JP6414014B2 - In-vehicle inverter device and in-vehicle electric compressor - Google Patents

Description

The present invention relates to an in-vehicle inverter device and an in-vehicle electric compressor .

  2. Description of the Related Art Conventionally, an in-vehicle inverter device that has a switching element and converts DC power into AC power is known (see, for example, Patent Document 1). The in-vehicle inverter device is used to drive an electric motor of an electric compressor mounted on a vehicle, as shown in Patent Document 1, for example.

Japanese Patent No. 5039515

  Here, both common mode noise and normal mode noise can be mixed in the DC power to be converted by the in-vehicle inverter device. In this case, for example, there may be a case where power conversion by the in-vehicle inverter device is not normally performed due to these noises. However, in terms of being mounted on a vehicle, it is not preferable to increase the size of the in-vehicle inverter device.

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a vehicle-mounted inverter device capable of reducing common mode noise and normal mode noise included in DC power while suppressing an increase in size and the vehicle-mounted inverter device. It is providing the vehicle-mounted electric compressor provided with this inverter apparatus.

  An in-vehicle inverter device that achieves the above object has a circuit formed of a plurality of switching elements, converts DC power into AC power, is provided on the input side of the circuit, and A noise reduction unit for reducing common mode noise and normal mode noise included in DC power, the noise reduction unit comprising: a core; a first winding wound around the first winding part of the core; and the core DC power that is constituted by a common mode choke coil having a second winding wound around the second winding portion and in which common mode noise and normal mode noise are reduced by the common mode choke coil is input to the circuit. It is characterized by that.

  According to this configuration, common mode noise included in the DC power to be converted is reduced by the common mode choke coil. Further, the common mode choke coil generates a leakage magnetic flux when a normal mode current flows. Thereby, normal mode noise can be reduced using a common mode choke coil. Therefore, it is possible to input DC power with reduced common mode noise and normal mode noise into the circuit without providing a dedicated coil for reducing normal mode noise. Can be suppressed.

  In the in-vehicle inverter device, a smoothing capacitor constituting a low-pass filter circuit in cooperation with the common mode choke coil is provided on the output side of the common mode choke coil and on the input side of the circuit, and each switching element is The carrier frequency, which is the frequency of the carrier signal used for PWM control, may be set higher than the cut-off frequency of the low-pass filter circuit. According to such a configuration, ripple noise due to switching of each switching element is attenuated by the low-pass filter circuit, so that the ripple noise can be prevented from flowing out of the in-vehicle inverter device.

  With respect to the in-vehicle inverter device described above, the frequency of normal mode noise varies depending on the vehicle type, and the resonance frequency of the low-pass filter circuit is a noise frequency band that includes a range of frequency variations of normal mode noise that is assumed. It is better to set higher. According to such a configuration, even when the frequency of the normal mode noise varies depending on the vehicle type, it is possible to suppress an excessively large normal mode noise from flowing into the in-vehicle inverter device. Thereby, versatility can be improved.

  In the above-described in-vehicle inverter device, the noise reduction unit is input with DC power of the in-vehicle power storage device shared with the in-vehicle device having the switching element, and the switching of the switching element in the in-vehicle device is performed. The frequency varies according to the vehicle type, and the noise frequency band may include a variation range of the switching frequency of the switching element of the on-vehicle device that is assumed. According to such a configuration, the in-vehicle inverter device can be applied to a plurality of vehicle types in which the switching frequency of the switching element of the in-vehicle device is different. For example, when the switching element of the on-vehicle device is PWM-controlled, the switching frequency of the switching element of the on-vehicle device is the frequency of the carrier signal used for PWM control of the switching element.

  About the said inverter apparatus for vehicle mounting, the said smoothing capacitor is good in it being a film capacitor. Film capacitors are superior in durability to electrolytic capacitors and the like, and tend to be small, while it is difficult to ensure high capacitance. In this regard, in the configuration in which the resonance frequency of the low-pass filter circuit is set higher than the noise frequency band, the capacitance of the smoothing capacitor can be lowered. Thereby, a film capacitor can be adopted as the smoothing capacitor. By adopting a film capacitor as the smoothing capacitor, it is possible to reduce the size and improve the durability of the low-pass filter circuit as compared with a configuration in which an electrolytic capacitor is used as the smoothing capacitor.

  About the said vehicle-mounted inverter apparatus, the said smoothing capacitor and the said common mode choke coil are good to be unitized. According to such a configuration, it is possible to reduce the size of the noise reduction unit, and thereby it is possible to suppress an increase in the size of the in-vehicle inverter device.

  About the said inverter apparatus for vehicle mounting, the said core is good to have the exposed part which the said coil | winding was not wound and the surface exposed. According to such a configuration, when a normal mode current flows through both windings, magnetic flux tends to leak from the exposed portion. Then, normal mode noise can be reduced by this leakage magnetic flux. Therefore, the effect mentioned above can be acquired.

  About the said inverter apparatus for vehicle mounting, at least one of the said 1st coil | winding and the said 2nd coil | winding is provided with the high density part and low density part from which the turns per unit length of a winding axis direction differ relatively. It is good to be. According to such a configuration, since at least one of the first winding and the second winding includes the high density portion and the low density portion, when the normal mode current flows in both windings, the common mode choke coil Magnetic flux leaks easily. Thereby, the effect mentioned above can be acquired.

  In the in-vehicle inverter device, the number of turns of the first winding and the number of turns of the second winding may be different. According to such a configuration, since the number of turns of the two windings is different, the magnetic flux generated in both is different. As a result, when a normal mode current flows through both windings, the common mode choke coil easily leaks magnetic flux. Therefore, the effect mentioned above can be acquired.

An in-vehicle electric compressor that achieves the above object includes the above-described in-vehicle inverter device and a housing that houses an electric motor and a compression unit, and an output side of the circuit is connected to the electric motor. It is characterized by that. According to this configuration, the in-vehicle inverter device is used to drive the electric motor of the in-vehicle electric compressor. Here, generally, a certain amount of electric power is required to drive the electric motor of the electric compressor. For this reason, as a vehicle-mounted inverter device for driving an electric motor, it is necessary to convert relatively large DC power into AC power. Since the coil for normal mode noise applicable to such a large DC power tends to be large, the noise reduction unit tends to be large.

  On the other hand, according to the present configuration, as described above, the vehicle-mounted inverter device having the noise reduction unit described above is employed as the one that drives the electric motor of the electric compressor. The electric compressor can be operated while achieving both the suppression of the increase in size and the reduction of both noises.

  According to the present invention, it is possible to reduce common mode noise and normal mode noise included in DC power while suppressing an increase in the size of an in-vehicle inverter device.

The partially broken figure which shows typically the outline | summary of the vehicle-mounted inverter apparatus, an electric compressor, and a vehicle-mounted air conditioner. The disassembled perspective view which shows the structure of a noise reduction part typically. Sectional drawing which shows the structure of a noise reduction part typically. The partially broken figure of a common mode choke coil. The equivalent circuit diagram which shows the electric constitution of the inverter apparatus for vehicle mounting. The circuit diagram which shows a part of electrical structure of PCU. The graph which shows the frequency characteristic of the low-pass filter circuit with respect to normal mode noise. The graph which shows the frequency characteristic of a low-pass filter circuit with respect to the ripple noise which generate | occur | produces in a power module. The front view which shows typically the common mode choke coil of another example. The front view which shows typically the common mode choke coil of another example.

  Hereinafter, an in-vehicle inverter device and an embodiment of an electric compressor equipped with the in-vehicle inverter device will be described. The electric compressor of this embodiment is mounted on a vehicle and is used in an in-vehicle air conditioner. That is, the electric compressor of this embodiment is for vehicle use. Hereinafter, after describing the outline of the in-vehicle air conditioner and the electric compressor, the in-vehicle inverter device will be described.

