Electric compressor

Abstract

The invention provides an electric compressor capable of uniformizing loss and heat generation of a switching element and coping with a wide range without enlarging the size. An electric compressor (1) is provided with an inverter (16) that has a plurality of switching elements (18A-18F) and supplies power to a motor (8). An electric compressor (1) is provided with: a housing (2) that constitutes a motor chamber (4) in which a motor is incorporated, and an inverter housing section (6) in which an inverter is mounted; a partition wall (3) between the motor chamber and the inverter housing part; and a plurality of connection terminals (10A, 10B), one end of which is electrically connected to the motor, the connection terminals being provided so as to protrude from the motor in the direction of the partition wall, the connection terminals being provided so as to be dispersed and pass through the partition wall, and the other end of which is electrically connected to the inverter. The switching elements are arranged on the partition walls in a dispersed manner so as to correspond to the respective connection terminals.

Description

Technical Field

[0001] The present invention relates to an electric compressor including an inverter having a plurality of switching elements and supplying power to a motor. Background Art

[0002] For example, as a refrigerant compressor used in an air conditioning device of an electric vehicle, an inverter-integrated electric compressor is used in which an inverter is installed in an inverter housing formed in a housing. In this case, a three-phase motor is housed in a motor chamber of the housing, and a glass sealing plate (assembly) is provided between the motor chamber and the inverter housing.

[0003] In addition, six switching elements (IGBT, etc.) constituting the inverter are arranged on the next wall and connected to the circuit substrate of the inverter. As a result, the switching elements are cooled by the low-temperature refrigerant flowing in the motor chamber via the next wall. That is, the housing itself becomes a heat sink for the switching elements. Moreover, it becomes a structure that electrically connects three sealing pins arranged and mounted on the sealing plate to the circuit substrate of the inverter (for example, refer to patent document 1). Prior art literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2015-183668 Patent Document 2: Japanese Patent No. 4804381 Patent Document 3: Japanese Patent No. 6574044

[0005] However, in the conventional structure where the sealing pin is provided on the sealing plate, the distance between the sealing pin and each switching element is different, so the wiring length to each phase of the motor is different for each phase. Therefore, the surge voltage varies for each phase, so the loss / heat generation of the switching element is uneven, which makes control difficult, and causes problems such as the switching element with more loss / heat generation deteriorating first.

[0006] In addition, in recent years, the widening of the voltage range has also been promoted in this electric compressor. For example, an inverter has been developed that uses a half-bridge to counteract the neutral point of the motor without bundling it, thereby widening the voltage range (for example, refer to Patent Document 2). In this case, the twelve switching elements must be arranged on the wall of the housing, but in the structure in which the sealing pins are installed on the sealing plate as in the past, there is no freedom in the arrangement of the switching elements. In addition, the number of sealing pins is also increased, so when considering the insulation withstand voltage and cooling efficiency, it is difficult to arrange all of them on the wall without increasing the size of the housing, so it is expected to be improved.

[0007] On the other hand, there has been proposed an electric compressor in which three power supply pins (connection terminals) protrude from a motor, penetrate through a partition wall of a case, and are connected to an inverter (see, for example, Patent Document 3). Summary of the invention

[0008] The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an electric compressor which can make the loss and heat generation of a switching element uniform and can cope with a wide range without increasing the size.

[0009] The electric compressor of the present invention includes an inverter having multiple switching elements and supplying power to a motor. The electric compressor is characterized in that it includes: a shell, which constitutes a motor chamber with a built-in motor and an inverter accommodating portion with an inverter installed; a partition between the motor chamber and the inverter accommodating portion; and multiple connecting terminals, one end of which is electrically connected to the motor and protrudes from the motor toward the partition, each connecting terminal is dispersedly arranged and passes through the partition, and the other end is electrically connected to the inverter, and the switching elements are dispersedly arranged on the partition in a form corresponding to each connecting terminal.

[0010] The electric compressor according to the second aspect of the invention is characterized in that in the above invention, the switching element is located near each connection terminal and is provided on the partition wall.

[0011] The electric compressor according to the third aspect of the invention is characterized in that, in the first aspect of the invention, the connection terminals are dispersedly arranged at equal intervals in the circumferential direction of the motor.

[0012] The electric compressor according to the fourth invention is characterized in that, in the above inventions, three connection terminals are provided, and the inverter includes six switching elements, two of which are arranged corresponding to each connection terminal.

[0013] The electric compressor according to invention 5 is characterized in that in inventions 1 to 3, four connection terminals are provided, and the inverter includes eight switching elements, two of which are arranged corresponding to each connection terminal.

[0014] The electric compressor of invention 6 is characterized in that in invention 1 or invention 2, six connection terminals are provided, and the inverter includes seven switching elements and one diode, and the switching elements and the diode are dispersedly arranged in a form corresponding to each connection terminal.

[0015] The electric compressor according to invention 7 is characterized in that in inventions 1 to 3, six connection terminals are provided, and the inverter includes twelve switching elements, two of which are arranged corresponding to each connection terminal.

[0016] According to the present invention, in an electric compressor including an inverter having a plurality of switching elements and supplying power to a motor, the electric compressor includes: a housing constituting a motor chamber in which a motor is built-in and an inverter housing portion in which an inverter is installed; a partition wall between the motor chamber and the inverter housing portion; and a plurality of connecting terminals, one end of which is electrically connected to the motor and protrudes from the motor toward the partition wall, each connecting terminal being dispersedly arranged and the other end passing through the partition wall being electrically connected to the inverter, and the switching elements being dispersedly arranged on the partition wall in a form corresponding to each connecting terminal, thereby enabling the wiring length to each phase of the motor to be equal or close to a value, enabling the surge voltage in each phase to be equal, and making the loss / heat generation of each switching element uniform.

[0017] Furthermore, the degree of freedom in the configuration of the switching elements is increased, so even if the number of connection terminals and switching elements increases, they can be configured while satisfying insulation withstand voltage and cooling efficiency without increasing the size of the housing. This also makes it possible to smoothly cope with a wider range of voltages.

