member 47, respectively.
(effect)
According to this embodiment, the following effects can be obtained. First, electrical noise generated in the compressor driving device 20 and the motor driving device 35 is effectively suppressed by the filter 25. 2A shows a filter 25 of the embodiment, FIG. 2B shows a modified example 25A thereof, and FIG. 2C shows a conventional filter 105 (see FIG. 6B). Note that FIG. 2D shows a reference example 115 in which the normal mode coil 117 is inserted into only one wiring 116. In any case, the magnitude of the electrical noise was measured by the positive electrode wiring 13 and the negative electrode wiring 15 between the DC power supply 10 and the compressor driving device 20. The measurement results (relationship between noise level and frequency) in each case are shown in FIG.

  In FIG. 3, the noise level when the filter 25 of the embodiment is used is indicated by a curve x, and the noise level when the conventional filter 105 is used is indicated by a curve y. In the entire range of frequencies from 0.2 MHz to 2.0 MHz, the curve x indicating the noise level of the embodiment is lower than the curve y indicating the noise level of the conventional example. In particular, the difference is large at frequencies of 0.5 MHz to 1.6 MHz corresponding to the AM band.

  Further, as shown in FIG. 3D, the noise reduction effect of the filter 115 (reference example) in which the normal mode coil 117 is inserted only in one wiring 116 is shown by a curve z. As can be seen, the frequency from 0.2 MHz to 1.4 MHz is almost the same as the conventional example of FIG. 3B, but is inferior to this at frequencies of 1.4 MHz or higher. Comparison between the curve x and the curve z shows the effectiveness of arranging the normal mode coils 26 and 27 in both the positive electrode wiring 13 and the negative electrode wiring 15 as in the filter 25 of the embodiment. Further, from the comparison between the curve x and the curve y, the effectiveness of arranging the common mode coil 28 between the positive electrode wiring 13 and the negative electrode wiring 15 and the ground 57 is understood.

In FIG. 2A, a positive-side common mode capacitor and a negative-side common mode capacitor can be arranged on the downstream side (right side) of the pair of normal mode coils 26 and 27 and the common mode coil 28, respectively. It has been confirmed that the addition of such a pair of common mode capacitors further reduces the noise level than the curve x.

  Further, as shown in FIG. 2B, a modification in which the pair of normal mode coils 26 and 27 and one common mode coil 28 are exchanged in the direction of current flow (direction connecting the DC power supply 10 and the electric compressor 32). It has been confirmed that the noise reduction effect similar to that of the embodiment of FIG.

Second, radiation of electrical noise from the DC power supply 10, the compressor driving device 20, the electric compressor 32, and the motor driving device 35 is prevented, and the positive wiring 13, the negative wiring 15, the three-phase wiring 33, and the positive wiring. The radiation of electrical noise from the 41, the negative electrode wiring 43 and the three-phase wiring 46 is prevented. Thirdly, a single DC power supply 10 can be used for driving and control of the air conditioning system and driving and control of the traveling system, and the accommodation space of the DC power supply 10 is reduced as compared with the case where they are provided separately.
<Second embodiment>
In the second embodiment shown in FIG. 4, the compressor driving device 20 and the electric compressor 32 are structurally integrated. Specifically, the electric compressor 32 is also accommodated in the metal housing 60 in which the compressor driving device 20 and the filter 25 are accommodated. The inverter bridge circuit 22 and the electric compressor 32 are connected by an AC wiring 62. Further, the metal casing 60 is grounded to the GND 57 by a single ground wiring 62.

  Other configurations are basically the same as those of the first embodiment. Therefore, the three-phase AC motor 45 (see FIG. 1) is driven by the DC power source 10 via the motor driving device 35 (see FIG. 1).

  The specific effects of the second embodiment are as follows. The shield of the AC wiring 61 between the compressor driving device 22 and the electric compressor 32 is not necessary, and the noise reduction effect of the filter 25 is conspicuous. That is, if there is no leakage of common mode noise in the wirings 13 and 15, an almost noise-free air conditioner can be realized. Further, only one ground wiring 62 is required between the compressor driving device 20 and the electric compressor 32 and the GND 57. Further, a dedicated metal housing for housing the coil electric compressor 32 is not necessary.

BRIEF DESCRIPTION OF THE DRAWINGS It is whole explanatory drawing which shows 1st Example of this invention. Various filters are shown, (a) is an AM band cut-off filter of the first embodiment, (b) is a modification of the filter of the first embodiment, (c) is a filter of a conventional example, and (d) is a reference example. Indicates a filter. It is a graph which shows the noise reduction effect by the various filters of FIG. It is principal part explanatory drawing which shows 2nd Example of this invention. It is explanatory drawing which shows the best form for inventing. (A) is a general explanatory view of a conventional example, and (b) is a main portion explanatory view thereof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: DC power supply 12: 1st metal housing 13: 1st positive electrode wiring 15: 1st negative electrode wiring 14, 16: 1st shield member 20: Compressor drive device 25: AM band cutoff filter 26: Positive side normal mode coil 27 : Negative side normal mode coil 28: Common mode coil 30: Second metal casing

Claims (9)

A DC power source housed in the first metal housing 12; an electric compressor; a compressor driving device for driving the electric compressor by DC power housed in the second metal housing and supplied from the DC power source; and the DC power source And a filter disposed between the compressor driving device and the electric compressor for reducing electrical noise generated by the compressor driving device, and a first positive electrode wiring and a first negative electrode wiring between the DC power source and the filter are shielded. An automotive air conditioner comprising a shield part,
The filter includes a positive-side normal mode coil disposed on the first positive electrode wiring extending from the positive electrode of the DC power source to the compressor driving device, and the first negative electrode extending from the negative electrode of the DC power source to the compressor driving device. An automotive air conditioner comprising: a negative-side normal mode coil arranged in wiring; and a first positive-electrode wiring and a common mode coil arranged between the first negative-electrode wiring and GND.   The automotive air conditioner according to claim 1, wherein the positive electrode side normal mode coil and the negative electrode side normal mode coil have the same inductance.   The automotive air conditioner according to claim 2, wherein the electric compressor and the compressor driving device are structurally integrated.   The automobile air conditioner according to claim 3, wherein the filter is accommodated in the second metal casing.   5. The automotive air conditioner according to claim 4, wherein the electric compressor is housed in a third metal casing, and an AC wiring between the compressor driving device and the electric compressor is shielded by a second shield part.   2. The automotive air conditioner according to claim 1, wherein the positive-side normal mode coil and the negative-side normal mode coil are located closer to the DC power source than the common mode coil.   The automotive air conditioner according to claim 6, wherein a positive-side common mode capacitor and a negative-side common mode capacitor are disposed on the compressor driving device side of the common mode coil.   The automobile air conditioner according to claim 1, wherein the automobile is a hybrid car or the like, and the traveling three-phase AC motor is driven by a motor driving device supplied with DC power from the DC power supply.   The said motor drive device is accommodated in the 4th metal housing | casing, The 2nd positive electrode wiring and 2nd negative electrode wiring between the said DC power supply and this motor drive device are shielded by the 3rd shield member. Automotive air conditioner.

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