  As shown in FIG. 1, an in-vehicle air conditioner 100 includes an electric compressor 10 and an external refrigerant circuit 101 that supplies a refrigerant as a fluid to the electric compressor 10. The external refrigerant circuit 101 has, for example, a heat exchanger and an expansion valve. The in-vehicle air conditioner 100 cools and heats the interior of the vehicle by compressing the refrigerant by the electric compressor 10 and performing heat exchange and expansion of the refrigerant by the external refrigerant circuit 101.

  The in-vehicle air conditioner 100 includes an air conditioning ECU 102 that controls the entire in-vehicle air conditioner 100. The air conditioning ECU 102 is configured to be able to grasp the in-vehicle temperature, the set temperature of the car air conditioner, and the like, and transmits various commands such as an ON / OFF command to the electric compressor 10 based on these parameters.

  The electric compressor 10 includes a housing 11 in which a suction port 11 a into which a refrigerant is sucked from an external refrigerant circuit 101 is formed, and a compression unit 12 and an electric motor 13 housed in the housing 11.

  The housing 11 has a substantially cylindrical shape as a whole, and is formed of a material having heat conductivity (for example, a metal such as aluminum). The housing 11 has a discharge port 11b through which a refrigerant is discharged. The housing 11 is grounded to the vehicle body.

  The compression unit 12 compresses the refrigerant sucked into the housing 11 from the suction port 11a and causes the compressed refrigerant to be discharged from the discharge port 11b by rotating a rotating shaft 21 described later. In addition, the specific structure of the compression part 12 is arbitrary, such as a scroll type, a piston type, and a vane type.

  The electric motor 13 drives the compression unit 12. The electric motor 13 includes, for example, a columnar rotation shaft 21 that is rotatably supported with respect to the housing 11, a cylindrical rotor 22 that is fixed to the rotation shaft 21, and a stator 23 that is fixed to the housing 11. And have. The axial direction of the rotating shaft 21 and the axial direction of the cylindrical housing 11 coincide with each other. The stator 23 includes a cylindrical stator core 24 and a coil 25 wound around teeth formed on the stator core 24. The rotor 22 and the stator 23 face each other in the radial direction of the rotating shaft 21. When the coil 25 is energized, the rotor 22 and the rotating shaft 21 rotate, and the refrigerant is compressed by the compression unit 12. The drive current of the electric motor 13 is higher than the signal current or the like, and is, for example, 10 A or more, preferably 20 A or more.

  As shown in FIG. 1, the electric compressor 10 includes an in-vehicle inverter device 30 that drives the electric motor 13 and an inverter case 31 in which the in-vehicle inverter device 30 is accommodated.

  The inverter case 31 is formed of a heat conductive material (for example, a metal such as aluminum). The inverter case 31 includes a plate-like base member 32 that is in contact with the housing 11, specifically, the wall portion 11 c opposite to the discharge port 11 b of both wall portions in the axial direction of the housing 11, and the base A bottomed cylindrical cover member 33 assembled to the member 32. The base member 32 and the cover member 33 are fixed to the housing 11 by a bolt 34 as a fixing tool. As a result, the inverter case 31 and the in-vehicle inverter device 30 housed in the inverter case 31 are attached to the housing 11. That is, the in-vehicle inverter device 30 of this embodiment is integrated with the electric compressor 10.

  Incidentally, since the inverter case 31 and the housing 11 are in contact with each other, they are thermally coupled. The in-vehicle inverter device 30 is disposed at a position where it is thermally coupled to the housing 11. Note that a communication hole or the like that communicates the space in the inverter case 31 and the space in the housing 11 is not provided, so that the refrigerant does not directly flow into the inverter case 31.

  The wall portion 11 c of the housing 11 to which the inverter case 31 is attached is disposed on the opposite side of the compression portion 12 with respect to the electric motor 13. If attention is paid to this point, it can be said that the inverter case 31 is disposed on the opposite side of the compression unit 12 with respect to the electric motor 13. The compression unit 12, the electric motor 13, and the in-vehicle inverter device 30 are arranged in the axial direction of the rotating shaft 21. That is, the electric compressor 10 of the present embodiment is a so-called inline type.

  The in-vehicle inverter device 30 includes, for example, a circuit board 41 fixed to the base member 32 and a power module 42 mounted on the circuit board 41. The output side of the power module 42 is electrically connected to the coil 25 of the electric motor 13 via an airtight terminal (not shown) provided on the wall portion 11 c of the housing 11. The power module 42 includes a plurality of switching elements Qu1, Qu2, Qv1, Qv2, Qw1, Qw2 (hereinafter also simply referred to as switching elements Qu1-Qw2). In the present embodiment, the power module 42 corresponds to “a circuit formed of a plurality of switching elements” and “a conversion circuit”.

  A connector 43 is provided on the inverter case 31 (specifically, the cover member 33). Direct current power is supplied from the DC power source E mounted on the vehicle to the in-vehicle inverter device 30 via the connector 43, and the air conditioning ECU 102 and the in-vehicle inverter device 30 are electrically connected. The vehicle is provided with a power supply capacitor C0 connected in parallel to the DC power supply E (see FIG. 5). The power supply capacitor C0 is constituted by, for example, an electrolytic capacitor.

  The in-vehicle inverter device 30 includes two wirings EL1 and EL2 that electrically connect the connector 43 and the input side of the power module 42. The first wiring EL1 is connected to the positive terminal (positive terminal) of the DC power source E via the connector 43 and is connected to the first module input terminal 42a that is the first input terminal of the power module 42. Yes. The second wiring EL2 is connected to the negative terminal of the DC power source E via the connector 43 and to the second module input terminal 42b that is the second input terminal of the power module 42. Yes. The in-vehicle inverter device 30 is configured such that each switching element Qu1 to Qw2 is periodically turned on / off in a situation where direct current power is input to the power module 42 via the two wirings EL1 and EL2. Is converted into AC power, and the AC power is output to the coil 25 of the electric motor 13. Thereby, the electric motor 13 is driven.

  Note that the current (in other words, electric power) handled by the in-vehicle inverter device 30 is large enough to drive the electric motor 13, and is larger than the signal current (in other words, electric power). For example, the current handled by the in-vehicle inverter device 30 is 10 A or more, preferably 20 A or more. The DC power source E is an in-vehicle power storage device such as a secondary battery or a capacitor.

  Here, the DC power transmitted from the connector 43 toward the power module 42, specifically, the DC power transmitted through both the wirings EL1 and EL2, may include common mode noise and normal mode noise.

  Common mode noise is noise in which currents in the same direction flow through both wirings EL1 and EL2. The common mode noise is electrically generated, for example, by the in-vehicle inverter device 30 (in other words, the electric compressor 10) and the DC power source E via a path (for example, a vehicle body) other than the wirings EL1 and EL2. This can happen when connected. The normal mode noise is noise having a predetermined frequency superimposed on DC power, and when instantaneously viewed, currents flowing in opposite directions through the wirings EL1 and EL2 flow. It can be said that the normal mode noise is an inflow ripple component included in DC power flowing into the in-vehicle inverter device 30. Details of the normal mode noise will be described later.

  In contrast, the in-vehicle inverter device 30 according to the present embodiment includes a noise reduction unit 50 that reduces common mode noise and normal mode noise included in DC power transmitted from the connector 43 toward the power module 42. ing. The noise reduction unit 50 is provided on both the wirings EL <b> 1 and EL <b> 2, and the DC power supplied from the connector 43 is input to the power module 42 through the noise reduction unit 50.

The noise reduction unit 50 will be described in detail.
As shown in FIGS. 2 to 4, the noise reduction unit 50 includes a common mode choke coil 51, for example. The common mode choke coil 51 has a core 52 and a first winding 53a and a second winding 53b wound around the core 52.

