JP2011205723A - Drum washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drum washing machine which has a simple configuration and can increase voltage, improve power factor and reduce harmonic current.SOLUTION: The drum washing machine includes a phase detecting circuit 39 for easily detecting a voltage phase of an AC power supply 31 by using a unidirectional photocoupler 41. A start point of short-circuit signal Ps is generated as a point when a detection signal of a photocoupler 41 of the phase detecting circuit 39 changes from OFF to ON and as a point with an elapse of a predetermined time Td after it changes from ON to OFF, and a pulse width Tw of the short-circuit signal Ps is changed so that a DC voltage Vd of an inverter becomes a predetermined target voltage Vt. Thus, the current waveform is made close to sine wave and symmetric between the positive and negative sides, and the power supply harmonic is reduced.

Description

  The present invention relates to a drum-type washing machine in which a drum motor is driven by an inverter circuit in order to drive a rotating drum containing laundry at a rotational speed corresponding to each process such as washing and dehydration.

  Conventionally, this type of drum type washing and drying machine has been generally used for inverters from washing to drying due to demands for low noise, power saving, water saving, etc. Power supply environment deterioration such as waves is a problem. In particular, in a drum type washing / drying machine that shares a DC voltage supply source for an inverter circuit for a drum motor that rotates and drives a rotary drum and an inverter circuit that drives a compressor motor for a heat pump, the compressor motor In the dehydrating and drying operation process in which the dehydrating operation and the heat pump drying operation are performed at the same time, the AC power source current waveform does not become a sine wave, and only the peak current increases and the power factor and power harmonic performance deteriorate. The problem occurs.

  Therefore, there is provided a motor drive circuit provided with means for short-circuiting the AC power supply via a reactor connected in series with the AC power supply between the rectifier circuit for supplying the DC voltage Vd to the inverter circuit for driving the motor and the AC power supply. It has been proposed (see, for example, Patent Document 1).

  FIG. 7 is a block diagram showing a motor drive device using a power conversion device used in the conventional washing machine described in Patent Document 1. In FIG.

  In FIG. 7, the power conversion apparatus 100 includes a reactor 2 having one end connected to one output end of a single-phase AC power source 1, a short-circuit unit 3 that short-circuits the AC power source 1 through the reactor 2, and an AC power source 1. A rectifier circuit 4 connected via an input current detection circuit 30 between the other end of the reactor 2 on the side not connected to the other end and the other end of the AC power supply 1 on the side not connected to the reactor 2; 4 between the smoothing capacitor 6 connected in series to both ends of the DC output 4, the AC input of the rectifier circuit 4, and the connection point between the smoothing capacitor 61 and the smoothing capacitor 62 constituting the smoothing capacitor 6. Means 5, zero cross detection circuit 8 for detecting zero cross of AC power supply 1, and DC voltage Vd across smoothing capacitor 6 are input and short circuit means 3 is operated using zero cross signal 92 as a reference timing. A short circuit pulse signal 96 to be output, a control circuit 7 that outputs a rectifier circuit switching signal 97 to the rectifier circuit switching means 5, an input current input from the AC power supply 1 is detected, and an input current value 98 is input to the control circuit 7. And an input current detection circuit 30 for outputting.

  FIG. 7 also shows a motor drive system 101 including an inverter circuit 10 connected to a DC output of the power conversion device 100 and a compressor 20 incorporating a motor (motor).

  The zero cross detection circuit 8 receives the voltage across the AC power supply 1 and switches from the High signal to the Low signal or from the Low signal to the High signal at the timing when the AC voltage Vs of the AC power supply 1 passes through the zero cross point and the polarity changes. A zero cross signal 92 is output. The zero cross signal 92 is input to the control circuit.

  The control circuit 7 uses the rising or falling edge of the input zero-cross signal 92 as a reference timing, the period until the short-circuit means 3 starts the short-circuit operation, that is, the delay time Td, and the short-circuit period, that is, the pulse width. Tw is set, and a short-circuit pulse signal 96 (High, Low signal) is output to the short-circuit means 3. The delay time Td and the pulse width Tw are previously stored in the control circuit 7 or calculated by the control circuit 7.

