Power supply unit and washing machine

Abstract

This reduces the harmonic components in the power supply current without the need for a reactor. [Solution] The power supply unit 200 is connected to an AC power supply 700 and includes a rectifier circuit 210 that rectifies the power supply voltage from the AC power supply 700, a smoothing unit 220 connected to the rectifier circuit 210 that smooths the rectified power supply voltage and supplies it to multiple loads, and a control circuit 600 that controls the power supply to the main motor 320, the heat pump motor 420, and the fan motor 520. The control circuit 600 includes a current sensor that detects the load current flowing through each of the main motor 320, the heat pump motor 420, and the fan motor 520, a determination unit 621 that determines whether the sum of the load currents exceeds a threshold, and a limiting unit 622 that, if it is determined that the sum exceeds a threshold, limits the power supplied to the second motor other than the first motor, which is a specific motor among the main motor 320, the heat pump motor 420, and the fan motor 520.

Description

Technical Field

[0006] , , , ,

[0001] The present disclosure relates to a power supply device for an electric device and a washing machine.

Background Art

[0002] Patent Document 1 includes a converter that rectifies a power supply voltage, an inverter connected to the converter, and a control device that controls the operation of the inverter. The control device performs vibration suppression control to suppress vibration of the torque of the electric motor, and limits the compensation value of the vibration suppression control so that the harmonic component included in the power supply current flowing between the AC power supply and the converter is reduced, and discloses a power conversion device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since a reactor is connected between the rectifier circuit and the AC power supply in the technology shown in Patent Document 1, there is a problem that the circuit scale increases.

[0005] The present disclosure has been made to solve such problems, and provides a power supply device and a washing machine capable of reducing harmonic components included in a power supply current without providing a reactor.

Means for Solving the Problems

[0006] A control device in one aspect of the present disclosure is a power supply device for an electrical device, comprising: a rectifier circuit connected to an AC power source and rectifying a power supply voltage from the AC power source; a smoothing capacitor connected to the rectifier circuit and smoothing the rectified power supply voltage and supplying it to a plurality of loads; and a control circuit for controlling the power supply to the plurality of loads, wherein the control circuit comprises: a current detection unit for detecting the load current flowing through each of the plurality of loads; a determination unit for determining whether the sum of the load currents of each of the plurality of loads exceeds a threshold; and, if it is determined that the sum exceeds the threshold, a limiting unit for limiting the power supplied to a second load other than a first load, which is a specific load among the plurality of loads. [Effects of the Invention]

[0007] This disclosure demonstrates that harmonic components in the power supply current can be reduced without the need for a reactor. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view of the washing machine in this embodiment. [Figure 2] This is a circuit diagram of the power supply unit for the washing machine in this embodiment. [Figure 3] This is a detailed configuration diagram of the control circuit in this embodiment. [Figure 4] This flowchart shows a first example of the processing performed by the interlocking control unit in this embodiment. [Figure 5] This flowchart shows a second example of the processing performed by the interlocking control unit in this embodiment. [Figure 6] This flowchart shows a third example of the processing performed by the interlocking control unit in this embodiment. [Figure 7] This flowchart shows an example of the gate signal generation process in this embodiment. [Figure 8]The upper graph shows the temporal progression of power input from the AC power source when interlocking control is applied, and the lower graph shows the temporal progression of the harmonic components of the power supply current supplied from the AC power source when interlocking control is applied. [Figure 9] This is a graph showing a first example of a control pattern in the dehydration mode in Modification 1 of the present disclosure. [Figure 10] This is a graph showing a second example of a control pattern in the dehydration mode in Modification 1 of the present disclosure. [Figure 11] This is a graph showing an example of a control pattern in the drying mode in Modification 2 of the present disclosure. [Figure 12] This graph shows the effect of suppressing harmonic components in this embodiment. [Modes for carrying out the invention]

[0009] (Knowledge forming the basis of this disclosure) Electrical appliances such as washing machines use power supply units that include a rectifier circuit and smoothing capacitor that convert the AC power supply voltage to a DC voltage, and an inverter circuit that converts the DC voltage from the smoothing capacitor back to an AC voltage and supplies it to an AC load. In such power supply units, the harmonic components of the power supply current flowing between the AC power supply and the rectifier circuit become large. If the harmonic components become excessive, this affects the quality of the grid power supply. Therefore, such power supply units have limits set for each of the multiple harmonic components according to standards (standards of the Japan Electronics and Information Technology Industries Association).

[0010] If a reactor is placed between the rectifier circuit and the AC power supply, the reactor will function like a low-pass filter and reduce harmonic components. However, adding a reactor increases the circuit size. Also, if an AC load requiring a large current is connected to the inverter circuit, the current flowing through the reactor will be pulled towards the AC load, and the reactor alone may not be able to suppress harmonic components effectively.

[0011] On the other hand, in such a power supply device, there is also known one that employs a rectifier circuit having a boosting function as the rectifier circuit. In this case, since the rectifier circuit includes a switching element, current can be passed through the reactor at an arbitrary timing, and harmonic components can be suppressed even when an AC load that requires a large current is connected to the inverter circuit. However, such a rectifier circuit having a boosting function requires a reactor and a switching element, so the circuit scale increases.

[0012] The power conversion device shown in Patent Document 1 balances the imbalance between the positive-polarity power supply current and the negative-polarity current power supply by vibration suppression control, thereby reducing the harmonic components included in the power supply current flowing between the AC power supply and the converter. However, since the voltage conversion device shown in Patent Document 1 also requires a reactor, the circuit scale increases.

[0013] By the way, harmonic components tend to increase as the power supplied to the AC load increases. Therefore, if the power supplied to the AC load can be suppressed to an arbitrary value, the harmonic components can be suppressed. Among electrical devices, there are also those provided with a power supply device in which a plurality of AC loads are connected to one rectifier circuit via a plurality of inverter circuits. In such an electrical device, depending on the operation mode, there may be an AC load with a high importance among the plurality of AC loads, and it is not always necessary to supply the required power to all the AC loads. Further, the same applies not only to AC loads but also to DC loads.

[0014] Therefore, the inventors of the present invention have obtained the knowledge that if power is preferentially supplied to a load with a high importance while restricting the power supplied to a load with a low importance, the total power supplied to all the loads can be suppressed, and thereby, harmonic components can be suppressed without providing a reactor, leading to the idea of the present disclosure.

[0015] Hereinafter, embodiments of the washing machine will be described in detail with reference to the drawings. However, detailed descriptions that are more than necessary may be omitted. For example, detailed descriptions of well-known matters or duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the following description overly redundant and to facilitate the understanding of those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0016] (Embodiment) FIG. 1 is a schematic cross-sectional view of a washing machine 100 according to the present embodiment. This washing machine 100 washes and dries items to be processed such as clothes.

[0017] [Overall Structure of the Washing Machine] The washing machine 100 includes a housing 110. The housing 110 has an inlet through which items to be processed are inserted. The housing 110 has a door portion 111 for opening and closing the inlet. The housing 110 houses internal devices for executing a washing mode, a rinsing mode, a dehydration mode, and a drying mode.

