washing machine
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MIDEA GROUP CO LTD
- Filing Date
- 2023-03-20
- Publication Date
- 2026-08-03
Smart Images
Figure 0007899121000001 
Figure 0007899121000002 
Figure 0007899121000003
Abstract
Description
Technical Field
[0001] Embodiments of the present invention relate to washing machines.
Background Art
[0002] A washing machine equipped with an inverter circuit for driving a motor is known.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] The problem to be solved by the present invention is to provide a washing machine capable of suppressing the occurrence of problems even when the wiring length becomes long.
Means for Solving the Problems
[0005] The washing machine according to the embodiment includes a motor, a power conversion circuit, a driver circuit, 1 a shunt resistor, The second shunt resistor, the third shunt resistor, and the first a surge voltage absorbing element , a second surge voltage absorption element and a third surge voltage absorption element and. The power conversion circuit is a power conversion circuit that converts DC power into AC power and outputs it to the motor, and has first to sixth switching elements connected in a three-phase bridge, and first to sixth diodes electrically connected in anti-parallel to the first to sixth switching elements. The first to third switching elements are included in the upper arm, and the fourth to sixth switching elements are included in the lower arm. The driver circuit is connected to the control terminals of each of the fourth to sixth switching elements, controls the fourth to sixth switching elements, and has a ground terminal. The 1 shunt resistor is the fourth switching element Child andIt is connected to ground. The second shunt resistor is The fifth switching element is connected to the ground. The third shunt resistor is connected to the sixth switching element and the ground. The first surge voltage absorption element is connected to the fourth switching element. and the above 1 The connection point with the shunt resistor and the connection point between the ground terminal of the driver circuit and the ground. Power supply ground connection point It is electrically connected in parallel with the power conversion circuit and the driver circuit between them. The second surge voltage absorbing element is electrically connected in parallel with the power conversion circuit and the driver circuit between the connection point between the fifth switching element and the second shunt resistor and the power supply ground connection point. The third surge voltage absorbing element is electrically connected in parallel with the power conversion circuit and the driver circuit between the connection point between the sixth switching element and the third shunt resistor and the power supply ground connection point. A package component including the power conversion circuit and the driver circuit is provided. The connection point between the fourth switching element and the first shunt resistor is the first terminal of the package component. The connection point between the fifth switching element and the second shunt resistor is the second terminal of the package component. The connection point between the sixth switching element and the third shunt resistor is the third terminal of the package component. The power supply ground connection point is the fourth terminal of the package component. The first surge voltage absorbing element is located outside the package component and connected to the first terminal. The second surge voltage absorbing element is located outside the package component and connected to the second terminal. The third surge voltage absorbing element is located outside the package component and connected to the third terminal. The first surge voltage absorbing element, the second surge voltage absorbing element, and the third surge voltage absorbing element are connected to the fourth terminal via a confluence point that is electrically connected to each other. [Brief explanation of the drawing]
[0006] [Figure 1] A cross-sectional view showing a washing machine according to the first embodiment. [Figure 2] A diagram showing the configuration of the internal control system of the washing machine according to the first embodiment. [Figure 3] A diagram showing the configuration of an inverter circuit that can be used in a washing machine according to the first embodiment. [Figure 4] This figure shows the basic circuit configuration when driving a motor using the inverter circuit according to the first embodiment. [Figure 5] A diagram showing the control of the motor when rotating the drum according to the first embodiment. [Figure 6] A diagram showing the implementation structure of a washing machine according to the first embodiment. [Figure 7] A diagram showing the implementation structure of a washing machine according to the first embodiment. [Figure 8] A diagram showing the implementation structure of a washing machine according to the first embodiment. [Figure 9] A diagram showing the implementation structure of a washing machine according to the first embodiment. [Figure 10] A diagram showing the mounting structure of the surge voltage absorption element in the first embodiment. [Figure 11] A diagram showing the mounting structure of the surge voltage absorption element in the second embodiment. [Figure 12] This figure shows the basic circuit configuration when driving a motor using an inverter circuit according to a third modified embodiment. [Figure 13] A diagram showing the implementation structure of a washing machine according to a third modified embodiment. [Figure 14]A diagram showing the mounting structure of the surge voltage absorption element in a third modified example of the embodiment. [Modes for carrying out the invention]
[0007] The washing machine of the embodiment will be described below with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. Duplication of these components may be omitted. In this application, "based on XX" means "based on at least XX," and may also include cases where XX is based on another element in addition to XX. Furthermore, "based on XX" is not limited to cases where XX is used directly, but may also include cases where XX has been processed or modified. In this application, "XX or YY" is not limited to cases where either XX or YY is used, but may also include cases where both XX and YY are used. This is also true when there are three or more optional elements. XX and YY are arbitrary elements (e.g., arbitrary information).
[0008] (First Embodiment) <Overall Structure> First, the first embodiment will be described. Figure 1 is a cross-sectional view showing a washing machine 100 according to the first embodiment. In Figure 1, the outer casing 1 is hollow and has a front panel, a rear panel, a left panel, a right panel, a bottom panel, and a top panel, and a through-hole-shaped entrance / exit 2 is formed in the front panel of the outer casing 1. A door 3 is attached to the front panel of the outer casing 1. This door 3 can be operated by the user from the front between a closed state and an open state, and when the door 3 is closed, the entrance / exit 2 is closed, and when the door 3 is open, the entrance / exit 2 is open. A water receiving tank 4 is fixed inside the outer casing 1. This water receiving tank 4 is cylindrical with a closed rear surface and is arranged in an inclined state with its axis line CL sloping downward from front to rear. The front of this water receiving tank 4 is open, and when the door 3 is closed, the door 3 airtightly closes the front of the water receiving tank 4.
[0009] On the rear plate of the water receiving tank 4, a motor 40a for rotating the drum, which is located outside the water receiving tank 4, is fixed. This motor 40a is a three-phase brushless DC motor with controllable speed, and the rotating shaft 6 of the motor 40a protrudes into the interior of the water receiving tank 4. This rotating shaft 6 is arranged to overlap with the axis line CL of the water receiving tank 4, and a drum 7 is fixed to the rotating shaft 6 inside the water receiving tank 4. The rotating shaft 6 is directly connected to the drum shaft of the drum 7, for example, without passing through a reduction gear. The drum 7 has a cylindrical shape with a closed rear surface and rotates integrally with the rotating shaft 6 in the operating state of the motor 40a. The front surface of this drum 7 faces the entrance / exit 2 from the rear through the front surface of the water receiving tank 4, and laundry is put in and taken out through the entrance / exit 2, the front surface of the water receiving tank 4, and the front surface of the drum 7 from the front in the open state of the door 3 inside the drum 7.