[0018] In this case, if the switching element is located near each connection terminal and provided on the partition wall as in the second aspect of the invention, the length of the wiring from the switching element to the connection terminal can be shortened, thereby reducing the surge voltage.

[0019] Furthermore, as in the third aspect of the present invention, if the connection terminals are dispersedly arranged at equal intervals in the circumferential direction of the motor, it is possible to smoothly achieve uniformity in the length of wiring to each phase of the motor.

[0020] Specifically, when three connection terminals are provided and the inverter has six switching elements, as in the fourth aspect of the invention, two switching elements are arranged corresponding to each connection terminal.

[0021] Even when four connection terminals are provided and the inverter has eight switching elements, two switching elements are arranged corresponding to each connection terminal as in the fifth aspect of the present invention.

[0022] Furthermore, when six connection terminals are provided and the inverter has seven switching elements and one diode, as in the sixth aspect of the present invention, the switching elements and the diode are dispersedly arranged in a manner corresponding to the respective connection terminals.

[0023] Even when six connection terminals are provided and the inverter has twelve switching elements, two switching elements may be arranged corresponding to each connection terminal as in the seventh aspect of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic longitudinal sectional view of an electric compressor according to an embodiment of the present invention. Figure 2 yes Figure 1 A circuit diagram of an embodiment of an electric compressor (Embodiment 1). Figure 3 Yes Figure 2 A plan view of the electric compressor of the embodiment, with the cover and the substrate removed, as viewed from the inverter housing side. Figure 4 Yes Description Figure 2 FIG. 1 is a diagram of the operation of the inverter of an embodiment. Figure 5 yes Figure 1 Circuit diagram of another embodiment of the electric compressor (Example 2). Figure 6 Yes Figure 5 A plan view of the electric compressor of the embodiment, with the cover and the substrate removed, as viewed from the inverter housing side. Figure 7 Yes Description Figure 5 FIG. 1 is a diagram of the operation of the inverter of an embodiment. Figure 8 yes Figure 1 A circuit diagram of another embodiment of an electric compressor (Embodiment 3). Fig. 9 Yes Figure 8 A plan view of the electric compressor of the embodiment, with the cover and the substrate removed, as viewed from the inverter housing side. Fig.10 Yes Description Figure 8 FIG. 1 is a diagram of the operation of the inverter of an embodiment. Fig.11 yes Figure 1 A circuit diagram of yet another embodiment of an electric compressor (Embodiment 4). Fig.12 Yes Fig.11 A plan view of the electric compressor of the embodiment, with the cover and the substrate removed, as viewed from the inverter housing side. Fig.13 Yes Description Fig.11 FIG. 1 is a diagram of the operation of the inverter of an embodiment. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Example 1

[0026] First, use Figure 1 to Figure 4 Hereinafter, an electric compressor (inverter-integrated electric compressor) 1 according to an embodiment of the present invention will be described. The electric compressor 1 of the embodiment constitutes a part of a refrigerant circuit of a vehicle air conditioning system mounted on an electric vehicle.

[0027] (1) Structure of the Electric Compressor 1 exist Figure 1 In the embodiment, the metal (aluminum in the embodiment) housing 2 (radiator) of the electric compressor 1 is divided into a motor chamber 4 and an inverter housing 6 by a partition wall 3 (a part of the housing 2) intersecting the axial direction of the housing 2, and a scroll-type compression mechanism 7 and a motor 8 (electric motor) driving the compression mechanism 7 are housed in the motor chamber 4. In the embodiment, the motor 8 is an IPMSM (Interior Permanent Magnet Synchronous Motor) composed of a stator 9 fixed to the housing 2 and a rotor 11 rotating inside the stator 9.

[0028] A bearing portion 12 is formed at the center of the motor chamber 4 side of the partition wall 3. One end of the drive shaft 13 of the rotor 11 is supported by the bearing portion 12, and the other end of the drive shaft 13 is connected to the compression mechanism 7. A suction port 14 is formed near the partition wall 3 at a position of the housing 2 corresponding to the motor chamber 4. If the rotor 11 (drive shaft 13) of the motor 8 rotates to drive the compression mechanism 7, the low-temperature refrigerant as the working fluid flows into the motor chamber 4 of the housing 2 from the suction port 14, and is sucked and compressed by the compression mechanism 7.

[0029] And, it becomes the following structure: the refrigerant compressed by the compression mechanism 7 to become high temperature and high pressure is discharged from the discharge port not shown to the refrigerant circuit outside the shell 2. In addition, the low-temperature refrigerant flowing in from the suction port 14 passes near the partition wall 3 and around the motor 8, and is attracted to the compression mechanism 7, so the partition wall 3 is also cooled.

[0030] In the embodiment, a busbar 5 is installed at the coil end on the side of the partition wall 3 of the stator 9. The busbar 5 is annular and is connected to the coils 9U, 9V, 9W (9V, 9W) of each phase of the UVW phase of the stator 9 of the motor 8. Figure 2 ) is electrically connected. In addition, in this embodiment, three connection terminals 10A, 10B, and 10C are installed on the bus bar 5, and are protruded toward the partition wall 3. One end of each connection terminal 10A, 10B, and 10C is electrically connected to the coil 9U, 9V, and 9W of each phase of the motor 8 via the bus bar 5.

[0031] In the embodiment, the connection terminals 10A, 10B, 10C are dispersed at equal intervals (intervals of 120° with the axis of the housing 2 as the center) in the circumferential direction of the motor 8. In addition, through holes 15 (three locations) are formed in the partition wall 3 at positions corresponding to the connection terminals 10A, 10B, 10C. Furthermore, the connection terminals 10A, 10B, 10C pass through the through holes 15, that is, through the partition wall 3, and their other ends enter the inverter housing portion 6. Figure 3In addition, each through hole 15 and each connection terminal 10A, 10B, 10C are insulated and sealed by an O-ring or the like (not shown).