[0018] The housing 110 includes a water tank 114 and a rotating drum 115. The rotating drum 115 is provided with a number of small holes 117 formed in its peripheral wall. The rotating drum 115 houses the items to be processed inserted through the inlet. The water tank 114 stores water in the washing mode and the rinsing mode. The water tank 114 is elastically supported by a suspension mechanism 118 fixed to the bottom wall of the housing 110.

[0019] At the upper part of the peripheral wall of the water tank 114, a water supply port 120 is provided. The water supply port 120 supplies water to the water tank 114 in the washing mode and the rinsing mode. At the lower part of the peripheral wall of the water tank 114, a drain port 121 is provided. The drain port 121 drains the water used for washing and rinsing.

[0020] An exhaust port 122 is formed on the upper part of the peripheral wall of the water tank 114. In drying mode, the exhaust port 122 exhausts air from the water tank 114 to dry the material being processed. An air inlet 123 is formed on the rear end wall of the water tank 114. In drying mode, the air inlet 123 allows the air exhausted from the exhaust port 122 to flow into the processing chamber 112.

[0021] A main motor 320 for rotating the rotating drum 115 is mounted on the outer surface of the rear end wall of the water tank 114.

[0022] A water supply unit 125 is provided above the water tank 114. The water supply unit 125 supplies water to the processing chamber 112. The upstream end of the water supply unit 125 is exposed on the outer surface of the housing 110 and is connected to a hose (not shown) extending from a water tap.

[0023] A drainage path 129 is provided on the underside of the tank 114. The drainage path 129 drains the water from the tank 114.

[0024] A circulating air passage 131 is provided on the outside of the water tank 114. The circulating air passage 131 is connected between the air intake 123 and the exhaust 122. A fan 152 is positioned inside the circulating air passage 131. The fan 152 draws air from the processing chamber 112 through the exhaust 122 and returns the drawn-out air to the processing chamber 112 through the air intake 123.

[0025] A dehumidifying unit 156 and an adsorbent material 139 are arranged within the circulating air passage 131. The dehumidifying unit 156 and the adsorbent material 139 remove moisture from the air flowing through the circulating air passage 131.

[0026] A heating unit 153 is positioned downstream of the dehumidifying unit 156 and the adsorbent 139. The dehumidifying unit 156 and the heating unit 153 constitute a heat pump device. The dehumidifying unit 156 includes an expansion valve for expanding the refrigerant and fins that are cooled by the expanded refrigerant. The heating unit 153 includes a compressor for compressing the refrigerant and fins that are heated by the compressed refrigerant.

[0027] [Circuit Configuration] Figure 2 is a circuit diagram of the power supply unit 200 of the washing machine 100 in this embodiment. The power supply unit 200 includes a rectifier circuit 210, a smoothing unit 220, and inverter circuits 310, 410, and 510.

[0028] The rectifier circuit 210 is connected to the AC power supply 700 and rectifies the power supply voltage from the AC power supply 700. The rectifier circuit 210 includes four diodes 11, 12, 13, and 14 connected in a full bridge configuration. The connection point between diode 11 and diode 13 is connected to one end of the AC power supply 700, forming the first AC input terminal 61. The connection point between diode 12 and diode 14 is connected to the other end of the AC power supply 700, forming the second AC input terminal 62. The rectifier circuit 210 full-wave rectifies the power supply voltage supplied from the AC power supply 700.

[0029] AC power supply 700 is a grid power supply that provides AC power at predetermined frequencies such as 50Hz and 60Hz.

[0030] The smoothing unit 220 smooths the power supply voltage rectified by the rectifier circuit 210. As a result, a DC voltage is generated between the positive node 64 and the negative node 65.

[0031] The smoothing section 220 includes smoothing capacitors 21 and 22. One end of the smoothing section 220 is connected to the cathodes of diodes 11 and 12, respectively, and to the positive node 64. The other end of the smoothing section 220 is connected to the anodes of diodes 13 and 14, respectively, and to the negative node 65. The connection point 63 between smoothing capacitors 21 and 22 is connected to the other end of the AC power supply 700 via the second AC input terminal 62.

[0032] Inverter circuits 310, 410, and 510 are each composed of three-phase inverter circuits. One end of each inverter circuit is connected to the positive node 64, and the other end is connected to the negative node 65.

[0033] The inverter circuit 310 converts the DC voltage output from the smoothing unit 220 into an AC voltage and supplies that AC voltage to the main motor 320.

[0034] The inverter circuit 410 converts the DC voltage output from the smoothing unit 220 into an AC voltage and supplies that AC voltage to the heat pump motor 420.

[0035] The inverter circuit 510 converts the DC voltage output from the smoothing unit 220 into an AC voltage and supplies that AC voltage to the fan motor 520.

[0036] The inverter circuit 310 includes switching elements 31, 32, 33, 34, 35, 36, and a current sensor 37. Switching elements 31 and 34 constitute a V-phase leg. The connection point of switching elements 31 and 32 is connected to the main motor 320 and constitutes a V-phase AC output terminal 72.

[0037] Switching element 32 and switching element 35 constitute a U-phase leg. The connection point of switching element 32 and switching element 35 is connected to the main motor 320 and constitutes a U-phase AC output terminal 71.

[0038] Switching element 33 and switching element 36 constitute a W-phase leg. The connection point of switching element 33 and switching element 36 is connected to the main motor 320 and constitutes a W-phase AC output terminal 73.

[0039] The switching elements 31-36 are composed of, for example, IGBTs (Insulated Gate Bipolar Transistors). However, this is just one example, and the switching elements 31-36 may also be composed of MOSFETs (metal-oxide-semiconductor field-effect transistors). Reverse flow diodes are connected to the switching elements 31-36. Reverse direction means the opposite direction to the forward direction, where the forward direction is defined as the direction in which current flows from the collector to the emitter.

[0040] The current sensor 37 is connected between the U-phase AC output terminal 71 and the main motor 320 to detect the load current I1. The load current I1 is the output AC current supplied to the main motor 320 by the inverter circuit 310. The current sensor 37 may also be connected between the V-phase AC output terminal 72 or the W-phase AC output terminal 73 and the main motor 320.

[0041] The inverter circuit 410 includes switching elements 41, 42, 43, 44, 45, 46, and a current sensor 47. Switching elements 41 and 44 constitute a V-phase leg. The connection point of switching elements 41 and 42 is connected to a heat pump motor 420 and constitutes a V-phase AC output terminal 82.

[0042] Switching element 42 and switching element 45 constitute a U-phase leg. The connection point of switching element 42 and switching element 45 is connected to the heat pump motor 420 and constitutes a U-phase AC output terminal 81.

[0043] Switching element 43 and switching element 46 constitute a W-phase leg. The connection point of switching element 33 and switching element 36 is connected to the heat pump motor 420 and constitutes a W-phase AC output terminal 83.