[0010] A plurality of through holes 8 are formed in the drum 7, and the internal space of the drum 7 is connected to the internal space of the water receiving tank 4 through each of the plurality of through holes 8. A plurality of baffles 9 are fixed to this drum 7. Each of these plurality of baffles 9 moves in the circumferential direction around the axis line CL as the drum 7 rotates, and the laundry in the drum 7 is agitated by moving in the circumferential direction while being caught by each of the plurality of baffles 9 and then falling by gravity.
[0011] Inside the outer box 1, a water supply valve 10 is fixed. This water supply valve 10 has an inlet and an outlet, and the inlet of the water supply valve 10 is connected to a faucet of a water supply pipe. This water supply valve 10 is driven by a water supply valve motor (not shown), and the outlet of the water supply valve 10 can be switched between an open state and a closed state according to the rotation amount of the water supply valve motor. The outlet of this water supply valve 10 is connected to a water injection case 12. In the open state of the water supply valve 10, tap water is injected into the water injection case 12 through the water supply valve 10, and in the closed state of the water supply valve 10, tap water is not injected into the water injection case 12. This water injection case 12 is fixed inside the outer box 1 at a position higher than the water receiving tank 4 and has a cylindrical water injection port 13. This water injection port 13 is inserted into the inside of the water receiving tank 4, and the tap water injected into the water injection case 12 from the water supply valve 10 is injected into the inside of the water receiving tank 4 from the water injection port 13.
[0012] At the bottom of the water receiving tank 4, the upper end of a drain pipe 14 is connected, and a drain valve 15 is interposed in the drain pipe 14. This drain valve 15 is driven by a drain valve motor (not shown), and can be switched between an open state and a closed state according to the rotation amount of the drain valve motor. In the closed state of this drain valve 15, the tap water injected into the water receiving tank 4 from the water injection port 13 is stored in the water receiving tank 4, and in the open state of the drain valve 15, the tap water in the water receiving tank 4 is discharged to the outside of the water receiving tank 4 through the drain pipe 14.
[0013] On the bottom plate of the outer box 1, a main duct 17 is fixed at a position below the water receiving tank 4. This main duct 17 is cylindrical and oriented in the front-rear direction. The lower end of a front duct 18 is connected to the front end of the main duct 17. This front duct 18 is cylindrical and oriented in the vertical direction, and the upper end of the front duct 18 is connected to the internal space of the water receiving tank 4 at the front end of the water receiving tank 4. A fan casing 19 is fixed to the rear end of the main duct 17. This fan casing 19 has a through-hole-shaped intake port 20 and a cylindrical exhaust port 21, and the internal space of the fan casing 19 is connected to the internal space of the main duct 17 through the intake port 20.
[0014] A motor 40b is fixed to the fan casing 19, located outside the fan casing 19, to rotate the fan. This motor 40b is a speed-controllable three-phase brushless DC motor. The motor 40b has a rotating shaft 23 that protrudes into the inside of the fan casing 19, and a fan 24 is fixed to the rotating shaft 23, located inside the fan casing 19. This fan 24 is a centrifugal type that draws in air axially and discharges it radially. The intake port 20 of the fan casing 19 faces the fan 24 in the axial direction of the fan 24, and the exhaust port 21 of the fan casing 19 faces the fan 24 in the radial direction of the fan 24.
[0015] The lower end of the rear duct 25 is connected to the exhaust port 21 of the fan casing 19. This rear duct 25 is cylindrical and oriented vertically, and its upper end is connected to the internal space of the water receiving tank 4 at the rear end of the water receiving tank 4. These rear duct 25, fan casing 19, main duct 17, front duct 18, and water receiving tank 4 constitute an annular circulation duct 26 with the internal space of the water receiving tank 4 as its starting and ending points. When the motor 40b is operating with the door 3 closed, the fan 24 rotates in a constant direction, causing air in the water receiving tank 4 to be drawn from the front duct 18 through the main duct 17 into the fan casing 19, and then returned from the fan casing 19 through the rear duct 25 into the water receiving tank 4.
[0016] A compressor 27 is fixed inside the outer casing 1. This compressor 27 is located outside the circulation duct 26 and has a discharge port for discharging refrigerant and a suction port for drawing in refrigerant. This compressor 27 is driven by a motor 40c (see Figure 2), which is a speed-controllable three-phase brushless DC motor.
[0017] A condenser 29 is fixed inside the main duct 17. This condenser 29 heats the air and consists of a single refrigerant pipe 30 that bends in a meandering manner, with multiple plate-shaped heating fins 31 fixed in contact with each of them on the outer surface. The refrigerant pipe 30 of this condenser 29 is connected to the discharge port of the compressor 27, and when the motor 40c is operating, the refrigerant discharged from the discharge port of the compressor 27 enters the refrigerant pipe 30 of the condenser 29.
[0018] <Control system configuration> Figure 2 shows the configuration of the internal control system of the washing machine according to the first embodiment. In Figure 2, inverter circuits 50a, 50b, and 50c are drive circuits that drive motors 40a, 40b, and 40c, respectively. The inverter circuits 50a, 50b, and 50c realize power conversion circuits 48a, 48b, and 48c that convert DC power from the power supply circuit 71 into three-phase AC power, and driver circuits 49a, 49b, and 49c that drive the power conversion circuits 48a, 48b, and 48c, respectively. Motor 40a is a motor that rotates the drum 7. Motor 40b is a motor that rotates the fan 24. Motor 40c is a motor that drives the compressor.
[0019] Control circuits 70a and 70b consist of a CPU (Central Processing Unit) and an MPU (Micro Processing Unit). Control circuits 70a and 70b can communicate data bidirectionally, for example, via serial communication. An operation panel 73 is connected to control circuit 70a. Various actuators 74 for controlling the water supply valve 10 and the drain valve 15 are also connected to control circuit 70a. Control circuit 70a supplies a PWM (Pulse Width Modulation) control signal to the inverter circuit 50a to drive motor 40a. Control circuit 70b supplies PWM control signals to the inverter circuits 50b and 50c to drive motors 40b and 40c. In addition, detection signals for detecting rotor position and motor rotation are supplied to control circuit 70a from sensor 41a.
[0020] The power supply circuit 71 generates, for example, 280V DC power from a 100V AC power source using voltage doubling rectification. This high-voltage DC power is then supplied to the inverter circuits 50a, 50b, and 50c.
[0021] The control power supply circuit 72 generates a low-voltage DC power supply for control. The DC power supply from the control power supply circuit 72 is supplied to the control circuits 70a, 70b, and 70c and the inverter circuits 50a, 50b, and 50c.
[0022] <Motor drive system circuit> Next, the configuration of the motor drive system in the washing machine 100 according to the first embodiment will be described. As shown in Figure 2, the washing machine according to this embodiment is equipped with three motors 40: a motor 40a for rotating the drum 7, a motor 40b for rotating the fan 24, and a motor 40c for driving the compressor. An inverter circuit 50 (50a, 50b, 50c) is provided to drive these motors 40 (40a, 40b, 40c). In the washing machine according to this embodiment, an IPM (Intelligent Power Module) module package component is used as the inverter circuit 50 (50a, 50b, 50c). The IPM module package component integrates discrete components such as switching elements with drive circuits and protection circuits. Using an IPM module allows for miniaturization of the circuit and also reduces costs.
