Electric compressor

Abstract

To obtain a more satisfactory damping effect.SOLUTION: A first coil 34A and a second coil 34B are disposed in parallel with each other so as to generate an annular magnetic flux φ100 passing both the inside of a first linear part 51A and the inside of a third linear part 51B by a current i1 flowing to a first winding wire 60A and a third winding wire 60B. The annular magnetic flux φ100 passing both the inside of the first linear part 51A and the inside of the third linear part 51B is generated by the current i1 flowing to the first winding wire 60A and the third winding wire 60B, such that leakage magnetic fluxes generated from the first coil 34A and the second coil 34B are strengthened each other. Thus, mutual inductance is generated. Damping effects generated in a first conductor 70A and a second conductor 70B then become greater in proportion to the mutual inductance.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an electric compressor. [Background technology]

[0002] The electric compressor includes a compression unit, an electric motor, and an inverter device. The compression unit compresses a fluid. The electric motor drives the compression unit. The inverter device drives the electric motor. The inverter device includes an inverter circuit. The inverter circuit converts DC power to AC power. The inverter device includes a noise reduction unit. The noise reduction unit is provided on the input side of the inverter circuit. The noise reduction unit includes a common mode choke coil and a smoothing capacitor. The smoothing capacitor, together with the common mode choke coil, forms a low-pass filter circuit. The noise reduction unit reduces common mode noise and normal mode noise contained in the DC power before it is input to the inverter circuit.

[0003] A common mode choke coil includes an annular core and first and second windings wound around the first core. The second winding faces the first winding while being spaced apart from it. Patent Document 1, for example, discloses a common mode choke coil including an annular conductor that straddles and surrounds the first and second windings. In this case, a normal mode current flowing through the core induces an induced current in the conductor. When the induced current flows in the conductor, a magnetic flux that resists the leakage flux generated when the normal mode current flows is generated in the conductor. The induced current flowing in the conductor is then converted into thermal energy, causing the conductor to act as a magnetic resistor, resulting in a damping effect. As a result, the resonance peak generated by the low-pass filter circuit is suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-180218 Summary of the Invention [Problem to be solved by the invention]

[0005] However, it is desirable to obtain a better damping effect in such an electric compressor. [Means for solving the problem]

[0006] An electric compressor that solves the above-mentioned problems includes a compression unit that compresses a fluid, an electric motor that drives the compression unit, and an inverter device that drives the electric motor, the inverter device including an inverter circuit that converts DC power into AC power, and a noise reduction unit that is provided on the input side of the inverter circuit and reduces common mode noise and normal mode noise included in the DC power before it is input to the inverter circuit, the noise reduction unit including a common mode choke coil and a smoothing capacitor that forms a low pass filter circuit together with the common mode choke coil, the common mode choke coil including a first coil and a second coil, the first coil including a ring-shaped first core, a first winding wound around the first core, a second winding wound around the first core and facing but spaced from the first winding, and a ring-shaped first conductor that straddles and surrounds the first winding and the second winding, a portion of the first conductor faces the first winding via a first hole inside the first core, and the first core extends linearly, the second coil has a first straight portion around which at least a portion of the first winding is wound, and a second straight portion extending parallel to the first straight portion and around which at least a portion of the second winding is wound, the second coil comprises an annular second core, a third winding wound around the second core, a fourth winding wound around the second core and facing away from the third winding, and a second annular conductor spanning and surrounding the third winding and the fourth winding, a portion of the second conductor facing away from the third winding via a second hole inside the second core, and the second core comprises The rotor has a third straight portion that extends in a straight line and around which at least a portion of the third winding is wound, and a fourth straight portion that extends parallel to the third straight portion and around which at least a portion of the fourth winding is wound, the first winding and the third winding are electrically connected, and the second winding and the fourth winding are electrically connected, and the first coil and the second coil are arranged side by side so that a circular magnetic flux that passes through both the first straight portion and the third straight portion is generated by a current flowing through the first winding and the third winding.

[0007] According to this configuration, currents flowing through the first and third windings generate a circular magnetic flux that passes through both the first and third linear sections, causing the leakage magnetic fluxes from the first and second coils to reinforce each other. This generates mutual inductance. The damping effect generated in the first and second conductors increases in proportion to the mutual inductance. Therefore, a better damping effect can be achieved than, for example, when the first and second coils are arranged without any special care.

[0008] In the above-described electric compressor, the first coil and the second coil may be arranged side by side such that the first straight portion and the third straight portion are aligned on the same straight line, the second straight portion and the fourth straight portion are aligned on the same straight line, and a current flowing through the second winding and the fourth winding generates a circular magnetic flux that passes through both the second straight portion and the fourth straight portion.

[0009] In the above-described electric compressor, the first coil and the second coil may be arranged side by side so that the first core and the second core surround the same axis and so that a circular magnetic flux passing through both the second straight portion and the fourth straight portion is generated by a current flowing through the second winding and the fourth winding.

[0010] In these configurations, currents flowing through the second and fourth windings generate a circular magnetic flux that passes through both the second and fourth straight sections, causing the leakage magnetic fluxes from the first and second coils to reinforce each other. This generates mutual inductance. The damping effect generated in the first and second conductors increases in proportion to the mutual inductance. This results in a superior damping effect.

[0011] In the electric compressor, the first coil and the second coil may be arranged side by side so that the first straight portion, the second straight portion, the third straight portion, and the fourth straight portion are arranged in parallel. This allows the first coil and the second coil to be arranged on the same plane, thereby improving productivity of the electric compressor.

[0012] In the electric compressor, the first core and the second core may have the same shape. This results in excellent productivity of the electric compressor. [Effects of the Invention]

[0013] According to the present invention, a better damping effect can be obtained. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view of an electric compressor according to an embodiment. [Figure 2] FIG. 2 is a circuit diagram showing the electrical configuration of the electric compressor. [Figure 3] FIG. 2 is a perspective view showing a first core, a first winding, and a second winding. [Figure 4] FIG. 2 is a perspective view of a first coil. [Figure 5] FIG. 2 is a plan view showing a first coil and a second coil. [Figure 6] 10 is a graph showing the frequency characteristics of the gain of a low-pass filter circuit. [Figure 7] FIG. 10 is a plan view showing a first coil and a second coil in another embodiment. [Figure 8] FIG. 10 is a perspective view showing a first coil and a second coil in another embodiment. [Figure 9] FIG. 2 is a side view showing the first coil and the second coil. [Figure 10] FIG. 2 is a side view showing the first coil and the second coil. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of an electric compressor will now be described with reference to Figures 1 to 6. The electric compressor of this embodiment is used in, for example, a vehicle air conditioner. <Vehicle air conditioning device 10> As shown in Fig. 1, the vehicle air conditioning system 10 includes an electric compressor 11 and an external refrigerant circuit 12. The external refrigerant circuit 12 supplies a refrigerant as a fluid to the electric compressor 11. The external refrigerant circuit 12 includes, for example, a heat exchanger and an expansion valve. The vehicle air conditioning system 10 cools and heats the interior of the vehicle by compressing the refrigerant with the electric compressor 11 and exchanging heat and expanding the refrigerant with the external refrigerant circuit 12.

