Electrically driven compressor installed in a vehicle

Abstract

An electrically driven compressor installed in a vehicle is provided, which can increase the reduction effect for noise generated at an inverter circuit and the like without increasing the capacitance of the Y capacitor. An electrically driven compressor (1) installed in a vehicle comprises, in a metal housing body (2), an inverter board (17) on which an inverter circuit (34) is mounted, which converts direct current from a high-voltage battery (41) into alternating current and applies it to an electric motor (8). It comprises a common-mode coil (54) inserted into a high-voltage supply line (46, 47) from the high-voltage battery (41), a Y capacitor (56) connected between the high-voltage supply line (46, 47) and the housing body (2), and an inductor (57) connected in series with the Y capacitor (56).

Description

TECHNICAL FIELD

[0001] The present invention relates to an electrically driven compressor installed in a vehicle, which comprises an inverter board in a housing body on which an inverter circuit is mounted. STATE OF THE ART

[0002] In a vehicle air conditioning system for air conditioning the passenger compartment of an electrically powered vehicle, an electrically driven compressor with an electric motor is used instead of a compressor driven by an internal combustion engine. In this case, an inverter circuit consisting of multiple switching elements converts high-voltage direct current (e.g., approximately 300 V DC) from a battery installed in the vehicle into alternating current and applies it to the electric motor.

[0003] The switching of the switching elements of the inverter circuit is controlled by a control device, in which case a high-voltage circuit including a high-voltage supply line from the battery installed in the vehicle and a low-voltage circuit including the control device are arranged on the same inverter board and mounted in an inverter receiving portion formed in the housing body of the electrically driven compressor installed in the vehicle.

[0004] This attempts to improve EMI by connecting a common-mode coil to the high-voltage power supply line of the high-voltage circuit, connecting a Y capacitor between the high-voltage power supply line and the case body, and returning common-mode noise current from the inverter circuit and the like to the noise source (noise return path) (see, for example, Patent Document 1). LIST OF REFERENCE DOCUMENTSPATENT DOCUMENTS

[0005] Patent document 1: JP 6571358 B2 SUMMARY OF THE INVENTIONOBJECTS OF THE INVENTION

[0006] An LPF (Low Path Filter) consisting of the common-mode coil and the Y-capacitor is effective for reducing comparatively low-frequency noise of about 1 MHz, while a resonant filter consisting of only a Y-capacitor (and a parasitic inductance) is effective for reducing high-frequency noise in the VHF (or Very High Frequency) range of 30 MHz to 50 MHz that occurs when switching the switching elements of the inverter circuit. This noise reduction effect is strongly influenced by the position on the inverter board (impedance characteristic).

[0007] Therefore, it is common practice to create several mounting patterns in advance to arrange Y capacitors at different positions on the inverter board, and to conduct an EMI test during test operation to determine the positions for the Y capacitors where the effect against high-frequency noise is high (impedance), thereby verifying the noise reduction effect in the VHF range.

[0008] However, an arrangement with multiple mounting patterns on the inverter board leads to an increase in board size, which ultimately results in the problem of increasing the size of the electric compressor installed in the vehicle. Another problem is that if, after finding an effective combination of Y capacitor positions for mass production, mounting patterns not required (patterns without mounting) are systematically combined, the EMI effect changes due to this change in arrangement.

[0009] Also, the Y capacitor between the high-voltage power line and the chassis (grounded to the vehicle body) must withstand a sufficiently high voltage for vehicle safety. However, the withstand voltage of each Y capacitor is limited by product design, so in actual use, approximately two to four Y capacitors are connected in series. Since the Y capacitors currently widely used are those with the highest withstand voltage and capacitance among the products available for vehicle installation, it is difficult to increase capacitance by re-selection of components. Therefore, if the capacitance is to be increased to improve EMI in the VHF range, even more Y capacitor groups, with two to four connected in series, must be connected in parallel, resulting in a huge increase in cost.