[0023] Figure 3 shows the configuration of an inverter circuit 50 that can be used in a washing machine according to this embodiment. As shown in Figure 3, the inverter circuit 50 includes IGBTs (Insulated Gate Bipolar Transistors) 52a to 52f as first to sixth switching elements, and driver circuits 51a and 51b that control the switching elements. Note that instead of IGBTs 52a to 52f, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) or the like may be used as switching elements.
[0024] The inverter circuit 50 implements a power conversion circuit 48 (corresponding to power conversion circuits 48a to 48c in Figure 2) that converts DC power to three-phase AC power, and driver circuits 51a and 51b (corresponding to driver circuits 49a to 49c in Figure 2) that control the power conversion circuit 48. The power conversion circuit 48 includes a first switching element (IGBT 52a) to a sixth switching element (IGBT 52f), and a first diode (diode 53a) to a sixth diode (diode 53f) that are electrically connected in antiparallel to the first switching element (IGBT 52a) to the sixth switching element (IGBT 52f). The first switching element (IGBT 52a), the second switching element (IGBT 52b), and the third switching element (IGBT 52c) are electrically connected in parallel to the positive electrode wire 81. The first switching element (IGBT52a) and the fourth switching element (IGBT52d) are electrically connected in series, and the connection point 91a between the first switching element (IGBT52a) and the fourth switching element (IGBT52d) is connected to the first terminal (U-phase terminal) of the motor 40. The second switching element (IGBT52b) and the fifth switching element (IGBT52e) are electrically connected in series, and the connection point 91b between the second switching element (IGBT52b) and the fifth switching element (IGBT52e) is connected to the second terminal (V-phase terminal) of the motor 40. The third switching element (IGBT52c) and the sixth switching element (IGBT52f) are electrically connected in series, and the connection point 91c between the third switching element (IGBT52c) and the sixth switching element (IGBT52f) is connected to the third terminal (W-phase terminal) of the motor 40.
[0025] The six IGBTs 52a to 52f are connected in a three-phase bridge configuration. Three IGBTs 52a to 52c are included in the upper arm, and three IGBTs 52d to 52f are included in the lower arm. The gates (control terminals) of IGBTs 52a to 52c in the upper arm are connected to driver circuit 51a (high-voltage driver circuit). The gates (control terminals) of IGBTs 52d to 52f in the lower arm are connected to driver circuit 51b (low-voltage driver circuit).
[0026] In this embodiment, any one of the fourth switching element (IGBT52d), the fifth switching element (IGBT52e), and the sixth switching element (IGBT52f) is an example of the "first element". Any other one of the fourth switching element (IGBT52d), the fifth switching element (IGBT52e), and the sixth switching element (IGBT52f) is an example of the "second element". The remaining one of the fourth switching element (IGBT52d), the fifth switching element (IGBT52e), and the sixth switching element (IGBT52f) is an example of the "third element".
[0027] Diodes 53a to 53f are electrically connected in reverse in parallel to each of the IGBTs 52a to 52f. Diodes 53a to 53f are flywheel diodes and are connected to conduct in the opposite direction to IGBTs 52a to 52f, respectively.
[0028] The driver circuit 51a supplies PWM drive signals to the gates of the IGBTs 52a to 52c on the upper arm. The driver circuit 51a has a ground terminal 51g1 that is connected to terminal VNC (ground terminal of the control power supply) of the package component PKG, which will be described later.
[0029] The driver circuit 51b supplies an inverting PWM drive signal to the gates of the IGBTs 52d to 52f on the lower arm. The driver circuit 51b has a ground terminal 51g2 that is connected to terminal VNC (ground terminal of the control power supply) of the package component PKG, which will be described later.
[0030] The package component PKG of the inverter circuit 50 has a case PC and a plurality of terminals. The case PC is a housing that integrally houses the IGBTs 52a to 52f, diodes 53a to 53f, and driver circuits 51a and 51b described above. The plurality of terminals protrude from the outside of the case PC. The plurality of terminals include, for example, the terminals described below. For example, terminals U, V, and W are output terminals for the U phase, V phase, and W phase, respectively. Terminals NU, NV, and NW are terminals connected to the emitters of the lower arm side switching elements (IGBTs 52d to 52f) for the U phase, V phase, and W phase, respectively. Terminals UFB, VFB, and WFB are terminals for bootstrap for the U phase, V phase, and W phase, respectively. Terminals UP, VP, and WP are input terminals for the PWM control signals for the U phase, V phase, and W phase, respectively. Terminals UN, VN, and WN are input terminals for the U-phase, V-phase, and W-phase inverting PWM control signals, respectively. Terminal P is a terminal for the high-voltage power supply. Terminals CP and CN are terminals for the control power supply. Terminal VNC is the ground terminal for the control power supply. Terminal VNC is connected to the control power supply ground GND2 (see Figure 4). Terminal VNC is the connection point between the ground terminals 51g1 and 51g2 of the driver circuits 51a and 51b and the ground GND2, and is an example of a "power supply ground connection point". Ground GND2 is connected to ground GND1 (see Figure 4). In this embodiment, an example of a "ground" is realized by ground GND1 and ground GND2.
[0031] In other words, in Figure 3, high-voltage power is supplied to the collectors of IGBT52a, 52b, and 52c on the upper arm from terminal P. The emitter of IGBT52a on the upper arm is connected to the collector of IGBT52d on the lower arm, and the U-phase output terminal U is derived from the connection point 91a between the emitter of IGBT52a and the collector of IGBT52d. The emitter of IGBT52b on the upper arm is connected to the collector of IGBT52e on the lower arm, and the V-phase output terminal V is derived from the connection point 91b between the emitter of IGBT52b and the collector of IGBT52e. The emitter of IGBT52c on the upper arm is connected to the collector of IGBT52f on the lower arm, and the W-phase output terminal W is derived from the connection point 91c between the emitter of IGBT52c and the collector of IGBT52f.
[0032] Terminals NU, NV, and NW are derived from the emitters of IGBTs 52d, 52e, and 52f on the lower arm, respectively. Capacitors 62a, 62b, and 62c for bootstrap are connected to terminals UFB, VFB, and WFB, respectively (see Figure 4). PWM control signals from terminals UP, VP, and WP are supplied to driver circuit 51a. Inverting PWM control signals from terminals UN, VN, and WN are supplied to driver circuit 51b. Terminal CP of the control power supply is connected to driver circuit 51a. Terminal CN of the control power supply is connected to driver circuit 51b. The ground terminal VNC of the control power supply is connected to driver circuit 51b.