  The core 52 is formed in, for example, a polygonal (rectangular in this embodiment) annular shape. As shown in FIGS. 2 and 4, the core 52 includes a first winding part 52a around which the first winding 53a is wound, a second winding part 52b around which the second winding 53b is wound, Both windings 53a and 53b are not wound and have an exposed portion 52d where the surface 52c of the core 52 is exposed. Both windings 53a and 53b are arranged to face each other in a state in which the winding axis directions coincide with each other. In the present embodiment, the number of turns (number of turns) of both the windings 53a and 53b is set to be the same.

  In the present embodiment, the core 52 is composed of one part. However, the present invention is not limited to this, and the core 52 may be configured, for example, by connecting two symmetrical parts, or may be configured by three or more parts.

  As shown in FIG. 2, the common mode choke coil 51 includes a first input terminal 61 and a first output terminal 62 drawn from the first winding 53a, and a second input terminal 63 drawn from the second winding 53b. And a second output terminal 64.

  As shown in FIGS. 3 and 5, the first wiring EL <b> 1 used to connect the + terminal of the DC power source E and the power module 42 is the first wiring that connects the connector 43 and the first input terminal 61. A connector-side wiring EL11 and a first module-side wiring EL12 that connects the first output terminal 62 and the first module input terminal 42a are provided.

  The second wiring EL2 used to connect the negative terminal of the DC power source E and the power module 42 includes a second connector-side wiring EL21 that connects the connector 43 and the second input terminal 63, and a second output terminal. 64 and a second module side wiring EL22 for connecting the second module input terminal 42b. As a result, the DC power of the DC power source E is input to the power module 42 through both the connector-side wirings EL11 and EL21 → the both windings 53a and 53b → the both module-side wirings EL12 and EL22. That is, the module-side wirings EL12 and EL22 connect the output side of the common mode choke coil 51 and the input side of the power module 42. In this case, it can be said that the windings 53a and 53b are provided on the wirings EL1 and EL2. Both terminals 61 and 62 can also be said to be both ends of the first winding 53a, and both terminals 63 and 64 can also be said to be both ends of the second winding 53b.

  The common mode choke coil 51 has a relatively large impedance (specifically, an inductance) when a common mode current flows through both wirings EL1 and EL2, and has an impedance when a normal mode current flows through both wirings EL1 and EL2. Is configured to be relatively small. More specifically, the windings 53a and 53b generate magnetic fluxes that reinforce each other when a common mode current, which is a current in the same direction, flows through the wirings EL1 and EL2 (in other words, both windings 53a and 53b). On the other hand, when normal mode currents, which are currents in opposite directions, flow through both wirings EL1, EL2, they are wound so as to generate magnetic fluxes that cancel each other.

  Here, since the exposed portion 52d is provided in the core 52, a leakage magnetic flux is generated in the common mode choke coil 51 in a situation where a normal mode current flows through both the wirings EL1 and EL2. That is, the common mode choke coil 51 has a predetermined inductance with respect to the normal mode current.

  As illustrated in FIGS. 2 and 3, the noise reduction unit 50 includes bypass capacitors 71 and 72 that reduce common mode noise, and a smoothing capacitor 73 that is provided separately from the bypass capacitors 71 and 72. The smoothing capacitor 73 is composed of, for example, a film capacitor. These electrical connections will be described later.

  In the present embodiment, the in-vehicle inverter device 30 includes an attachment member 80 to which the common mode choke coil 51, both bypass capacitors 71 and 72, and the smoothing capacitor 73 are attached. The attachment member 80 includes, for example, a plate-like attachment base portion 81, and a first frame 82 and a second frame 83 erected from one plate surface of the attachment base portion 81. The attachment base portion 81 is fixed to the circuit board 41, for example.

  The first frame 82 is formed so as to correspond to the shape of the core 52, and in detail, is a rectangular frame formed slightly larger than the core 52. The common mode choke coil 51 is fitted in the first frame 82 and is accommodated in the first frame 82.

  The second frame 83 is substantially rectangular as a whole. A partition wall 84 is provided in the second frame 83. By the partition wall 84, the space in the second frame 83 is partitioned into three accommodating spaces 91 to 93. The accommodation spaces 91 to 93 are formed corresponding to the shapes of the capacitors 71 to 73. And each capacitor | condenser 71-73 is accommodated in the accommodation space 91-93 corresponding to the said each capacitor | condenser 71-73. Thereby, the common mode choke coil 51 and the capacitors 71 to 73 are unitized (modularized). In other words, the mounting member 80 unitizes the common mode choke coil 51 and the capacitors 71 to 73 as a unit.

  As shown in FIG. 2, a through hole 81 a into which each of the terminals 61 to 64 can be inserted is formed in the mounting base portion 81. Each terminal 61, 62, 63, 64 is connected to the corresponding wiring EL11, EL12, EL21, EL22 while being inserted through the through hole 81a. Although illustration is omitted, each of the capacitors 71 to 73 is also provided with a terminal, and the terminal is connected to a wiring or the like through a through hole formed in the mounting member 80.

  Incidentally, the common mode choke coil 51 is disposed at a position farther from the power module 42 than the capacitors 71 to 73. Specifically, each of the capacitors 71 to 73 is disposed between the common mode choke coil 51 and the power module 42.

  Further, the windings 53 a and 53 b and the capacitors 71 to 73 are thermally coupled to the wall portion 11 c of the housing 11. Specifically, the windings 53 a and 53 b and the capacitors 71 to 73 are in contact with the base member 32 that is in contact with the wall portion 11 c of the housing 11. The heat generated in the windings 53 a and 53 b and the capacitors 71 to 73 is transmitted to the base member 32 and the wall portion 11 c and absorbed by the refrigerant in the housing 11.

Next, the electrical connection of the noise reduction unit 50 will be described together with the electrical configuration of the in-vehicle inverter device 30 with reference to FIG.
As already described, the noise reduction unit 50 is provided on the input side of the power module 42 (specifically, the switching elements Qu1 to Qw2). Specifically, the common mode choke coil 51 of the noise reduction unit 50 is interposed between both the connector side wirings EL11 and EL21 and both the module side wirings EL12 and EL22.

  Here, the common mode choke coil 51 generates a leakage magnetic flux when a normal mode current flows. In view of this point, as shown in FIG. 5, the common mode choke coil 51 can be regarded as having virtual normal mode coils L1 and L2 separately from both windings 53a and 53b. That is, the common mode choke coil 51 of this embodiment has both windings 53a and 53b and virtual normal mode coils L1 and L2 in terms of an equivalent circuit. Virtual normal mode coils L1, L2 and windings 53a, 53b are connected in series with each other.

  Both bypass capacitors 71 and 72 are connected in series with each other. Specifically, the noise reduction unit 50 includes a bypass line EL <b> 3 that connects one end of the first bypass capacitor 71 and one end of the second bypass capacitor 72. The bypass line EL3 is grounded to the vehicle body.

  The series connection body of the bypass capacitors 71 and 72 is connected in parallel to the common mode choke coil 51. Specifically, the other end of the first bypass capacitor 71 opposite to the one end is connected to the first winding 53a (first output terminal 62) and the power module 42 (first module input terminal 42a). It is connected to one module side wiring EL12. The other end of the second bypass capacitor 72 opposite to the one end is a second module side wiring that connects the second winding 53b (second output terminal 64) and the power module 42 (second module input terminal 42b). It is connected to EL22.