[0010] The present invention has been made to solve this technical problem of the prior art, and has an object to provide an electrically driven compressor installed in a vehicle, which can increase the reduction effect for noise generated at an inverter circuit and the like without increasing the capacitance of the Y capacitor. SOLUTION OF THE TASKS

[0011] An electrically driven compressor of the present invention installed in a vehicle includes, in a metal case body, an inverter board on which an inverter circuit is mounted that converts direct current from a battery installed in the vehicle into alternating current and applies it to an electric motor, and is characterized by a common mode coil inserted into a high voltage supply line from the battery installed in the vehicle, a Y capacitor connected between the high voltage supply line and the case body, and an inductor connected in series with the Y capacitor.

[0012] An electrically driven compressor installed in a vehicle of an invention of claim 2 is characterized in that in the above invention, the Y capacitor is formed of a ceramic capacitor group in which a plurality of surface mount type ceramic capacitors are connected in series, wherein the inductor is a surface mount type chip inductor or a chip bead.

[0013] An electrically driven compressor installed in a vehicle of an invention of claim 3 is characterized in that in the invention of claim 1, a resonance frequency of a series circuit of the inductor with the Y capacitor is shifted to the low side.

[0014] An electrically driven compressor installed in a vehicle of an invention of claim 4 is characterized in that in the invention of claim 1, a mounting pattern of Y capacitors is formed at a plurality of positions and the inductor is connected to at least one of the Y capacitors.

[0015] An electrically driven compressor installed in a vehicle of an invention of claim 5 is characterized in that in the above inventions, on the inverter board are arranged a high-voltage circuit including a high-voltage supply line from the battery installed in the vehicle, the Y capacitor and the inductor, and a low-voltage circuit including a control device that controls the inverter circuit. EFFECTS OF THE INVENTION

[0016] Since the vehicle-mounted electrically driven compressor of the present invention includes, in a metal case body, an inverter board on which an inverter circuit is mounted that converts direct current from a battery installed in the vehicle into alternating current and supplies it to an electric motor, a common mode coil inserted into a high-voltage power supply line from the battery installed in the vehicle, a Y capacitor connected between the high-voltage power supply line and the case body, and an inductor connected in series with the Y capacitor, without increasing the capacitance of the Y capacitor, the resonance frequency of the series connection of the inductor and the Y capacitor can be shifted to the low side.

[0017] Even if the Y capacitor is formed by a series connection ceramic capacitor group in which surface mount type ceramic capacitors are connected in series and the composite capacitance is reduced and the resonance frequency is increased, it is possible to efficiently return switching surge noise in the VHF range, which occurs during the operation of the electric motor of the electrically driven compressor installed in a vehicle, at the Y capacitor and the inductor to the inverter circuit which is the noise source, and prevent its leakage to the outside, thus improving EMI.

[0018] Noise radiated by the control device does not pose a particular problem, since the inverter board is shielded by the metal housing body in which it is housed.

[0019] Also, to increase the capacitance, it is not necessary to further connect series-connected ceramic capacitor groups in parallel, and instead it is sufficient to connect a low-cost inductor such as a chip inductor or a chip bead, which can achieve a huge cost reduction and downsizing of the electrically driven compressor installed in a vehicle.

[0020] Since an EMI improvement is possible in an arrangement with multiple mounting patterns of the Y capacitors on the inverter board by connecting the inductor in series with at least one of them during the mounting of the Y capacitors, the problem of lower EMI reproducibility that occurs when the patterns are sequentially combined without assembly also disappears, since the sequential combination of the mounting patterns found to be effective for EMI in test operation is not required, unlike in the prior art, which enables a significant reduction in development time.