[0033] Figure 4 shows the basic circuit configuration when the motor 40 is driven using the inverter circuit 50 described above. As shown in Figure 4, terminals U, V, and W of the inverter circuit 50 are connected to the U-phase, V-phase, and W-phase terminals of the motor 40. Terminals NU, NV, and NW are connected to one end of the shunt resistors 61a, 61b, and 61c, respectively. The other ends of the shunt resistors 61a, 61b, and 61c are connected to the ground GND1 of the high-voltage power supply, respectively. Capacitors 68a, 68b, and 68c are electrically connected in parallel to the shunt resistors 61a, 61b, and 61c, respectively.
[0034] One end of the bootstrap capacitors 62a, 62b, and 62c are connected to terminals UFB, VFB, and WFB, respectively. The other ends of capacitors 62a, 62b, and 62c are connected to terminals U, V, and W, respectively. Terminals UP, VP, and WP are connected to the control circuit 70 to receive the PWM control signal. Terminals UN, VN, and WN are connected to the control circuit 70 to receive the inverting PWM control signal.
[0035] A high-voltage power supply is provided to terminal P. For example, a 280V DC power supply obtained by voltage doubling and rectifying a 100V commercial AC power supply is used as the high-voltage power supply. A snubber capacitor 65 is connected between terminal P and the ground GND1 of the high-voltage power supply.
[0036] Terminals CP and CN are supplied with power from, for example, a 15V control power supply. Terminal VNC serves as the ground terminal for the control power supply. A Zener diode 63 and a capacitor 64 are provided between terminals CN and VNC to stabilize the voltage.
[0037] In such an inverter circuit 50, the motor 40 is driven as follows. In Figure 4, the control circuit 70 outputs U-phase, V-phase, and W-phase PWM control signals and an inverting PWM signal to drive the motor 40. These PWM control signals and inverting PWM control signals are supplied to driver circuits 51a and 51b from terminals UP, VP, WP and terminals UN, VN, WN. Driver circuits 51a and 51b generate PWM drive signals and inverting PWM drive signals with the voltage required to drive IGBTs 52a to 52f (e.g., 15V) from the PWM control signal (e.g., 3.3V) from the control circuit 70. These PWM drive signals and inverting PWM drive signals are supplied to the gates of IGBTs 52a to 52c on the upper arm and IGBTs 52d to 52f on the lower arm. This PWM drive signal and inverting PWM drive signal cause the IGBTs 52a-52c on the upper arm and 52d-52f on the lower arm to switch so that when one is on, the other is off. As a result, the high-voltage DC power supply from terminal P is converted into a three-phase AC power supply and supplied to the motor 40.
[0038] In a configuration where the upper arm's IGBTs 52a-52c and the lower arm's IGBTs 52d-52f are bridged, the emitter voltage of the upper arm's IGBTs 52a-52c becomes high. Therefore, a bootstrap circuit repeatedly charges and discharges capacitors 62a-62c to maintain the gate-emitter voltage of the upper arm's IGBTs 52a-52c at a predetermined control voltage (e.g., 15V).
[0039] In this configuration, when the motor 40 is driven using the inverter circuit 50, shunt resistors 61a, 61b, and 61c are connected to terminals NU, NV, and NW of the inverter circuit 50, respectively. The shunt resistors 61a, 61b, and 61c are used to monitor the current flowing through the motor 40. Controlling the motor 40a of the washing machine 100 is complex, involving actions such as reversing the motor 40a during washing and agitation, rotating the motor 40a at high speed during spin-drying, and regenerative braking the motor 40a. Therefore, in this embodiment, three shunt resistors 61a, 61b, and 61c are used to monitor the currents of the U, V, and W phases.
[0040] In other words, Figure 5 is a diagram showing the control of motor 40a when rotating drum 7. In Figure 5, the horizontal axis represents elapsed time, and the vertical axis represents rotational speed. As shown in Figure 5, in the motor 40a of the washing machine 100, the rotational speed and direction of the motor change in various ways during each process such as washing, rinsing, and spinning. Period T1 in the figure is the state in which the drum 7 is rotated at a low rotational speed and mainly performs forward and reverse movements, and includes the process of filling with water for washing and rinsing, and the process of draining and loosening the fabric. In period T1, the current flowing through motor 40a tends to be large when there is a lot of water and the amount of laundry in drum 7 is about half full. Period T2 shows the process of spinning the drum 7 at a high rotational speed. Thus, the motor 40a that rotates drum 7 has a wide range of rotational speeds and also includes reverse movements. For this reason, a method is adopted in which three shunt resistors 61a, 61b, and 61c are arranged to ensure high reliability and enable the detection of a large amount of current information. Furthermore, the washing machine 100 is equipped with multiple motors 40, including motors 40a, 40b, and 40c. This can lead to noise interference between the inverter circuits 50a to 50c. Therefore, the configuration includes three shunt resistors 61a, 61b, and 61c, which can detect the currents of the U, V, and W phases, respectively.
[0041] In the inverter circuit 50 described above, the driver circuits 51a and 51b are driven by a control power supply (e.g., 15V) supplied from terminals CP and CN. In contrast, IGBTs 52a to 52f switch a high-voltage power supply (e.g., 280V) from terminal P. Therefore, two DC power supplies are used: a control power supply to drive the driver circuits 51a and 51b, and a high-voltage power supply switched by IGBTs 52a to 52f. If a potential difference occurs between the ground GND1 of the high-voltage power supply and the ground GND2 of the control power supply, surge noise will occur, which can cause malfunctions.
[0042] The ground GND1 of the high-voltage power supply and the ground GND2 of the control power supply are connected at the shunt resistors 61a to 61c. Since a large current flows through the shunt resistors 61a to 61c, a potential difference is likely to occur between the ground GND1 of the high-voltage power supply and the ground GND2 of the control power supply. Furthermore, if the wiring La to Lc in the shunt resistors 61a to 61c becomes longer, the wiring inductance increases, and the current change due to the switching of IGBTs 52a to 52f increases the potential difference between the ground GND1 of the high-voltage power supply and the ground GND2 of the control power supply. For this reason, it is desirable to keep the wiring La to Lc in the shunt resistors 61a to 61c as short as possible.
[0043] However, when mounting the inverter circuit 50's package components PKG onto a circuit board, physical constraints limit the length of the wiring La to Lc in the shunt resistor 61a to 61c section. In other words, when mounting the inverter circuit 50's package components PKG onto a circuit board, a heat sink is required for heat dissipation. Also, since a large current flows through the shunt resistors 61a to 61c, it is necessary to use high-power rated resistors such as cement resistors for the shunt resistors 61a to 61c. When cement resistors are used for the shunt resistors 61a to 61c, it is necessary to secure mounting space for the shunt resistors 61a to 61c. For this reason, it is difficult to lay out the shunt resistors 61a to 61c close to the inverter circuit 50's package components PKG, and as a result, the wiring La to Lc in the shunt resistor 61a to 61c section becomes long.