[0032] (2) Structure of the inverter 16 Furthermore, an inverter 16 for driving and controlling the motor 8 is housed in the inverter housing portion 6 divided by the partition wall 3 and the motor chamber 4. In the case of this embodiment, the inverter 16 is composed of a substrate 17, six upper and lower arm switch elements 18A to 18F located on one side (partition wall 3 side) of the substrate 17 and wired on the substrate 17, a control unit 21 wired on the other side of the substrate 17, and an HV connector and a LV connector not shown. In the embodiment, each switch element 18A to 18F is composed of an insulated gate bipolar transistor (IGBT) in which a MOS structure is assembled on the gate.

[0033] The other ends of the connection terminals 10A, 10B, 10C entering the inverter housing portion 6 from the partition wall 3 are electrically connected to the substrate 17 of the inverter 16 by means of a press-fit terminal (not shown). Figure 3 As shown, the upper arm switching element 18A and the lower arm switching element 18D of the U-phase half-bridge circuit 19U constituting the three-phase inverter circuit (three-phase inverter circuit) 28 described later are located near the left and right sides of the connecting terminal 10A, and are arranged on the surface of the inverter housing portion 6 side of the adjacent wall 3 in a heat exchange relationship.

[0034] In addition, the upper arm switching element 18B and the lower arm switching element 18E of the half-bridge circuit 19V constituting the V phase of the inverter circuit 28 are located near the left and right of the connection terminal 10B, and are arranged on the surface of the inverter housing portion 6 side of the adjacent wall 3 in a heat exchange relationship. Moreover, the upper arm switching element 18C and the lower arm switching element 18F of the half-bridge circuit 19W constituting the W phase of the inverter circuit 28 are located near the left and right of the connection terminal 10C, and are arranged on the surface of the inverter housing portion 6 side of the adjacent wall 3 in a heat exchange relationship.

[0035] Thus, in the embodiment, two switching elements 18A to 18F are dispersedly arranged corresponding to each connection terminal 10A to 10C, and are provided on the partition wall 3. In addition, the terminal portion 22 of each switching element 18A to 18F stands up to the substrate 17 side in a state of becoming the side of each connection terminal 10A to 10C, and is electrically connected to the substrate 17 of the inverter 16. In this way, the inverter 16 having the inverter circuit 28 is configured to supply power to the motor 8 via the connection terminals 10A to 10C and the bus bar 5.

[0036] In addition, each switch element 18A to 18F is in close contact with the partition wall 3 via a sheet material (not shown) for insulation and / or heat dissipation, and is in a heat exchange relationship with the partition wall 3 of the housing 2. At this time, each switch element 18A to 18F is arranged at a position avoiding the parts corresponding to the bearing 12 and the drive shaft 13. Moreover, as described above, the partition wall 3 is cooled by the refrigerant sucked into the motor chamber 4, so each switch element 18A to 18F is in a heat exchange relationship with the sucked refrigerant via the partition wall 3, and the refrigerant sucked into the motor chamber 4 is cooled via the partition wall 3, and each switch element 18A to 18F itself is in a form of heat dissipation to the refrigerant via the partition wall 3. That is, the partition wall 3 (a part of the housing 2) of the electric compressor 1 becomes a heat sink for each switch element 18A to 18F.

[0037] (3) Circuit Structure of Inverter 16 Then, in Figure 2 In the embodiment, the inverter 16 includes the three-phase inverter circuit (three-phase inverter circuit) 28 and the control unit 21. The inverter circuit 28 is a circuit that converts the DC voltage (e.g., DC 300V) of the DC power supply (battery of the electric vehicle) 29 into a three-phase AC voltage and applies it to the coils 9U, 9V, and 9W of the stator 9 of the motor 8. In addition, the coils 9U, 9V, and 9W of the stator 9 of the motor 8 of this embodiment are bundled at the neutral point.

[0038] The inverter circuit 28 includes the U-phase half-bridge circuit 19U, the V-phase half-bridge circuit 19V, and the W-phase half-bridge circuit 19W. The half-bridge circuits 19U to 19W of each phase each include the upper arm switching elements 18A to 18C and the lower arm switching elements 18D to 18F. Furthermore, each switching element 18A to 18F has a built-in freewheeling diode connected in reverse parallel.

[0039] The collectors of the upper arm switching elements 18A to 18C of the inverter circuit 28 are connected to the positive power supply line 31 (HV+) of the DC power supply 29. On the other hand, the emitters of the lower arm switching elements 18D to 18F of the inverter circuit 28 are connected to the negative power supply line 32 (HV-) of the DC power supply 29.

[0040] Furthermore, the emitter of the upper arm switching element 18A of the U-phase half-bridge circuit 19U is connected to the collector of the lower arm switching element 18D, and their connection point (arm midpoint) is connected to one end of the U-phase coil 9U of the motor 8. Furthermore, the emitter of the upper arm switching element 18B of the V-phase half-bridge circuit 19V is connected to the collector of the lower arm switching element 18E, and their connection point (arm midpoint) is connected to one end of the V-phase coil 9V of the motor 8. Furthermore, the emitter of the upper arm switching element 18C of the W-phase half-bridge circuit 19W is connected to the collector of the lower arm switching element 18F, and their connection point (arm midpoint) is connected to one end of the W-phase coil 9W of the motor 8. In addition, the other ends of the respective coils 9U to 9W are bundled and become neutral points as described above.

[0041] The above-mentioned connection terminal 10A constitutes a part of the wiring 33U between the connection point of the upper arm switch element 18A and the lower arm switch element 18D of the U-phase half-bridge circuit 19U and the U-phase coil 9U of the motor 8. In addition, the connection terminal 10B constitutes a part of the wiring 33V between the connection point of the upper arm switch element 18B and the lower arm switch element 18E of the V-phase half-bridge circuit 19V and the V-phase coil 9V of the motor 8. Moreover, the connection terminal 10C constitutes a part of the wiring 33W between the connection point of the upper arm switch element 18C and the lower arm switch element 18F of the W-phase half-bridge circuit 19W and the W-phase coil 9W of the motor 8.