  The short-circuit means 3 performs a short-circuit opening / closing operation according to the short-circuit pulse signal 96. When the short-circuit pulse signal 96 output from the control circuit 7 is High, the short-circuit means 3 performs a short-circuit operation. The short-circuit means 3 is composed of a diode bridge and an IGBT, or a power semiconductor switching element such as a bipolar transistor or MOSFET, and short-circuits the AC power supply 1 via the reactor 2 in accordance with a short-circuit pulse signal 96. The power factor of the AC power supply 1 is improved by this short-circuit opening / closing operation.

  The rectifier circuit switching means 5 is composed of a bidirectional switch including a combination of a power relay, a triac, a diode bridge and a power semiconductor switching element (IGBT, bipolar transistor, MOSFET) or the like, and a rectifier circuit switching signal 97 (output from the control circuit 7). The rectifier circuit 4 is switched in response to the High and Low signals. When the rectifier circuit switching signal 97 is a Low signal, the rectifier circuit 4 is switched to a full-wave rectifier circuit, and when the rectifier circuit switch signal 97 is a High signal, it is switched to a voltage doubler rectifier circuit.

  The control circuit 7 receives the zero-cross signal 92, the DC voltage value 93 that is the DC voltage Vd across the smoothing capacitor 6, and the input current value 98, and outputs a short circuit pulse signal 96 and a rectifier circuit switching signal 97. .

  The current conversion device 100 performs an operation of short-circuiting the AC power source 1 once or a plurality of times in the power source half cycle through the reactor 2 to widen the conduction angle of the power source current and improve the power factor of the AC power. Is converted to DC power. The power converter 100 includes rectifier circuit switching means 5 and switches the rectifier circuit 4 to a full-wave rectifier circuit or a voltage doubler rectifier circuit. Therefore, in addition to controlling the DC voltage Vd with the pulse width Tw, a wide range of DC voltage Vd can be output.

JP 2004-72806 A

  However, the conventional configuration shown in Patent Document 1 requires the accuracy of a zero cross detection circuit that detects a point at which the power supply voltage becomes zero volts. That is, the odd-order harmonic current is suppressed as the current waveform approaches a sine wave by the short-circuit operation of the power supply voltage via the reactor. However, when the point of the short-circuit operation is shifted between the positive side and the negative side of the power supply voltage, the current waveforms of the positive and negative currents differ, and the even-order harmonic current increases. Therefore, since the accuracy of the zero-cross detection circuit is required, it is necessary to configure the zero-cross detection circuit with two comparators, a bidirectional photocoupler, and the like, which increases the mounting area and cost.

  The present invention solves the above-described conventional problems, and provides a drum type washing machine capable of boosting, improving power factor, and improving harmonic current with a simple configuration without using a complicated zero-cross detection circuit. The purpose is that.

  In order to solve the above-described conventional problems, the drum type washing machine of the present invention includes a reactor connected in series with one end of an AC power source and one end of the rectifier circuit, and one end of the reactor and the input side of the rectifier circuit. A short-circuit having a short-circuit control element having one end connected to one end and the other end connected to the other end of the AC power supply; and a control unit that drives the inverter circuit and controls a series of washing operations The control unit includes a phase detection circuit that simply detects a voltage phase of the AC power source with a unidirectional photocoupler, and a DC voltage detection unit that detects a DC voltage Vd output across the smoothing capacitor. And a short-circuit signal generator for generating a short-circuit signal for conducting the short-circuit control element, wherein the short-circuit signal generator is a photocoupler of the phase detection circuit at least during a partial period of the dehydration process. A point that changes from OFF to ON and a point that changes from ON to OFF after a predetermined time Td is generated as a starting point, and the pulse width Tw of the short circuit signal is set to the preset target voltage Vt. It is intended to change.

  This allows simple detection of the phase of the power supply voltage with a unidirectional photocoupler, regardless of whether the power supply voltage is positive or negative, and the power supply via the reactor after a stable delay time from the zero cross point. Since the voltage can be short-circuited, the current waveform approaches a sine wave and becomes a symmetric current waveform in both positive and negative phases, so that the power supply harmonics can be improved.