[0044] Figures 6, 7, and 8 show the mounting structure of the shunt resistors 61a to 61c on the substrate 60.
[0045] Figure 6 shows, for example, a case where surface-mount type shunt resistors 61a to 61c are provided. When surface-mount type shunt resistors 61a to 61c are provided, in order to secure the mounting area (mounting area) for each shunt resistor, the wiring connecting the package component PKG and the three shunt resistors 61a to 61c spreads out in the direction in which the three shunt resistors 61a to 61c are aligned. As a result, the wiring length of each wire La to Lc becomes longer.
[0046] Figures 7 and 8 show, for example, a case where tall, cement-type shunt resistors 61a to 61c are provided. Here, a large heat sink 55 for heat dissipation is attached to the package component PKG of the inverter circuit 50. Therefore, when tall shunt resistors 61a to 61c are arranged, the shunt resistors 61a to 61c cannot be mounted on the underside of the heat sink 55. In this case, the mounting position of the shunt resistors 61a to 61c will be in the area outside the heat sink 55 (the area that does not overlap with the heat sink 55) when viewed from the thickness direction of the circuit board 56. As a result, the distance between the terminals of the package component PKG of the inverter circuit 50 and the shunt resistors 61a to 61c becomes longer. Consequently, the wiring length of each wiring La to Lc becomes longer.
[0047] Therefore, in this embodiment, ceramic capacitors with excellent high-frequency characteristics are connected as surge voltage absorption elements between the connection points (terminals NU, NV, and NW) between the emitters of the IGBTs 52d to 52f of the lower arm and the shunt resistors 61a to 61c, and the ground GND2 of the control power supply. More specifically, as shown in Figure 9, a ceramic capacitor 67a (first surge voltage absorption element) is connected between terminal NU and terminal VNC, a ceramic capacitor 67b (second surge voltage absorption element) is connected between terminal NV and terminal VNC, and a ceramic capacitor 67c (third surge voltage absorption element) is connected between terminal NW and terminal VNC.
[0048] In other words, as shown in Figure 3, terminals NU (first terminal), NV (second terminal), NW (third terminal), and VNC (fourth terminal) are led out to the outside from the package component PKG that constitutes the inverter circuit 50. Terminals NU, NV, and NW are connected to the emitters of IGBTs 52d to 52f on the lower arms of the U, V, and W phases, respectively. Terminal VNC is the ground GND2 terminal of the control power supply. Note that in the package component PKG, terminals NU, NV, NW and terminal VNC are positioned opposite each other.
[0049] Therefore, as shown in Figure 9, by connecting ceramic capacitor 67a (first surge voltage absorption element) between terminal NU and terminal VNC, ceramic capacitor 67b (second surge voltage absorption element) between terminal NV and terminal VNC, and ceramic capacitor 67c (third surge voltage absorption element) between terminal NW and terminal VNC, ceramic capacitors 67a to 67c are connected between the emitters of IGBTs 52d to 52f on the lower arm and the connection point of shunt resistors 61a to 61c, and the ground GND2 of the control power supply, respectively.
[0050] When mounting the package components PKG of the inverter circuit 50 onto the circuit board 56, as shown in Figure 10, the package components PKG of the inverter circuit 50 are mounted on the upper surface 56a (first surface, see Figure 8) of the circuit board 56, and on the lower surface 56b (second surface) opposite to the upper surface 56a of the circuit board 56, ceramic capacitors 67a, 67b, and 67c are connected between terminal NU and terminal VNC, between terminal NU and terminal NV, and between terminal NW and terminal VNC, respectively. In this case, since terminals NU, NV, and NW are positioned opposite each other to terminal VNC, the ceramic capacitors 67a, 67b, and 67c can be positioned at the shortest distance by connecting them so as to span between terminal NU and terminal VNC, between terminal NU and terminal NV, and between terminal NW and terminal VNC. Furthermore, the ceramic capacitors 67a, 67b, and 67c are positioned on the opposite side of the circuit board 56 from the package components PKG of the inverter circuit 50. At least a portion of each of the ceramic capacitors 67a, 67b, and 67c is positioned within the region that overlaps with the package components PKG of the inverter circuit 50 when viewed in the thickness direction of the circuit board 56.
[0051] In this way, by connecting ceramic capacitors 67a, 67b, and 67c between terminals NU and VNC, between terminals NU and NV, and between terminals NW and VNC, respectively, the potential difference between the high-voltage power supply ground GND1 and the control power supply ground GND2 that occurs when IGBTs 52a to 52f switch is absorbed by the ceramic capacitors 67a to 67c, thereby reducing the effects of surge noise.
[0052] The driver circuits 51a and 51b have a voltage rating of, for example, 20V, and if the surge exceeds -5V, the difference with the control voltage of 15V becomes 20V. Also, if the surge fluctuation is on the positive side, the gate drive voltage of the lower arm IGBTs 52d to 52 will decrease, the collector-emitter saturation voltage will rise, the losses will increase, and the element may fail. It has been confirmed that if the wiring La to Lc in the shunt resistor section 61a to 61c is several tens of millimeters (for example, 50 mm), it is possible to suppress the surge to within ±5V by using ceramic capacitors of a few μF (for example, 1 μF) as 67a to 67c.
[0053] As shown in the figure, in the washing machine according to this embodiment, three motors 40 are arranged: a motor 40a for rotating the drum 7, a motor 40b for starting the circulation fan, and a motor 40c for the compressor. Three inverter circuits 50a, 50b, and 50c are provided to drive these motors 40a, 41b, and 40c.
[0054] The motor 40a that rotates the drum 7 is controlled by control circuit 70a, and the motor 40b for starting the circulation fan and the motor 40c for the compressor are controlled by control circuit 70b. In total, two control circuits 70a and 70b control motors 40a to 40c. The two control circuits 70a and 70b are connected by serial communication and operate in coordination.
[0055] Here, the motor 40a that rotates the drum 7 is a direct-drive brushless DC motor with the rotor directly connected to the drive shaft. In particular, the starting torque is large during washing forward and reverse rotation, and the current tends to increase. Similarly, for the motor 40c that drives the compressor, as drying progresses and the temperature of the condenser 29 rises, the refrigerant pressure increases, the load torque increases, and the current increases. For this reason, it is desirable to connect the motor 40a that rotates the drum 7 and the motor 40c for the compressor to the surge absorption element consisting of the ceramic condensers 67a to 67c mentioned above to suppress the generation of surge noise. In contrast, the motor 40b that starts the fan has a small current flowing through it, so it generates less surge noise, and it is not necessary to connect the surge absorption element consisting of the ceramic condensers 67a to 67c mentioned above to it.
