JP2017164018A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a washing machine capable of preventing failure of a circuit due to a rush current at automatic recovery from power failure, in the inverter driven washing machine.SOLUTION: A washing machine includes: an inverter circuit 4 for performing drive control on a motor 5 for driving a washing and dewatering tub 21 and a pulsator 26; a rectifying circuit 3 for generating an inverter power supply supplied to the inverter circuit 4 from a commercial power supply 1; means for detecting electricity conduction of the commercial power supply; and control means 10 having a rush current prevention circuit 9 to the rectifying circuit 3, for controlling an operation of the washing machine, and for, after cutting of electricity conduction is detected by the means for detecting electric conduction of the commercial power supply, validating the rush current prevention circuit 9 to the rectifying circuit 3 (turning off a relay 9b) before detecting power failure. The washing machine can prevent failure of a circuit due to a rush current at automatic recovery from power failure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a washing machine for washing laundry such as clothes by rotating a laundry dewatering tank or a pulsator.

  2. Description of the Related Art In recent years, with regard to commercial power sources that are expected to have various power environments, there is an increased possibility of a power failure during operation even in a washing machine that is used in a general household during a time period when the amount of power used is large. Some current washing machines store a process in which a power failure has occurred in a memory, and automatically resume from that process after the commercial power supply is restored (see, for example, Patent Document 1).

  5 and 6 are diagrams showing an outline of a conventional pulsator type washing machine. FIG. 5 is a cross-sectional view seen from the side of a conventional washing machine. FIG. 6 schematically shows an outline of a circuit of a conventional washing machine. The configuration will be described below.

  In FIG. 5, the main body 28 of the washing machine supports the receiving cylinder 22 in a suspension and vibration-proof manner by a suspension 27. The washing / dehydrating shaft 25 has a biaxial structure in which the washing shaft 25a is housed in the hollow portion of the dewatering shaft 25b so that they can rotate independently of each other. The washing / dehydrating tub 21 housed in the receiving cylinder 22 so as to be rotatable about the dehydrating shaft 25b has a number of dewatering holes 21a on the side wall, a fluid balancer 21b on the inner periphery, and a central bottom portion. A pulsator 26 formed in a pan-shaped shape having an inclined outer periphery is disposed so as to be rotatable about the washing shaft 25a.

  The transmission mechanism 24 includes therein a reduction gear (not shown) for washing and a switching clutch mechanism (not shown) for the washing shaft 25a and the dewatering shaft 25b. The switching clutch mechanism is opened and closed by clutch operating means 18 such as a traction motor. The washing / dehydrating motor 5 is attached to the bottom of the receiving cylinder 22 and transmits power to the washing shaft 25a and the dehydrating shaft 25b via the transmission mechanism 24. The rotation detecting means 6 for detecting the rotation of the washing / dehydrating motor 5 is installed in a stator 52 arranged so as to face the magnet 51 built in the rotor 50. Further, the water supply valve 16 and the water discharge valve 17 for supplying and discharging water to and from the washing and dewatering tank 21 are respectively attached to the upper part of the main body 28 and the lower part of the receiving cylinder 22.

  In FIG. 6, the control device 7 uses a three-phase alternating current of appropriate frequency and voltage from a commercial power source 1 to a motor 5 using an inverter circuit 4 from an inverter power source created by a rectifier circuit 3 (inverter power source circuit). Apply voltage. That is, the control means 10 mounted in the control device 7 is input from the current value calculated from the current detection means 14 (current sensors 14a to 14c) using the current detection circuit 15 and the inverter power supply voltage detection means 31. Based on the measured voltage value and the position of the rotor 50 detected from the rotation sensors 6a to 6c (magnetic detection elements) constituting the rotation detection means 6, the inverter drive circuit 11 is set to the rotor position detected above. The corresponding 6 sets of PWM output are performed. The inverter drive circuit 11 drives the inverter circuit 4 by controlling the switching elements 4 a to 4 f according to the PWM waveform input from the control means 10.

  As a result, when the PWM voltage generated from the inverter DC power supply is applied to the motor 5, a current flows through the three-phase windings 5 a to 5 c of the motor 5, and the motor 5 rotates. The water supply valve 16, the drain valve 17, and the clutch operating means 18 are synchronized with the input of a zero cross signal (hereinafter referred to as ZVS) that is the output of the power supply voltage zero cross detecting circuit 30, and the switching means driving circuit 12 and the switching means 8. Driven by. ZVS is a rectangular wave pulse signal, and its rising / falling edge corresponds to the power supply voltage zero cross.