  The drum type washing machine of the present invention can realize a drum type washing machine capable of boosting, improving the power factor, and improving the harmonic current with a simple configuration without using a complicated zero cross detection circuit.

The longitudinal cross-sectional view of the drum type washing-drying machine in Embodiment 1 of this invention Inside rear view of the drum type washing and drying machine Block diagram showing the motor drive device of the drum type washing and drying machine Circuit diagram of the main part of the motor drive unit of the drum type washer / dryer Operation waveform diagram of the motor drive unit (A) The figure which shows the change of the input current to the full wave rectifier circuit by the operation | movement of the short circuit of the motor drive device, (B) The input current to the full wave rectifier circuit in the conventional motor drive device without the short circuit Illustration Block diagram showing a conventional motor drive device

  According to a first aspect of the present invention, there is provided a rotary drum having a rotation center axis in a horizontal direction or an inclination direction, a water tank that rotatably holds the rotary drum, a drum motor that rotationally drives the rotary drum, and an AC power source. A rectifying circuit for rectifying alternating current; a smoothing capacitor connected to the output terminal of the rectifying circuit; an inverter circuit connected in parallel to the smoothing capacitor for driving and controlling the drum motor; and one end of the alternating current power source; A reactor connected in series with one end of the rectifier circuit, and a short circuit control in which one end is connected between one end of the reactor and one end on the rectifier circuit input side, and the other end is connected to the other end of the AC power supply A short circuit having an element, and a controller that drives the inverter circuit and controls a series of washing operations, the controller having a single voltage phase of the AC power supply A phase detection circuit for simple detection by a photocoupler, a DC voltage detection unit for detecting a DC voltage Vd output across the smoothing capacitor, and a short-circuit signal generation for generating a short-circuit signal for conducting the short-circuit control element The short-circuit signal generator is configured to determine a point at which the photocoupler of the phase detection circuit changes from off to on and a point after a predetermined time Td after changing from on to off during at least a part of the dehydration process. It is generated as a starting point, and the pulse width Tw of the short circuit signal is changed so that the DC voltage Vd becomes a preset target voltage Vt, so that the phase of the power supply voltage can be easily detected by a unidirectional photocoupler. Therefore, it is possible to short-circuit the power supply voltage via the reactor after a stable delay time from the zero cross point, regardless of whether the power supply voltage is positive or negative. Since the can current waveform becomes a symmetrical current waveform in both the positive and negative phase with approaches to a sine wave, improve the power harmonics.

  According to a second invention, in the first invention, the control unit is configured to turn off the photocoupler of the phase detection circuit after the photocoupler is turned on, then turn it off and turn it on again, and the phase detection circuit. The time Ton during which the photocoupler is turned on is measured, and the time Td from when the photocoupler of the phase detection circuit, which is one of the starting points of the short circuit signal generation unit, is turned off is calculated as (Tt− (Ton * 2) ) / 2 to control the generation of the short circuit signal, the power supply voltage can be short-circuited through the reactor after a stable delay time from the zero cross point even if the power supply voltage fluctuates. Thus, it is possible to improve the power supply harmonics.

  In a third aspect based on the second aspect, the control unit calculates a time Td (Tt− (Ton−Ton) after the photocoupler of the phase detection circuit, which is one of the starting points of the short circuit signal generation unit, is turned off. * 2))) / 2, and if the calculated Td value becomes a negative value, by controlling the pulse width Tw of the short circuit signal to zero, Even if frequency disturbance occurs, it is possible to prevent an unnecessary short circuit operation of the power supply voltage, and to improve the safety of the device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the thing of 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 longitudinal sectional view of a drum type washing / drying machine according to a first embodiment of the present invention, and FIG. 2 is an internal rear view thereof.

  In this washing machine, a water tank 52 is supported in a suspended state in a washing machine body 51 by a suspension structure (not shown). A rotating drum 53 formed in a cylindrical shape with a bottom is supported in the water tank 52 so that its axial center is inclined downward from the front side toward the back side. On the front side of the water tank 52 is formed a clothing doorway 54 leading to the opening end of the rotary drum 53, and by opening the door 55 that closes the opening provided on the upward inclined surface on the front side of the washing machine body 51 so as to be openable and closable. The laundry can be taken in and out of the rotary drum 53 through the clothing entrance 54.