[0021] This is extremely useful for an electrically driven compressor installed in a vehicle, where the high-voltage circuit and the low-voltage circuit are located on the inverter board. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a schematic sectional view of an electrically driven compressor installed in a vehicle according to an embodiment of the present invention. Fig. Figure 2 shows a block diagram of an electrical circuit of the electrically driven compressor installed in a vehicle, assuming the EMI measurement from Fig. 1. Fig. Figure 3 shows a plan view of the electrically driven compressor installed in a vehicle from Fig. 1. Fig. 4 shows a partially enlarged view of the inductor part of Fig. 3. Fig. Figure 5 shows an equivalent circuit diagram of a Y capacitor connected in series with the inductor. Fig. Figure 6 shows an equivalent circuit diagram of the Y capacitor alone. Fig. Figure 7 shows an explanatory view of the impedance characteristic in the case of Fig. 5 and Fig. 6. DESCRIPTION OF THE EMBODIMENTS

[0022] An embodiment of the present invention will be described in detail below with reference to the accompanying figures. Fig. 1, an electrically driven compressor (a so-called integrated inverter type electrically driven compressor) 1 of an embodiment to which the present invention is applied will first be described. The vehicle-mounted electrically driven compressor 1 of the embodiment forms part of a refrigerant cycle of a vehicle air conditioning device installed in an electrically driven vehicle such as a hybrid vehicle, an electric vehicle, or the like. (1) Structure of the electrically driven compressor 1 installed in a vehicle

[0023] In Fig. 1, the interior of a tubular casing body 2 made of metal (in the embodiment, aluminum with a fixed thickness) of the electrically driven compressor 1 installed in a vehicle is divided into a compression mechanism accommodating portion 4 and an inverter accommodating portion 6 by a partition wall 3 crossing an axial direction of the casing body 2, wherein a compression mechanism 7, for example, of the scroll type, and an electric motor 8 driving the compression mechanism 7 are accommodated inside the compression mechanism accommodating portion 4.

[0024] In this case, the electric motor 8 of the embodiment is an IPMSM (Interior Permanent Magnet Synchronous Motor) with a stator 9 that is fixed to the housing body 2 and a rotor 11 rotating on the inside of the stator 9.

[0025] A bearing portion 12 is formed in the central portion of the partition wall 3 on the side of the compression mechanism accommodating portion 4. One end of a drive shaft 13 of a rotor 11 is supported by the bearing portion 12, while the other end of the drive shaft 13 is coupled to the compression mechanism 7. A suction port 14 is formed in the region of the partition wall 3 at a position of the casing body 2 corresponding to the compression mechanism accommodating portion 4. When the rotor 11 of the electric motor 8 (the drive shaft 13) rotates and the compression mechanism 7 is driven, low-temperature refrigerant, which is a working fluid, flows into the compression mechanism accommodating portion 4 of the casing body 2 through the suction port 14 and is sucked and compressed by the compression mechanism 7.

[0026] The refrigerant, which has a high temperature and high pressure due to compression by the compression mechanism 7, is discharged from the housing body 2 to the refrigerant circuit through a discharge port (not shown). The low-temperature refrigerant flowing in through the intake port 14 passes through the area of ​​the partition wall 3, flows past the electric motor 8, and is sucked in by the compression mechanism 7, thus also cooling the electric motor 8 and the partition wall 3.

[0027] The inverter accommodating section 6, which is separated from the compression mechanism accommodating section 4 by the partition wall 3, accommodates an inverter device 16 that controls the drive of the electric motor 8. In this case, the inverter device 16 is configured to supply electrical power to the electric motor 8 via a hermetically sealed terminal and a lead wire passing through the partition wall 3. (2) Structure of the inverter device 16

[0028] In the exemplary embodiment, the inverter device 16 is formed, among other things, with an inverter board 17, six switching elements 18 wired on one side surface of the inverter board 17, a control device 36 wired on the other side surface of the inverter board 17, and an HV connector and an LV connector (not shown). In the exemplary embodiment, the switching elements 18 are formed by insulated-gate bipolar transistors (IGBTs) incorporating a gate section with a MOS structure.

[0029] In this case, the individual switching elements 18 form a three-phase inverter circuit 34 described below, and terminal portions 22 of the individual switching elements 18 are connected to the inverter board 17. The inverter device 16 thus assembled is accommodated in the inverter accommodation portion 6 and mounted on the partition wall 3 such that one side surface on which the switching elements 18 are located is the side of the partition wall 3, and is closed by a cover 23. In this case, the inverter board 17 is fixed to the partition wall 3 via a boss portion 24 projecting from the partition wall 3.