  The commercial power supply 1 and the rectifier circuit 3 are always connected via an inrush current prevention circuit 9 so that the washing machine can recover from a power failure. The rectifier circuit 3, which is an inverter power supply circuit, is composed of a voltage doubler rectifier circuit so that the voltage becomes stable even when the washing / dehydrating motor 5 is driven, and uses smoothing capacitors 3b and 3c having large capacities. . Therefore, when the power plug is inserted into the commercial power source 1, a large current may flow through the rectifier circuit 3 to charge the smoothing capacitors 3b and 3c. This is the inrush current. An excessive inrush current may promote deterioration of the rectifying element 3a and the smoothing capacitors 3b and 3c themselves.

  The inrush current prevention circuit 9 can select whether the relay drive circuit 13 is connected to the commercial power source 1 through the current limiting resistor 9a or directly connected to the commercial power source 1 by short-circuiting the current limiting resistor 9a by the relay 9b. It has become.

  FIG. 7 is a state transition diagram showing the behavior of the washing machine when the user normally connects the power plug to the commercial power source. When the power plug is not connected to the commercial power source 1, the relay 9 b is open, and when the power plug is inserted into the commercial power source 1, the process shifts to the ZVS synchronization process 1 that is in an operation standby state. Here, when the user operates and the washing machine starts the washing operation, the process proceeds to the ZVS synchronization process 2 which is the washing operation state, and the relay 9b is closed. In this way, when the washing / dehydrating motor 5 operates, the current can be supplied to the circuit without being affected by the current limiting resistor 9a, and a large current at the moment when the power plug is connected is suppressed by the current limiting resistor 9a. Will be. Moreover, in order to prevent the harmonic current in charging / discharging of the large-capacity smoothing capacitors 3b and 3c from affecting the commercial power source 1, the reactor 2 may be installed.

  The operation at this time will be described in detail as follows. FIG. 9 is a flowchart showing a control operation of the washing machine at the time of power failure or power-on, and FIG. 8 is a state transition diagram at that time.

  As described above, when the power plug of the washing machine is connected to the commercial power source 1, the control means 10 performs initial setting of the control means 10 and initial setting of the control device 7 such as turning on the relay 9b (step S1). , ZVS synchronization processing (in the flowchart of FIG. 9, the above-described ZVS synchronization processing 1 and 2 are collectively referred to as step S2). In the ZVS synchronization process 2, the control device 7 drives a load such as the water supply valve 16 in synchronization with ZVS. When the ZVS synchronization processing ends, the control device 7 shifts to an edge waiting state for the next ZVS (steps S3 to S4). Steps S3 to S4 are steps in which means for detecting energization of the commercial power supply is operating.

  Here, when the commercial power supply is interrupted and the edge of the ZVS pulse is interrupted for several pulses, the means for detecting energization of the commercial power supply detects the energization interruption and starts the brake process to the washing / dehydrating motor 5 (step S5) Each load is turned off (step S6). Thereafter, the state shifts to an edge waiting state of the next ZVS (instantaneous voltage drop waiting state. Steps S7 and S9). At this time, if the ZVS is restored, a restoration process (step S8) for restarting the stopped load including the motor 5 is performed, and the process returns to the ZVS synchronization process 2. However, if the interruption of ZVS continues for a certain period of time, the controller 7 may run out of charge on the smoothing capacitors 3b and 3c, and the control unit 10 may stop moving. Enter processing.

  Specifically, the control means 10 writes information indicating where the immediately preceding process is in the storage means 32 such as a nonvolatile memory (step S10), and performs a stop process of the control means 10 itself and the control device 7 (step S10). S11), the relay 9b is turned off (step S12). Then, after confirming that the brake process has ended (step S13), the process ends. At this time, the lid locking means 19 maintains the locked state for safety.

  Thereafter, when the commercial power supply is restored, the control means 10 performs its own initial setting (step S15), reads information on the process at the time of power failure from the storage means 32 (step S16), and has information on the process where the power failure occurred. (Step S17), the setting is made to resume the washing operation from the process (step S18), and the control device 7 is initialized such as turning on the relay 9b (step S1). If there is no information on the process in which the power failure has occurred, it is determined that the power is turned on normally, and after the initial setting (step S1), the process shifts to an initial standby state waiting for operation (steps S2 to S4).