[0044] The configuration of switching elements 41-46 is the same as that of switching elements 31-36.

[0045] The current sensor 47 is connected between the U-phase AC output terminal 81 and the heat pump motor 420 to detect the load current I2. The load current I2 is the output AC current supplied to the heat pump motor 420 by the inverter circuit 410. The current sensor 47 may also be connected between the V-phase AC output terminal 82 or the W-phase AC output terminal 83 and the heat pump motor 420.

[0046] The inverter circuit 510 includes switching elements 51, 52, 53, 54, 55, 56, and a current sensor 57. Switching elements 51 and 54 constitute a V-phase leg. The connection point of switching elements 51 and 52 is connected to a fan motor 520 and constitutes a V-phase AC output terminal 92.

[0047] Switching element 52 and switching element 55 constitute a U-phase leg. The connection point of switching element 52 and switching element 55 is connected to the fan motor 520 and constitutes a U-phase AC output terminal 91.

[0048] Switching element 53 and switching element 56 constitute a W-phase leg. The connection point of switching element 53 and switching element 56 is connected to the fan motor 520 and constitutes a W-phase AC output terminal 93.

[0049] The configuration of switching elements 51-56 is the same as that of switching elements 31-36.

[0050] The current sensor 57 is connected between the U-phase AC output terminal 91 and the fan motor 520 to detect the load current I3. The load current I3 is the output AC current supplied to the fan motor 520 by the inverter circuit 510. The current sensor 57 may also be connected between the V-phase AC output terminal 92 or the W-phase AC output terminal 93 and the fan motor 520.

[0051] The main motor 320 is a three-phase motor that rotates the rotating drum 115.

[0052] The heat pump motor 420 is a three-phase motor that drives the compressor that constitutes the heating unit 153.

[0053] The fan motor 520 is a three-phase motor that drives the fan 152.

[0054] The control circuit 600, for example, consists of a microcontroller and controls the washing machine 100. The control circuit 600 controls the power supply to the main motor 320, the heat pump motor 420, and 520.

[0055] The inverter circuit 310 and main motor 320, the inverter circuit 410 and heat pump motor 420, and the inverter circuit 510 and fan motor 520 are examples of multiple loads.

[0056] In the example shown in Figure 2, there are three loads, but this is just an example, and the number of loads may be two or four or more. The rectifier circuit 210 is composed of a voltage doubler rectifier circuit, but it may also be composed of a half-wave rectifier circuit or a full-wave rectifier circuit. In that case, the smoothing section 220 is composed of smoothing capacitors 21 and 22, but it may also be composed of a single capacitor. Current sensors 37, 47, and 57 are examples of current detection sections.

[0057] Figure 3 is a detailed configuration diagram of the control circuit 600 in this embodiment. The control circuit 600 includes a speed command generation unit 610, an interlocking control unit 620, a first drive unit 630, a second drive unit 640, and a third drive unit 650.

[0058] The speed command generation unit 610 generates speed command values ​​V11, V12, and V13 for the main motor 320, heat pump motor 420, and fan motor 520, respectively. Speed ​​command values ​​V11, V12, and V13 are target values ​​for the rotational speeds of the main motor 320, heat pump motor 420, and fan motor 520, respectively. The speed command generation unit 610 should generate speed command values ​​V11, V12, and V13 according to a predetermined control pattern for the target rotational speeds of the main motor 320, heat pump motor 420, and fan motor 520, depending on the operating mode of the washing machine 100.

[0059] The interlocking control unit 620 includes a determination unit 621 and a limiting unit 622. The determination unit 621 determines whether the sum of the load currents I1, I2, and I3 exceeds a threshold value. The threshold value is a predetermined value that represents the value of the harmonic components of each order contained in the power supply current from the AC power supply 700, which may exceed the limit value defined by the standard.

[0060] The limiting unit 622, when it determines that the sum exceeds a threshold, limits the power supplied to the second motor (an example of a second load), which is a specific motor among the main motor 320, heat pump motor 420, and fan motor 520, excluding the first motor (an example of a first load). The number of first motors is, for example, one or more. The number of second motors is, for example, one or more. Note that the number of first and second motors may be just one.

[0061] The limiting unit 622 limits the power supplied to the second load by, for example, making the slope of the speed command value for the second motor gentler than the original speed command value, or by lowering the speed command value compared to the original speed command value.

[0062] Speed ​​command value V11 is the original speed command value for the main motor 320, and speed command value V21 is the limited speed command value for the main motor 320. Speed ​​command value V12 is the original speed command value for the heat pump motor 420, and speed command value V22 is the limited speed command value for the heat pump motor 420. Speed ​​command value V13 is the original speed command value for the fan motor 520, and speed command value V22 is the limited speed command value for the fan motor 520.

[0063] Furthermore, if the speed command value V11, speed command value V12, or speed command value V13 corresponds to the first motor, the limiting unit 622 outputs the speed command value V11, speed command value V12, or speed command value V13 as is, as speed command value V21, speed command value V22, or speed command value V23. In other words, the limiting unit 622 outputs the speed command value corresponding to the first motor as is to the first drive unit 630, the second drive unit 640, or the third drive unit 650.

[0064] The limiting unit 622 may, for example, determine as the first motor a predetermined priority motor from among the main motor 320, the heat pump motor 420, and the fan motor 520, according to the operating mode of the power supply unit 200.

[0065] Alternatively, the limiting unit 622 may determine the motor with the largest load current among the main motor 320, heat pump motor 420, and fan motor 520 as the first motor.

[0066] Alternatively, the limiting unit 622 may determine the motor with the largest load current among the main motor 320, heat pump motor 420, and fan motor 520 as the first motor, and determine a predetermined load other than the first motor as the second load according to the operating mode of the washing machine 100.

[0067] The first drive unit 630 outputs a gate signal to the inverter circuit 310. The first drive unit 630 includes a current command generation unit 631, a voltage command generation unit 632, and a gate signal generation unit 633.

[0068] The current command generation unit 631 generates current command values ​​for the U, V, and W phases using PI (proportional-integral) control so that the speed error between the speed command value V21 and the current speed V1 of the main motor 320 is zero. The current speed V1 is generated by differentiating sensing data detected by an angle sensor (not shown) such as a rotary encoder on the main motor 320 using a differentiator (not shown). If an angle sensor is not used, the current speed V1 may be estimated from the motor current.

[0069] The voltage command generation unit 632 generates voltage command values ​​for the U, V, and W phases using PI control so that the current error between the load current I1 and the respective current command values ​​for the U, V, and W phases is zero.

[0070] The gate signal generation unit 633 generates gate signals for each of the switching elements 31 to 36 by comparing the voltage command values ​​of the U, V, and W phases with a triangular wave, and inputs the generated gate signals to each of the switching elements 31 to 36. The gate signals are PWM signals.