  The rotating drum 53 is formed with a large number of through holes 56 communicating with the inside of the water tank 52 on its peripheral surface, and provided with stirring protrusions (not shown) at a plurality of positions on the inner peripheral surface. The rotary drum 53 is rotationally driven in the forward and reverse directions by a drum motor 57 attached to the back side of the water tank 52. Further, a water injection pipe 58 and a drainage pipe 59 are connected to the water tank 52, and water is poured into and drained into the water tank 52 by control of a water injection valve and a drain valve (not shown).

  When the door 55 is opened and the laundry and detergent are put into the rotating drum 53 and the operation is started by an operation on the operation panel 60 provided on the front surface of the washing machine body 51, for example, a water injection pipe is placed in the water tank 52. A predetermined amount of water is injected from the path 58, and the drum drum 57 rotates the rotary drum 53 to start the washing process. By the rotation of the rotating drum 53, the laundry accommodated in the rotating drum 53 is lifted in the rotating direction by the stirring protrusion provided on the inner peripheral wall of the rotating drum 53, and the stirring operation of dropping from an appropriate raised height position. Is repeated, so that the laundry has the effect of tapping and washing.

  After the required washing time, the dirty washing liquid is discharged from the drainage pipe 59, and the washing liquid contained in the laundry is dehydrated by a dehydrating operation that rotates the rotating drum 53 at a high speed. Rinsing is performed by pouring water from the path 58. Also in this rinsing step, the laundry stored in the rotary drum 53 is rinsed by repeating the stirring operation of being lifted and dropped by the stirring protrusion by the rotation of the rotary drum 53.

  This drum type washing and drying machine is provided with a function of drying laundry stored in the rotary drum 53, and the air in the water tank 52 is exhausted and dehumidified by the circulation air passage 11, and dried by heating. Air is blown into the water tank 52 again. In the middle of the circulation air passage 11, a dehumidifying means such as an evaporator 12, a heat pump composed of a heating means such as a condenser 13, and a circulation fan 14 serving as an air blowing means are provided. As shown in FIG. 1, the evaporator 12 and the condenser 13 constitute a heat exchanging portion 15 with the circulating air, and are arranged at the lowest portion of the circulating air passage 11.

  By rotating the circulation fan 14, an air flow is generated in the circulation air flow path 11, and the air in the rotating drum 53 containing the laundry is circulated from the water tank 52 to the circulation fan 14 through the through holes 56. High-temperature air that is always dried by being exhausted to the introduction pipe 16 and dehumidifying the evaporator 12 located upstream of the circulation fan 14 by dew condensation and heating by heat exchange with the condenser 13. Is done.

  The dried high-temperature air is sent from the circulation fan 14 to the air duct 17 to the water tank 52 and blown into the water tank 52. The high-temperature dry air blown into the water tank 52 enters the rotary drum 2 through the through holes 56 and escapes to the water tank 52 while being exposed to laundry such as clothes, and is again introduced into the circulating air introduction pipe line 16. A drying process is implemented by the repetition of the circulation of the air in the above circulation ventilation path 11.

  In the drying process using the circulation air passage 11, foreign matter such as lint generated from laundry such as clothes is circulated in the air circulated through the circulation air passage 11, and the eyes of the evaporator and the condenser are circulated. Since clogging, clogging into the rotating part of the circulation fan 14, and a drying process such as accumulation on the inner surface of the circulation fan 14 are likely to be hindered, foreign substances in the circulation air may be trapped in the circulation air passage 11. A filter 18 for removal is provided.

  FIG. 3 is a block diagram showing a motor driving device of the drum type washer / dryer according to the first embodiment of the present invention.

  The motor driving device has a function of controlling the driving of the drum motor 57, the circulation fan 14, the driving fan motor, and the compressor motor for the heat exchanging unit 15. FIG. 3 shows the drum motor 57 and the compressor. Only the portion involved in driving the motor 45 is shown. Each of the drum motor 57 and the compressor motor 45 is a permanent magnet synchronous motor including a stator having a three-phase winding and a rotor having a two-pole permanent magnet.