[0016] The vehicle air conditioner 10 includes an air conditioning ECU 13. The air conditioning ECU 13 controls the entire vehicle air conditioner 10. The air conditioning ECU 13 is configured to be able to grasp the vehicle interior temperature, the set temperature of the car air conditioner, etc. The air conditioning ECU 13 then transmits various commands, such as ON / OFF commands, to the electric compressor 11 based on parameters such as the vehicle interior temperature and the set temperature of the car air conditioner.

[0017] <Electric Compressor 11> The electric compressor 11 includes a housing 14. The housing 14 is made of a heat-conductive metal material such as aluminum. The housing 14 is grounded to the body of the vehicle.

[0018] The housing 14 has a suction housing 15 and a discharge housing 16. The suction housing 15 and the discharge housing 16 are assembled together. The suction housing 15 has a plate-shaped end wall 15a and a cylindrical peripheral wall 15b. The peripheral wall 15b extends cylindrically from the outer periphery of the end wall 15a. The discharge housing 16 is assembled to the suction housing 15 while closing the opening of the suction housing 15. This defines an internal space within the housing 14.

[0019] The housing 14 has an intake port 14a. Refrigerant is drawn into the intake port 14a from the external refrigerant circuit 12. The intake port 14a is formed in a peripheral wall 15b of the intake housing 15. More specifically, the intake port 14a is formed in a portion of the peripheral wall 15b of the intake housing 15 that is closer to the end wall 15a than the discharge housing 16. The housing 14 has a discharge port 14b. The discharge port 14b discharges the refrigerant to the external refrigerant circuit 12. The discharge port 14b is formed in the discharge housing 16.

[0020] The electric compressor 11 includes a rotating shaft 17, a compression unit 18, and an electric motor 19. The rotating shaft 17, the compression unit 18, and the electric motor 19 are housed in a housing 14. The rotating shaft 17 is supported in a rotatable state relative to the housing 14. The rotating shaft 17 is disposed in the housing 14 with the axial direction of the rotating shaft 17 coinciding with the axial direction of the peripheral wall 15b.

[0021] <Compression section 18> The compression section 18 is accommodated within the suction housing 15. The compression section 18 is, for example, a scroll type configured with a fixed scroll (not shown) fixed within the suction housing 15 and an orbiting scroll (not shown) arranged opposite the fixed scroll. The compression section 18 is disposed within the suction housing 15 at a position closer to the discharge port 14b than to the suction port 14a. The compression section 18 is connected to the rotary shaft 17. The compression section 18 is driven by the rotation of the rotary shaft 17 to compress the refrigerant.

[0022] <Electric Motor 19> The electric motor 19 is accommodated within the suction housing 15. The electric motor 19 is disposed between the compression section 18 and the end wall 15a within the suction housing 15. The electric motor 19 has a rotor 20 and a stator 21. The stator 21 has a cylindrical stator core 22 and three-phase coils 23u, 23v, and 23w.

[0023] The three-phase coils 23u, 23v, and 23w are each wound around the stator core 22. The three-phase coils 23u, 23v, and 23w are, for example, Y-connected. The connection of the three-phase coils 23u, 23v, and 23w is not limited to Y-connection and may be any other connection. The connection of the three-phase coils 23u, 23v, and 23w may be, for example, delta-connected.

[0024] The rotor 20 has a cylindrical shape. The rotor 20 is fixed to the rotary shaft 17. This allows the rotary shaft 17 to rotate integrally with the rotor 20. The stator 21 is fixed to the peripheral wall 15b of the suction housing 15. The rotor 20 and the stator 21 face each other in the radial direction of the rotary shaft 17.

[0025] The rotor 20 rotates when the three-phase coils 23u, 23v, and 23w are energized in a predetermined pattern. The rotation of the rotor 20 rotates the rotary shaft 17, which drives the compression section 18. The electric motor 19 therefore drives the compression section 18. The refrigerant flowing through the external refrigerant circuit 12 is drawn into the housing 14 through the suction port 14a. The compression section 18 compresses the refrigerant drawn into the housing 14. The compressed refrigerant is discharged into the external refrigerant circuit 12 through the discharge port 14b.

[0026] <Cover member 25> The housing 14 has a cover member 25. The cover member 25 is formed of a heat-conductive metal material such as aluminum. The cover member 25 has a plate-shaped end wall 25a and a cylindrical peripheral wall 25b. The cover member 25 is attached to the end wall 15a of the suction housing 15 with the open end of the peripheral wall 25b abutting against the end wall 15a. The cover member 25 is fixed to the suction housing 15 with bolts 26. The opening of the peripheral wall 25b of the cover member 25 is closed by the end wall 15a. As a result, the end wall 15a and the cover member 25 form an inverter accommodating chamber S1. Therefore, the housing 14 has the inverter accommodating chamber S1.

[0027] <Connector 27 and Power Storage Device 28> The electric compressor 11 includes a connector 27. The connector 27 is electrically connected to an electricity storage device 28 mounted on the vehicle. The connector 27 is provided on the cover member 25. The electricity storage device 28 is a power source that supplies electric power to devices mounted on the vehicle. The electricity storage device 28 is a DC power source. The electricity storage device 28 is, for example, a secondary battery or a capacitor.

[0028] <Inverter device 30> The electric compressor 11 includes an inverter device 30. The inverter device 30 is accommodated in an inverter accommodating chamber S1. Therefore, the housing 14 accommodates the inverter device 30. The inverter device 30 is electrically connected to the power storage device 28 via a connector 27.