[0042] then, Figure 4 1 shows an example of control operation of the control unit 21 of the inverter 16 in this embodiment. In the figure, cu, cv, cw are normalized pulse width command values, and vu, vv, vw are voltages applied to the UVW phases of the motor 8, respectively. In addition, Iu, Iv, Iw are examples of currents flowing through the motor 8.

[0043] The control unit 21 switches (on / off) the switching elements 18A to 18F of the half-bridge circuits 19U, 19V, 19W of each phase of the inverter circuit 28, thereby applying three-phase AC voltages vu, vv, vw to the coils 9U, 9V, 9W of the motor 8. Figure 4 In the example, "1" is applied when the upper arm switching elements 18A to 18C are turned on, and "-1" is applied when the lower arm switching elements 18D to 18F are turned on. In addition, vu, vv, and vw are expressed as the value obtained by subtracting the neutral point potential vmid of the motor 8 from the output voltage of the inverter circuit 16.

[0044] like Figure 4As shown, a three-phase AC voltage is applied to the motor 8 through the inverter 16, thereby the motor 8 is driven to rotate. At this time, in the present invention, as described above, the three connection terminals 10A to 10C protruding from the motor 8 in the direction of the partition wall 3 are dispersedly arranged, and the other end that passes through the partition wall 3 is electrically connected to the inverter 16, and the switching elements 18A to 18F are dispersedly arranged on the partition wall 3 in a form corresponding to each connection terminal 10A to 10C, so that the length (wiring length) of the wiring 33U to 33W of each phase of the motor 8 can be equal or close to it. As a result, the surge voltage in each phase UVW can be equalized, and the loss / heat generation of each switching element 18A to 18F can be uniform.

[0045] Furthermore, in the embodiment, the switch elements 18A to 18F are arranged to correspond to the connection terminals 10A to 10C in pairs, and are located near the connection terminals 10A to 10C and disposed on the partition wall 3. Therefore, the wiring lengths from the switch elements 18A and 18D to the connection terminal 10A, from the switch elements 18B and 18E to the connection terminal 10B, and from the switch elements 18C and 18F to the connection terminal 10C are shortened, and the surge voltage can be further reduced.

[0046] In the embodiment, the connection terminals 10A to 10C are dispersed at equal intervals in the circumferential direction of the motor 8 , so that the wiring lengths (lengths of the wirings 33U to 33W) to the UV and W phases of the motor 8 can be uniformed smoothly. Example 2

[0047] Next, refer to Figure 5 to Figure 7 Other embodiments of the present invention will be described. Figure 1 Same as Figure 1 to Figure 4 Components denoted by the same reference numerals perform the same or similar functions. The inverter 16 of this embodiment is a four-wire inverter, and the inverter circuit 28 includes two switching elements 18G and 18H (18G and 18H) constituting a fourth half-bridge circuit 19M in addition to the six switching elements 18A to 18F of the above embodiment (Embodiment 1). Figure 5 ).

[0048] That is, the inverter circuit 28 of the inverter 16 of this embodiment is composed of a total of eight switching elements 18A to 18H. In this case, the collector of the upper arm switching element 18G of the fourth half-bridge circuit 19M is connected to the positive side power supply line 31, and the emitter of the lower arm switching element 18H is connected to the negative side power supply line 32.

[0049] The emitter of the upper arm switching element 18G of the half-bridge circuit 19M is connected to the collector of the lower arm switching element 18H, and their connection point (arm midpoint) is connected to the neutral point of the motor 8 via the field coil 34 .

[0050] Thus, the inverter 16 of this embodiment has eight switching elements 18A to 18H, so as to provide a connection terminal, in addition to the three connection terminals 10A to 10C described above, another connection terminal 10D is provided. In addition, the connection terminal 10D is also mounted on the bus bar 5, and one end thereof is electrically connected to the neutral point of the motor 8 via the bus bar 5. In addition, the connection terminal 10D also protrudes from the bus bar 5, passes through the same through hole 15 of the partition wall 3 (through the partition wall 3), and is electrically connected to the substrate 17 of the inverter 16 via a press-fit terminal or the like in the same manner as described above.

[0051] In this embodiment, the connection terminal 10D constitutes a part of a wiring 33M between a connection point between the upper arm switching element 18G and the lower arm switching element 18H of the fourth half-bridge circuit 19M and the neutral point of the motor 8 .

[0052] In this embodiment, the connection terminals 10A, 10B, 10D, and 10C are dispersed at equal intervals (intervals of 90° with the axis of the housing 2 as the center) in the circumferential direction of the motor 8. Figure 6 ). Moreover, in this embodiment, Figure 6 As shown, the upper arm switching element 18A and the lower arm switching element 18D of the U-phase half bridge circuit 19U are located near the left and right of the connection terminal 10A and are arranged on the surface of the partition wall 3 on the inverter housing portion 6 side in a heat exchange relationship.

[0053] In addition, the upper arm switching element 18B and the lower arm switching element 18E of the half-bridge circuit 19V of the V phase of the inverter circuit 28 are located near the left and right of the connection terminal 10B, and are arranged on the surface of the inverter accommodating portion 6 side of the adjacent wall 3 in a heat exchange relationship. Moreover, the upper arm switching element 18C and the lower arm switching element 18F of the half-bridge circuit 19W of the W phase of the inverter circuit 28 are located near the left and right of the connection terminal 10C, and are arranged on the surface of the inverter accommodating portion 6 side of the adjacent wall 3 in a heat exchange relationship.

