JP2009061164A - Laundry apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laundry apparatus capable of reliably detecting the defective phase of a motor at a low cost. <P>SOLUTION: A control circuit for a washing and drying machine detects disconnection when a state where the current value of one phase in three-phase currents to be output from an inverter circuit to a drum motor becomes equal to or less than a prescribed value compared with the current values of the other two phases, continues for a prescribed time (steps A3-A13). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laundry machine such as a washing machine or a dryer having a function of detecting disconnection of a motor.

  Conventionally, as a technique for detecting a failure of a switching element constituting an inverter and a disconnection abnormality of a drive unit including a motor, for example, as disclosed in Patent Document 1, energization is performed for each phase when the motor is stopped. There is one that determines an abnormality based on the current value. This technique is relatively simple and has high detection reliability. Further, since it is not necessary to add a special circuit to a normal motor control circuit, it can be implemented at low cost and is widely implemented.

  However, in principle, this method has a problem that an abnormality cannot be detected when the motor is rotating. Moreover, although it is assumed in Patent Document 1 that it is applied to an air conditioner, the situation is different in a washing machine or the like, and wiring may be damaged by vibration generated when a rotating tub such as a drum is rotating. If the disconnection occurs during operation, the operation is continued as it is until the next time the power is turned on again and the use is started.

  In Patent Document 2, when detecting a phase loss (disconnection) of a compressor, a three-phase AC power source is used as an inverter power source, and a phase loss abnormality is detected when the difference between the phase power source currents exceeds a predetermined value. Yes. However, generally, most of the washing machines and dryers for home use use a single-phase AC power supply, and therefore the technique of Patent Document 2 cannot be applied. Moreover, in patent document 2, since the point which performs a detection is the power supply side which is not directly linked with the phase failure of the motor, there is a problem that the certainty of detection is lacking. Furthermore, since a dedicated means such as a current transformer is required to detect the current, a cost increase is also a problem.

  Patent Document 3 discloses a technique for detecting a bus current of an inverter circuit with a current transformer in an air conditioner and detecting an abnormality based on the magnitude of the ripple fluctuation. However, with this technology, when the ripple fluctuation becomes relatively large, it is caused by an abnormal factor such as an open phase or a normal operating range factor such as a motor load fluctuation. However, there is a problem that it is difficult to discriminate.

  For example, in the case of a washing machine, a motor used for a washing operation or a dehydrating operation has a large load fluctuation due to clothing imbalance, and therefore, the technique of Patent Document 3 cannot be applied. Also, in the case of a dryer, unlike the air conditioner, the refrigerant used is a liquid at a higher temperature and pressure, and is returned to the compressor as a result. The technique of Reference 3 cannot be applied.

  Patent Document 4 is an improvement of Patent Document 2 in that a circuit for converting the current fluctuation into a frequency is provided when the fluctuation of the DC bus current of the inverter circuit is detected, and the frequency is lowered when the phase is lost. As a result of the detection, the problem of being limited to a three-phase AC power source and requiring a dedicated current detector as in Patent Document 2 is solved. However, an increase in cost is unavoidable in that a circuit for performing current-frequency conversion is necessary. In addition, in the vector control method in which a sine wave energization is performed on the motor, current fluctuations in a normal state are reduced, and thus there is a possibility of erroneous detection.

Patent Document 5 relates to a washing machine, and some methods for detecting abnormality are disclosed. One of them is that when the lower arm side switching element constituting the inverter circuit is ON and the value of the current detected by the current detection means becomes “0”, it is determined that an abnormality has occurred. There is something that stops the operation.
Japanese Patent Laid-Open No. 06-205599 JP-A-63-228916 Japanese Patent Laid-Open No. 04-156222 Japanese Patent Laid-Open No. 03-261395 Japanese Patent Laid-Open No. 10-145960

However, when the above-mentioned technique of Patent Document 5 is actually performed and evaluated, the S / N ratio of the current detection means is bad, and it is not possible to make a determination by capturing a state where the current value is “0”. It was. For example, in a washing machine, since the load range of the motor in the washing operation and the dehydrating operation is wide, the current value changes to about several tens mA to 10 A. When the current value is large, the noise tends to increase as a matter of course. Therefore, a unique method is necessary for good detection within a wide current detection range.
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a laundry machine that can reliably detect a phase failure of a motor at a low cost.