[0029] The inverter device 30 has a circuit board 30a. The circuit board 30a is accommodated in the inverter accommodating chamber S1. The circuit board 30a is disposed opposite the end wall 15a at a predetermined distance in the axial direction of the rotating shaft 17. The circuit board 30a is accommodated in the inverter accommodating chamber S1 with the thickness direction of the circuit board 30a aligned with the axial direction of the rotating shaft 17.

[0030] The inverter device 30 drives the electric motor 19. The inverter device 30 includes an inverter circuit 31 and a noise reduction unit 32. The inverter circuit 31 converts DC power into AC power. The noise reduction unit 32 is provided on the input side of the inverter circuit 31. The noise reduction unit 32 reduces common mode noise and normal mode noise contained in the DC power before it is input to the inverter circuit 31.

[0031] <Inverter circuit 31> 2, the inverter circuit 31 includes two connection lines EL1 and EL2. The inverter circuit 31 includes u-phase switching elements Qu1 and Qu2 corresponding to the u-phase coil 23u. The inverter circuit 31 includes v-phase switching elements Qv1 and Qv2 corresponding to the v-phase coil 23v. The inverter circuit 31 includes w-phase switching elements Qw1 and Qw2 corresponding to the w-phase coil 23w. Each of the switching elements Qu1 to Qw2 is a power switching element such as an IGBT. The switching elements Qu1 to Qw2 each include freewheeling diodes (body diodes) Du1 to Dw2.

[0032] The u-phase switching elements Qu1 and Qu2 are connected in series. A u-phase coil 23u is connected between the u-phase switching elements Qu1 and Qu2. The series connection of the u-phase switching elements Qu1 and Qu2 is electrically connected to both connection lines EL1 and EL2.

[0033] The v-phase switching elements Qv1, Qv2 are connected in series. A connection is made between the v-phase switching elements Qv1, Qv2 to the v-phase coil 23v. The series connection of the v-phase switching elements Qv1, Qv2 is electrically connected to both connection lines EL1, EL2.

[0034] The w-phase switching elements Qw1, Qw2 are connected in series. The w-phase coil 23w is connected between the w-phase switching elements Qw1, Qw2. The series connection of the w-phase switching elements Qw1, Qw2 is electrically connected to both connection lines EL1, EL2.

[0035] The inverter device 30 includes a control unit 33. The control unit 33 controls the switching operation of each of the switching elements Qu1 to Qw2. The control unit 33 can be realized, for example, by one or more dedicated hardware circuits and / or one or more processors (control circuits) that operate according to a computer program (software). The processor includes a CPU and memory such as RAM and ROM, and the memory stores, for example, program code or instructions configured to cause the processor to execute various processes. The memory, i.e., computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer.

[0036] The control unit 33 is electrically connected to the air conditioning ECU 13 via the connector 27. The control unit 33 periodically turns on / off each of the switching elements Qu1 to Qw2 based on a command from the air conditioning ECU 13. Specifically, the control unit 33 performs pulse width modulation control (PWM control) on each of the switching elements Qu1 to Qw2 based on a command from the air conditioning ECU 13. More specifically, the control unit 33 generates a control signal using a carrier signal (carrier wave signal) and a command voltage value signal (comparison signal). Then, the control unit 33 converts DC power to AC power by performing ON / OFF control on each of the switching elements Qu1 to Qw2 using the generated control signal.

[0037] <Noise reduction unit 32> The noise reduction unit 32 includes a common mode choke coil 34 and a smoothing capacitor 35. The smoothing capacitor 35, together with the common mode choke coil 34, constitutes a low-pass filter circuit 36. The low-pass filter circuit 36 is provided on the connection lines EL1 and EL2. The low-pass filter circuit 36 is provided between the connector 27 and the inverter circuit 31 in terms of the circuit. The common mode choke coil 34 is provided on both connection lines EL1 and EL2.

[0038] The smoothing capacitor 35 is provided on the inverter circuit 31 side with respect to the common mode choke coil 34. The smoothing capacitor 35 is an X capacitor connected in parallel to the inverter circuit 31. The smoothing capacitor 35 is electrically connected to both connection lines EL1 and EL2. The common mode choke coil 34 and the smoothing capacitor 35 form an LC resonant circuit. That is, the low-pass filter circuit 36 of this embodiment is an LC resonant circuit including the common mode choke coil 34.

[0039] The common mode choke coil 34 includes a first coil 34A and a second coil 34B. The noise reduction unit 32 includes the first coil 34A and the second coil 34B. Therefore, the noise reduction unit 32 of this embodiment includes two common mode choke coils 34. The first coil 34A and the second coil 34B are connected in series. The first coil 34A is located closer to the inverter circuit 31 than the second coil 34B.

[0040] The noise reduction unit 32 includes two first capacitors 37. The two first capacitors 37 are connected in series. The space between the two first capacitors 37 is grounded to the vehicle body via the housing 14. The two first capacitors 37 are provided on the inverter circuit 31 side of the first coil 34A. The two first capacitors 37 are connected in parallel to the first coil 34A. The two first capacitors 37 are connected in parallel to the smoothing capacitor 35. The two first capacitors 37 are located between the first coil 34A and the smoothing capacitor 35.

[0041] The noise reduction unit 32 includes two second capacitors 38. The two second capacitors 38 are connected in series. The space between the two second capacitors 38 is grounded to the vehicle body via the housing 14. The two second capacitors 38 are provided on the inverter circuit 31 side of the second coil 34B. The two second capacitors 38 are connected in parallel to the second coil 34B. The two second capacitors 38 are connected in parallel to the first coil 34A. The two second capacitors 38 are located between the first coil 34A and the second coil 34B.

[0042] The first coil 34A and the second coil 34B suppress transmission of high-frequency noise generated on the vehicle side to the inverter circuit 31 of the electric compressor 11. The first coil 34A and the second coil 34B utilize leakage inductance as normal inductance. As a result, the first coil 34A and the second coil 34B are used as L components in a low-pass filter circuit (LC filter) 36 for removing normal mode noise (differential mode noise). In other words, the first coil 34A and the second coil 34B can handle common mode noise and normal mode noise (differential mode noise). Therefore, in the electric compressor 11 of this embodiment, the common mode choke coil 34 handles both modes of noise, rather than using a common mode choke coil and a normal mode (differential mode) choke coil separately.

[0043] <First coil 34A> As shown in Figures 3 and 4, the first coil 34A includes a first core 50A, a first winding 60A, a second winding 61A, and a first conductor 70A. The first core 50A is annular. The first core 50A is made of a ferromagnetic material. The first core 50A is made of, for example, a ferrite core. The first core 50A has a first straight portion 51A, a second straight portion 52A, a first connecting portion 53A, and a second connecting portion 54A.