  The smoothing capacitor 73 is provided on the output side of the common mode choke coil 51 and on the input side of the power module 42. Specifically, the smoothing capacitor 73 is provided between the series connection body of the bypass capacitors 71 and 72 and the power module 42, and is connected in parallel to both. Specifically, one end of the smoothing capacitor 73 is connected to the portion from the connection point P1 to the first bypass capacitor 71 in the first module side wiring EL12 to the power module 42, and the other end of the smoothing capacitor 73 is connected to the second module. The side wiring EL22 is connected to a portion from the connection point P2 with the second bypass capacitor 72 to the power module 42.

  With this configuration, the low-pass filter circuit 94 is formed by the common mode choke coil 51 and the smoothing capacitor 73. In other words, the smoothing capacitor 73 constitutes the low-pass filter circuit 94 in cooperation with the common mode choke coil 51. The low-pass filter circuit 94 reduces normal mode noise. The low-pass filter circuit 94 can also be said to be an LC filter.

  As shown in FIG. 5, the coil 25 of the electric motor 13 has a three-phase structure including, for example, a u-phase coil 25u, a v-phase coil 25v, and a w-phase coil 25w. Each coil 25u-25w is Y-connected, for example.

  The power module 42 includes u-phase switching elements Qu1, Qu2 corresponding to the u-phase coil 25u, v-phase switching elements Qv1, Qv2 corresponding to the v-phase coil 25v, and w-phase switching elements Qw1, corresponding to the w-phase coil 25w. Qw2. Each of the switching elements Qu1 to Qw2 is a power switching element such as an IGBT. The switching elements Qu1 to Qw2 include freewheeling diodes (body diodes) Du1 to Dw2.

  The u-phase switching elements Qu1 and Qu2 are connected to each other in series via a connection line, and the connection line is connected to the u-phase coil 25u via a u-phase module output terminal 42u. And direct-current power from DC power supply E is input with respect to the serial connection body of each u-phase switching element Qu1, Qu2. Specifically, the collector of the first u-phase switching element Qu1 is connected to the first module input terminal 42a, and is connected to the first module-side wiring EL12 via the first module input terminal 42a. The emitter of the second u-phase switching element Qu2 is connected to the second module input terminal 42b, and is connected to the second module side wiring EL22 via the second module input terminal 42b.

  The other switching elements Qv1, Qv2, Qw1, and Qw2 have the same connection mode as the u-phase switching elements Qu1 and Qu2, except that the corresponding coils are different. In this case, it can be said that the switching elements Qu1 to Qw2 are connected to the module-side wirings EL12 and EL22.

  Further, the connection line connecting the v-phase switching elements Qv1 and Qv2 in series is connected to the v-phase coil 25v via the v-phase module output terminal 42v, and the w-phase switching elements Qw1 and Qw2 are connected in series. The connecting line to be connected is connected to the w-phase coil 25w via the w-phase module output terminal 42w. That is, the module output terminals 42 u to 42 w of the power module 42 are connected to the electric motor 13.

  The in-vehicle inverter device 30 includes a control unit 95 that controls the power module 42 (specifically, switching operations of the switching elements Qu1 to Qw2). The control unit 95 is electrically connected to the air conditioning ECU 102 via the connector 43, and periodically turns each switching element Qu1 to Qw2 on and off based on a command from the air conditioning ECU 102.

  Specifically, the control unit 95 performs pulse width modulation control (PWM control) on the in-vehicle inverter device 30 (specifically, the switching elements Qu1 to Qw2) based on a command from the air conditioning ECU 102. More specifically, the control unit 95 generates the first control signal using the first carrier signal (carrier wave signal) and the first command voltage value signal (comparison target signal). And the control part 95 converts direct-current power into alternating current power by performing ON / OFF control of each switching element Qu1-Qw2 using the produced | generated 1st control signal. It is assumed that the frequency of the first carrier signal is the first carrier frequency f1.

  As shown in FIGS. 5 and 6, a vehicle includes a PCU (power control unit) 103 as an example of a vehicle-mounted device, in addition to the vehicle-mounted inverter device 30. The PCU 103 uses a direct current power supplied from the DC power source E to drive a traveling motor mounted on the vehicle. That is, in this embodiment, the PCU 103 and the in-vehicle inverter device 30 are connected in parallel to the DC power source E, and the DC power source E is shared by the PCU 103 and the in-vehicle inverter device 30. .

  The PCU 103 includes, for example, a boost converter 104 that boosts DC power of a DC power supply E, and a travel inverter 105 that converts DC power boosted by the boost converter 104 into drive power that can be driven by a travel motor. . As shown in FIG. 6, the boost converter 104 includes a plurality (more specifically, two) boost switching elements Qa1 and Qa2, a power supply capacitor C0, and a boost choke coil La. Both boosting switching elements Qa1 and Qa2 are composed of, for example, IGBTs and are connected in series with each other. One end of the boosting choke coil La is connected to the + terminal of the DC power source E, and the other end of the boosting choke coil La is connected to a connection line that connects both the boosting switching elements Qa1 and Qa2. The negative terminal of the DC power source E is connected to the emitter terminal of the second boost switching element Qa2. The collector terminal of the first boost switching element Qa1 and the emitter terminal of the second boost switching element Qa2 are connected to the traveling inverter 105.

  The PCU 103 includes a PCU control unit 106 that controls both boosting switching elements Qa1 and Qa2. The PCU control unit 106 outputs DC power having a desired voltage value to the traveling inverter 105 by performing pulse width modulation control (PWM control) on both step-up switching elements Qa1 and Qa2. Specifically, the PCU control unit 106 generates a second control signal using the second carrier signal (carrier wave signal) and the second command voltage value signal (comparison target signal). Then, the PCU control unit 106 performs ON / OFF control of both boosting switching elements Qa1 and Qa2 by using the generated second control signal, so that the DC power of the DC power source E is changed to a desired voltage value (in detail). Is converted to DC power having a voltage value suitable for driving a motor for traveling. In such a configuration, the frequency of the second carrier signal used for PWM control of both boosting switching elements Qa1 and Qa2 is defined as a second carrier frequency f2.

  Here, the normal mode noise is noise generated due to the switching of both boost switching elements Qa1 and Qa2, and the normal mode noise includes a noise component having the same frequency as the second carrier frequency f2. . The second carrier frequency f2 varies depending on the vehicle type. For this reason, the frequency of the normal mode noise varies depending on the vehicle type.

  In such a configuration, the frequency band including the assumed normal mode noise frequency fluctuation range is defined as a noise frequency band Bn. The noise frequency band Bn is a band set corresponding to the second carrier frequency f2 assumed to fluctuate, and is set to include at least a fluctuation range of the second carrier frequency f2 assumed. In the present embodiment, the noise frequency band Bn is a band from the assumed minimum value of the second carrier frequency f2 to the assumed maximum value of the second carrier frequency f2. The noise frequency band Bn is, for example, 2 kHz to 12 kHz. Further, if attention is paid to the fact that the normal mode noise is an inflow ripple component of DC power input to the in-vehicle inverter device 30, the noise frequency band Bn varies with the frequency of the inflow ripple component that varies depending on the vehicle type. It can also be said to be a frequency band including a range.

  Note that the fluctuation range of the second carrier frequency f2 (in other words, the noise frequency band Bn) may be set assuming a plurality of vehicle types with different second carrier frequencies f2, and the specific vehicle type and number to be assumed Etc. may be appropriately set in advance in consideration of practicality. In other words, the noise frequency band Bn may be set so as to include a variation range of the second carrier frequency f2 when a plurality of vehicle types having different second carrier frequencies f2 are assumed in advance. May be appropriately set in consideration of practicality.

  Further, since the normal mode noise is caused by the switching of the switching elements Qa1 and Qa2 for boosting, the expected fluctuation range of the normal mode noise frequency is at least the assumed fluctuation range of the second carrier frequency f2. Contains.