[0030] In this state of attaching the inverter device 16 to the partition wall 3, the switching elements 18 adhere closely to the partition wall 3 directly or via a fixed insulating heat conduction member and are in heat exchange relationship with the partition wall 3 of the housing body 2. Since the partition wall 3 is cooled by the refrigerant sucked into the compression mechanism accommodating portion 4 as already discussed, the switching elements 18 are in heat exchange relationship with the sucked refrigerant via the partition wall 3 and are cooled across the thickness of the partition wall 3 by the refrigerant sucked into the compression mechanism accommodating portion 4, so that the switching elements 18 themselves dissipate heat through the partition wall 3. That is, the housing body 2 (partition wall 3) acts as the heat sink of the switching elements 18. (3) Circuit configuration of the inverter device 16

[0031] Now, the inverter device 16 of the present invention is in Fig. 2, among others, the inverter circuit 34 formed of the IGBT for driving the electric motor 8, the control device 36 formed of a microcomputer, a driver, and the like and controlling the inverter circuit 34, a high-voltage circuit filter (EMI filter) 37, a low-voltage power supply 38, a LIN transceiver 39, which are wired on the inverter board 17 and accommodated in the inverter accommodating section 6 as described above.

[0032] A high-voltage battery (HV power source: vehicle battery) 41 of, for example, about 300 V DC is installed in the vehicle to supply power to and drive the electric motor 8 of the vehicle-mounted electrically driven compressor 1 and a traveling motor (not shown), and the inverter device 16 is connected to the high-voltage battery 41 via an HV connector (not shown).

[0033] In the case of an EMI measurement of a component (electrically driven compressor alone), 46 in Fig. 2 denotes an anode-side high-voltage supply line connected to the anode (+) side of the high-voltage battery 41 via a LISN (Limited Liability Network) 48, and 47 denotes a cathode-side high-voltage supply line connected to the cathode (-) side of the high-voltage battery 41 via a LISN 49. A high-voltage circuit filter 37 is connected to the anode-side high-voltage supply line 46 and the cathode-side high-voltage supply line 47. In the case of a vehicle, LISN 48 and LISN 49 are not connected.

[0034] The high-voltage circuit filter 37 is provided with an X-capacitor 51 connected between the anode-side high-voltage supply line 46 and the cathode-side high-voltage supply line 47, a differential-mode coil 52 inserted behind the X-capacitor 51 into the anode-side high-voltage supply line 46, a smoothing capacitor 53 connected behind the differential-mode coil 52 between the anode-side high-voltage supply line 46 and the cathode-side high-voltage supply line 47, a common-mode coil 54 connected behind the smoothing capacitor 53, a plurality of Y-capacitors (representatively indicated by 56) connected behind the common-mode coil 54, respectively, between the anode-side high-voltage supply line 46, the cathode-side high-voltage supply line 47 and the case body 2 are connected, and an inductor 57 which, in the exemplary embodiment, is connected in series with a Y capacitor 56.

[0035] The X capacitor 51 is a capacitor for reducing differential mode noise, and the Y capacitor 56 is a capacitor for reducing common mode noise. It is also a capacitor that smooths the ripple of the smoothing capacitor 53 and serves to treat high frequencies, the starting point of impedance equalization, as short circuits. The high-voltage circuit filter 37 is connected between the high-voltage battery 41 and the inverter circuit 34 and functions to reduce EMI noise generated by the switching of the inverter circuit 34.

[0036] The function of the inductor 57 is described in detail below. The inverter circuit 34 is connected to the electric motor 8 via a busbar 43, and the housing body 2 is grounded (by current flow) to the body 42 (ground plate).