[0044] As shown in FIG. 3, the first linear portion 51A extends linearly. The first linear portion 51A and the second linear portion 52A are, for example, rectangular prism-shaped. At least a portion of the first winding 60A is wound around the first linear portion 51A. The second linear portion 52A is, for example, rectangular prism-shaped. The second linear portion 52A extends parallel to the first linear portion 51A. Therefore, the first linear portion 51A and the second linear portion 52A are arranged such that the axis of the first linear portion 51A and the axis of the second linear portion 52A extend in the same direction. The second linear portion 52A faces the first linear portion 51A while being spaced apart from it. At least a portion of the second winding 61A is wound around the second linear portion 52A. Therefore, the first winding 60A and the second winding 61A are wound around the first core 50A. The second winding 61A faces the first winding 60A while being spaced apart from it.

[0045] Resin members (not shown) are provided between the first core 50A and the first winding 60A, and between the first core 50A and the second winding 61A. The resin members ensure insulation between the first core 50A and the first winding 60A, and between the first core 50A and the second winding 61A.

[0046] The first connecting portion 53A has, for example, a quadrangular prism shape. The first connecting portion 53A connects a first end of the first straight portion 51A and a first end of the second straight portion 52A. The second connecting portion 54A has, for example, a quadrangular prism shape. The second connecting portion 54A connects a second end of the first straight portion 51A and a second end of the second straight portion 52A.

[0047] In this way, the first core 50A has a first hole 55A formed inside by arranging the first straight portion 51A, the second straight portion 52A, the first connecting portion 53A, and the second connecting portion 54A so that they form a ring shape as a whole.

[0048] As shown in FIG. 4, the first conductor 70A is a metal film. Any metal can be used for the first conductor 70A, but preferably it is copper foil, which is a non-magnetic material. The first conductor 70A is annular. More specifically, the first conductor 70A is strip-shaped and has no ends. The first conductor 70A is, for example, a rectangular cylindrical shape. The first conductor 70A has a constant thickness. The thickness of the first conductor 70A can be any thickness, but is preferably 10 μm to 100 μm. In this embodiment, the thickness of the first conductor 70A is 35 μm. The first conductor 70A has sufficient strength to maintain the shape of the first conductor 70A.

[0049] The first conductor 70A straddles and surrounds the first winding 60A and the second winding 61A. Specifically, it covers the entire first winding 60A, the entire second winding 61A, and a portion of the first hole 55A inside the first core 50A. A portion of the first conductor 70A faces the first core 50A through the first hole 55A inside the first core 50A. The first connecting portion 53A and the second connecting portion 54A are exposed and not covered by the first conductor 70A. Note that insulating layers are interposed between the first conductor 70A and the first winding 60A and the second winding 61A, respectively. The first conductor 70A is thermally coupled to the end wall 15a of the suction housing 15.

[0050] When the first winding 60A and the second winding 61A are energized, currents i1 and i2 flow. Accordingly, magnetic fluxes φ1 and φ2 are generated in the first core 50A, and leakage magnetic fluxes φ3 and φ4 are generated. The magnetic fluxes φ1 and φ2 are magnetic fluxes in opposite directions. An induced current i10 flows circumferentially inside the first conductor 70A to generate a magnetic flux in a direction that resists the leakage magnetic fluxes φ3 and φ4. Thus, the induced current i10 flows circumferentially inside the first conductor 70A to generate a magnetic flux in a direction that resists the leakage magnetic fluxes φ3 and φ4 generated by energizing the first winding 60A and the second winding 61A. The induced current i10 flows in a circle around the first core 50A. The first conductor 70A is formed thin, which increases its resistance, allowing it to more efficiently convert the induced current i10 into heat.

[0051] <Second coil 34B> As shown in FIGS. 3 and 4, the second coil 34B includes a second core 50B, a third winding 60B, a fourth winding 61B, and a second conductor 70B. The second core 50B is annular. The second core 50B is made of a ferromagnetic material. The second core 50B is made of, for example, a ferrite core. The second core 50B has a third straight portion 51B, a fourth straight portion 52B, a third connecting portion 53B, and a fourth connecting portion 54B. The first core 50A and the second core 50B have the same shape.

[0052] As shown in FIG. 3 , the third straight portion 51B extends linearly. The third straight portion 51B and the fourth straight portion 52B are, for example, rectangular prism-shaped. At least a portion of the third winding 60B is wound around the third straight portion 51B. The fourth straight portion 52B is, for example, rectangular prism-shaped. The fourth straight portion 52B extends parallel to the third straight portion 51B. Therefore, the third straight portion 51B and the fourth straight portion 52B are arranged such that the axis of the third straight portion 51B and the axis of the fourth straight portion 52B extend in the same direction. The fourth straight portion 52B faces the third straight portion 51B while being spaced apart from it. At least a portion of the fourth winding 61B is wound around the fourth straight portion 52B. Therefore, the third winding 60B and the fourth winding 61B are wound around the second core 50B. The fourth winding 61B faces the third winding 60B while being spaced apart from it.

[0053] Resin members (not shown) are provided between the second core 50B and the third winding 60B and between the second core 50B and the fourth winding 61B. The resin members ensure insulation between the second core 50B and the third winding 60B and between the second core 50B and the fourth winding 61B.

[0054] The third connecting portion 53B has, for example, a quadrangular prism shape. The third connecting portion 53B connects a first end of the third straight portion 51B and a first end of the fourth straight portion 52B. The fourth connecting portion 54B has, for example, a quadrangular prism shape. The fourth connecting portion 54B connects a second end of the third straight portion 51B and a second end of the fourth straight portion 52B.

[0055] In this way, the second core 50B has a second hole 55B formed inside by arranging the third straight portion 51B, the fourth straight portion 52B, the third connecting portion 53B, and the fourth connecting portion 54B so that they form a ring shape as a whole.

[0056] As shown in FIG. 4, the second conductor 70B is a metal film. Any metal can be used for the second conductor 70B, but preferably it is copper foil, which is a non-magnetic material. The second conductor 70B is annular. More specifically, the second conductor 70B is strip-shaped and has no ends. The second conductor 70B is, for example, a rectangular cylindrical shape. The second conductor 70B has a constant thickness. The thickness of the second conductor 70B can be any thickness, but is preferably 10 μm to 100 μm. In this embodiment, the thickness of the second conductor 70B is 35 μm. The second conductor 70B has a sufficient strength to maintain the shape of the second conductor 70B.