[0071] The second drive unit 640 outputs a gate signal to the inverter circuit 410. The second drive unit 640 includes a current command generation unit 641, a voltage command generation unit 642, and a gate signal generation unit 643.

[0072] The current command generation unit 641 generates current command values ​​for the U, V, and W phases using PI (proportional-integral) control so that the speed error between the speed command value V22 and the current speed V2 of the heat pump motor 420 is zero. The current speed V2 is estimated from the motor current and voltage command values ​​of the heat pump motor 420.

[0073] The voltage command generation unit 642 generates voltage command values ​​for the U, V, and W phases using PI control so that the current error between the load current I2 and the respective current command values ​​for the U, V, and W phases is zero.

[0074] The gate signal generation unit 643 generates gate signals for each of the switching elements 41 to 46 by comparing the voltage command values ​​of the U, V, and W phases with a triangular wave, and inputs the generated gate signals to each of the switching elements 41 to 46.

[0075] The third drive unit 650 outputs a gate signal to the inverter circuit 510. The third drive unit 650 includes a current command generation unit 651, a voltage command generation unit 652, and a gate signal generation unit 653.

[0076] The current command generation unit 651 generates current command values ​​for the U, V, and W phases using PI (proportional-integral) control so that the speed error between the speed command value V23 and the current speed V3 of the fan motor 520 becomes zero.

[0077] The voltage command generation unit 652 generates voltage command values ​​for the U, V, and W phases using PI control so that the current error between the load current I3 and the respective current command values ​​for the U, V, and W phases is zero. The current speed V3 is generated by differentiating sensing data detected by an angle sensor (not shown) such as a rotary encoder on the fan motor 520 using a differentiator (not shown). If an angle sensor is not used, the current speed V3 may be estimated from the motor current.

[0078] The gate signal generation unit 653 generates gate signals for each of the switching elements 51 to 56 by comparing the voltage command values ​​of the U, V, and W phases with a triangular wave, and inputs the generated gate signals to each of the switching elements 51 to 56.

[0079] [Operation] Figure 4 is a flowchart showing a first example of the processing of the interlocking control unit 620 in this embodiment.

[0080] (Step S11) Current sensors 37, 47, and 57 detect load currents I1, I2, and I3, respectively. The detected load currents I1, I2, and I3 are input to the control circuit 600.

[0081] (Step S12) The determination unit 621 calculates the sum of the load currents I1, I2, and I3 (hereinafter referred to as the total load current) and determines whether the calculated total load current is greater than the threshold value.

[0082] (Step S13) The limiting unit 622 determines whether the priority motor is the main motor 320. If the priority motor is the main motor 320 (YES in step S13), the process proceeds to step S14; if the priority motor is not the main motor 320 (NO in step S13), the process proceeds to step S15. Whether or not a motor is a priority motor is predetermined according to the operating mode.

[0083] (Step S14) The limiting unit 622 generates speed command values ​​V22 and V23 by limiting the speed command values ​​V12 and V13 of the heat pump motor 420 and the fan motor 520, and inputs the generated speed command values ​​V22 and V23 to the current command generation unit 641 and the current command generation unit 651, respectively. In this case, the limiting unit 622 inputs the speed command value V11 of the main motor 320 as speed command value V21 to the current command generation unit 631.

[0084] For example, if the total load current exceeds a threshold, the limiting unit 622 may generate a speed command value V22 that is a predetermined speed lower than the speed specified by the speed command value V12. In this case, the limiting unit 622 may generate the speed command value V23 in the same way as the speed command value V22.

[0085] Alternatively, the limiting unit 622 may generate the speed command value V22 by setting the slope at which the speed command value V22 increases to be smaller than the slope at which the speed command value V12 increases when the total load current exceeds a threshold. In this case, the limiting unit 622 can generate the speed command value V23 in the same way as the speed command value V22. This lowers the acceleration rate of the speed command value V22 compared to the acceleration rate of the speed command value V12.

[0086] (Step S15) The limiting unit 622 determines whether the priority motor is the heat pump motor 420. If the priority motor is the heat pump motor 420 (YES in step S15), the process proceeds to step S16; if the priority motor is not the heat pump motor 420 (NO in step S15), the process proceeds to step S17.

[0087] (Step S16) The limiting unit 622 generates speed command values ​​V21 and V23 by limiting the speed command values ​​V11 and V13 of the main motor 320 and the fan motor 520, and inputs the generated speed command values ​​V21 and V23 to the current command generation unit 631 and the current command generation unit 651, respectively. In this case, the limiting unit 622 inputs the speed command value V12 of the heat pump motor 420 as speed command value V22 directly to the current command generation unit 641.

[0088] For example, if the total load current exceeds a threshold, the limiting unit 622 may generate a speed command value V21 that is a predetermined speed lower than the speed specified by the speed command value V11. In this case, the limiting unit 622 may generate the speed command value V23 in the same way as the speed command value V21.

[0089] Alternatively, the limiting unit 622 may generate the speed command value V21 by setting the slope at which the speed command value V21 increases to be smaller than the slope at which the speed command value V11 increases when the total load current exceeds a threshold. In this case, the limiting unit 622 can generate the speed command value V23 in the same way as the speed command value V21. This lowers the acceleration rate of the speed command value V21 compared to the acceleration rate of the speed command value V11.

[0090] (Step S17) The limiting unit 622 generates speed command values ​​V21 and V22 by limiting the speed command values ​​V11 and V12 of the main motor 320 and the heat pump motor 420, and inputs the generated speed command values ​​V21 and V22 to the current command generation unit 631 and the current command generation unit 641, respectively. In this case, the limiting unit 622 inputs the speed command value V13 of the fan motor 520 as speed command value V23 to the current command generation unit 651.

[0091] For example, if the total load current exceeds a threshold, the limiting unit 622 may generate a speed command value V21 that is a predetermined speed lower than the speed specified by the speed command value V11. In this case, the limiting unit 622 may generate the speed command value V22 in the same way as the speed command value V21.

[0092] Alternatively, the limiting unit 622 may generate the speed command value V21 by setting the slope at which the speed command value V21 increases to be smaller than the slope at which the speed command value V11 increases when the total load current exceeds a threshold. In this case, the limiting unit 622 may generate the speed command value V22 in the same way as the speed command value V21.

[0093] Once steps S14, S16, and S17 are completed, the process returns to step S11.

[0094] Figure 5 is a flowchart showing a second example of the processing of the interlocking control unit 620 in this embodiment. In the flowchart of the second example, the motor with the largest load current is determined as the first motor, rather than the priority motor.

[0095] The processing in steps S21 and S22 is the same as in steps S11 and S12. Also, the processing in steps S24, S26, and S27 is the same as in steps S14, S16, and S17.

[0096] (Step S23) The limiting unit 622 determines whether the motor with the largest load current (maximum motor) is the main motor 320. If the maximum motor is the main motor 320 (YES in step S23), the process proceeds to step S24. If the maximum motor is not the main motor 320 (NO in step S23), the process proceeds to step S25.