  The resonance frequency f3 of the low-pass filter circuit 94 is set higher than the noise frequency band Bn. Specifically, the capacitance of the smoothing capacitor 73 corresponds to the leakage flux of the common mode choke coil 51 (in other words, the inductances of the virtual normal mode coils L1 and L2) so that the resonance frequency f3 is higher than the noise frequency band Bn. Is set.

  The capacitance of the smoothing capacitor 73 is set lower than the capacitance of the power supply capacitor C0 so that normal mode noise is absorbed by the power supply capacitor C0. More specifically, the magnitude of normal mode noise flowing into the in-vehicle inverter device 30 (specifically, the low-pass filter circuit 94) varies depending on the capacitance ratio between the capacitance of the smoothing capacitor 73 and the capacitance of the power supply capacitor C0. To do. Specifically, as the capacitance of the smoothing capacitor 73 becomes lower than the capacitance of the power supply capacitor C0, the normal mode noise that flows in tends to decrease. In this regard, in this embodiment, the capacitance of the smoothing capacitor 73 is larger than the capacitance of the power supply capacitor C0 so that the normal mode noise in the noise frequency band Bn is attenuated by a predetermined threshold ratio (for example, −3 dB). It is set low.

  Furthermore, the first carrier frequency f1, which is the frequency of the first carrier signal used for the PWM control of the switching elements Qu1 to Qw2, is set higher than the cut-off frequency fc of the low-pass filter circuit 94.

  Although illustration and the like are omitted for convenience of explanation, actually, both the wirings EL1 and EL2 have predetermined resistance and inductance, and these parameters are slightly affected by the frequency characteristics of the low-pass filter circuit 94. Influence.

Next, the operation of this embodiment will be described.
The noise reduction unit 50 reduces (absorbs) common mode noise and normal mode noise included in both wirings EL1 and EL2. Specifically, when a common mode current flows through both wirings EL1, EL2, magnetic fluxes that reinforce each other are generated in both windings 53a, 53b. For this reason, the common mode choke coil 51 has a relatively high inductance with respect to the common mode current. Therefore, common mode noise is reduced by the common mode choke coil 51 and the bypass capacitors 71 and 72.

  Further, when a normal mode current flows through both the wirings EL1, EL2, magnetic fluxes canceling each other are generated in both windings 53a, 53b. In this case, the magnetic flux generated in both windings 53a and 53b leaks to some extent without completely canceling each other. By generating this leakage magnetic flux, the common mode choke coil 51 has a predetermined inductance with respect to the normal mode current. For this reason, normal mode noise is reduced. Then, DC power in which common mode noise and normal mode noise are reduced by the common mode choke coil 51 is input to the power module 42 via the module side wirings EL12 and EL22.

  Note that the inductance of the common mode choke coil 51 with respect to the normal mode current is lower than the inductance of the common mode choke coil 51 with respect to the common mode current. For this reason, the loss by the noise reduction part 50 in the direct-current power which transmits wiring EL1, EL2 is comparatively small.

Next, the frequency characteristics of the low-pass filter circuit 94 will be described with reference to FIGS.
As shown in FIG. 7, the resonance frequency f3 of the low-pass filter circuit 94 is set to be higher than the noise frequency band Bn. Further, the capacitance of the smoothing capacitor 73 is set sufficiently lower than the capacitance of the power supply capacitor C0. For this reason, even when the second carrier frequency f2 varies for each vehicle type, normal mode noise flowing into the in-vehicle inverter device 30 is reduced.

  Further, as shown in FIG. 8, the first carrier frequency f1 is set higher than the cut-off frequency fc of the low-pass filter circuit 94. Thereby, noise caused by switching of each of the switching elements Qu1 to Qw2, specifically, ripple noise of the first carrier frequency f1 and ripple noise of the harmonic component of the first carrier frequency f1 are absorbed by the low-pass filter circuit 94. The For this reason, the ripple noise generated from the power module 42 is restricted from flowing out of the in-vehicle inverter device 30.

According to the embodiment described above in detail, the following effects are obtained.
(1) A vehicle-mounted inverter device 30 that converts DC power into AC power is provided on the input side of the power module 42 formed by a plurality of switching elements Qu1 to Qw2 and included in the DC power. The noise reduction part 50 which reduces common mode noise and normal mode noise is provided. The noise reduction unit 50 includes a core 52, a first winding 53 a wound around the first winding portion 52 a of the core 52, and a second winding 53 b wound around the second winding portion 52 b of the core 52. A common mode choke coil 51 is provided. The in-vehicle inverter device 30 is configured such that DC power in which common mode noise and normal mode noise are reduced by the common mode choke coil 51 is input to the power module 42. Specifically, the in-vehicle inverter device 30 includes module-side wirings EL12 and EL22 that connect the common mode choke coil 51 and the power module 42.

  According to this configuration, the common mode choke coil 51 reduces common mode noise included in the DC power to be converted by the in-vehicle inverter device 30. Further, the common mode choke coil 51 generates a leakage magnetic flux when a normal mode current flows. Thereby, normal mode noise can be reduced. Therefore, DC power with both common mode noise and normal mode noise reduced can be input to the power module 42 without providing a dedicated coil for reducing normal mode noise. Increase in size can be suppressed.

  More specifically, if the DC power to be converted by the in-vehicle inverter device 30 includes common mode noise or normal mode noise, power conversion by the in-vehicle inverter device 30 may not be performed normally. There is a concern about an adverse effect such as generation of unnecessary electromagnetic waves caused by noise. In particular, since the power handled by the in-vehicle inverter device 30 is usually larger than the signal power, the above-described adverse effect is likely to be remarkable.

  Here, as the noise reduction unit, for example, a coil for reducing common mode noise and a coil for reducing normal mode noise may be separately provided. However, in this case, since a plurality of coils are required, there is a concern about an increase in the size of the noise reduction unit. In particular, since the power handled by the in-vehicle inverter device 30 is larger than the power of the signal, it is necessary to adopt a coil that can withstand a relatively large power as the above two coils, and such a coil is large. easy.

  In contrast, the noise reduction unit 50 of the present embodiment employs a common mode choke coil 51. The common mode choke coil 51 can reduce both common mode noise and normal mode noise. Accordingly, the common mode choke coil 51 and the power module 42 can be directly connected using the module side wirings EL12 and EL22 without providing a coil for normal mode noise. Therefore, it is possible to reduce common mode noise and normal mode noise included in the DC power to be converted by the in-vehicle inverter device 30 while suppressing an increase in the size of the noise reduction unit 50.

  (2) If both the coil for normal mode noise and the coil for common mode noise are provided, heat is generated from both coils. For this reason, the total calorific value of the noise reduction unit 50 tends to increase. In particular, since the electric power handled by the in-vehicle inverter device 30 is large, the amount of generated heat tends to increase.

  On the other hand, in the present embodiment, the amount of heat generation can be reduced by the amount that the coil for normal mode noise can be omitted. Thereby, since the heat generation of the noise reduction unit 50 can be suppressed, the heat generation of the in-vehicle inverter device 30 that is likely to cause a problem in the in-vehicle inverter device 30 that handles high power can be suitably suppressed.

  (3) The vehicle-mounted air conditioner 100 includes the vehicle-mounted electric compressor 10 having the electric motor 13 and the vehicle-mounted inverter device 30. The in-vehicle inverter device 30 is used to drive the electric motor 13 of the in-vehicle electric compressor 10. Specifically, the output side of the power module 42 is connected to the electric motor 13. The electric motor 13 generally requires a large AC power to be driven. For this reason, as the vehicle-mounted inverter device 30 for driving the electric motor 13, it is necessary to convert relatively large DC power into AC power. A coil for normal mode noise applicable to such a large DC power tends to be large. Therefore, the noise reduction part 50 tends to become large.