[0054] In addition, the upper arm switching element 18G and the lower arm switching element 18H of the fourth half-bridge circuit 19M of the inverter circuit 28 are located near the left and right of the connection terminal 10D, and are arranged on the surface of the inverter accommodating portion 6 side of the partition wall 3 in a heat exchange relationship. In this way, in this embodiment, each switching element 18A to 18H is also dispersedly arranged in correspondence with each connection terminal 10A to 10D, and is provided on the partition wall 3. In addition, the terminal portion 22 of each switching element 18A to 18H stands up to the substrate 17 side in a state of becoming the side of each connection terminal 10A to 10D, and is electrically connected to the substrate 17 of the inverter 16.

[0055] Therefore, in this embodiment, the inverter 16 having the inverter circuit 28 also becomes a structure that supplies power to the motor 8 via the connection terminals 10A to 10D and the bus bar 5. In addition, each switching element 18G and 18H is also closely attached to the partition wall 3 via an insulating and / or heat dissipation sheet, and is in a heat exchange relationship with the partition wall 3 of the housing 2, and is cooled by the refrigerant sucked into the motor chamber 4 via the partition wall 3, and each switching element 18G and 18H itself is in a form of heat dissipation to the refrigerant via the partition wall 3. The rest is the same as the above embodiment.

[0056] then, Figure 7 1 shows an example of control operation of the control unit 21 of the inverter 16 in this embodiment. In the figure, cu, cv, cw are normalized pulse width command values, and vu, vv, vw are voltages applied to the UVW phases of the motor 8, respectively. In addition, vmid is the neutral point voltage of the motor 8. Moreover, Iu, Iv, Iw are examples of currents flowing through the motor 8.

[0057] In this case, the control unit 21 also switches (turns on / off) the switching elements 18A to 18F of the half-bridge circuits 19U, 19V, 19W of each phase of the inverter circuit 28, and applies the three-phase AC voltages vu, vv, and vw to the coils 9U, 9V, and 9W of the motor 8. The fourth half-bridge circuit 19M always turns on the lower arm switching element 18H. In addition, the pulse width command values ​​cu, cv, and cw change the PWM command value so that the on time of all the upper arm switching elements 18A to 18C becomes longer.

[0058] In the case of this embodiment, the DC current Imid can flow through the excitation coil 34. By flowing the current through the excitation coil 34, a strong magnetic flux effect or a weak magnetic flux effect can be imparted, thereby enabling efficient driving in the high-speed region and the low-speed region. Figure 5 As described in the circuit diagram, the direction is given in such a way that it becomes 0 when added.

[0059] Furthermore, in this embodiment, the four connection terminals 10A to 10D protruding from the motor 8 toward the partition wall 3 are also dispersedly arranged, and the switching elements 18A to 18H are dispersedly arranged on the partition wall 3 in a form corresponding to the respective connection terminals 10A to 10D, so that the lengths (wiring lengths) of the wirings 33U to 33W and 33M to the respective phases and the neutral point of the motor 8 can be made equal or close to the same. Thus, the surge voltages in the wirings to the respective phases UVW and the neutral point can be made equal, and the losses / heat generation of the respective switching elements 18A to 18H can be made uniform.

[0060] Furthermore, in this embodiment, the switch elements 18A to 18H are arranged to correspond to the connection terminals 10A to 10D in pairs, and are located near them and arranged on the partition wall 3. Therefore, the wiring lengths from the switch elements 18A and 18D to the connection terminal 10A, from the switch elements 18B and 18E to the connection terminal 10B, from the switch elements 18C and 18F to the connection terminal 10C, and from the switch elements 18G and 18H to the connection terminal 10D are shortened, which can further reduce the surge voltage.

[0061] In addition, in this embodiment, the connection terminals 10A, 10B, 10D, and 10C are also dispersed at equal intervals in the circumferential direction of the motor 8, so that the wiring length (the length of wiring 33U~33W, 33M) to the UVW phases and neutral point of the motor 8 can be smoothly uniformed.

[0062] Moreover, the degree of freedom in the configuration of the switching elements 18A to 18H is increased, so even if the connection terminals are four 10A to 10D and the switching elements are increased to eight 18A to 18H, they can be configured while satisfying the insulation withstand voltage and cooling efficiency without increasing the size of the housing 2. Example 3

[0063] Next, refer to Figures 8 to 10 Another embodiment of the present invention is described. Figure 1 Same as Figure 1 to Figure 7 Components denoted by the same reference numerals perform the same or similar functions. The inverter 16 of this embodiment is also a four-wire inverter, but the inverter circuit 28 is different from the above-mentioned embodiment (Example 2) and has a structure that only has the lower arm switching element 18H from the neutral point of the motor 8 through the diode 36 and the excitation coil 34.

[0064] That is, in this example, in addition to the six switching elements 18A to 18F, another switching element 18H and a diode 36 ( Figure 8 ). That is, the inverter circuit 28 of the inverter 16 of this embodiment is composed of a total of seven switching elements 18A to 18F and 18H, and is further provided with a diode 36. In this case, the collector of the seventh switching element 18H is connected to the excitation coil 34, and the emitter is connected to the negative power supply line 32. Moreover, the excitation coil 34 is connected to the neutral point of the motor 8 via the diode 36. In addition, the diode 36 has the direction of the excitation coil 34 as the forward direction.

[0065] Thus, the inverter 16 of this embodiment has seven switching elements 18A to 18F, 18H and a diode 36, so as to provide the connection terminals, in addition to the three connection terminals 10A to 10C described above, three connection terminals 10D, 10E, and 10F are provided. In addition, each connection terminal 10D to 10F is also mounted on the bus bar 5, and one end thereof is electrically connected to the motor 8 via the bus bar 5. In addition, the connection terminals 10D to 10F also protrude from the bus bar 5, pass through the same through hole 15 of the partition wall 3 (through the partition wall 3), and are electrically connected to the substrate 17 of the inverter 16 via a press-fit terminal or the like in the same manner as described above.