[0056] (advantage) This embodiment relates to a motor 40 and a power conversion circuit 48 that converts DC power to AC power and outputs it to the motor 40, the power conversion circuit 48 having a three-phase bridge connection of first to sixth switching elements (IGBT 52a to 52e) and first to sixth diodes 53a to 53f electrically connected in antiparallel to the first to sixth switching elements (IGBT 52a to 52e), the first to third switching elements (IGBT 52a to 52c) included in the upper arm and the fourth to sixth switching elements (IGBT 52d to 52f) included in the lower arm, and the control terminals of each of the fourth to sixth switching elements (IGBT 52d to 52f) The driver circuit 51b is connected to the gate and controls the fourth to sixth switching elements (IGBT 52d to 52f) and has a ground terminal 51g2. When any one of the fourth to sixth switching elements (IGBT 52d to 52f) is designated as the first element, a shunt resistor 61a is connected between the first element and ground. A surge voltage absorption element (ceramic capacitor 67a) is electrically connected in parallel with the power conversion circuit 48 and the driver circuit 51b between the connection point between the first element and the shunt resistor 61a and the connection point between the ground terminal 51g2 of the driver circuit 51b and ground. According to this embodiment, even when the wiring length is long, surge generation due to the potential difference between the ground terminal 51g2 and the ground can be suppressed.
[0057] In this embodiment, the shunt resistor is set as the first shunt resistor 61a, the surge voltage absorption element (ceramic capacitor 67a) is set as the first surge voltage absorption element, the connection point between the ground terminal 51g2 of the driver circuit 51b and the ground is set as the power supply ground connection point, and the remaining two elements of the fourth to sixth switching elements (IGBT 52d to 52f) that are not the first element are set as the second element and the third element, and the second shunt resistor 61b connected between the second element and the ground and the third element The device further comprises a third shunt resistor 62c connected between the child and the ground, a second surge voltage absorbing element 67b electrically connected in parallel with the power conversion circuit 48 and the driver circuit 51b between the connection point between the second element and the second shunt resistor 61b and the power supply ground connection point, and a third surge voltage absorbing element 67c electrically connected in parallel with the power conversion circuit 48 and the driver circuit 51b between the connection point between the third element and the third shunt resistor 62c and the power supply ground connection point. According to this embodiment, a configuration with three shunt resistors 61a, 61b, and 61c can suppress surges generated by the shunt resistors 61a, 61b, and 61c.
[0058] This embodiment includes a package component PKG containing the power conversion circuit 48 and the driver circuit 51b, wherein the connection point between the fourth switching element (IGBT 52d) and the first shunt resistor 61a is the first terminal (terminal NU) of the package component PKG, the connection point between the fifth switching element (IGBT 52d) and the second shunt resistor 61b is the second terminal (terminal NV) of the package component PKG, and the connection point between the sixth switching element (IGBT 52e) and the third shunt resistor 62c is the third terminal (terminal NV) of the package component PKG. The child network (NW) is connected to the power supply ground connection point, the fourth terminal (terminal VNC) of the package component PKG, the first surge voltage absorption element (ceramic capacitor 67a) is connected between the first terminal (terminal NU) and the fourth terminal (terminal VNC), the second surge voltage absorption element (ceramic capacitor 67b) is connected between the second terminal (terminal NV) and the fourth terminal (terminal VNC), and the third surge voltage absorption element (ceramic capacitor 67b) is connected between the third terminal (terminal NW) and the fourth terminal (terminal VNC). According to this embodiment, with a configuration that includes three shunt resistors 61a, 61b, and 61c, first to third surge voltage absorption elements (ceramic capacitors 67a to 67c) for suppressing surges generated by the shunt resistors 61a, 61b, and 61c can be mounted on the wiring board.
[0059] In this embodiment, the first surge voltage absorbing element (ceramic capacitor 67a) is connected outside the package component PKG between the first terminal (terminal NU) and the fourth terminal (terminal VNC), the second surge voltage absorbing element (ceramic capacitor 67b) is connected outside the package component PKG between the second terminal (terminal NV) and the fourth terminal (terminal VNC), and the third surge voltage absorbing element (ceramic capacitor 67c) is connected outside the package component PKG between the third terminal and the fourth terminal (terminal VNC). According to this embodiment, the first to third surge voltage absorption elements (ceramic capacitors 67a to 67c) for suppressing surges can be connected with short wiring.
[0060] In this embodiment, each of the first to third surge voltage absorption elements is a ceramic capacitor 67a to 67c. According to this embodiment, surge noise can be reliably reduced by using a ceramic capacitor with excellent high-frequency characteristics as a surge voltage absorption element.
[0061] In this embodiment, the circuit board 56 further includes a first surface (top surface 56a) on which the package component PKG is mounted, and a second surface (bottom surface 56b) located on the opposite side of the first surface. The first surge voltage absorption element (ceramic capacitor 67a), the second surge voltage absorption element (ceramic capacitor 67b), and the third surge voltage absorption element (ceramic capacitor 67c) are arranged on the second surface (bottom surface 56b) side of the circuit board 56. According to this embodiment, surge voltage absorption elements can be connected with short wiring.
[0062] In this embodiment, the first surge voltage absorbing element (ceramic capacitor 67a), the second surge voltage absorbing element (ceramic capacitor 67b), and the third surge voltage absorbing element (ceramic capacitor 67c) are arranged in a region that overlaps with the package component PKG when viewed in the thickness direction of the circuit board 56. According to this embodiment, surge voltage absorption elements can be connected with short wiring without being affected by the physical influence of heat sinks or other components.
[0063] In this embodiment, when the motor is a first motor 40a, the power conversion circuit 48 is a first power conversion circuit 48a, and the driver circuit is a first driver circuit 49a, there is a second motor 40b that uses less current than the first motor 40a, and a power conversion circuit 48b that converts DC power to AC power and outputs it to the second motor 40b, and has first to sixth switching elements (IBGT52a~52f) connected in a three-phase bridge connection, and first to sixth diodes 53a~53f electrically connected in antiparallel to the first to sixth switching elements (IBGT52a~52f), and the first to third switching elements (IBGT52a~52c) are included in the upper arm, and the fourth to sixth The second power conversion circuit 48b includes switching elements (IBGT52e~52f) in its lower arm, a second driver circuit 51b connected to the control terminals of the fourth to sixth switching elements (IGBT52e~52f) of the second power conversion circuit 48b, controlling the fourth to sixth switching elements (IGBT52e~52f), and having a ground terminal, and a shunt resistor (ceramic capacitor 67a) connected between the fourth switching element (IGBT52e) of the second power conversion circuit 48b and the ground, and surge voltage absorption elements (same type of surge voltage absorption elements) are not provided for the second power conversion circuit 48b and the second driver circuit 49b. According to this embodiment, when there are multiple motors, surge voltage absorption elements are not provided in inverter circuits with low current, thereby suppressing the generation of surge noise while reducing circuit size and costs.