  On the other hand, in the present embodiment, by adopting the in-vehicle inverter device 30 having the noise reduction unit 50 described above as the one that drives the electric motor 13, the increase in the size of the in-vehicle inverter device 30 is suppressed. The electric compressor 10 can be operated while achieving both the reduction of both noises.

  (4) The in-vehicle inverter device 30 is integrated with the electric compressor 10. Specifically, the electric compressor 10 includes a housing 11 in which the compression unit 12 and the electric motor 13 are accommodated, and a wall portion 11 c disposed on the opposite side of the compression unit 12 with respect to the electric motor 13 in the housing 11. And an inverter case 31 in which an in-vehicle inverter device 30 is accommodated. The compression unit 12, the electric motor 13, and the in-vehicle inverter device 30 are arranged in the axial direction of the rotating shaft 21. Thereby, it can suppress that the physique of the electric compressor 10 becomes large in the radial direction of the rotating shaft 21.

  In this case, the installation space of the in-vehicle inverter device 30 is limited as compared with a so-called camel-back type electric compressor in which the in-vehicle inverter device 30 is disposed on the outer side in the radial direction of the rotating shaft 21 with respect to the housing 11. Easy to be. For this reason, it is difficult to secure an installation space for the noise reduction unit 50. On the other hand, in the present embodiment, the noise reduction unit 50 can be reduced in size by omitting the coil for normal mode noise. Therefore, the noise reduction unit 50 can be installed in a relatively narrow space. . Thereby, in the so-called in-line type electric compressor 10 in which the compression unit 12, the electric motor 13, and the in-vehicle inverter device 30 are arranged in the axial direction of the rotary shaft 21, the noise reduction unit 50 is installed relatively easily. it can.

  (5) The noise reduction unit 50 includes a smoothing capacitor 73 that forms a low-pass filter circuit 94 in cooperation with the common mode choke coil 51. The smoothing capacitor 73 is provided on the output side of the common mode choke coil 51 and on the input side of the power module 42. Specifically, the in-vehicle inverter device 30 includes a first module-side wiring EL12 that connects the first output terminal 62 of the first winding 53a and the first module input terminal 42a of the power module 42. The in-vehicle inverter device 30 includes a second module-side wiring EL22 that connects the second output terminal 64 of the second winding 53b and the second module input terminal 42b of the power module 42. The smoothing capacitor 73 is connected to both the module-side wirings EL12 and EL22.

  In such a configuration, the frequency of normal mode noise varies depending on the vehicle type. In this case, the resonance frequency f3 of the low-pass filter circuit 94 is set to be higher than the noise frequency band Bn including the assumed fluctuation range of the normal mode noise frequency. Specifically, the capacitance of the smoothing capacitor 73 corresponds to the leakage flux of the common mode choke coil 51 (in other words, the inductances of the virtual normal mode coils L1 and L2) so that the resonance frequency f3 is higher than the noise frequency band Bn. Is set. Further, the capacitance of the smoothing capacitor 73 is larger than the capacitance of the power supply capacitor C0 connected in parallel to the DC power supply E so that the normal mode noise in the noise frequency band Bn is attenuated by a predetermined threshold ratio or more. It is set low. According to such a configuration, even when the frequency of the normal mode noise varies depending on the vehicle type, it is possible to suppress an excessively large normal mode noise from flowing into the in-vehicle inverter device 30. Thereby, versatility can be improved.

  More specifically, in general, when the vehicle-mounted inverter device 30 is mounted on a vehicle, it is necessary to verify whether or not the vehicle-mounted inverter device 30 is applicable to the vehicle. In the conformity verification, it is verified whether the second carrier frequency f2 is the same value as the resonance frequency f3 of the low-pass filter circuit 94 or a value that is close enough to hinder the operation. When the second carrier frequency f2 is the same as or close to the resonance frequency f3 of the low-pass filter circuit 94, a resonance phenomenon occurs. In this case, the normal mode noise flowing into the in-vehicle inverter device 30 becomes excessively large, and in the worst case, the adaptation becomes impossible. And as already demonstrated, since the 2nd carrier frequency f2 differs for every vehicle model, the said conformity verification is performed for every vehicle model.

  In this regard, in this embodiment, the resonance frequency f3 of the low-pass filter circuit 94 is set to be higher than the noise frequency band Bn. Accordingly, since the occurrence of resonance phenomenon can be suppressed in a plurality of vehicle types having different normal mode noise frequencies, the in-vehicle inverter device 30 can be applied to the plurality of vehicle types. Therefore, versatility can be improved. In addition, since the conformity verification can be omitted, it is possible to simplify the work when the in-vehicle inverter device 30 is mounted on the vehicle.

  Here, from the viewpoint of setting the resonance frequency f3 outside the noise frequency band Bn, it is also conceivable to set the resonance frequency f3 lower than the noise frequency band Bn. In particular, although details will be described later, since the first carrier frequency f1 can be lowered by setting the resonance frequency f3 lower than the noise frequency band Bn, the power loss of the power module 42 can be reduced. However, in the present embodiment, the common mode choke coil 51 is employed as a component of the low pass filter circuit 94. The common mode choke coil 51 can reduce both common mode noise and normal mode noise. However, due to its characteristics, a large leakage flux cannot be secured, and the inductances of the virtual normal mode coils L1 and L2 tend to be low. . For this reason, the resonant frequency f3 prescribed | regulated by the leakage magnetic flux of the common mode choke coil 51 and the capacitance of the smoothing capacitor 73 tends to become high.

  On the other hand, for example, it is conceivable to increase the capacitance of the smoothing capacitor 73 and lower the resonance frequency f3. However, in this case, since the capacitance of the smoothing capacitor 73 approaches the capacitance of the power supply capacitor C0, the normal mode noise is hardly absorbed by the power supply capacitor C0, and the normal mode noise flowing into the in-vehicle inverter device 30 is large. Become.

  On the other hand, in the present embodiment, since the resonance frequency f3 is set higher than the noise frequency band Bn, the capacitance of the smoothing capacitor 73 is sufficiently higher than the capacitance of the power supply capacitor C0 (specifically, noise). The normal mode noise of the frequency band Bn can be lowered (to the extent that it is attenuated by a predetermined threshold ratio or more). Thereby, both reduction of both normal mode noise and common mode noise and improvement in versatility can be achieved. Furthermore, by adopting the smoothing capacitor 73 having a low capacitance, it is possible to reduce the size of the low-pass filter circuit 94, and thereby to reduce the size of the in-vehicle inverter device 30.

  (6) The first carrier frequency f1, which is the frequency of the first carrier signal used for PWM control of the switching elements Qu1 to Qw2 of the power module 42, is set higher than the cut-off frequency fc of the low-pass filter circuit 94. ing. Thereby, it can suppress that the ripple noise resulting from switching of each switching element Qu1-Qw2 flows out out of the inverter apparatus 30 for vehicle mounting.

  More specifically, it is usually preferable to set the first carrier frequency f1 to be low in view of the power loss of the power module 42. However, when the first carrier frequency f1 is lowered in a situation where the resonance frequency f3 is set higher than the noise frequency band Bn, the inventors of the present invention have ripple noise caused by switching of the switching elements Qu1 to Qw2. It has been found that it flows out of the in-vehicle inverter device 30 and adversely affects the PCU 103 and the like. Specifically, the cutoff frequency fc tends to be relatively high because the resonance frequency f3 is set higher than the noise frequency band Bn. If an attempt is made to lower the first carrier frequency f1 under such circumstances, the first carrier frequency f1 becomes lower than the cutoff frequency fc. Then, since the ripple noise does not flow to the smoothing capacitor 73, the low-pass filter circuit 94 may not be able to absorb the ripple noise.