[0066] In this embodiment, the connection terminal 10D constitutes a part of the wiring 33M between the collector of the lower arm switching element 18H and the excitation coil 34, the connection terminal 10E constitutes a part of the wiring 33D1 between the excitation coil 34 and the diode 36, and the connection terminal 10F constitutes a part of the wiring 33D2 between the diode 36 and the neutral point of the motor 8.

[0067] Furthermore, in the case of this embodiment, the connection terminals 10A, 10B, 10F, 10E, 10D, and 10C are dispersedly arranged in the circumferential direction of the motor 8 ( Fig. 9 ). Moreover, in this embodiment, Fig. 9 As shown, the upper arm switching element 18A and the lower arm switching element 18D of the U-phase half bridge circuit 19U are located near the left and right of the connection terminal 10A and are arranged on the surface of the partition wall 3 on the inverter housing portion 6 side in a heat exchange relationship.

[0068] In addition, the upper arm switching element 18B and the lower arm switching element 18E of the half-bridge circuit 19V of the V phase of the inverter circuit 28 are located near the left and right of the connection terminal 10B, and are arranged on the surface of the inverter accommodating portion 6 side of the adjacent wall 3 in a heat exchange relationship. Moreover, the upper arm switching element 18C and the lower arm switching element 18F of the half-bridge circuit 19W of the W phase of the inverter circuit 28 are located near the left and right of the connection terminal 10C, and are arranged on the surface of the inverter accommodating portion 6 side of the adjacent wall 3 in a heat exchange relationship.

[0069] In addition, the seventh lower arm switching element 18H of the inverter circuit 28 is located near the connection terminal 10D and is arranged on the surface of the inverter housing portion 6 side of the adjacent wall 3 in a heat exchange relationship. In addition, the diode 36 is located between the connection terminal 10E and the connection terminal 10F and is located near them and is arranged on the surface of the inverter housing portion 6 side of the adjacent wall 3 in a heat exchange relationship.

[0070] Thus, in this embodiment, the switching elements 18A to 18F are also dispersedly arranged in pairs corresponding to the connection terminals 10A to 10C, and are provided on the partition wall 3. In addition, the terminal portions 22 of the switching elements 18A to 18F and 18H and the terminal 37 of the diode 36 stand up toward the substrate 17 side in a state of becoming the connection terminals 10A to 10F side, and are electrically connected to the substrate 17 of the inverter 16.

[0071] Therefore, in this embodiment, the inverter 16 having the inverter circuit 28 also becomes a structure that supplies power to the motor 8 via the connection terminals 10A to 10F and the bus bar 5. In addition, the switching element 18H and the diode 36 are also closely attached to the partition wall 3 via the insulating and / or heat dissipation sheet, and are in a heat exchange relationship with the partition wall 3 of the housing 2. The refrigerant sucked into the motor chamber 4 via the partition wall 3 is cooled, and the switching element 18H and the diode 36 themselves are in a form of heat dissipation to the refrigerant via the partition wall 3. The rest is the same as the above embodiment.

[0072] then, Fig.10 1 shows an example of control operation of the control unit 21 of the inverter 16 in this embodiment. In the figure, cu, cv, cw are normalized pulse width command values, and vu, vv, vw are voltages applied to the UVW phases of the motor 8, respectively. In addition, vmid is the neutral point voltage of the motor 8. Moreover, Iu, Iv, Iw are examples of currents flowing through the motor 8.

[0073] In this case, the control unit 21 also switches (turns on / off) the switching elements 18A to 18F of the half-bridge circuits 19U, 19V, 19W of each phase of the inverter circuit 28, and applies the three-phase AC voltages vu, vv, and vw to the coils 9U, 9V, and 9W of the motor 8. On the other hand, the lower arm switching element 18H passing through the excitation coil 34 is always turned on. In addition, if the definition of the current of the motor 8 is set to the inflow direction, a negative current flows as the DC current Imid. The rest is the same as the case of the second embodiment.

[0074] In this embodiment, the six connection terminals 10A to 10F protruding from the motor 8 toward the partition wall 3 are also dispersed, and the switching elements 18A to 18F, 18H and the diode 36 are dispersed on the partition wall 3 in a form corresponding to the respective connection terminals 10A to 10F, so that the lengths (wiring lengths) of the wirings 33U to 33W, 33M, 33D1, and 33D2 to the respective phases and the neutral point of the motor 8 can be made equal or close to the same value. As a result, the surge voltages in the wirings to the respective phases UVW and the neutral point can be made equal, and the losses / heat generation of the respective switching elements 18A to 18F, 18H and the diode 36 can be made uniform.

[0075] In addition, in this embodiment, the switching elements 18A to 18F are respectively corresponding to the connection terminals 10A to 10C in pairs, and are located near them and arranged on the partition wall 3. The switching element 18H corresponds to the connection terminal 10D, and is located near it and arranged on the partition wall 3. The diode 36 corresponds to the connection terminals 10E and 10F, and is located near them and arranged on the partition wall 3. Therefore, the wiring length from the switching elements 18A and 18D to the connection terminal 10A, from the switching elements 18B and 18E to the connection terminal 10B, from the switching elements 18C and 18F to the connection terminal 10C, from the switching element 18H to the connection terminal 10D, and from the diode 36 to the connection terminals 10E and 10F is shortened, which can further reduce the surge voltage.

[0076] In addition, the degree of freedom in the configuration of the switching elements 18A to 18F, 18H, and the diode 36 is increased, so even if the number of connecting terminals is six, 10A to 10F, the number of switching elements is increased to seven, 18A to 18F, 18H, and the diode 36 is added, they can be configured while satisfying the insulation withstand voltage and cooling efficiency without increasing the size of the housing 2. Example 4

[0077] Next, refer to Figure 11 to Figure 13 Another embodiment of the present invention will be described. Figure 1 Same as Figures 1 to 10 Components denoted by the same reference numerals perform the same or similar functions. The inverter 16 of this embodiment is a six-wire inverter, and the inverter circuit 28 includes three half-bridge circuits 19U1, 19V1, and 19W1 ( Fig.11 ) Furthermore, the neutral points of the phases of the motor 8 are not bundled, and the half-bridge circuits 19U to 19W and the half-bridge circuits 19U1 to 19W1 are opposed to each other with the coils 9U to 9W of the motor 8 interposed therebetween.