[0057] The second conductor 70B straddles and surrounds the third winding 60B and the fourth winding 61B. Specifically, it covers the entire third winding 60B, the entire fourth winding 61B, and a portion of the second hole 55B inside the second core 50B. A portion of the second conductor 70B faces the second core 50B through the second hole 55B inside the second core 50B. The third connecting portion 53B and the fourth connecting portion 54B are exposed and not covered by the second conductor 70B. Note that insulating layers are interposed between the second conductor 70B and the third winding 60B and the fourth winding 61B, respectively. The second conductor 70B is thermally coupled to the end wall 15a of the suction housing 15.

[0058] When the third winding 60B and the fourth winding 61B are energized, currents i1 and i2 flow. Accordingly, magnetic fluxes φ11 and φ12 are generated in the second core 50B, and leakage magnetic fluxes φ13 and φ14 are generated. The magnetic fluxes φ11 and φ12 are opposite in direction to each other. An induced current i20 flows circumferentially inside the second conductor 70B to generate a magnetic flux in a direction that resists the leakage magnetic fluxes φ13 and φ14. Thus, the induced current i20 flows circumferentially inside the second conductor 70B to generate a magnetic flux in a direction that resists the leakage magnetic fluxes φ13 and φ14 generated by energizing the third winding 60B and the fourth winding 61B. The induced current i20 flows in a circular direction around the second core 50B. The second conductor 70B is formed thin, which increases its resistance, allowing it to more efficiently convert the induced current i20 into heat.

[0059] <Positional Relationship Between First Coil 34A and Second Coil 34B> 5, the first coil 34A and the second coil 34B are arranged side by side such that the first linear portion 51A and the third linear portion 51B are aligned on the same straight line, and the second linear portion 52A and the fourth linear portion 52B are aligned on the same straight line. The second connecting portion 54A and the third connecting portion 53B are adjacent to each other in the juxtaposition direction of the first coil 34A and the second coil 34B. The first coil 34A and the second coil 34B are arranged side by side such that the central axis L1 of the first core 50A and the central axis L2 of the second core 50B extend parallel to each other.

[0060] The first winding 60A and the third winding 60B are connected in series. Therefore, the first winding 60A and the third winding 60B are electrically connected. The second winding 61A and the fourth winding 61B are connected in series. Therefore, the second winding 61A and the fourth winding 61B are electrically connected. The current flowing through the first winding 60A in the first straight portion 51A, the current flowing through the second winding 61A in the second straight portion 52A, the current flowing through the third winding 60B in the third straight portion 51B, and the current flowing through the fourth winding 61B in the fourth straight portion 52B all flow in the same circumferential direction.

[0061] <Operation of the embodiment> Next, the operation of this embodiment will be described. Fig. 6 is a graph showing the frequency characteristics of the gain (attenuation) of the low-pass filter circuit 36 with respect to incoming normal mode noise. The solid line in Fig. 6 shows an example where the first conductor 70A is present in the first coil 34A. The dashed-dotted line in Fig. 6 shows an example where the first conductor 70A is not present in the first coil 34A. In Fig. 6, the frequency on the horizontal axis is expressed in logarithm. Gain is a parameter that indicates the amount by which normal mode noise can be reduced.

[0062] 6, when the first conductor 70A is not present in the first coil 34A, the Q value of the low-pass filter circuit 36 is relatively high, which makes it difficult to reduce normal mode noise at a frequency close to the resonant frequency of the low-pass filter circuit 36.

[0063] On the other hand, when the first conductor 70A is present in the first coil 34A, the first conductor 70A is positioned so that it passes through the loop of the leakage magnetic fluxes φ3 and φ4. The first conductor 70A is configured to generate an induced current (eddy current) that generates a magnetic flux in a direction that cancels out the leakage magnetic fluxes φ3 and φ4 due to the leakage magnetic fluxes φ3 and φ4. This allows the first conductor 70A to function as a component that lowers the Q value of the low-pass filter circuit 36. Therefore, as shown by the solid line in FIG. 6, the Q value of the low-pass filter circuit 36 is lowered. Therefore, normal mode noise having a frequency near the resonant frequency of the low-pass filter circuit 36 is also reduced by the low-pass filter circuit 36.

[0064] As described above, the first coil 34A employs a metal shield structure using the strip-shaped, endless first conductor 70A to reduce common-mode noise. Furthermore, by actively utilizing the leakage magnetic flux generated by the normal mode current (differential mode current), appropriate filter characteristics are achieved that also reduce normal mode noise (differential mode noise). In other words, the strip-shaped, endless first conductor 70A generates a magnetic flux that resists the leakage magnetic flux generated when the normal mode current (differential mode current) is passed through it. This current flows through the first conductor 70A by electromagnetic induction and is dissipated as heat. The first conductor 70A acts as a magnetic resistor, providing a damping effect and suppressing the resonance peak generated by the low-pass filter circuit 36. The second coil 34B also functions similarly to the first coil 34A.

[0065] As shown in FIG. 5, the first coil 34A and the second coil 34B are arranged side by side such that the first linear portion 51A and the third linear portion 51B are aligned on the same line, and the second linear portion 52A and the fourth linear portion 52B are aligned on the same line. When the first winding 60A and the third winding 60B are energized, a current i1 flows through the first winding 60A and the third winding 60B, and the leakage magnetic fluxes φ3 and φ13 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other. This generates a magnetic flux φ100 that passes through the first linear portion 51A and the third linear portion 51B. The direction of the magnetic flux φ100 is the same as the direction of the leakage magnetic fluxes φ3 and φ13. The magnetic flux φ100 is generated by the current i1 flowing through the first winding 60A and passes through the third linear portion 51B. Further, a magnetic flux φ100 is generated by a current i1 flowing through the third winding 60B and passes through the first straight portion 51A.

[0066] Therefore, the first coil 34A and the second coil 34B are arranged side by side so that the magnetic flux φ100 generated by the current i1 flowing through the first winding 60A and passing through the third straight portion 51B has the same direction as the magnetic flux φ13 generated by the current i1 flowing through the third winding 60B and passing through the third straight portion 51B, and so that the magnetic flux φ100 generated by the current i1 flowing through the third winding 60B and passing through the first straight portion 51A has the same direction as the magnetic flux φ3 generated by the current i1 flowing through the first winding 60A and passing through the first straight portion 51A. The first coil 34A and the second coil 34B are arranged side by side so that the current i1 flowing through the first winding 60A and the third winding 60B generates a circular magnetic flux φ100 that passes through both the first straight portion 51A and the third straight portion 51B.