[0097] (Step S25) The limiting unit 622 determines whether the maximum motor is the heat pump motor 420. If the maximum motor is the heat pump motor 420 (YES in step S25), the process proceeds to step S26. If the maximum motor is not the heat pump motor 420 (NO in step S25), the process proceeds to step S27.

[0098] Once steps S24, S26, and S27 are completed, the process returns to step S21.

[0099] Figure 6 is a flowchart showing a third example of the processing of the interlocking control unit 620 in this embodiment. The flowchart of the third example has a configuration that combines the flowcharts of the first and second examples.

[0100] Steps S41 and S42 are the same as steps S11 and S12.

[0101] (Step S43) The limiting unit 622 determines whether the maximum motor is the main motor 320. If the maximum motor is the main motor 320 (YES in step S43), the process proceeds to step S45. If the maximum motor is not the main motor 320 (NO in step S43), the process proceeds to step S44.

[0102] (Step S44) The limiting unit 622 determines whether the maximum motor is the heat pump motor 420. If the maximum motor is the heat pump motor 420 (YES in step S44), the process proceeds to step S48. If the maximum motor is not the heat pump motor 420, i.e., if the maximum motor is the fan motor 520 (NO in step S44), the process proceeds to step S51.

[0103] (Step S45) The limiting unit 622 determines which of the heat pump motor 420 and the fan motor 520 has a higher priority, that is, which is the priority motor. If the priority motor is the heat pump motor 420 (heat pump motor in step S45), the process proceeds to step S46. If the priority motor is the fan motor 520 (fan motor in step S45), the process proceeds to step S47.

[0104] (Step S46) The limiting unit 622 limits the speed command value V13 of the fan motor 520 and generates a speed command value V23. An example of the method for limiting the speed command value V13 is the same as the method in step S14 described above.

[0105] (Step S47) The limiting unit 622 limits the speed command value V12 of the heat pump motor 420 and generates a speed command value V22. An example of a method for limiting the speed command value V12 is the same as the method in step S14 described above.

[0106] (Step S48) The limiting unit 622 determines which of the fan motor 520 and the main motor 320 has a higher priority, that is, which is the priority motor. If the priority motor is the fan motor 520 (fan motor in step S48), the process proceeds to step S49. If the priority motor is the main motor 320 (main motor in step S48), the process proceeds to step S50.

[0107] (Step S49) The limiting unit 622 limits the speed command value V11 of the main motor 320 and generates a speed command value V21. One example of a method for limiting the speed command value V11 is the same as the method in step S16 described above.

[0108] (Step S50) The limiting unit 622 limits the speed command value V13 of the fan motor 520 and generates a speed command value V23. An example of the method for limiting the speed command value V13 is the same as the method in step S14 described above.

[0109] (Step S51) The limiting unit 622 determines which of the main motor 320 and the heat pump motor 420 has a higher priority, that is, which is the priority motor. If the priority motor is the main motor 320 (main motor in step S51), the process proceeds to step S52. If the priority motor is the heat pump motor 420 (heat pump motor in step S51), the process proceeds to step S53.

[0110] (Step S52) The limiting unit 622 limits the speed command value V12 of the heat pump motor 420 and generates a speed command value V22. An example of a method for limiting the speed command value V12 is the same as the method in step S14 described above.

[0111] (Step S53) The limiting unit 622 limits the speed command value V11 of the main motor 320 and generates a speed command value V21. One example of a method for limiting the speed command value V11 is the same as the method in step S16 described above.

[0112] Once steps S46, S47, S49, S50, S52, and S53 are completed, the process returns to step S41.

[0113] Figure 7 is a flowchart showing an example of the gate signal generation process in this embodiment. The gate signal generation process is the same in the first drive unit 630, the second drive unit 640, and the third drive unit 650, so the first drive unit 630 will be used as an example to explain the process below.

[0114] (Step S30) The current command generation unit 631 obtains the speed command value V21 from the interlock control unit 620. The current command generation units 641 and 651 obtain the speed command values ​​V22 and V23, respectively, from the interlock control unit 620.

[0115] (Step S31) The current command generation unit 631 calculates the speed error between the speed command value V21 obtained in step S30 and the current speed V1 of the main motor 320.

[0116] (Step S32) The current command generation unit 631 calculates the current command values ​​for the U, V, and W phases so that the speed error calculated in step S31 becomes zero.

[0117] (Step S33) The current command generation unit 631 outputs the current command values ​​for the U, V, and W phases to the voltage command generation unit 632.

[0118] (Step S34) The voltage command generation unit 632 calculates the current error between the load current I1 and the current command values ​​for the U, V, and W phases.

[0119] (Step S35) The voltage command generation unit 632 calculates the voltage command values ​​for the U, V, and W phases so that the current error calculated in step S34 becomes zero.

[0120] (Step S36) The voltage command generation unit 632 outputs the respective voltage command values ​​for the U, V, and W phases to the gate signal generation unit 633.

[0121] (Step S37) The gate signal generation unit 633 generates gate signals for each of the switching elements 31 to 36 by comparing the voltage command values ​​of the U, V, and W phases with a triangular wave, and inputs the generated gate signals to each of the switching elements 31 to 36.

[0122] Once step S37 is completed, the process returns to step S30. The above process is repeated until the main motor 320 is driven.

[0123] [Examples] The upper part of Figure 8 is a graph showing the temporal progression of power input from the AC power supply 700 when interlocking control is applied, and the lower part of Figure 8 is a graph showing the temporal progression of the harmonic components of the power supply current from the AC power supply 700 when interlocking control is applied.

[0124] Interlocking control refers to the control described in Figures 4, 5, and 6, which is a control that limits the power supplied to the second motor in order to limit harmonic components when the sum of the load currents I1, I2, and I3 exceeds a threshold.

[0125] Figure 8 shows the various waveforms when the washing mode, spin-drying mode, washing mode, spin-drying mode, and drying mode are executed in that order.

[0126] As shown in the upper part of Figure 8, when interlocking control is applied, the power supply power falls below the power reference value REF. As a result, as shown in the lower part of Figure 8, the 1st, 3rd, and 5th harmonic components decrease in conjunction with the decrease in power supply power. Consequently, it is possible to suppress the harmonic components from exceeding the limits specified in the standard.

[0127] Figure 12 is a graph showing the harmonic component suppression effect of the power supply device 200 in this embodiment. In Figure 12, the left figure shows the harmonic component graph when interlocking control is not applied, and the right figure shows the harmonic component graph when interlocking control is applied.

[0128] The solid line shows the experimental results obtained using a circuit simulator. In Figure 12, the vertical axis represents the harmonic component (A), and the horizontal axis represents the order.

[0129] As shown in the left diagram of Figure 12, when interlocking control is not applied, the 3rd, 5th, and 7th harmonic components are all high.

[0130] In contrast, when linked control is applied, as shown in the right-hand figure of Figure 12, harmonic components are significantly suppressed across all orders, and the suppression effect of harmonic components is particularly pronounced in the 3rd, 5th, and 7th orders.