[0078] In this case, the half-bridge circuits 19U1 to 19W1 of each phase also have upper arm switching elements 18A1 to 18C1 and lower arm switching elements 18D1 to 18F1, respectively. In addition, each switching element 18A1 to 18F1 also has a built-in freewheeling diode connected in reverse parallel. In addition, the collector of the upper arm switching element 18A1 to 18C1 is connected to the positive side power line 31 of the DC power supply 29. On the other hand, the emitter of the lower arm switching element 18D1 to 18F1 is connected to the negative side power line 32 of the DC power supply 29.

[0079] Furthermore, the emitter of the upper arm switch element 18A1 of the U-phase half-bridge circuit 19U1 is connected to the collector of the lower arm switch element 18D1, and their connection point (arm midpoint) is connected to the other end of the U-phase coil 9U of the motor 8. Furthermore, the emitter of the upper arm switch element 18B1 of the V-phase half-bridge circuit 19V1 is connected to the collector of the lower arm switch element 18E1, and their connection point (arm midpoint) is connected to the other end of the V-phase coil 9V of the motor 8. Furthermore, the emitter of the upper arm switch element 18C1 of the W-phase half-bridge circuit 19W1 is connected to the collector of the lower arm switch element 18F1, and their connection point (arm midpoint) is connected to the other end of the W-phase coil 9W of the motor 8.

[0080] Thus, the inverter 16 of this embodiment has a total of twelve switching elements 18A to 18F, 18A1 to 18F1, so as to provide the connection terminals, in addition to the three connection terminals 10A to 10C described above, three connection terminals 10D to 10F (a total of six) are provided. In addition, the connection terminals 10D to 10F are also mounted on the busbar 5, and one end of them is electrically connected to the motor 8 via the busbar 5. In addition, the connection terminals 10D to 10F also protrude from the busbar 5, pass through the same through-hole 15 of the partition wall 3 (through the partition wall 3), and are electrically connected to the substrate 17 of the inverter 16 via a press-fit terminal, etc., as described above.

[0081] In this embodiment, the connection terminal 10D constitutes a part of the wiring 33U1 between the connection point of the upper arm switching element 18A1 and the lower arm switching element 18D1 of the half-bridge circuit 19U1 and the other end of the U-phase coil 9U of the motor 8. In addition, the connection terminal 10E constitutes a part of the wiring 33V1 between the connection point of the upper arm switching element 18B1 and the lower arm switching element 18E1 of the half-bridge circuit 19V1 and the other end of the V-phase coil 9V of the motor 8. Moreover, the connection terminal 10F constitutes a part of the wiring 33W1 between the connection point of the upper arm switching element 18C1 and the lower arm switching element 18F1 of the half-bridge circuit 19W1 and the other end of the W-phase coil 9W of the motor 8.

[0082] In this embodiment, the connection terminals 10A to 10F are dispersed at equal intervals (intervals of 60° with the axis of the housing 2 as the center) in the circumferential direction of the motor 8. Fig.12 ). Moreover, in this embodiment, Fig.12 As shown, the upper arm switching element 18A and the lower arm switching element 18D of the U-phase half bridge circuit 19U are located near the left and right of the connection terminal 10A and are arranged on the surface of the partition wall 3 on the inverter housing portion 6 side in a heat exchange relationship.

[0083] In addition, the upper arm switching element 18B and the lower arm switching element 18E of the half-bridge circuit 19V of the V phase of the inverter circuit 28 are located near the left and right of the connection terminal 10B, and are arranged on the surface of the inverter accommodating portion 6 side of the adjacent wall 3 in a heat exchange relationship. Moreover, the upper arm switching element 18C and the lower arm switching element 18F of the half-bridge circuit 19W of the W phase of the inverter circuit 28 are located near the left and right of the connection terminal 10C, and are arranged on the surface of the inverter accommodating portion 6 side of the adjacent wall 3 in a heat exchange relationship.

[0084] In addition, the upper arm switching element 18A1 and the lower arm switching element 18D1 of the other U-phase half-bridge circuit 19U1 are located near the left and right of the connection terminal 10D, and are arranged on the surface of the inverter accommodating portion 6 of the adjacent wall 3 in a heat exchange relationship. In addition, the upper arm switching element 18B1 and the lower arm switching element 18E1 of the other V-phase half-bridge circuit 19V1 are located near the left and right of the connection terminal 10E, and are arranged on the surface of the inverter accommodating portion 6 of the adjacent wall 3 in a heat exchange relationship. Moreover, the upper arm switching element 18C1 and the lower arm switching element 18F1 of the other W-phase half-bridge circuit 19W1 are located near the left and right of the connection terminal 10F, and are arranged on the surface of the inverter accommodating portion 6 of the adjacent wall 3 in a heat exchange relationship.

[0085] Thus, in this embodiment, the switching elements 18A to 18F and 18A1 to 18F1 are also dispersedly arranged in pairs corresponding to the connection terminals 10A to 10F, and are provided on the partition wall 3. In addition, the terminal portions 22 of the switching elements 18A to 18F and 18A1 to 18F1 stand up toward the substrate 17 side in a state of becoming the connection terminals 10A to 10F side, and are electrically connected to the substrate 17 of the inverter 16.

[0086] Therefore, in this embodiment, the inverter 16 having the inverter circuit 28 also becomes a structure that supplies power to the motor 8 via the connection terminals 10A to 10F and the bus bar 5. In addition, each switching element 18A1 to 18F1 is also closely attached to the partition wall 3 via an insulating and / or heat dissipation sheet, and is in a heat exchange relationship with the partition wall 3 of the housing 2, and is cooled by the refrigerant sucked into the motor chamber 4 via the partition wall 3, and each switching element 18A1 to 18F1 itself is in a form of heat dissipation to the refrigerant via the partition wall 3. The rest is the same as the above embodiment.