JP-A-2-121695

  However, in such a conventional washing machine, in a washing machine that automatically returns in the event of a power failure, there may be some problems when restarting from a power failure.

  This is because the inverter-driven washing machine has a relatively large capacity of the smoothing capacitors 3b and 3c, so that the inrush current is large as described above. However, the conventional washing machine is judged to be out of power due to a long power interruption. Therefore, until then, if the electric charges of the smoothing capacitors 3b and 3c become below a certain level, an excessive inrush current may flow when the power is restored, which may promote deterioration of the circuit components. This is a case where the power supply is restored at the time of the sag low waiting process when the relay 9b is not yet turned off, or the case where the relay 9b is turned on immediately after reading the information stored in the storage means 32 when returning from a power failure. .

  Even if there is little deterioration due to current, if the reactor 2 is large, the power line in the subsequent stage of the reactor 2 is boosted due to the inrush current, and the power supply is detected by detecting the breakdown of circuit components due to voltage or abnormal voltage. There was a possibility that the automatic recovery from the power failure could not be achieved.

  In order to solve the above-described conventional problems, a washing machine of the present invention includes an inverter circuit that drives and controls a motor that drives a laundry dewatering tub and a pulsator, and an inverter power source that generates an inverter power source that is supplied from a commercial power source to the inverter circuit A circuit, means for detecting energization of a commercial power supply, and an inrush current prevention circuit for the inverter power supply circuit, controlling operation of the washing machine, and means for detecting energization of the commercial power supply detects an interruption of energization Then, before detecting a power failure, a control means for enabling the inrush current prevention circuit to the inverter power supply circuit is provided.

  As a result, it is possible to prevent a circuit failure due to an inrush current at the time of automatic recovery from a power failure.

  The washing machine of the present invention can prevent a circuit failure due to an inrush current at the time of automatic recovery from a power failure.

The flowchart which shows the operation | movement at the time of the power failure of the washing machine in Embodiment 1 of this invention, and a power failure reset. The flowchart which shows the operation | movement at the time of the power failure of the washing machine in Embodiment 2 of this invention, and a power failure reset. The flowchart which shows the operation | movement at the time of the power failure of the washing machine in Embodiment 3 of this invention, and a power failure reset. The flowchart which shows the operation | movement at the time of the power failure of the washing machine in Embodiment 4 of this invention, and a power failure reset. Sectional view seen from the side of a conventional washing machine Circuit block diagram of a conventional washing machine State transition diagram showing the behavior of a washing machine when a user normally connects a power plug to a commercial power supply in a conventional washing machine State transition diagram showing the behavior of a conventional washing machine at the time of power failure and recovery from power failure The flowchart which shows the operation | movement at the time of the power failure of a conventional washing machine, and power failure recovery

  According to a first aspect of the present invention, there is provided an inverter circuit for driving and controlling a motor for driving a washing / dehydrating tub and a pulsator, an inverter power supply circuit for generating an inverter power supply supplied from the commercial power supply to the inverter circuit, and means for detecting energization of the commercial power supply And an inrush current prevention circuit to the inverter power supply circuit, the operation of the washing machine is controlled, and the means for detecting the energization of the commercial power source detects the energization interruption before the power failure is detected, By providing the control means for enabling the inrush current prevention circuit to the inverter power supply circuit, it is possible to prevent a circuit failure due to the inrush current at the time of automatic recovery from a power failure.

  According to a second aspect of the invention, there is provided an inverter circuit for driving and controlling a motor for driving a washing / dehydrating tub and a pulsator, an inverter power supply circuit for generating an inverter power supply to be supplied to the inverter circuit from a commercial power supply, and means for detecting energization of the commercial power supply And an inrush current preventing circuit for the inverter power supply circuit and a means for detecting the voltage of the inverter power supply, and the means for controlling the operation of the washing machine and detecting the energization of the commercial power supply detects the energization interruption. After that, when the voltage of the inverter power supply becomes a predetermined value or less, it is provided with a control means for enabling an inrush current prevention circuit to the inverter power supply circuit. Can be prevented.

  According to a third invention, in the first or second invention, the control means delays a predetermined time when the means for detecting energization of the commercial power supply detects energization start after recovery from a power failure. By invalidating the inrush current prevention circuit to the inverter power supply circuit after the lapse of time and starting the washing operation, it is possible to more reliably prevent a circuit failure due to the inrush current at the time of automatic recovery from a power failure, The operation of the washing machine after resumption can be performed stably and reliably.