[0064] (Second Embodiment) In the first embodiment described above, ceramic capacitors 67a to 67c are used as surge voltage absorption elements. In contrast, in this second embodiment, Schottky diodes are used as surge voltage absorption elements. That is, Figure 11 is an explanatory diagram of the connection of the surge voltage absorption elements in the second embodiment. As shown in Figure 11, in the second embodiment, Schottky diodes 167a, 167b, and 167c are connected as surge voltage absorption elements between terminals NU, NV, and NW of the package component PKG of the inverter circuit 50 and terminal VNC, respectively. As a result, Schottky diodes 167a, 167b, and 167c are connected as surge voltage absorption elements between the connection point between the emitters of the IGBTs 52d to 52f of the lower arm and the shunt resistors 61a to 61c, and the ground GND2 of the control power supply. Here, when the package components PKG of the inverter circuit 50 are mounted on the first surface 56a of the circuit board 56, the Schottky diodes 167a, 167b, and 167c are located on the second surface 56b side of the circuit board 56. At least a portion of each of the Schottky diodes 167a, 167b, and 167c is located within the region that overlaps with the package components PKG of the inverter circuit 50 when viewed in the thickness direction of the circuit board 56.
[0065] (modified version) Several variations are described below. In each variation, the configuration is the same as that of the first embodiment, except for the configuration described below. In the following, a variation is described in which a ceramic capacitor is provided as the surge voltage absorption element. However, in these variations, as with the second embodiment, a Schottky diode or another element may be provided as the surge voltage absorption element.
[0066] (First variation) In the above embodiment, three surge voltage absorption elements (e.g., ceramic capacitors 67a to 67c) are provided corresponding to three switching elements (e.g., IGBTs 52d to 52f) connected to three shunt resistors 61a, 61b, and 61c, respectively. Alternatively, one or two surge voltage absorption elements may be provided corresponding to only one or two of the three switching elements (e.g., IGBTs 52d to 52f) connected to the three shunt resistors 61a, 61b, and 61c, respectively, where the wiring length is relatively longer. In other words, one or two surge voltage absorption elements may be provided for a three-shunt structure. In this case, for example, the switching element with the longest wiring length among the three switching elements is an example of the "first element".
[0067] (Second variation) In the above embodiment, three shunt resistors 61a, 61b, and 61c are provided corresponding to the U-phase, V-phase, and W-phase. Alternatively, the washing machine 100 may have only two shunt resistors (e.g., shunt resistors 61a and 61b) corresponding to any two phases of the U-phase, V-phase, and W-phase (i.e., corresponding to the first and second elements). In this case, the washing machine 100 may have only two surge voltage absorbing elements (e.g., ceramic capacitors 67a and 67b) corresponding to the two phases of the U-phase, V-phase, and W-phase for which the shunt resistors are provided.
[0068] The two surge voltage absorbing elements (e.g., ceramic capacitors 67a and 67b) are provided, for example, outside the package component PKG and are positioned on the lower surface 56b side (second surface side) of the circuit board 56. At least a portion of each of the two surge voltage absorbing elements (e.g., ceramic capacitors 67a and 67b) is positioned within the region that overlaps with the package component PKG of the inverter circuit 50 when viewed in the thickness direction of the circuit board 56.
[0069] (Third variation) In the above embodiment, three shunt resistors 61a, 61b, and 61c are connected between terminals NU, NV, and NW of the inverter circuit 50's package component PKG and the ground GND1 of the high-voltage power supply. This allows for the detection of the U-phase, V-phase, and W-phase currents of the motor 40, respectively. Alternatively, only one shunt resistor may be connected between terminals NU, NV, and NW of the inverter circuit 50's package component PKG and the ground GND1 of the high-voltage power supply. If there is only one shunt resistor, terminals NU, NV, and NW connected to the emitters of the IGBTs 52d to 52f on the lower arm can be combined into one. Therefore, only one surge voltage absorption element may be used.
[0070] Figure 12 shows the basic circuit configuration when driving the motor 40 using the inverter circuit 50 according to the third modified example. In this third modified example, for example, a shunt resistor 61a is connected between the first connection point (junction point) C1, which is the connection point where the emitters (or terminals NU, NV, and NW) of the IGBTs 52d to 52f of the lower arm are connected to each other, and the ground GND1. A capacitor 68a is electrically connected in parallel to the shunt resistor 61a.
[0071] In this third modification, a ceramic capacitor 67a (see Figure 13) is connected as a surge voltage absorption element between the emitter connection point (first connection point C1) of the IGBTs 52d to 52f of the lower arm and the ground GND2 of the control power supply. In other words, the ceramic capacitor 67a is connected between the first connection point C1, which is the emitter connection point of the IGBTs 52d to 52f of the lower arm, and the second connection point C2 (e.g., terminal VNC), which is the connection point between the ground terminal 51g of the driver circuit 51b and the ground GND. The ceramic capacitor 67a is electrically connected in parallel with the power conversion circuit 48 and the driver circuit 51b.
[0072] Figure 13 shows the mounting structure of the washing machine 100 according to the third modified example. In the third modified example, for example, the terminals NU, NV, and NW of the package PKG are connected to each other on the circuit board 56 (for example, they are connected to each other by wiring patterns included in the circuit board 56). A ceramic capacitor 67a (surge voltage absorption element) is connected between any one of the terminals NU, NV, or NW (for example, terminal NV) and terminal VNC. The ceramic capacitor 67a may be connected between terminal NU and terminal VNC, or between terminal NW and terminal VNC, instead of the above configuration.
[0073] Figure 14 shows the mounting structure of the surge voltage absorption element in this third modified example. The ceramic capacitor 67a is mounted on the upper surface 56a (first surface, see Figure 8) of the circuit board 56, with the package component PKG of the inverter circuit 50 mounted on the lower surface 56b (second surface) opposite to the upper surface 56a of the circuit board 56, and is connected between terminals NU and NV. At least a portion of the ceramic capacitor 67a is positioned within the region that overlaps with the package component PKG of the inverter circuit 50 when viewed in the thickness direction of the circuit board 56.
[0074] (Other variations) The surge voltage absorption element is not limited to ceramic capacitors or Schottky diodes; other capacitors, surge suppressors, or varistors may also be used.
[0075] Furthermore, the surge voltage absorption element does not need to be directly inserted between the ground terminal of the driver circuit's control power supply and the emitter terminal of the switching element on the lower arm. It can be inserted near the driver circuit's package at a location that is easily accessible in the layout.