[0067] When the second winding 61A and the fourth winding 61B are energized, a current i2 flows through the second winding 61A and the fourth winding 61B, and the leakage magnetic fluxes φ4 and φ14 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other. As a result, a magnetic flux φ200 is generated that passes through the second straight portion 52A and the fourth straight portion 52B. The direction of the magnetic flux φ200 is the same as the direction of the leakage magnetic fluxes φ4 and φ14. The magnetic flux φ200 is generated by the current i2 flowing through the second winding 61A and passes through the fourth straight portion 52B. Meanwhile, the magnetic flux φ100 is generated by the current i2 flowing through the fourth winding 61B and passes through the third straight portion 51B.

[0068] Therefore, the first coil 34A and the second coil 34B are arranged side by side so that the magnetic flux φ200 generated by the current i2 flowing through the second winding 61A and passing through the fourth straight portion 52B has the same direction as the magnetic flux φ14 generated by the current i2 flowing through the fourth winding 61B and passing through the fourth straight portion 52B, and so that the magnetic flux φ200 generated by the current i2 flowing through the fourth winding 61B and passing through the second straight portion 52A has the same direction as the magnetic flux φ4 generated by the current i2 flowing through the second winding 61A and passing through the second straight portion 52A. The first coil 34A and the second coil 34B are arranged side by side so that the current i2 flowing through the second winding 61A and the fourth winding 61B generates a circular magnetic flux φ200 that passes through both the second straight portion 52A and the fourth straight portion 52B.

[0069] In this way, the current i1 flowing through the first winding 60A and the third winding 60B generates a circular magnetic flux φ100 that passes through both the first linear portion 51A and the third linear portion 51B. Therefore, the leakage magnetic fluxes φ3 and φ13 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other, thereby generating mutual inductance. Furthermore, the current i2 flowing through the second winding 61A and the fourth winding 61B generates a circular magnetic flux φ200 that passes through both the second linear portion 52A and the fourth linear portion 52B, thereby generating the leakage magnetic fluxes φ4 and φ14 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other, thereby generating mutual inductance. Furthermore, the damping effect generated in each of the first conductor 70A and the second conductor 70B increases in proportion to the mutual inductance. Therefore, for example, compared to when the first coil 34A and the second coil 34B are arranged without any special consideration, a better damping effect can be obtained, and the resonance peak generated by the low-pass filter circuit 36 can be further easily suppressed.

[0070] <Effects of the embodiment> The above embodiment can provide the following effects. (1) The current i1 flowing through the first winding 60A and the third winding 60B generates a circular magnetic flux φ100 that passes through both the first straight portion 51A and the third straight portion 51B, causing the leakage magnetic fluxes generated by the first coil 34A and the second coil 34B to reinforce each other. This generates mutual inductance. The damping effect generated in the first conductor 70A and the second conductor 70B increases in proportion to the mutual inductance. Therefore, a better damping effect can be obtained compared to, for example, a case in which the first coil 34A and the second coil 34B are arranged without any special consideration.

[0071] (2) The first coil 34A and the second coil 34B are arranged side by side so that the first linear portion 51A and the third linear portion 51B are aligned on the same line, the second linear portion 52A and the fourth linear portion 52B are aligned on the same line, and the current i2 flowing through the second winding 61A and the fourth winding 61B generates a circular magnetic flux φ200 that passes through both the second linear portion 52A and the fourth linear portion 52B. As a result, the current i2 flowing through the second winding 61A and the fourth winding 61B generates a circular magnetic flux φ200 that passes through both the second linear portion 52A and the fourth linear portion 52B, which reinforces the leakage magnetic fluxes generated by the first coil 34A and the second coil 34B. This generates mutual inductance. The damping effect generated in the first conductor 70A and the second conductor 70B increases in proportion to the mutual inductance. Therefore, a better damping effect can be obtained.

[0072] (3) The first core 50A and the second core 50B have the same shape, which improves the productivity of the electric compressor 11. <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0073] As shown in FIG. 7, the first coil 34A and the second coil 34B may be arranged side by side such that the first straight portion 51A, the second straight portion 52A, the third straight portion 51B, and the fourth straight portion 52B are aligned in parallel.

[0074] The first straight portion 51A and the third straight portion 51B are adjacent to each other in the juxtaposition direction of the first coil 34A and the second coil 34B. The first coil 34A and the second coil 34B are arranged side by side such that the central axis L1 of the first core 50A and the central axis L2 of the second core 50B extend parallel to each other.

[0075] The first winding 60A and the third winding 60B are connected in series. The second winding 61A and the fourth winding 61B are connected in series. The current i1 flowing in the first winding 60A at the first straight portion 51A and the current i1 flowing in the third winding 60B at the third straight portion 51B flow in opposite circumferential directions. The current i2 flowing in the second winding 61A at the second straight portion 52A and the current i2 flowing in the fourth winding 61B at the fourth straight portion 52B flow in opposite circumferential directions.

[0076] When the first winding 60A and the third winding 60B are energized, a current i1 flows through the first winding 60A and the third winding 60B, and the leakage magnetic fluxes φ3 and φ13 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other. As a result, a magnetic flux φ100 is generated that passes through the first straight portion 51A and the third straight portion 51B. The direction of the magnetic flux φ100 is the same as the direction of the leakage magnetic fluxes φ3 and φ13. The magnetic flux φ100 is generated by the current i1 flowing through the first winding 60A and passes through the third straight portion 51B. The magnetic flux φ100 is also generated by the current i1 flowing through the third winding 60B and passes through the first straight portion 51A.

[0077] Therefore, the first coil 34A and the second coil 34B are arranged side by side so that the magnetic flux φ100 generated by the current i1 flowing through the first winding 60A and passing through the third straight portion 51B has the same direction as the magnetic flux φ13 generated by the current i1 flowing through the third winding 60B and passing through the third straight portion 51B, and so that the magnetic flux φ100 generated by the current i1 flowing through the third winding 60B and passing through the first straight portion 51A has the same direction as the magnetic flux φ3 generated by the current i1 flowing through the first winding 60A and passing through the first straight portion 51A. The first coil 34A and the second coil 34B are arranged side by side so that the current i1 flowing through the first winding 60A and the third winding 60B generates a circular magnetic flux φ100 that passes through both the first straight portion 51A and the third straight portion 51B.