  On the other hand, in the present embodiment, the ripple noise can be reduced by the low-pass filter circuit 94 by making the first carrier frequency f1 higher than the cut-off frequency fc of the low-pass filter circuit 94 as described above. it can. Thus, ripple noise generated in the power module 42 of the in-vehicle inverter device 30 flows out of the in-vehicle inverter device 30 (in other words, out of the electric compressor 10) without providing a dedicated filter or the like. Can be suppressed. That is, the low-pass filter circuit 94 functions to reduce normal mode noise and common mode noise flowing into the in-vehicle inverter device 30 during the operation of the PCU 103, and ripple noise flows out during the operation of the in-vehicle inverter device 30. Acts as a reduction.

  (7) The smoothing capacitor 73 is a film capacitor. According to this configuration, the low-pass filter circuit 94 can be reduced in size and improved in durability as compared with a configuration in which an electrolytic capacitor is used as the smoothing capacitor 73.

  In particular, a film capacitor is superior in durability to an electrolytic capacitor and tends to be small in size, but tends to have a low capacitance. For this reason, when a high capacitance is required, it is difficult to employ a film capacitor. On the other hand, in the present embodiment, as already described, the capacitance of the smoothing capacitor 73 can be reduced by making the resonance frequency f3 higher than the noise frequency band Bn. Thereby, it is easy to employ a film capacitor.

  Furthermore, the film capacitor has superior temperature characteristics compared to the electrolytic capacitor. For this reason, compared with the case where an electrolytic capacitor is employed as the smoothing capacitor 73, it is possible to cope with the start-up of the electric compressor 10 under a low temperature condition.

  (8) The in-vehicle inverter device 30 shares the DC power source E with the PCU 103 as the in-vehicle device. The PCU 103 includes boosting switching elements Qa1 and Qa2 that are periodically turned on and off. For this reason, the DC power input to the in-vehicle inverter device 30 (specifically, the noise reduction unit 50) includes normal mode noise corresponding to the switching frequency of the boost switching elements Qa1 and Qa2. Specifically, the normal mode noise includes a noise component having the same frequency as the second carrier frequency f2, which is the frequency of the second carrier signal used for PWM control of the boosting switching elements Qa1 and Qa2. Since the switching frequency of the boosting switching elements Qa1 and Qa2 varies depending on the vehicle type, the frequency of the normal mode noise varies depending on the vehicle type.

  In such a configuration, the noise frequency band Bn includes a variation range of the switching frequency (that is, the second carrier frequency f2) of the boosting switching elements Qa1 and Qa2 when a plurality of vehicle types having different second carrier frequencies f2 are assumed. As a result, the in-vehicle inverter device 30 can be applied to the plurality of vehicle types.

(9) The smoothing capacitor 73 and the common mode choke coil 51 are unitized. Thereby, further size reduction of the noise reduction part 50 can be achieved.
In particular, the common mode choke coil 51 and the smoothing capacitor 73 are unitized so that the common mode choke coil 51 is disposed at a position farther from the power module 42 than the smoothing capacitor 73. This makes it difficult for the power module 42 to be affected by the magnetic flux generated by the common mode choke coil 51. Therefore, malfunction of each switching element Qu1-Qw2 resulting from the magnetic flux which generate | occur | produces in the common mode choke coil 51 can be suppressed.

  (10) Both windings 53 a and 53 b are thermally coupled to the wall portion 11 c of the housing 11. Specifically, both the windings 53 a and 53 b are in contact with the base member 32 that is in contact with the wall portion 11 c of the housing 11. Thereby, both windings 53a and 53b can be cooled using a refrigerant, and the heat generation of the common mode choke coil 51 can be suppressed through the cooling.

  (11) The core 52 includes a first winding portion 52a around which the first winding 53a is wound, a second winding portion 52b around which the second winding 53b is wound, and both windings 53a and 53b. An exposed portion 52d that is not wound and has an exposed surface 52c. Thereby, when a normal mode current flows through both wirings EL1, EL2 (specifically, both windings 53a, 53b), a leakage magnetic flux is generated. Therefore, the effect (1) can be obtained.

In addition, you may change the said embodiment as follows.
As shown in FIG. 9, both windings 110 and 111 may be wound around the entire core 52. In this case, the windings 110 and 111 may have high density portions 110a and 111a and low density portions 110b and 111b having relatively different winding densities. The winding density is the number of turns (number of turns) per unit length in the winding axis direction. Even in this case, leakage magnetic flux is generated from the common mode choke coil 51. Note that either the first winding 110 or the second winding 111 may have a high density portion and a low density portion. In this case, both the exposed portion and the low density portion coexist. In short, it is sufficient that at least one of the first winding 110 and the second winding 111 has a high density portion and a low density portion.

  As shown in FIG. 10, the first number of turns N1 that is the number of turns of the first winding 120a may be different from the second number of turns N2 that is the number of turns of the second winding 120b. For example, the first winding number N1 may be larger than the second winding number N2. In this case, the length of the first winding 120a in the winding axis direction is longer than the length of the second winding 120b in the winding axis direction. Even in this case, the leakage magnetic flux generated in the common mode choke coil 51 can be increased when the normal mode current flows through both the windings 120a and 120b. However, if attention is paid to the fact that the common mode noise can be further reduced, it is preferable that the number of turns N1 and N2 is the same. In addition, it is not restricted to the said other example, For example, the 2nd winding number N2 may be larger than the 1st winding number N1.

In addition, the different examples may be combined with each other, and the different examples and the embodiment may be appropriately combined.
○ On the both sides in the winding axis direction with respect to the first winding 53a in the core 52, the positional deviation or loosening of the first winding 53a in the winding axis direction is regulated and protrudes from the surface 52c of the core 52. A flange portion may be provided. In this case, the projecting dimension of the flange portion is preferably set so that the side surface of the flange portion is flush with the outer peripheral surface of the first winding 53a or inside the outer peripheral surface. Accordingly, it is possible to avoid a situation in which the flange portion and the base member 32 are in contact with each other and the first winding 53a and the base member 32 are not in contact with each other. The same applies to the second winding 53b side.

○ The base member 32 may be omitted. In this case, both the windings 53a and 53b and the wall 11c of the housing 11 are preferably in direct contact.
○ The shape of the core 52 is arbitrary. For example, a UU core, an EE core, a toroidal core, or the like may be used as the core.

  The electric compressor 10 according to the embodiment is a so-called inline type, but is not limited to this, for example, a so-called camelback in which an in-vehicle inverter device 30 is disposed on the outer side in the radial direction of the rotating shaft 21 with respect to the housing 11. It may be a mold. In short, the installation position of the in-vehicle inverter device 30 is arbitrary.

  In the embodiment, the common mode choke coil 51 and the capacitors 71 to 73 are unitized. However, the present invention is not limited to this. For example, the common mode choke coil 51 and the smoothing capacitor 73 may be unitized, and the bypass capacitors 71 and 72 may be separate. Further, the common mode choke coil 51 and the bypass capacitors 71 and 72 may be unitized, and the smoothing capacitor 73 may be separate. Further, the common mode choke coil 51, the bypass capacitors 71 and 72, and the smoothing capacitor 73 may be separate from each other.

The installation position of the common mode choke coil 51 and both bypass capacitors 71 and 72 is arbitrary as long as it is within the inverter case 31.
O Both module side wirings EL12 and EL22 may be omitted, and both output terminals 62 and 64 of the common mode choke coil 51 may be directly connected to both module input terminals 42a and 42b of the power module 42. Further, the smoothing capacitor 73 and the like may be directly connected to both output terminals 62 and 64.

  O Although the electric compressor 10 was used for the vehicle-mounted air conditioner 100, it is not restricted to this. For example, when a fuel cell is mounted on the vehicle, the electric compressor 10 may be used in an air supply device that supplies air to the fuel cell. That is, the fluid to be compressed is not limited to the refrigerant, but may be any air.