[0076] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]
[0077] 40, 40a~40c…Motor; 50, 50a~50c…Inverter circuit; 51a, 51b…Driver circuit; 52a~52f…IGBT; 53a~53f…Diode; 61a~61c…Shunt resistor; 67a~67c…Ceramic capacitor
Claims
1. Motor and, A power conversion circuit that converts DC power to AC power and outputs it to the motor, comprising a first to sixth switching element connected in a three-phase bridge configuration, and a first to sixth diode electrically connected in antiparallel to the first to sixth switching element, wherein the first to third switching element is included in the upper arm and the fourth to sixth switching element is included in the lower arm, A driver circuit connected to the control terminals of each of the fourth to sixth switching elements, which controls the fourth to sixth switching elements and has a ground terminal, A first shunt resistor connected between the fourth switching element and ground, A second shunt resistor connected between the fifth switching element and the ground, A third shunt resistor connected between the sixth switching element and the ground, Between the connection point between the fourth switching element and the first shunt resistor and the power supply ground connection point which is the connection point between the ground terminal of the driver circuit and the ground, a first surge voltage absorption element is electrically connected in parallel with the power conversion circuit and the driver circuit, Between the connection point of the fifth switching element and the second shunt resistor and the power supply ground connection point, a second surge voltage absorption element is electrically connected in parallel with the power conversion circuit and the driver circuit. Between the connection point of the sixth switching element and the third shunt resistor and the power supply ground connection point, a third surge voltage absorption element is electrically connected in parallel with the power conversion circuit and the driver circuit. Equipped with, A package component including the power conversion circuit and the driver circuit is provided. The connection point between the fourth switching element and the first shunt resistor is the first terminal of the package component, the connection point between the fifth switching element and the second shunt resistor is the second terminal of the package component, the connection point between the sixth switching element and the third shunt resistor is the third terminal of the package component, and the power supply ground connection point is the fourth terminal of the package component. The first surge voltage absorption element is located outside the package component and connected to the first terminal. The second surge voltage absorption element is located outside the package component and connected to the second terminal. The third surge voltage absorption element is located outside the package component and connected to the third terminal. The first surge voltage absorbing element, the second surge voltage absorbing element, and the third surge voltage absorbing element are connected to the fourth terminal via a confluence point that is electrically connected to each other. washing machine.
2. A motor and, A power conversion circuit that converts DC power to AC power and outputs it to the motor, comprising a first to sixth switching element connected in a three-phase bridge configuration, and a first to sixth diode electrically connected in antiparallel to the first to sixth switching element, wherein the first to third switching element is included in the upper arm and the fourth to sixth switching element is included in the lower arm, A driver circuit connected to the control terminals of each of the fourth to sixth switching elements, which controls the fourth to sixth switching elements and has a ground terminal, A first shunt resistor connected between the fourth switching element and ground, A second shunt resistor connected between the fifth switching element and the ground, Between the connection point between the fourth switching element and the first shunt resistor and the power supply ground connection point which is the connection point between the ground terminal of the driver circuit and the ground, a first surge voltage absorption element is electrically connected in parallel with the power conversion circuit and the driver circuit, Between the connection point of the fifth switching element and the second shunt resistor and the power supply ground connection point, a second surge voltage absorption element is electrically connected in parallel with the power conversion circuit and the driver circuit. Equipped with, A package component including the power conversion circuit and the driver circuit is provided. The connection point between the fourth switching element and the first shunt resistor is the first terminal of the package component, the connection point between the fifth switching element and the second shunt resistor is the second terminal of the package component, the sixth switching element is connected to the third terminal of the package component, and the power supply ground connection point is the fourth terminal of the package component. The first surge voltage absorption element is located outside the package component and connected to the first terminal. The second surge voltage absorption element is located outside the package component and connected to the second terminal. The first surge voltage absorbing element and the second surge voltage absorbing element are connected to the fourth terminal via a confluence point that is electrically connected to each other. washing machine.
3. Each of the first surge voltage absorption element and the second surge voltage absorption element is a ceramic capacitor. The washing machine according to claim 1 or claim 2.
4. The circuit board further includes a first surface on which the package components are mounted and a second surface located on the opposite side from the first surface. The first surge voltage absorption element and the second surge voltage absorption element are arranged on the second side of the circuit board. The washing machine according to claim 1 or claim 2.
5. At least a portion of each of the first surge voltage absorption element and the second surge voltage absorption element is positioned within a region that overlaps with the package component when viewed in the thickness direction of the circuit board. The washing machine according to claim 4.
6. When the motor is designated as the first motor, the power conversion circuit as the first power conversion circuit, and the driver circuit as the first driver circuit, A second motor that uses less current than the first motor, A power conversion circuit that converts DC power to AC power and outputs it to the second motor, comprising a first to sixth switching element connected in a three-phase bridge configuration, and a first to sixth diode electrically connected in antiparallel to the first to sixth switching element, wherein the first to third switching element is included in the upper arm and the fourth to sixth switching element is included in the lower arm, A second driver circuit is connected to the control terminals of each of the fourth to sixth switching elements of the second power conversion circuit, controls the fourth to sixth switching elements, and has a ground terminal. A shunt resistor connected between the fourth switching element of the second power conversion circuit and the ground, Furthermore, With respect to the second power conversion circuit and the second driver circuit, a surge voltage absorbing element of the same type as the first surge voltage absorbing element is not provided. The washing machine according to claim 1 or claim 2.
7. Motor and, A power conversion circuit that converts DC power to AC power and outputs it to the motor, comprising a first to sixth switching element connected in a three-phase bridge configuration, and a first to sixth diode electrically connected in antiparallel to the first to sixth switching element, wherein the first to third switching element is included in the upper arm and the fourth to sixth switching element is included in the lower arm, A driver circuit connected to the control terminals of each of the fourth to sixth switching elements, which controls the fourth to sixth switching elements and has a ground terminal, A shunt resistor is connected between the first connection point, which is the connection point of the fourth switching element, the fifth switching element, and the sixth switching element, and ground. Between the first connection point and the second connection point, which is the connection point between the ground terminal of the driver circuit and the ground, a surge voltage absorption element is electrically connected in parallel with the power conversion circuit and the driver circuit. Equipped with, A package component including the power conversion circuit and the driver circuit is provided. The fourth switching element is connected to the first terminal of the package component, The fifth switching element is connected to the second terminal of the package component, The sixth switching element is connected to the third terminal of the package component, The second connection point is the fourth terminal of the package component, The first terminal, the second terminal, and the third terminal are connected to each other. The surge voltage absorption element is connected between any one of the first terminal, the second terminal, or the third terminal and the fourth terminal. washing machine.
8. The surge voltage absorption element is connected outside the package component between one of the first terminal, the second terminal, or the third terminal and the fourth terminal. The washing machine according to claim 7.
9. The circuit board further includes a first surface on which the package components are mounted and a second surface located on the opposite side from the first surface. The surge voltage absorption element is arranged on the second side of the circuit board. The washing machine according to claim 8.
10. At least a portion of the surge voltage absorption element is positioned within a region that overlaps with the package component when viewed in the thickness direction of the circuit board. The washing machine according to claim 9.