[0078] In this way, the current i1 flowing through the first winding 60A and the third winding 60B generates a circular magnetic flux φ100 that passes through both the first linear portion 51A and the third linear portion 51B. Therefore, the leakage magnetic fluxes φ3 and φ13 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other. This generates mutual inductance. The damping effect generated in the first conductor 70A and the second conductor 70B increases in proportion to the mutual inductance. Therefore, compared to, for example, a case in which the first coil 34A and the second coil 34B are arranged without any special consideration, a better damping effect can be obtained, further facilitating the suppression of resonance peaks generated by the low-pass filter circuit 36.

[0079] The first coil 34A and the second coil 34B are arranged side by side so that the first straight portion 51A, the second straight portion 52A, the third straight portion 51B, and the fourth straight portion 52B are arranged in parallel to each other. This allows the first coil 34A and the second coil 34B to be arranged on the same plane, which improves the productivity of the electric compressor 11.

[0080] As shown in FIGS. 8, 9, and 10, the first coil 34A and the second coil 34B may be arranged so that the central axis L1 of the first core 50A and the central axis L2 of the second core 50B are aligned. The first coil 34A and the second coil 34B are arranged side by side so that the first linear portion 51A and the third linear portion 51B are aligned parallel to each other. The first coil 34A and the second coil 34B are arranged side by side so that the second linear portion 52A and the fourth linear portion 52B are aligned parallel to each other. The first linear portion 51A and the third linear portion 51B are adjacent to each other in the juxtaposition direction of the first coil 34A and the second coil 34B. The second linear portion 52A and the fourth linear portion 52B are adjacent to each other in the juxtaposition direction of the first coil 34A and the second coil 34B.

[0081] The first winding 60A and the third winding 60B are connected in series. The second winding 61A and the fourth winding 61B are connected in series. The current i1 flowing in the first winding 60A at the first straight portion 51A and the current i1 flowing in the third winding 60B at the third straight portion 51B flow in opposite circumferential directions. The current i2 flowing in the second winding 61A at the second straight portion 52A and the current i2 flowing in the fourth winding 61B at the fourth straight portion 52B flow in opposite circumferential directions.

[0082] As shown in FIG. 9, when the first winding 60A and the third winding 60B are energized, a current i1 flows through the first winding 60A and the third winding 60B, and leakage magnetic fluxes φ3 and φ13 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other. As a result, a magnetic flux φ100 is generated that passes through the first straight portion 51A and the third straight portion 51B. The direction of the magnetic flux φ100 is the same as the direction of the leakage magnetic fluxes φ3 and φ13. The magnetic flux φ100 is generated by the current i1 flowing through the first winding 60A and passes through the third straight portion 51B. The magnetic flux φ100 is also generated by the current i1 flowing through the third winding 60B and passes through the first straight portion 51A.

[0083] Therefore, the first coil 34A and the second coil 34B are arranged side by side so that the magnetic flux φ100 generated by the current i1 flowing through the first winding 60A and passing through the third straight portion 51B has the same direction as the magnetic flux φ13 generated by the current i1 flowing through the third winding 60B and passing through the third straight portion 51B, and so that the magnetic flux φ100 generated by the current i1 flowing through the third winding 60B and passing through the first straight portion 51A has the same direction as the magnetic flux φ3 generated by the current i1 flowing through the first winding 60A and passing through the first straight portion 51A. The first coil 34A and the second coil 34B are arranged side by side so that the first core 50A and the second core 50B surround the same axis and so that the current i1 flowing through the first winding 60A and the third winding 60B generates a circular magnetic flux φ100 that passes through both the first straight portion 51A and the third straight portion 51B.

[0084] As shown in FIG. 10, when the second winding 61A and the fourth winding 61B are energized, a current i2 flows through the second winding 61A and the fourth winding 61B, and the leakage magnetic fluxes φ4 and φ14 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other. As a result, a magnetic flux φ200 is generated that passes through the second straight portion 52A and the fourth straight portion 52B. The direction of the magnetic flux φ200 is the same as the direction of the leakage magnetic fluxes φ4 and φ14. The magnetic flux φ200 is generated by the current i2 flowing through the second winding 61A and passes through the fourth straight portion 52B. Meanwhile, a magnetic flux φ100 is generated by the current i2 flowing through the fourth winding 61B and passes through the third straight portion 51B.

[0085] Therefore, the first coil 34A and the second coil 34B are arranged side by side so that the magnetic flux φ200 generated by the current i2 flowing through the second winding 61A and passing through the fourth straight portion 52B has the same direction as the magnetic flux φ14 generated by the current i2 flowing through the fourth winding 61B and passing through the fourth straight portion 52B, and so that the magnetic flux φ200 generated by the current i2 flowing through the fourth winding 61B and passing through the third straight portion 51B has the same direction as the magnetic flux φ4 generated by the current i2 flowing through the second winding 61A and passing through the second straight portion 52A. The first coil 34A and the second coil 34B are arranged side by side so that the first core 50A and the second core 50B surround the same axis and so that the current i2 flowing through the second winding 61A and the fourth winding 61B generates a circular magnetic flux φ200 that passes through both the second straight section 52A and the fourth straight section 52B.

[0086] In this way, the current i1 flowing through the first winding 60A and the third winding 60B generates a circular magnetic flux φ100 that passes through both the first linear portion 51A and the third linear portion 51B. Therefore, the leakage magnetic fluxes φ3 and φ13 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other, thereby generating mutual inductance. Furthermore, the current i2 flowing through the second winding 61A and the fourth winding 61B generates a circular magnetic flux φ200 that passes through both the second linear portion 52A and the fourth linear portion 52B, thereby generating the leakage magnetic fluxes φ4 and φ14 generated from the first coil 34A and the second coil 34B, respectively, reinforce each other, thereby generating mutual inductance. Furthermore, the damping effect generated in each of the first conductor 70A and the second conductor 70B increases in proportion to the mutual inductance. Therefore, for example, compared to when the first coil 34A and the second coil 34B are arranged without any special consideration, a better damping effect can be obtained, and the resonance peak generated by the low-pass filter circuit 36 can be further easily suppressed.

[0087] In the above embodiment, the first core 50A and the second core 50B do not have to have the same shape. In the above embodiment, the first conductor 70A and the second conductor 70B are not limited to a rectangular tubular shape, and may be, for example, a cylindrical shape.