  According to a fourth aspect of the present invention, in the first or second aspect of the invention, the control means detects the voltage of the inverter power supply when the means for detecting energization of the commercial power supply detects the start of energization after recovery from a power failure. When the value exceeds a predetermined value, the inrush current prevention circuit to the inverter power supply circuit is disabled and the washing operation is started, so that the circuit failure due to the inrush current can be more reliably prevented at the time of automatic recovery from a power failure. In addition, the operation of the washing machine after resumption can be performed more stably and reliably.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same structure as a prior art example attaches | subjects the same code | symbol, and abbreviate | omits description. Further, the present invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a flowchart showing a control operation of the washing machine at the time of power failure or power-on in Embodiment 1 of the present invention. Regarding the structure and circuit configuration of the washing machine, refer to FIGS. 5 and 6 which are the same as the conventional one, and FIG. 8 for the state transition diagram.

  About the washing machine comprised as mentioned above, the operation | movement and effect | action at the time of a power failure and a power failure recovery are demonstrated with the flowchart of FIG.

  As described above, when the power plug of the washing machine is connected to the commercial power source 1, the control means 10 performs initial setting of the control means 10 and initial setting of the control device 7 such as turning on the relay 9b (step S1). , ZVS synchronization processing (in the flowchart of FIG. 1, the above-described ZVS synchronization processing 1 and 2 are collectively referred to as step S2). In the ZVS synchronization process 2, the control device 7 drives a load such as the water supply valve 16 in synchronization with ZVS. When the ZVS synchronization processing ends, the control device 7 shifts to an edge waiting state for the next ZVS (steps S3 to S4). Steps S3 to S4 are steps in which means for detecting energization of the commercial power supply is operating.

  Here, when the commercial power supply is interrupted and the edge of the ZVS pulse is interrupted for several pulses, the means for detecting energization of the commercial power supply detects the energization interruption and starts the brake process to the washing / dehydrating motor 5 (step S5) Each load is turned off (step S6). Thereafter, the state shifts to an edge waiting state of the next ZVS (instantaneous voltage drop waiting state. Steps S7 and S9). At this time, if the ZVS is restored, a restoration process (step S8) for restarting the stopped load including the motor 5 is performed, and the process returns to the ZVS synchronization process 2. However, if the interruption of ZVS continues for a certain period of time, the controller 7 may run out of charge on the smoothing capacitors 3b and 3c, and the control unit 10 may stop moving. Enter processing.

  Specifically, the control means 10 writes information indicating where the immediately preceding process is in the storage means 32 such as a nonvolatile memory (step S10), and performs a stop process of the control means 10 itself and the control device 7 (step S10). S11), the relay 9b is turned off (step S12). Then, after confirming that the brake process has ended (step S13), the process ends. At this time, the lid locking means 19 maintains the locked state for safety.

  At this time, in the washing machine according to the first embodiment of the present invention, when waiting for an instantaneous voltage drop (instantaneous voltage drop) recovery, in step S12, the relay 9b is turned off before the power failure is detected. This step S12 is desirably executed after each load OFF in step S6.

  Thereafter, when the commercial power supply is restored, the control means 10 performs its own initial setting (step S15), reads information on the process at the time of power failure from the storage means 32 (step S16), and has information on the process where the power failure occurred. (Step S17), the setting is made to resume the washing operation from the process (step S18), and the control device 7 is initialized such as turning on the relay 9b (step S1). If there is no information on the process in which the power failure has occurred, it is determined that the power is turned on normally, and after the initial setting (step S1), the process shifts to an initial standby state waiting for operation (steps S2 to S4).

  As described above, the washing machine according to Embodiment 1 of the present invention has the inrush current prevention circuit for the inverter power supply circuit before the power failure is detected after the means for detecting the energization of the commercial power supply detects the power interruption. By enabling it, it is possible to prevent a circuit failure due to an inrush current at the time of automatic recovery from a power failure.

  Note that the power failure detection means and the power failure recovery detection means described above may not be one, and may not be a zero cross detection circuit. For example, it may be detected by power supply voltage detection means.

  The relay 9b may be turned off (step S12) before and after the normal ZVS wait and before the stop process.

  Depending on the configuration, the motor may not be braked.

  Note that the load of the motor or the like does not have to be the same as in the present embodiment, and may be inverter control or control by phototriac.