[0037] The anode-side high-voltage supply line 46, the cathode-side high-voltage supply line 47, the high-voltage circuit filter 37 formed by the X capacitor 51, the differential-mode coil 52, the smoothing capacitor 53, the common-mode coil 54, the Y capacitors 56, and the inductor 57, the inverter circuit 34, and the like constitute the high-voltage circuit 58 of the inverter device 16. The control device 36, the low-voltage supply 38, the LIN transceiver 39, and the like constitute the low-voltage circuit 59 of the inverter device 16. In the exemplary embodiment, the high-voltage circuit 58 and the low-voltage circuit 59 are arranged close to the same inverter board 17. (4) Structure of the inverter board 17

[0038] Next, Fig. 3 a top view of the inverter board 17 and Fig. 4 is an enlarged view of the part of the inductor 57 from Fig. 3. The inverter board 17 is a printed circuit board on which the individual elements of the inverter device 16 are wired, and since the Y capacitor 56 with its effect against high-frequency noise is greatly influenced by the position on the inverter board 17 (impedance characteristic) as discussed above, mounting patterns 61 (including 61A) are created in advance on the inverter board 17 at several positions that are considered to be effective as mounting positions of the Y capacitor 56.

[0039] In the exemplary embodiment, the mounting patterns 61 of Y capacitors 56 are formed at seven positions of the inverter board 17, which are assumed to be effective, and a Y capacitor 56 is connected to each mounting pattern 61. In the case of the exemplary embodiment, in order to ensure sufficient withstand voltage for a single Y capacitor 56 for vehicle safety, a plurality of surface-mount type ceramic capacitors 63 are connected in series and formed as a ceramic capacitor group. Actually, two to four series-connected surface-mount type ceramic capacitors 63 are used. In this exemplary embodiment, a single Y capacitor 56 is formed from three series-connected ceramic capacitor groups.

[0040] In the exemplary embodiment, the Y capacitor 56, which is connected to the mounting pattern shown in Fig. 3 and Fig. 4, designated 61A, the inductor 57 is connected in series. In the case of the exemplary embodiment, a surface-mount chip inductor is used for the inductor 57. A chip bead can also be used as the inductor 57. There is no limitation to a position, and the inductor 57 can be connected in series with a plurality of Y capacitors 56, and depending on the effect, the inductor 57 can also be connected in series with all of the Y capacitors 56. (5) Operation of the inverter device 16

[0041] The inverter circuit 34 is configured by the six switching elements 18 in a three-phase bridge circuit, and the switching elements 18 are controlled by gate drive signals generated by a gate driver of the control device 36. The control device 36 is configured by a microcomputer (CPU) and the gate driver. By switching and PWM-modulating the switching elements 18 of the inverter circuit 34 via the gate driver, it converts the DC voltage from the high-voltage battery 41 into AC voltage at a specified frequency and applies it to the electric motor 8. (6) Noise path of the inverter device 16

[0042] A surge voltage (oscillation voltage) is generated at the switching elements 18 forming the inverter circuit 34 during switching, which is why the inverter circuit 34 and the control device 36, the low-voltage power supply 38, and the LIN transceiver 39 constitute a noise source 60. The noise current generated by the noise source 60 flows through the stray capacitance between the inverter board 17, the busbar 43, the electric motor 8, and the housing body 2 (in Fig. 2 (noise current inflow path designated 62) to the housing body 2. It becomes common mode noise current and flows from the housing body 2 to the body 42 (in Fig. 2 with the hatched arrow), and since it flows into the LISN 48, 49 during the component EMI measurement, it is detected as noise. The noise then returns via the wiring to the inverter board 17 (noise). Fig. In Figure 2, the dashed arrow indicates radiated noise generated by the common-mode noise current, while the dotted arrows represent differential-mode noise current. The radiated noise occurs regardless of the component and the vehicle. (7) Operation of the Y capacitor 56 and the inductor 57

[0043] A portion of the common-mode noise current from the noise source 60 described above returns to the noise source 60 via the Y-capacitor 56 and the inductor 57 (return path) (the solid arrow through the Y-capacitor 56 in Fig. 2), which is why the common-mode noise current is reduced accordingly.