[0087] then, Fig.13 1 shows an example of control operation of the control unit 21 of the inverter 16 in this embodiment. In the figure, cu, cv, cw are normalized pulse width command values, and vu, vv, vw are voltages applied to the UVW phases of the motor 8, respectively. In addition, Iu, Iv, Iw are examples of currents flowing through the motor 8.

[0088] In this case, the control unit 21 also switches (turns on / off) the switching elements 18A to 18F of the half-bridge circuits 19U, 19V, 19W of each phase of the inverter circuit 28, and applies the three-phase AC voltages vu, vv, and vw to the coils 9U, 9V, and 9W of the motor 8. On the other hand, the operation of the upper arm switching elements 18A1 to 18C1 of the half-bridge circuits 19U1, 19V1, and 19W1 of each phase is reversed. That is, when the upper arm switching element 18A of the half-bridge circuit 19U is turned on, the lower arm switching element 18D1 of the opposing half-bridge circuit 19U1 is turned on.

[0089] Thus, the voltage applied to the coils 9U to 9W of each phase of the motor 8, UVW, can be applied within the range of positive and negative 2. Even in a simple operation, if judged by the amplitude, a voltage of about 2 times can be applied. In addition, the maximum voltage that can be applied is about 1.5 times to 2 times (the specific value varies according to the modulation method).

[0090] Furthermore, in this embodiment, the six connection terminals 10A to 10F protruding from the motor 8 toward the partition wall 3 are also dispersedly arranged, and the switching elements 18A to 18F, 18A1 to 18F1 are dispersedly arranged on the partition wall 3 in a form corresponding to the respective connection terminals 10A to 10F, so that the lengths (wiring lengths) of the wirings 33U to 33W, 33U1 to 33W1 to the respective phases of the motor 8 can be made equal or close to the same. Thus, the surge voltages in the wirings to the respective phases UVW can be made equal, and the losses / heat generation of the respective switching elements 18A to 18F, 18A1 to 18F1 can be made uniform.

[0091] Furthermore, in this embodiment, the switch elements 18A to 18F and 18A1 to 18F1 are arranged to correspond to the connection terminals 10A to 10F in pairs, and are located near the connection terminals and arranged on the partition wall 3. Therefore, the wiring lengths from the switch elements 18A and 18D to the connection terminal 10A, from the switch elements 18B and 18E to the connection terminal 10B, from the switch elements 18C and 18F to the connection terminal 10C, from the switch elements 18A1 and 18D1 to the connection terminal 10D, from the switch elements 18B1 and 18E1 to the connection terminal 10E, and from the switch elements 18C1 and 18F1 to the connection terminal 10F are shortened, thereby further reducing the surge voltage.

[0092] In addition, in this embodiment, the connection terminals 10A to 10F are also dispersed at equal intervals in the circumferential direction of the motor 8, so that the wiring length (the length of the wiring 33U to 33W, 33U1 to 33W1) to each phase of UVW of the motor 8 can be smoothly uniformed.

[0093] Furthermore, the degree of freedom in the arrangement of the switch elements 18A to 18F and 18A1 to 18F1 increases, so even if the number of the connection terminals is six, 10A to 10F, and the number of the switch elements is increased to twelve, 18A to 18F and 18A1 to 18F1, they can be arranged in a state that satisfies the insulation withstand voltage and cooling efficiency without increasing the size of the housing 2. Fig.11 The inverter 16 such as the inverter circuit 28 can also smoothly cope with the widening of the voltage range.

[0094] In addition, in the embodiments, the switching element is described as an IGBT, but it may be a MOSFET. In addition, the specific structure shown in each embodiment is not limited to this, and can be changed within the scope of the present invention. Description of Reference Numerals

[0095] 1 Electric compressor 2 Housing 3 Next door 4 Motor room 5 Busbar 6 Inverter housing 7 Compression mechanism 8 Motor 9 Stator 10A~10F Connection Terminals 16 Inverter 17 substrate 18A~18H、18A1~18F1 Switching elements 19U, 19U1 U-phase inverter 19V, 19V1 V-phase inverter 1 9W, 19W1 W phase inverter 21 Control Department 28 Inverter Circuit 36 diode

Claims

1. An electric compressor, comprising an inverter having a plurality of switching elements and supplying power to a motor, wherein the electric compressor is characterized by comprising: A housing, constituting a motor chamber in which the motor is built and an inverter housing in which the inverter is installed; a wall between the motor room and the inverter housing; as well as A plurality of connection terminals, one end of which is electrically connected to the motor and is protruding from the motor toward the partition wall. Each connection terminal is dispersedly arranged, passes through the partition wall, and the other end is electrically connected to the inverter. The switching elements are provided in a distributed manner on the partition walls so as to correspond to the connection terminals.

2. The electric compressor according to claim 1, characterized in that: The switching element is located near each of the connection terminals and is provided on the partition wall.

3. The electric compressor according to claim 1, characterized in that: The connection terminals are dispersedly arranged at equal intervals in a circumferential direction of the motor.

4. The electric compressor according to any one of claims 1 to 3, characterized in that: The number of the connection terminals is three, and the inverter includes six switching elements, with two of the switching elements being arranged corresponding to each of the connection terminals.

5. The electric compressor according to any one of claims 1 to 3, characterized in that: Four connection terminals are provided, and the inverter includes eight switching elements, with two switching elements being arranged corresponding to each of the connection terminals.

6. The electric compressor according to claim 1 or 2, characterized in that: Six connection terminals are provided, and the inverter includes seven switching elements and one diode, and the switching elements and the diode are dispersedly arranged in correspondence with the connection terminals.

7. The electric compressor according to any one of claims 1 to 3, characterized in that: Six connection terminals are provided, and the inverter includes twelve switching elements, with two switching elements being arranged corresponding to each of the connection terminals.

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