  The drum motor 57 is provided with three rotor position detection elements 21a, 21b, and 21c for detecting the rotor position. The rotor position detection elements 21a to 21c output a rotor position signal for every electrical angle of 60 degrees corresponding to the rotor magnetic pole position. The drum motor 57 is rotationally driven by the first inverter circuit 22. The first inverter circuit 22 is configured by connecting six switching elements 23 in a three-phase bridge, and a flywheel diode 24 is connected to each switching element 23 in parallel. The on / off state of each switching element 23 is PWM controlled by the first drive circuit 25.

  On the other hand, the compressor motor 45 is rotationally driven by the second inverter circuit 26. The compressor motor 45 has no rotor position detection element, and is position sensorless sine wave drive controlled based on a signal from the current detection means, for example. Similarly to the first inverter circuit 22, the second inverter circuit 26 is configured by connecting six switching elements 27 in a three-phase bridge, and a flywheel diode 28 is connected to each switching element 27 in parallel. The on / off state of each switching element 27 is PWM controlled by the second drive circuit 29.

  Actually, the motor drive device is also provided with a third inverter circuit and a third drive circuit for driving the fan motor for the circulation fan 14, but the configuration and operation thereof are the same as those of the second inverter circuit. Since it is the same as that of No. 26 and the 2nd drive circuit, illustration and description are omitted.

  The first drive circuit 25 and the second drive circuit 29 operate under the control of the control unit 46. A rotor position signal output from the rotor position detection elements 21 a to 21 c of the drum motor 57 is input to the control unit 46. Based on this rotor position signal, the first drive circuit 25 performs PWM control of the on / off state of each switching element 23, thereby controlling the energization of the three-phase windings of the stator of the drum motor 57 and driving the rotor synchronously. Is done. Although not shown, the control unit 46 further includes a rotation speed detection unit that detects the rotation speed of the rotor, that is, the rotation speed Nd of the drum motor 57, based on the rotor position signals from the three rotor position detection elements 21a to 21c. The rotation speed detection unit detects the period each time the state of the three rotor position signals changes, and calculates the rotation number Nd of the drum motor 57 from the period.

  Supply of electric power to the first and second inverter circuits 22 and 26 is performed by an AC power supply 31, a short circuit 32, and a rectifier 33. That is, a DC voltage Vd is generated from the AC voltage Vs supplied from the AC power supply 31 by the short circuit 32 and the rectifier 33 and applied to the first and second inverter circuits 22 and 26.

  The short circuit 32 includes a reactor 34 connected in series between the AC power supply 31 and the rectifying unit 33, and a short circuit control element 35 connected in parallel to the AC power supply 31 via the reactor 34. The short-circuit control element 35 can be constituted by a power semiconductor switching element such as a diode bridge and IGBT, a bipolar transistor, or a MOSFET, for example.

  The rectifier 33 includes a full-wave rectifier circuit 36, and a series circuit of smoothing capacitors 37 and 38 is connected to the full-wave rectifier circuit 36 in parallel. The DC voltage Vd across the smoothing capacitors 37 and 38 is applied to the first inverter circuit 22 and the second inverter circuit 26, and the DC power is converted into three-phase AC power and supplied to the drum motor 57 and the compressor motor 45. Is done.

  FIG. 4 is a circuit diagram around the phase detection circuit 39. As shown in the figure, the AC voltage at both ends of the AC power supply 31 is input to the phase detection circuit 39, which is composed of a voltage drop resistor, a rectifier diode 40, and a unidirectional photocoupler 41. A signal is output and supplied to the control unit 46.

  The control unit 46 also includes a DC voltage detection unit that detects the DC voltage Vd across the smoothing capacitors 37 and 38, and thus the DC voltage Vd applied to the first and second inverter circuits 22 and 26. Further, the control unit 46 includes a short circuit signal generation unit, and generates a short circuit signal Ps for conducting the short circuit control element 35 of the short circuit 32 at least during a partial period of the dehydration process.

  FIG. 5 shows operation waveforms around the phase detection circuit 39 when the AC power supply 31 is 50 Hz and 100 V.