[0044] Based on Fig. 5 to 7, the difference in noise improvement effect when the Y capacitor 56 alone is present and when the inductor 57 is connected in series with the Y capacitor 56 as in the present invention will be described. Fig. 5 is an equivalent circuit diagram for the case where the Y capacitor 56, which is arranged as in Fig. 4 is connected to the mounting pattern 61A, the inductor 57 is connected in series, and Fig. 6 is an equivalent circuit diagram for the case of a Y capacitor 56 alone, to which no inductor 57 is connected, where 65 in the individual views indicates the capacitance of the Y capacitor 56, 64 a parasitic series resistance of the Y capacitor 56 and 66 a parasitic series inductance of the Y capacitor 56.

[0045] L1 in Fig. 7 is the impedance characteristic in the case of Fig. 5 and L2 the impedance characteristic in the case of Fig. 6. As already discussed, in order to ensure sufficient dielectric strength for a single Y-capacitor 56 for vehicle safety purposes, three surface-mount ceramic capacitors 63 are connected in series in the exemplary embodiment and formed as a ceramic capacitor group. Therefore, in the case of the Y-capacitor 56 alone ( Fig. 6) the composite capacitance, while the resonance frequency (the frequency at which the impedance is lowest) is as defined by L2 in Fig. 7 and is approximately 150 MHz in the exemplary embodiment.

[0046] The improvement characteristic for common-mode noise by the Y capacitor becomes better the lower the impedance. In contrast, the noise current that occurs when switching the switching elements 18 of the inverter circuit 34 is between 30 MHz and 50 MHz, so that in the case of the Y capacitor 56 alone, as in Fig. 6 in the range from 30 MHz to 50 MHz (in Fig. 7 area marked X1) the impedance does not drop far enough and no sufficient noise improvement characteristic can be expected.

[0047] But if, as in Fig. 5 the inductor 57 is connected in series with the Y-capacitor 56, the impedance characteristic is as for L1 in Fig. 7. In the present invention, since the inductor 57 is connected in series with the Y capacitor 56, the resonance frequency is shifted to the low side. The configuration in the embodiment is such that the resonance frequency is in the range of 30 MHz to 50 MHz (X1 in Fig. 7) is shifted, so that the impedance characteristic in this area is greatly improved.

[0048] This makes it possible to efficiently return switching surge noise in the VHF range, which occurs during operation of the electric motor 8, at the Y capacitor 56 and the inductor 57 to the inverter circuit 34, which is the noise source 60, and to prevent its flow to the outside.

[0049] Since the resonance frequency is shifted to the low side when the inductor 57 is connected in series (L1), at a frequency above 50 MHz (especially from 100 MHz) the impedance increases compared to the case where only the Y-capacitor 56 is present alone (L2) (L1>L2: Fig.7). Noise above 100 MHz is primarily noise emanating from the control device 36, but since the impedance on the path by which the noise travels from the control device 36 to the housing body 2 is extremely high, it is not necessary to return the noise with a Y capacitor. Since noise radiated directly from the control device 36 is shielded by accommodating the inverter board 17, as in the exemplary embodiment, in the inverter receiving section 6 of the housing body 2, which is made of thick aluminum, the risk of leakage to the outside can be practically ignored.

[0050] Since the vehicle-mounted electrically driven compressor 1 according to the present invention, which includes, in the aluminum case body 2, the inverter board 17 on which the inverter circuit 34 is mounted, which converts direct current from the high-voltage battery 41 into alternating current and supplies it to the electric motor 8, comprises, as described above, the common mode coil 54 inserted into the anode-side high-voltage power supply line 46 and the cathode-side high-voltage power supply line 47 from the high-voltage battery 41, the Y capacitor 56 connected between the high-voltage power supply lines 46, 47 and the case body 2, and the inductor 57 connected in series with the Y capacitor 25, the resonance frequency of the series connection of the inductor 57 and the Y capacitor 56 can be shifted to the low side without increasing the capacitance of the Y capacitor 56.