[0131] [Effects, etc.] The power supply unit 200 limits the power supplied to the second motor (excluding the first motor), which is a specific motor, when the sum of the load currents I1, I2, and I3 flowing through the main motor 320, heat pump motor 420, and fan motor 520 exceeds a threshold. This allows the power supply unit 200 to suppress the total power supplied to the main motor 320, heat pump motor 420, and fan motor 520 in cases where the harmonic components in the power supply current flowing between the rectifier circuit 210 and the AC power supply 700 are likely to exceed the limits set by the standard. As a result, the power supply unit 200 can suppress the harmonic components in the power supply current without the need for a reactor. On the other hand, in cases where the harmonic components are not likely to exceed the limits, the main motor 320, heat pump motor 420, and fan motor 520 are supplied with the required power, thus ensuring stable operation in the operating mode.

[0132] Furthermore, the power supply unit 200 can reliably limit the power supplied to the second motor by making the slope of the speed command value to the second motor gentler or by lowering the speed command value.

[0133] Furthermore, the power supply unit 200 does not limit the power supplied to motors with higher priority according to the operating mode, thus ensuring stable operation of the operating mode while suppressing harmonic components.

[0134] Furthermore, since the power supply unit 200 determines the motor with the largest load current as the first motor, it can suppress harmonic components while ensuring stable operation of the operating mode.

[0135] The following variations of this disclosure may be adopted.

[0136] (Variation 1) In the above embodiment, the power supply unit 200 performed interlocking control when the sum of the load currents I1, I2, and I3 exceeded a threshold. In Modification 1, the power supply unit 200 drives the main motor 320, the heat pump motor 420, and the fan motor 520 in the dehydration mode according to a predetermined control pattern.

[0137] Specifically, in the dehydration mode, when the control circuit 600 increases the speed command value V21 of the main motor 320, it limits the speed command value V22 of the heat pump motor 420 and also limits the speed command value V23 of the fan motor 520.

[0138] Figure 9 is a graph showing a first example of a control pattern in the dehydration mode in Modification 1 of the present disclosure. In Figure 9, the upper section shows the temporal changes of the speed command values ​​V21, V22, and V23 of the main motor 320, the middle section shows the speed command values ​​V21, V22, and V23 of the heat pump motor 420, and the lower section shows the speed command values ​​of the fan motor 520. The control circuit 600 suppresses harmonic components by driving the main motor 320, the heat pump motor 420, and the fan motor 520 according to the control pattern shown in Figure 9.

[0139] In Figure 9, the vertical axis represents the speed command value, and the horizontal axis represents time. This is also the case in Figures 10 and 11, which will be discussed later.

[0140] In the dehydration mode, the main motor 320 is important, so the speed command value V21 of the main motor 320 is controlled without restriction, while the speed command values ​​V22 of the heat pump motor 420 and the fan motor 520 are restricted, respectively.

[0141] In Figure 9, speeds VH, VL, and VM may have different values ​​for the main motor 320, heat pump motor 420, and fan motor 520, respectively. The same applies to Figures 10 and 11, which will be discussed later.

[0142] Since the main motor 320 is not subject to restrictions, the speed command value V21 is the same as the original speed command value V11.

[0143] Time T1 marks the start of the dehydration mode. During the period from time T1 to T2, the speed command value V21 increases linearly from zero to speed VH (high speed). During the period from time T2 to T3, the speed command value V21 remains at speed VH. During the period from time T3 to T4, the speed command value V21 decreases linearly from speed VH to zero. From time T4 onward, the speed command value V21 increases linearly from zero to speed VL (low speed), which is lower than speed VH, and after maintaining speed VL for a certain period, the speed decreases linearly to zero, repeating this intermittent operation periodically.

[0144] In dehydration mode, the speed command value V22 of the heat pump motor 420 is limited. Specifically, during the period from time T1 to T2, the speed command value V22 increases from zero to speed VH, and in conjunction with this increase, the speed command value V22 is limited to speed VL2 (second low speed), which is lower than speed VL1 (first low speed). That is, during the period from time T1 to T3, the speed command value V22 would normally maintain speed VL1, but during the period from time T1 to T2, it is limited (reduced) to speed VL2. As a result, during the period from time T1 to T2, when the power consumption of the main motor 320 is high, the speed command value V21 of the heat pump motor 420 is limited, thereby suppressing the harmonic components of the power supply current supplied from the AC power supply 700.

[0145] During the period from time T2 to T3, the speed command value V22 maintains speed VL1. During the period from time T3 to T4, the speed command value V21 decreases from speed VH to zero, and in conjunction with this decrease, the speed command value V22 increases from speed VL1 to speed VH. From time T4 onward, the speed command value V21 operates intermittently with a peak speed of VL, and in conjunction with this intermittent operation, the speed command value V22 maintains speed VH.

[0146] In dehydration mode, the speed command value V23 of the fan motor 520 is limited. Specifically, from the start (time T1) to the end of the dehydration mode, the speed command value V23 is limited from speed VM (or speed VH) to speed VL. This more reliably suppresses the harmonic components of the power supply current supplied from the AC power supply 700.

[0147] Thus, in the dehydration mode, the main motor 320 is of high importance, while the heat pump motor 420 and fan motor 520 are not as important as the main motor 320. When the speed command value of the main motor 320 increases, the power supply unit 200 limits the speed command value of the heat pump motor 420 and also limits the speed command value of the fan motor 520. Therefore, even without providing a reactor in the rectifier circuit 210, the total power of the main motor 320, heat pump motor 420, and fan motor 520 is reduced, and harmonic components can be suppressed in the dehydration mode.

[0148] Figure 10 is a graph showing a second example of a control pattern in the dehydration mode in Modification 1 of the present disclosure. In Figure 10, the upper section shows the temporal changes of the speed command values ​​V21, V22, and V23 of the main motor 320, the middle section shows the speed command values ​​of the heat pump motor 420, and the lower section shows the speed command values ​​of the fan motor 520. The control circuit 600 suppresses harmonic components by driving the main motor 320, the heat pump motor 420, and the fan motor 520 according to the control pattern shown in Figure 10.

[0149] The second example of the control pattern differs from the first example in how the speed command value V22 of the heat pump motor 420 is limited. In the second example, at time T0, a predetermined time before time T1, the speed command value V22 is set to speed VL2. Then, the speed command value V22 is maintained at speed VL2 from period T0 to time T21, between time T2 and time T3. More specifically, the speed command value V22 maintains speed VL2 for a longer period from time T0 to time T21 than the acceleration period of the main motor 320 from time T1 to time T2. In other words, the timing of the first rise of the speed command value V22 is moved forward from time T1 to time T0, and consequently, the timing of the second rise of the speed command value V22 is moved backward from time T2 to time T21. This allows the heat pump motor 420 to be started prior to the start timing of the dewatering mode while suppressing power consumption. Furthermore, the rise time of the speed command value V23 has also been moved forward from time T1 to time T0.