  As shown in the figure, the phase detection circuit 39 uses the AC voltage Vs of the AC power supply 31 to generate a forward voltage Vf1 (about 0.7V) of the rectifier diode 40 and a forward voltage Vf2 (about 2V) of the LED of the photocoupler 40. The light receiving transistor of the photocoupler 41 is turned on only during a period Ton where the voltage is higher than the total voltage Vf (about 2.7 V), and a High signal is supplied to the control unit 46 in other periods. When the AC voltage Vs of the AC voltage 31 becomes higher than Vf again, the output of the phase detection circuit 39 becomes High again. If the time from the rising edge from Low to High to the rising edge from High again to Tt is Tt, Tt is equal to one cycle time of the AC power supply 31. The delay from the zero cross point at which the AC power supply 31 is 0 V to the rising edge of the phase detection circuit is 1 ms. Then, the short circuit signal Ps having the pulse width Tw is generated with the rising edge of the phase detection circuit 39 as a base point. Further, a short circuit signal Ps having a pulse width Tw is generated again after a predetermined time Td (2 ms in this embodiment) determined from the falling edge, and as a result, a delay of 1 ms from the zero cross point of the voltage Vs of the AC power supply 31 is generated. A short circuit signal Ps having a pulse width Tw is generated every half cycle starting from the point.

  The motor drive device having the above configuration is characterized by the operation of the short circuit 32. The short circuit 32 shorts the AC voltage Vs through the reactor 34 when the short control element 35 is turned on. In the short circuit state, the power of the AC voltage Vs is accumulated in the reactor 34, and the accumulated power is supplied to the rectifier 33 when the short circuit control element 35 is turned off. The supplied power is converted into direct current by the full-wave rectifier circuit 36, charges the smoothing capacitors 37 and 38, and changes the pulse width Tw so that the output direct-current voltage Vd becomes the preset target voltage Vt.

  FIG. 6A is an operation example of the short circuit 32 when the AC power supply 31 is AC 100 V / 50 Hz and the inverter circuit output is 600 W.

  As shown in the figure, a short circuit signal Ps having a pulse width Tw is generated every half cycle starting from a point 1 ms behind the zero cross point of the voltage Vs of the AC power supply 31. During the High period of the short circuit signal Ps, the short circuit control element 35 is turned on, a short circuit current due to the AC voltage Vs flows, and electric power is accumulated in the reactor 34. When the short circuit signal Ps becomes Low, the auxiliary input current Ia based on the electric power accumulated in the reactor 34 is passed through the full-wave rectifier circuit 36. The auxiliary input current Ia is superimposed on the current due to the AC voltage Vs, the peak current of the input current Ib to the full-wave rectifier circuit 36 is suppressed, and the current waveform is made close to a sine wave. The DC voltage Vd can be increased.

  For comparison, FIG. 6B shows the input current Ib to the full-wave rectifier circuit 36 when the short circuit 32 is not operated and the same inverter circuit output 600 W is obtained. As can be seen from the waveform, the current waveform collapses from the sine wave, the peak current increases, the power factor decreases, and the power supply harmonics deteriorate.

  In this embodiment, 50 Hz has been described as an example. However, by determining the power supply frequency and setting the optimum delay time Td at 60 Hz, the same effect can be obtained even if the power supply frequency changes in Japan. Can do.

  Further, a time Tt of one cycle from when the photocoupler 41 of the phase detection circuit 39 is turned on to once being turned off and then on again, and a time Ton during which the photocoupler 41 of the phase detection circuit 39 is turned on are measured. The starting point of the short-circuit signal Ps is the short-circuit signal starting from the point when the photocoupler 41 of the phase detection circuit 39 is turned on and the time Td = (Tt− (Ton * 2)) / 2 after the photocoupler 41 is turned off. If Ps is generated, even if the AC voltage Vs or the frequency of the AC power supply 31 changes, the same effect can be obtained stably and always. That is, taking FIG. 5 as an example, Tt = 20 ms because of 50 Hz, and Ton = 8 ms, so (20 ms− (8 ms * 2)) / 2 = 2 ms, and 2 ms after the photocoupler 41 is turned off, That is, the short circuit signal Ps can be generated 1 ms after the zero cross point at which the AC power source 31 changes to positive and 1 ms after the zero cross point at which the AC power source 31 changes to negative, and stable operation is possible even if the voltage or frequency of the AC power source 31 changes. Become.