[0051] Even if the Y capacitor 56 is formed by a series-connected ceramic capacitor group in which the surface-mount type ceramic capacitors 63 are connected in series, and the composite capacitance is reduced and the resonance frequency is increased, it is possible to efficiently return switching surge noise in the range of 30 MHz to 50 MHz, which occurs during the operation of the electric motor 8 of the electrically driven compressor 1 installed in a vehicle, at the Y capacitor 56 and the inductor 57 to the inverter circuit 34, which is the noise source, and prevent its leakage to the outside, thus improving the EMI.

[0052] Noise radiated by the control device 36 does not pose a particular problem, since the inverter board 17 is shielded by the aluminum housing body 2 in which it is housed.

[0053] Also, in order to increase the capacitance of the Y capacitor 56, it is not necessary to further connect series-connected ceramic capacitor groups in parallel, and it is sufficient to connect an inexpensive inductor 57 such as a chip inductor or a chip bead instead, thereby achieving a tremendous cost reduction and downsizing of the electrically driven compressor 1 installed in a vehicle.

[0054] Since, in an arrangement with a plurality of mounting patterns of Y capacitors 56 on the inverter board 17, EMI improvement is possible by connecting the inductor 57 in series with at least one of them when mounting the Y capacitors 56, the problem of lower EMI reproducibility that occurs when the patterns 61 are sequentially combined without assembly also disappears, since the sequential combination of the mounting patterns 61 found to be effective for EMI in test operation is not required, unlike in the prior art, which enables a significant reduction in the development time.

[0055] This is extremely useful in an electrically driven compressor 1 installed in a vehicle, in which the high-voltage circuit 58 and the low-voltage circuit 59 are arranged on the inverter board 17 as in the embodiment, since the influence of noise of the high-voltage circuit 58 on the low-voltage circuit 59 can be greatly reduced.

[0056] There is no limitation to the concrete design and number shown in the embodiment, and these can be changed in different ways as long as the essence of the present invention is not deviated from. LIST OF REFERENCE SYMBOLS 1 Electrically driven compressor installed in a vehicle 2 housing bodies 3 Partition wall 6 Inverter mounting section 8 Electric motor 16 Inverter device 17 Inverter board 18 Switching element 34 Inverter circuit 36 Control device 37 high-voltage circuit filters 41 High-voltage battery (battery installed in the vehicle) 46 anode-side high-voltage supply line (high-voltage supply line) 47 cathode-side high-voltage supply line (high-voltage supply line) 54 Common mode coil 56 Y-capacitor 57 Inductor 58 High-voltage circuit 59 Low-voltage circuit 69 Noise source 61 (61A) Assembly pattern 63 Ceramic capacitor

Claims

[1] An electrically driven compressor installed in a vehicle, comprising, in a metal housing body, an inverter board on which an inverter circuit is mounted, which converts direct current from a battery installed in the vehicle into alternating current and applies it to an electric motor, characterized by : a common-mode coil inserted into a high-voltage supply line from the battery installed in the vehicle, a Y capacitor connected between the high-voltage supply line and the housing body, and an inductor connected in series with the Y capacitor. [2] An electrically driven compressor installed in a vehicle according to claim 1, characterized bythat the Y capacitor is formed from a ceramic capacitor group in which a plurality of surface mount type ceramic capacitors are connected in series, wherein the inductor is a surface mount type chip inductor or a chip bead. [3] An electrically driven compressor installed in a vehicle according to claim 1, characterized by that a resonance frequency of a series circuit of the inductor with the Y capacitor is shifted to the low side. [4] An electrically driven compressor installed in a vehicle according to claim 1, characterized by that a mounting pattern of Y-capacitors is designed at several positions and the inductor is connected to at least one of the Y-capacitors. [5] An electrically driven compressor installed in a vehicle according to any one of claims 1 to 4, characterized bythat on the inverter board, a high-voltage circuit including a high-voltage supply line from the battery installed in the vehicle, the Y capacitor and the inductor, and a low-voltage circuit including a control device that controls the inverter circuit are arranged.

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