[0150] (Modification 2) In modified example 2, the power supply unit 200 drives the main motor 320, the heat pump motor 420, and the fan motor 520 in drying mode according to a predetermined control pattern.

[0151] Specifically, in drying mode, when the power supply unit 200 increases the speed command value V22 of the heat pump motor 420, it limits the speed command value V23 of the fan motor 520 and also limits the speed command value V21 of the main motor 320.

[0152] Figure 11 is a graph showing an example of a control pattern in drying mode in Modification 2 of the present disclosure. In Figure 11, the upper section shows the temporal progression of the speed command values ​​V21, V22, and V23 of the main motor 320, the middle section shows the speed command values ​​V21, V22, and V23 of the heat pump motor 420, and the lower section shows the speed command values ​​of the fan motor 520. The control circuit 600 suppresses harmonic components by driving the main motor 320, the heat pump motor 420, and the fan motor 520 according to the control pattern shown in Figure 11.

[0153] In drying mode, the heat pump motor 420 is important, so its speed command value V22 is not restricted, while the main motor 320 and fan motor 520 are restricted by speed command values ​​V21 and V23, respectively.

[0154] Since the heat pump motor 420 is not subject to restrictions, the speed command value V22 is the same as the original speed command value V12.

[0155] Time T1 marks the start of the drying mode. During the period from time T1 to T2, the speed command value V22 increases linearly from speed VL (low speed) to speed VH (high speed). During the period from time T2 to T3, the speed command value V22 remains at speed VH. During the period from time T3 to T4, the speed command value V22 decreases linearly from speed VH to speed VM (medium speed), which is intermediate between speed VH and speed VL. From time T4 onward, the speed command value V22 remains at speed VM.

[0156] In drying mode, the speed command value V23 of the fan motor 520 is limited. Specifically, during the period from time T1 to T2, the speed command value V22 increases from speed VL to speed VH, and in conjunction with this increase, the speed command value V23 decreases from speed VH to speed VM. During the period from time T2 to T3, the speed command value V22 maintains speed VH, and in conjunction with this maintenance, the speed command value V23 maintains speed VM. During the period from time T3 to T4, the speed command value V22 of the heat pump motor 420 decreases from speed VH to speed VM, and in conjunction with this decrease, the speed command value V23 increases from speed VM to speed VH. From time T4 onward, the speed command value V22 of the heat pump motor 420 maintains speed VM, and in conjunction with this maintenance, the speed command value V23 maintains speed VH.

[0157] In drying mode, the speed command value V21 of the main motor 320 is limited. Specifically, the speed command value V21 periodically repeats an intermittent operation in which it rises from zero to speed VL, maintains speed VL for a certain period, and then decreases back to zero. Although the speed command value V21 operates intermittently, its peak is limited to speed VL. As a result, the power consumption of the main motor 320 is suppressed, and the high-frequency components of the power supply current supplied from the AC power supply 700 can be further suppressed.

[0158] In drying mode, the heat pump motor 420 is of high importance, while the fan motor 520 and main motor 320 are not as important. According to modified example 2, when the speed command value of the heat pump motor 420 is increased, the speed command values ​​of the fan motor 520 and main motor 320 are limited. Therefore, the power supply unit 200 can suppress the total power of the main motor 320, heat pump motor 420, and fan motor 520 and suppress harmonic components in drying mode, even without providing a reactor in the rectifier circuit 210.

[0159] (Variation 3) In the example shown in Figure 2, the main motor 320, heat pump motor 420, and fan motor 520 are all AC loads, but multiple DC loads may be connected instead of AC loads. In this case, the multiple DC loads are connected to the output side of the smoothing unit 220, that is, between the positive node 64 and the negative node 65. In this case, the inverter circuits 310, 410, and 510 are not connected to the smoothing unit 220.

[0160] (Modification 4) The electrical appliance is not limited to the washing machine 100, but can be any electrical appliance that has a power supply unit with multiple loads connected to a single rectifier circuit. Other examples of electrical appliances include dishwashers, air conditioners, and refrigerators.

[0161] (Technology 1) A control device in one aspect of the present disclosure is a power supply device for an electrical device, comprising: a rectifier circuit connected to an AC power source and rectifying a power supply voltage from the AC power source; a smoothing capacitor connected to the rectifier circuit and smoothing the rectified power supply voltage and supplying it to a plurality of loads; and a control circuit for controlling the power supply to the plurality of loads, wherein the control circuit comprises: a current detection unit for detecting the load current flowing through each of the plurality of loads; a determination unit for determining whether the sum of the load currents of each of the plurality of loads exceeds a threshold; and, if it is determined that the sum exceeds the threshold, a limiting unit for limiting the power supplied to a second load other than a first load, which is a specific load among the plurality of loads.

[0162] This configuration limits the power supplied to a second load (other than the first load) when the sum of the load currents flowing through each of the multiple loads exceeds a threshold. This allows the configuration to suppress the total power supplied to multiple loads in cases where the harmonic components in the power supply current flowing between the rectifier circuit and the AC power supply are likely to exceed the limits set by the standard. As a result, this configuration can suppress the harmonic components in the power supply current without the need for a reactor. On the other hand, in cases where the likelihood of the harmonic components exceeding the limits is low, the power required by the multiple loads is supplied, ensuring stable operation of the operating mode.

[0163] (Technology 2) In the power supply device described in Technical 1, the limiting unit may limit the power supplied to the second load by making the slope of the speed command value for the second load gentler, or by lowering the speed command value.

[0164] This configuration allows for reliable limiting of the power supplied to the second load by making the slope of the speed command value to the second load gentler or by lowering the speed command value.

[0165] (Technology 3) In the power supply device described in Technology 1 or 2, the limiting unit may determine a predetermined load as the first load according to the operating mode of the electrical equipment.

[0166] This configuration does not limit the power supplied to a predetermined load according to the operating mode, thus ensuring stable operation of the operating mode while suppressing harmonic components.

[0167] (Technology 4) In the power supply device described in Technology 1 or 2, the limiting unit may determine the load with the largest load current as the first load.

[0168] This configuration determines the load with the maximum load current as the first load, thereby ensuring stable operation in the operating mode while suppressing harmonic components.

[0169] (Technology 5) In the power supply device described in Technology 1 or 2, the limiting unit may determine the load with the maximum load current as the first load, and determine a load other than the first load, which is predetermined according to the operating mode of the electrical equipment, as the second load.

[0170] In this configuration, the load with the maximum load current is determined as the first load, and among the loads other than the first load, a predetermined load according to the operating mode is determined as the second load. Therefore, high-frequency components can be suppressed more reliably while ensuring stable operation of the operating mode.

[0171] (Technology 6) In the power supply device described in any of Technical 1 to 5, each of the plurality of loads includes an inverter circuit and a motor driven by the inverter circuit, and the power supply device may also include a plurality of inverter circuits connected to the smoothing capacitor.