  Note that, depending on the circuit configuration and the like, the waveform at the time when the photocoupler 41 is turned on or off may differ, but it goes without saying that the shorter section is calculated as Ton.

  Further, when the calculated value Td = (Tt− (Ton * 2)) / 2 becomes a negative value, the waveform width of the power supply voltage should be distorted by controlling the pulse width Tw of the envelope signal to zero. Even if frequency disturbance occurs, unstable operation such as performing a plurality of short-circuit operations in the same phase can be prevented, and the safety of the device can be improved.

  As described above, the drum type washing and drying machine of the present embodiment includes the short circuit 32 including the reactor 34 and the short circuit control element 35, and transmits a short circuit signal for conducting the short circuit control element 35 to the power supply phase of the AC power supply 31. A phase detection circuit 39 using a simple unidirectional photocoupler 41 is generated starting from a point where the photocoupler changes from off to on and a point after a predetermined time Td after changing from on to off, and the pulse width Tw of the short circuit signal Is changed so that the DC voltage Vd becomes a preset target voltage Vt. As a result, the inverter voltage can be boosted and the power factor can be improved with a simple configuration without using a complicated zero-cross detection circuit, the power supply current can be made closer to a sine wave, and the waveform can be made positive and negative. It is possible to reduce the odd and even orders of the wave.

  As described above, the drum type washing machine according to the present invention can perform a stable inverter voltage boosting operation with a simple configuration without using a complicated zero-cross detection circuit. It is useful as a drum type washing machine capable of improving the above.

DESCRIPTION OF SYMBOLS 22 1st inverter circuit 25 1st drive circuit 26 2nd inverter circuit 29 2nd drive circuit 32 Short circuit 33 Rectification part 34 Reactor 39 Phase detection circuit 45 Compressor motor 46 Control part 51 Washing machine main body 52 Water tank 53 Rotating drum 57 Drum motor

Claims (3)

A rotating drum having a rotation center axis in a horizontal direction or an inclination direction, a water tank that rotatably holds the rotating drum, a drum motor that rotationally drives the rotating drum, and a rectifying circuit that rectifies AC from an AC power source A smoothing capacitor connected to the output terminal of the rectifier circuit, an inverter circuit connected in parallel to the smoothing capacitor to drive and control the drum motor, one end of the AC power supply, and one end of the rectifier circuit A short circuit including a reactor connected in series, a short circuit control element having one end connected between one end of the reactor and one end on the rectifier circuit input side, and the other end connected to the other end of the AC power supply; A control unit that drives the inverter circuit and controls a series of washing operations, and the control unit sets the voltage phase of the AC power source to a unidirectional photocoupler. A phase detection circuit for simple detection, a DC voltage detection unit for detecting a DC voltage Vd output across the smoothing capacitor, and a short circuit signal generation unit for generating a short circuit signal for conducting the short circuit control element The short-circuit signal generation unit generates a starting point from a point where the photocoupler of the phase detection circuit changes from OFF to ON and a point after a predetermined time Td from ON to OFF during at least a part of the dehydration process. The drum-type washing machine is characterized in that the pulse width Tw of the short circuit signal is changed so that the DC voltage Vd becomes a preset target voltage Vt. The control unit measures a time Tt of one cycle until the photocoupler of the phase detection circuit is turned on after the photocoupler of the phase detection circuit is turned on, and a time Ton when the photocoupler of the phase detection circuit is turned on, Control is performed so as to generate a short circuit signal by setting a time Td after the photocoupler of the phase detection circuit, which is one of the starting points of the short circuit signal generating unit, to be turned off, as (Tt− (Ton * 2)) / 2. Item 2. The drum type washing machine according to Item 1. The control unit obtains the time Td after the photocoupler of the phase detection circuit, which is one of the starting points of the short circuit signal generation unit, is turned off by (Tt− (Ton * 2)) / 2, and calculates the calculated Td value. The drum-type washing machine according to claim 2, wherein when the signal becomes a negative value, the pulse width Tw of the short circuit signal is controlled to zero.

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