  The memory, the power failure detection means, and the power failure recovery detection means may be built in the microcomputer.

(Embodiment 2)
The washing machine according to the second embodiment of the present invention has means for detecting the voltage of the inverter power supply, and after the means for detecting energization of the commercial power supply detects the energization interruption, the voltage of the inverter power supply falls below a predetermined value. In this case, the washing machine is provided with a control unit that enables an inrush current prevention circuit to the inverter power supply circuit, and this can prevent a circuit failure due to the inrush current at the time of automatic recovery from a power failure.

  FIG. 2 is a flowchart showing the control operation of the washing machine at the time of power failure of the washing machine or when the power is turned on in the second embodiment of the present invention. Regarding the structure and circuit configuration of the washing machine, refer to FIGS. 5 and 6 which are the same as the conventional one, and FIG. 8 for the state transition diagram.

  About the washing machine comprised as mentioned above, the operation | movement and effect | action at the time of a power failure and a power failure recovery are demonstrated with the flowchart of FIG.

  In the washing machine according to Embodiment 2 of the present invention, step S14 is added between step S7 and step S9 described in FIG. Is done. In step S14, the amount of charge in the smoothing capacitors 3b and 3c is monitored by the voltage by the inverter power supply voltage detecting means 31, and if the detected voltage becomes equal to or lower than a predetermined value, the process is similar to the conventional power failure determination process over time. In step S12, the relay 9b is turned off.

  The control operation of the washing machine in the other steps is the same as the flow described in FIG.

  This makes it possible to enable the inrush current prevention circuit to the inverter power supply circuit directly and earlier before detecting a power failure, so that the circuit failure caused by the inrush current more reliably at the time of automatic recovery from a power failure. Can be prevented.

  Although the relay 9b is turned off (step S12) during the sequence in the present embodiment, it may be performed asynchronously after waiting for ZVS or waiting for a momentary return.

  Even if the voltage drop is detected and the relay 9b is turned OFF, the stop process does not have to be performed immediately, and the stop process may be performed after a normal power failure detection time of a predetermined time.

(Embodiment 3)
In the washing machine according to the third embodiment of the present invention, the control means, after returning from a power failure, when the means for detecting energization of the commercial power source detects the start of energization, after the delay of a predetermined time has elapsed, This is a washing machine that disables the inrush current prevention circuit to the inverter power supply circuit and starts the washing operation. This can prevent circuit failure due to inrush current at the time of automatic recovery from a power failure, and after restarting The washing machine can be operated stably and reliably.

  FIG. 3 is a flowchart showing a control operation of the washing machine at the time of power failure of the washing machine or turning on the power in Embodiment 3 of the present invention. Regarding the structure and circuit configuration of the washing machine, refer to FIGS. 5 and 6 which are the same as the conventional one, and FIG. 8 for the state transition diagram.

  About the washing machine comprised as mentioned above, the operation | movement and effect | action at the time of a power failure and a power failure recovery are demonstrated with the flowchart of FIG.

  In the washing machine according to Embodiment 3 of the present invention, step S19 is added after the power failure is restored. The control operation of the washing machine in the previous steps is the same as the flow of the washing machine in the first embodiment of the present invention described in FIG.

  In step S19, a delay of a predetermined time, which is estimated that charge is sufficiently accumulated in the smoothing capacitors 3b and 3c, is inserted as a power supply stabilization wait time. Thereafter, the process proceeds to the ZVS synchronization process (step S2, more precisely, the ZVS synchronization process 2 in FIG. 8), and the relay 9b is turned on.

  Thereby, at the time of automatic recovery from a power failure, the failure of the circuit due to the inrush current can be more reliably prevented, and the operation of the washing machine after resumption can be performed stably and reliably.

  The delay may be inserted anywhere as long as the relay 9b is turned on in the ZVS synchronization process 2 state after the power failure is restored.

(Embodiment 4)
In the washing machine according to Embodiment 4 of the present invention, when the control unit detects the start of energization after the return from the power failure, the voltage of the inverter power source becomes equal to or higher than a predetermined value. Then, the inrush current prevention circuit to the inverter power supply circuit is invalidated, and the washing machine starts the washing operation. This makes it possible to prevent a circuit failure due to the inrush current at the time of automatic recovery from a power failure. The operation of the washing machine after resumption can be performed stably and reliably.