[0172] This configuration is applicable to AC loads because each of the multiple loads consists of an inverter circuit and a motor driven by the inverter circuit.

[0173] (Technology 7) A power supply device in another aspect of the present disclosure is a power supply device for a washing machine, comprising: a rectifier circuit connected to an AC power source and rectifying a power supply voltage from the AC power source; a smoothing capacitor connected to the rectifier circuit and smoothing the rectified power supply voltage; a first inverter circuit connected between the smoothing capacitor and a main motor for driving a rotating drum; a second inverter circuit connected between the smoothing capacitor and a heat pump motor for driving a compressor for compressing a refrigerant; a third inverter circuit connected between the smoothing capacitor and a fan motor for driving a fan that returns air exhausted from the processing chamber of the washing machine back into the processing chamber; and a control circuit for controlling the first, second, and third inverter circuits, wherein, in the dewatering mode, when increasing the speed command value of the main motor, the control circuit limits the speed command value of the heat pump motor and limits the speed command value of the fan motor.

[0174] In the dehydration mode, the main motor is of high importance, while the heat pump motor and fan motor are less important. In this configuration, when the speed command value of the main motor increases, the speed command value of the heat pump motor is limited, and the speed command value of the fan motor is also limited. Therefore, this configuration suppresses the total power supplied to multiple loads. As a result, this configuration can suppress harmonic components while ensuring the quality of the dehydration mode, even without providing a reactor in the rectifier circuit.

[0175] (Technology 8) A power supply device in yet another aspect of the present disclosure is a power supply device for a washing machine, comprising: a rectifier circuit connected to an AC power source and rectifying a power supply voltage from the AC power source; a smoothing capacitor connected to the rectifier circuit and smoothing the rectified power supply voltage; a first inverter circuit connected between the rectifier circuit and a main motor for driving a rotating drum; a second inverter circuit connected between the rectifier circuit and a heat pump motor for driving a compressor for compressing a refrigerant; a third inverter circuit connected between the rectifier circuit and a fan motor for returning exhaust air from the processing chamber of the washing machine back into the processing chamber; and a control circuit for controlling the first, second, and third inverter circuits, wherein, in drying mode, when the speed command value of the heat pump motor is increased, the control circuit limits the speed command value of the fan motor and limits the speed command value of the main motor.

[0176] In drying mode, the heat pump motor is highly important, while the fan motor and main motor are less important. In this configuration, when the speed command value of the heat pump motor increases, the speed command values ​​of the fan motor and main motor are limited. Therefore, this configuration suppresses the total power supplied to multiple loads. As a result, this configuration can suppress harmonic components while ensuring the quality of the drying mode, even without providing a reactor in the rectifier circuit. [Industrial applicability]

[0177] This disclosure can suppress harmonic components without the need for a reactor, and is therefore applicable to electrical equipment connected to a grid power supply. [Explanation of Symbols]

[0178] 37: Current sensor 47: Current Sensor 57: Current Sensor 61: First AC input terminal 62: Second AC input terminal 63: Connection point 64: Positive side node 65: Negative side node 100: Washing machine 112: Processing Room 200: Power supply 210: Rectifier circuit 220: Smooth section 310: Inverter Circuit 320: Main motor 410: Inverter Circuit 420: Heat pump motor 510: Inverter Circuit 520: Fan motor 600: Control circuit 610: Speed ​​command generation section 620: Interlocking Control Unit 621: Judgment section 622: Restriction section 630: First drive unit 631:Current command generation section 632: Voltage command generation unit 633: Gate signal generation unit 640: Second drive unit 641:Current command generation section 642: Voltage command generation unit 643: Gate signal generation unit 650: Third drive unit 651:Current command generation section 652: Voltage command generation unit 653: Gate signal generation unit 700: AC power supply

Claims

1. A power supply unit for electrical equipment, A rectifier circuit connected to an AC power source and which rectifies the power supply voltage from the AC power source, A smoothing capacitor connected to the rectifier circuit, which smooths the rectified power supply voltage and supplies it to multiple loads, The system includes a control circuit that controls the supply of power to the plurality of loads, The aforementioned control circuit is A current detection unit that detects the load current flowing through each of the aforementioned multiple loads, A determination unit that determines whether the sum of the load currents of each of the plurality of loads exceeds a threshold, If it is determined that the sum exceeds the threshold, the system includes a limiting unit that limits the power supplied to a second load other than the first load, which is a specific load among the plurality of loads. power supply.

2. The limiting unit limits the power supplied to the second load by making the slope of the speed command value with respect to the second load gentler, or by lowering the speed command value. The power supply device according to claim 1.

3. The limiting unit determines a predetermined load as the first load according to the operating mode of the electrical equipment. The power supply device according to claim 1 or 2.

4. The limiting unit determines the load with the largest load current as the first load. The power supply device according to claim 1 or 2.

5. The limiting unit determines the load with the maximum load current as the first load, and determines a load other than the first load, which is predetermined according to the operating mode of the electrical equipment, as the second load. The power supply device according to claim 1.

6. Each of the aforementioned plurality of loads includes an inverter circuit and a motor driven by the inverter circuit. The power supply device includes a plurality of inverter circuits connected to the smoothing capacitor, The power supply device according to claim 1 or 2.

7. A power supply unit for a washing machine, A rectifier circuit connected to an AC power supply and which rectifies the power supply voltage from the AC power supply, A smoothing capacitor connected to the rectifier circuit, which smooths the rectified power supply voltage, A first inverter circuit is connected between the smoothing capacitor and the main motor that drives the rotating drum. A second inverter circuit is connected between the smoothing capacitor and the heat pump motor that drives the compressor for compressing the refrigerant. A third inverter circuit is connected between the smoothing capacitor and a fan motor that drives a fan that returns the air exhausted from the processing chamber of the washing machine back into the processing chamber. The system comprises a control circuit for controlling the first, second, and third inverter circuits, The aforementioned control circuit is In the dehydration mode, when increasing the speed command value of the main motor, the speed command value of the heat pump motor is limited, and the speed command value of the fan motor is also limited. power supply.

8. A power supply unit for a washing machine, A rectifier circuit connected to an AC power supply and which rectifies the power supply voltage from the AC power supply, A smoothing capacitor connected to the rectifier circuit, which smooths the rectified power supply voltage, A first inverter circuit is connected between the rectifier circuit and the main motor that drives the rotating drum. A second inverter circuit is connected between the rectifier circuit and a heat pump motor that drives a compressor for compressing the refrigerant. A third inverter circuit is connected between the rectifier circuit and a fan motor that returns the air exhausted from the processing chamber of the washing machine back into the processing chamber. The system comprises a control circuit for controlling the first, second, and third inverter circuits, The aforementioned control circuit is In drying mode, when increasing the speed command value of the heat pump motor, the speed command value of the fan motor is limited, and the speed command value of the main motor is also limited. power supply.

9. A washing machine comprising the power supply device according to claim 1, 7, or 8.

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