[0088] In the above embodiment, the first conductor 70A and the second conductor 70B do not have to be copper foil, but may be, for example, aluminum foil, brass foil, stainless steel foil, or the like. In the embodiment, the first conductor 70A and the second conductor 70B are not limited to thin films as long as they are annular. The first conductor 70A and the second conductor 70B may be, for example, in the form of a relatively thick plate.

[0089] In the embodiment, the first straight portion 51A, the second straight portion 52A, the third straight portion 51B, and the fourth straight portion 52B do not have to be rectangular prism-shaped and may be cylindrical, for example. In short, the shapes of the first straight portion 51A, the second straight portion 52A, the third straight portion 51B, and the fourth straight portion 52B are not particularly limited as long as they extend in straight lines.

[0090] In the embodiment, for example, a part of the first winding 60A or a part of the second winding 61A may be wound around the first connecting portion 53A and the second connecting portion 54A. In short, it is sufficient that at least a part of the first winding 60A is wound around the first straight portion 51A, and at least a part of the second winding 61A is wound around the second straight portion 52A.

[0091] In the embodiment, for example, a part of the third winding 60B or a part of the fourth winding 61B may be wound around the third connecting portion 53B and the fourth connecting portion 54B. In short, it is sufficient that at least a part of the third winding 60B is wound around the third straight portion 51B and at least a part of the fourth winding 61B is wound around the fourth straight portion 52B.

[0092] In the above-described embodiment, the compression unit 18 is not limited to a scroll type, but may be, for example, a piston type or a vane type. In the above embodiment, the electric compressor 11 is used in the vehicle air-conditioning system 10, but the present invention is not limited to this. For example, the electric compressor 11 may be mounted on a fuel cell vehicle, and may use the compression unit 18 to compress air as a fluid to be supplied to the fuel cell. [Explanation of symbols]

[0093] 11...electric compressor, 18...compression section, 19...electric motor, 30...inverter device, 31...inverter circuit, 32...noise reduction section, 34...common mode choke coil, 34A...first coil, 34B...second coil, 35...smoothing capacitor, 36...low-pass filter circuit, 50A...first core, 50B...second core, 51A...first straight section, 51B...third straight section, 52A...second straight section, 52B...fourth straight section, 55A...first hole, 55B...second hole, 60A...first winding, 60B...third winding, 61A...second winding, 61B...fourth winding, 70A...first conductor, 70B...second conductor.

Claims

1. a compression section that compresses the fluid; an electric motor that drives the compression unit; an inverter device that drives the electric motor, The inverter device is an inverter circuit that converts DC power into AC power; a noise reduction unit that is provided on the input side of the inverter circuit and that reduces common mode noise and normal mode noise contained in the DC power before it is input to the inverter circuit, The noise reduction unit A common mode choke coil, a smoothing capacitor that configures a low-pass filter circuit together with the common mode choke coil, the common mode choke coil includes a first coil and a second coil, The first coil is an annular first core; a first winding wound around the first core; a second winding wound around the first core and facing and spaced apart from the first winding; a first annular conductor that straddles and surrounds the first winding and the second winding, a first conductor is disposed in a first hole on the inside of the first core, and a portion of the first conductor faces the first core through the first hole; The first core is a first straight portion that extends straight and around which at least a portion of the first winding is wound; a second linear portion extending parallel to the first linear portion and around which at least a portion of the second winding is wound, The second coil is an annular second core; a third winding wound around the second core; a fourth winding wound around the second core and facing and spaced apart from the third winding; a second annular conductor that straddles and surrounds the third winding and the fourth winding, a second conductor is disposed in a direction opposite to the second core through a second hole located inside the second core; The second core is a third linear portion that extends linearly and around which at least a portion of the third winding is wound; a fourth linear portion extending parallel to the third linear portion and around which at least a portion of the fourth winding is wound, the first winding and the third winding are electrically connected to each other, the second winding and the fourth winding are electrically connected to each other, the first coil and the second coil are arranged side by side such that a circular magnetic flux passing through both the first linear portion and the third linear portion is generated by a current flowing through the first winding and the third winding, the first coil and the second coil are arranged side by side such that the first straight portion and the third straight portion are aligned on the same straight line, the second straight portion and the fourth straight portion are aligned on the same straight line, and a current flowing through the second winding and the fourth winding generates a circular magnetic flux that passes through both the second straight portion and the fourth straight portion.

2. a compression section that compresses the fluid; an electric motor that drives the compression unit; an inverter device that drives the electric motor, The inverter device is an inverter circuit that converts DC power into AC power; a noise reduction unit that is provided on the input side of the inverter circuit and that reduces common mode noise and normal mode noise contained in the DC power before it is input to the inverter circuit, The noise reduction unit A common mode choke coil, a smoothing capacitor that configures a low-pass filter circuit together with the common mode choke coil, the common mode choke coil includes a first coil and a second coil, The first coil is an annular first core; a first winding wound around the first core; a second winding wound around the first core and facing and spaced apart from the first winding; a first annular conductor that straddles and surrounds the first winding and the second winding, a first conductor is disposed in a first hole on the inside of the first core, and a portion of the first conductor faces the first core through the first hole; The first core is a first straight portion that extends straight and around which at least a portion of the first winding is wound; a second linear portion extending parallel to the first linear portion and around which at least a portion of the second winding is wound, The second coil is an annular second core; a third winding wound around the second core; a fourth winding wound around the second core and facing and spaced apart from the third winding; a second annular conductor that straddles and surrounds the third winding and the fourth winding, a second conductor is disposed in a direction opposite to the second core through a second hole located inside the second core; The second core is a third linear portion that extends linearly and around which at least a portion of the third winding is wound; a fourth linear portion extending parallel to the third linear portion and around which at least a portion of the fourth winding is wound, the first winding and the third winding are electrically connected to each other, the second winding and the fourth winding are electrically connected to each other, the first coil and the second coil are arranged side by side such that a circular magnetic flux passing through both the first linear portion and the third linear portion is generated by a current flowing through the first winding and the third winding, the first coil and the second coil are arranged side by side such that the first linear portion, the second linear portion, the third linear portion, and the fourth linear portion are arranged in parallel, an electric compressor, wherein the first straight portion, the second straight portion, the third straight portion, and the fourth straight portion are arranged on the same plane;

3. 3. The electric compressor according to claim 1, wherein the first core and the second core have the same shape.

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