  FIG. 4 is a flowchart showing a control operation of the washing machine at the time of a power failure of the washing machine or turning on the power in Embodiment 4 of the present invention. Regarding the structure and circuit configuration of the washing machine, refer to FIGS. 5 and 6 which are the same as the conventional one, and FIG. 8 for the state transition diagram.

  About the washing machine comprised as mentioned above, the operation | movement and effect | action at the time of a power failure and a power failure recovery are demonstrated with the flowchart of FIG.

  In the washing machine according to the fourth embodiment of the present invention, step S20 is added after the power failure is restored. The control operation of the washing machine in the previous steps is the same as the flow of the washing machine in the first embodiment of the present invention described in FIG.

Step S20 is waiting for the smoothing capacitors 3b and 3c to be charged. The power supply voltage detecting means 31 for the inverter monitors the charge amount of the smoothing capacitors 3b and 3c with the voltage, and confirms that the detected voltage has become a predetermined value or more. After that, the process proceeds to the ZVS synchronization process (step S2, more precisely, the ZVS synchronization process 2 in FIG. 8), and the relay 9b is turned on.

  Thereby, at the time of automatic recovery from a power failure, the failure of the circuit due to the inrush current can be prevented more reliably, and the operation of the washing machine after resumption can be performed more stably and reliably.

  Note that the position where the smoothing capacitors 3b and 3c are waiting to be charged in step S20 may be anywhere after the recovery from the power failure until the relay 9b is turned on in the ZVS synchronization processing 2 state.

  As described above, the washing machine according to the present invention can prevent a circuit failure due to an inrush current at the time of an automatic return from a power failure in an inverter-driven washing machine, and thus operates according to the tightness of the power supply and demand situation. It is useful as a washing machine for homes where the possibility of power outages is increasing.

1 Commercial power supply 2 Reactor 3 Rectifier circuit (Inverter power supply circuit)
3a Rectifying element 3b, 3c Smoothing capacitor 4 Inverter circuit 4a-4f Switching element 5 Motor 5a-5c Three-phase winding 6 Rotation detection means 6a-6c Rotation sensor (magnetic detection element)
DESCRIPTION OF SYMBOLS 7 Control apparatus 8 Switching means 9 Inrush current prevention circuit 9a Current limiting resistor 9b Relay 10 Control means 11 Inverter drive circuit 12 Switching means drive circuit 13 Relay drive circuit 14 Current detection means 14a-14c Current sensor 15 Current detection circuit 16 Water supply valve 17 Drain valve 18 Clutch operating means 19 Lid lock means 21 Washing and dewatering tank 22 Receptacle 24 Transmission mechanism 25 Washing and dewatering shaft 26 Pulsator 27 Suspension 28 Main body 30 Power supply voltage zero cross detection circuit 31 Power supply voltage detection means for inverter 32 Storage means 50 Rotor 51 Magnet 52 Stator

Claims (4)

An inverter circuit for driving and controlling a motor for driving a washing and dewatering tub and a pulsator; an inverter power circuit for generating an inverter power supply to be supplied to the inverter circuit from a commercial power supply; means for detecting energization of the commercial power supply; and the inverter power supply circuit An inrush current prevention circuit to control the operation of the washing machine, and the means for detecting the energization of the commercial power supply detects the energization interruption and before the power outage is detected, the inrush to the inverter power supply circuit A washing machine comprising a control means for enabling a current prevention circuit. An inverter circuit for driving and controlling a motor for driving a washing and dewatering tub and a pulsator; an inverter power circuit for generating an inverter power supply to be supplied to the inverter circuit from a commercial power supply; means for detecting energization of the commercial power supply; and the inverter power supply circuit An inrush current prevention circuit and a means for detecting the voltage of the inverter power supply, and controlling the operation of the washing machine, and the means for detecting the energization of the commercial power supply detects the power interruption, and then the inverter power supply A washing machine comprising control means for enabling an inrush current preventing circuit to the inverter power supply circuit when the voltage of the inverter becomes equal to or lower than a predetermined value. The control means disables the inrush current prevention circuit to the inverter power supply circuit after a lapse of a predetermined time when the means for detecting energization of the commercial power supply detects the start of energization after recovery from a power failure. The washing machine according to claim 1 or 2, wherein a washing operation is started. When the voltage of the inverter power supply exceeds a predetermined value when the means for detecting energization of the commercial power supply detects the start of energization after the return from the power failure, the control means prevents inrush current into the inverter power supply circuit. The washing machine according to claim 1 or 2, wherein the circuit is disabled and a washing operation is started.

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