  The in-vehicle inverter device 30 may be used to drive other than the electric motor 13 of the electric compressor 10. For example, in a configuration in which a motor used for at least one of travel and power generation is mounted on the vehicle, the in-vehicle inverter device 30 may be used to drive the motor.

The control method of the boosting switching elements Qa1 and Qa2 is not limited to PWM control and is arbitrary.
The in-vehicle device is not limited to the PCU 103 and may be any device as long as it has a switching element that is periodically turned ON / OFF. For example, the in-vehicle device may be an inverter provided separately from the in-vehicle inverter device 30.

  The noise reduction unit 50 may have a configuration in which a common mode noise coil for reducing common mode noise and a normal mode noise coil for reducing normal mode noise are separately provided. That is, the noise reduction unit 50 is not limited to the configuration having the common mode choke coil 51.

  The specific circuit configuration of the noise reduction unit 50 is not limited to that of the embodiment. For example, the smoothing capacitor 73 may be omitted, or two smoothing capacitors 73 may be provided.

An electrolytic capacitor may be adopted as the smoothing capacitor 73.
The noise frequency band Bn may be the same frequency band as the fluctuation range of the second carrier frequency f2, and includes both the fluctuation range of the second carrier frequency f2 and the fluctuation range of the harmonic component of the second carrier frequency f2. It may be a frequency band. For example, the frequency band of normal mode noise is from the second carrier frequency f2 to the harmonic component of a predetermined order of the second carrier frequency f2. In this case, the noise frequency band Bn is a normal mode noise frequency band corresponding to the assumed minimum value of the second carrier frequency f2 and a normal mode noise frequency corresponding to the assumed maximum value of the second carrier frequency f2. You may set so that both a belt | band | zone may be included. The resonance frequency f3 of the low-pass filter circuit 94 is preferably set higher than the noise frequency band Bn. According to this configuration, it is possible to suppress an adverse effect on the in-vehicle inverter device 30 due to the normal mode noise of the harmonic component of the second carrier frequency f2.

Next, a preferable example that can be grasped from the embodiment and another example will be described below.
(A) The vehicle-mounted device includes a power supply capacitor connected in parallel to the vehicle-mounted power storage device, and the capacitance of the smoothing capacitor of the low-pass filter circuit is such that the resonance frequency of the low-pass filter circuit is the noise. It is set corresponding to the leakage magnetic flux of the common mode choke coil so as to be higher than the frequency band, and the normal mode noise in the noise frequency band is further attenuated by a predetermined threshold ratio or more. The in-vehicle inverter device according to claim 4 , wherein the inverter device is set lower than a capacitance of the capacitor.

  (B) A vehicle-mounted power storage device is shared with a predetermined vehicle-mounted device, and a DC motor supplied from the vehicle-mounted power storage device is driven by an electric motor provided in the vehicle-mounted electric compressor In an in-vehicle inverter device for converting to a possible AC power, an LC filter that reduces an inflow ripple component included in the DC power, and a DC power in which the inflow ripple component is reduced by the LC filter are converted into the AC power A conversion circuit having a plurality of PWM-controlled switching elements, wherein the LC filter is a low-pass filter circuit, and the resonance frequency of the LC filter is a variation in the frequency of the inflow ripple component A carrier signal set higher than a noise frequency band including a range and used for PWM control of the plurality of switching elements Carrier frequency is frequency-vehicle inverter device, characterized in that it is set higher than the cutoff frequency of the LC filter. Note that the first carrier frequency f1 in the embodiment corresponds to “a carrier frequency that is a frequency of a carrier signal used for PWM control of the plurality of switching elements”.

  DESCRIPTION OF SYMBOLS 10 ... Electric compressor, 11 ... Housing, 12 ... Compression part, 13 ... Electric motor, 30 ... In-vehicle inverter apparatus, 42 ... Power module, 50 ... Noise reduction part, 51 ... Common mode choke coil, 52 ... Core, 52a ... 1st winding part, 52b ... 2nd winding part, 52c ... Surface of core, 52d ... Exposed part, 53a, 110, 120a ... 1st winding, 53b, 111, 120b ... 2nd winding, 71 72 ... Bypass capacitor, 73 ... Smoothing capacitor, 94 ... Low pass filter circuit, 100 ... Air conditioner for vehicle installation, 103 ... PCU (vehicle equipment), 110a, 111a ... High density part, 110b, 111b ... Low density part, EL12: first module side wiring, EL22: second module side wiring, f1: first carrier frequency, f2: second carrier frequency, f3: low pass frequency The resonant frequency of the filter circuit, fc ... cut-off frequency, Bn ... noise frequency band, Qu1~Qw2 ... power module of the switching device, Qa1, Qa2 ... boosting switching element.

Claims (11)

In an in-vehicle inverter device that has a circuit formed of a plurality of switching elements and converts DC power to AC power,
Provided on the input side of the circuit, comprising a noise reduction unit for reducing common mode noise and normal mode noise included in the DC power,
The noise reduction unit is
A common mode choke coil having a core, a first winding wound around the first winding portion of the core, and a second winding wound around the second winding portion of the core ;
A smoothing capacitor that is provided on the output side of the common mode choke coil and on the input side of the circuit, and forms a low-pass filter circuit in cooperation with the common mode choke coil;
Including
DC power in which common mode noise and normal mode noise are reduced by the noise reduction unit is input to the circuit ,
A vehicle-mounted inverter device , wherein a carrier frequency, which is a frequency of a carrier signal used for PWM control of each switching element, is set higher than a cutoff frequency of the low-pass filter circuit . The frequency of normal mode noise varies depending on the vehicle type.
2. The in-vehicle inverter device according to claim 1 , wherein a resonance frequency of the low-pass filter circuit is set to be higher than a noise frequency band including a frequency fluctuation range of normal mode noise assumed. The noise reduction unit receives DC power of an in-vehicle power storage device shared with an in-vehicle device having a switching element,
The switching frequency of the switching element of the in-vehicle device varies depending on the vehicle type,
The in-vehicle inverter device according to claim 2 , wherein the noise frequency band includes a fluctuation range of a switching frequency of a switching element of the in-vehicle device that is assumed. The smoothing capacitor-vehicle inverter device according to claim 2 or claim 3 is a film capacitor. The noise reduction unit is supplied with DC power of an in-vehicle power storage device shared with a power control unit that drives a traveling motor,
The in-vehicle inverter device according to claim 1, wherein a resonance frequency of the low-pass filter circuit is set to be higher than a frequency of normal mode noise generated in the power control unit . DC power of the on-vehicle power storage device shared with the power control unit that drives the traveling motor and has a switching element is supplied to the noise reduction unit,
The in-vehicle inverter device according to claim 1, wherein a resonance frequency of the low-pass filter circuit is set higher than a switching frequency of a switching element of the power control unit . The in-vehicle inverter device according to any one of claims 1 to 6 , wherein the smoothing capacitor and the common mode choke coil are unitized. The in-vehicle inverter device according to any one of claims 1 to 7 , wherein the core has an exposed portion in which the windings are not wound and the surface is exposed. It said first winding and at least one of the second winding, of the claims 1-8 where the number of turns per unit length of the relatively winding axis direction is provided with a different density portions and low density portions The vehicle-mounted inverter apparatus as described in any one of Claims. The in-vehicle inverter device according to any one of claims 1 to 9 , wherein a number of turns of the first winding is different from a number of turns of the second winding. A compression section for compressing the fluid;
An electric motor for driving the compression unit;
A housing that houses the compression section and the electric motor;
An electric compressor for use in vehicles equipped with an inverter device for vehicle according to any one of claims 1-10 for driving the motor,
The on-vehicle electric compressor is characterized in that an output side of the circuit is connected to the electric motor.

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