The laundry device according to claim 1 is a three-phase brushless DC motor that generates a rotational driving force for performing a driving operation related to washing, a PWM control type inverter, and a current that individually detects a three-phase current of the motor. Detection means, control means for vector control of the motor, disconnection detection means for detecting disconnection of the motor, and when a disconnection is detected by the disconnection detection means, the rotation of the motor is stopped and a predetermined condition is established. In the case of having abnormality processing means for performing abnormality notification when
The disconnection detecting means detects a disconnection when a state in which a current value of one phase of the three-phase current is equal to or less than a predetermined value compared to other two-phase current values continues for a predetermined period. To do.
That is, the current of the phase in which the disconnection has occurred continues to be reduced more than the current of other healthy phases. Therefore, the disconnection can be detected by relatively comparing the current between the phases.

The laundry device according to claim 3 is a three-phase brushless DC motor that generates a rotational driving force for performing a driving operation related to washing, a PWM control type inverter, and a current that individually detects a three-phase current of the motor. Detection means, control means for vector control of the motor, disconnection detection means for detecting disconnection of the motor, and when a disconnection is detected by the disconnection detection means, the rotation of the motor is stopped and a predetermined condition is established. In the case of having abnormality processing means for performing abnormality notification when
The disconnection detecting means is configured to detect a state in which a current value of one phase of the three-phase current is equal to or lower than a predetermined value compared to other two-phase current values for a predetermined time, or a PWM output voltage of the inverter Is detected when the current value of all three phases is equal to or less than a predetermined value.
That is, when the output voltage of the inverter has reached a certain level, but the current value of each phase is extremely low, the inverter and the motor are in a high resistance state (high impedance state) due to the occurrence of disconnection. It is estimated that there is. Therefore, various disconnections can be detected together with the disconnection detection method similar to the first aspect.

According to the laundry device of the first aspect, even when noise is superimposed on the detected current, the disconnection between the inverter and the motor can be reliably detected.
According to the laundry machine of the third aspect, disconnection between the inverter and the motor can be detected more variously.

  Hereinafter, an embodiment in which the present invention is applied to a heat pump type washing / drying machine (laundry equipment) will be described with reference to the drawings. First, in FIG. 18, a water tank 2 is elastically supported by a plurality of support devices 3 in a horizontal state inside the outer box 1. A rotating drum 4 is rotatably disposed in the water tank 2 in the same state as that of the water tank 2. The rotating drum 4 has a large number of dewatering holes 4a (only part of which are shown) serving as ventilation holes on the peripheral side wall and the rear wall, and also functions as a washing tub, a dewatering tub, and a drying chamber. A plurality of baffles 4 b (only one is shown) are provided on the inner peripheral surface of the rotating drum 4.

  Each of the outer box 1, the water tank 2 and the rotating drum 4 has openings 5, 6 and 7 for putting in and out the laundry on the front surface (right side in the figure), and the opening 5 And the opening 6 are connected in a watertight manner by an elastically deformable bellows 8. The opening 5 of the outer box 1 is provided with a door 9 for opening and closing the opening. The rotating drum 4 has a rotating shaft 10 on the back surface, and the rotating shaft 10 is supported by a bearing (not shown) and attached to the outside of the back surface portion of the water tank 2. A drum motor (washing / dehydrating motor) 11 comprising an outer rotor type three-phase brushless DC motor as a motor is driven to rotate.

  A casing 13 is supported on the bottom plate 1a of the outer box 1 via a plurality of support members 12, and a discharge port 13a and a suction port 13b are formed at the upper right end portion and the upper left end portion of the casing 13, respectively. ing. Moreover, the compressor 15 of the heat pump (refrigeration cycle) 14 is installed in the bottom plate 1a. Further, in the casing 13, a condenser 16 and an evaporator 17 of the heat pump 14 are installed in order from the right side to the left side, and a blower fan 18 is disposed at the right end portion. FIG. 19 shows a configuration of the heat pump 14 in which each part is connected by a refrigerant circulation pipe 80. In this figure, an adjustment valve 81 for adjusting the flow rate of the refrigerant is also shown. A dish-shaped water receiving portion 13 c is formed at a portion of the casing 13 located below the evaporator 17.

  In the water tank 2, an intake port 19 is formed in the upper part of the front surface part, and an exhaust port 20 is formed in the lower part of the back surface part. The intake port 19 is connected to the discharge port 13 a of the casing 13 through a linear duct 21 and an extendable connecting duct 22. Further, the exhaust port 20 is connected to the suction port 13 b of the casing 13 via an annular duct 23 and an extendable connecting duct 24. The annular duct 23 is attached to the outside of the back surface of the water tank 2 and is formed concentrically with the drum motor 11. That is, the inlet side of the annular duct 23 is connected to the exhaust port 20, and the outlet side is connected to the suction port 13 b via the connecting duct 24. The casing 13, the connecting duct 22, the linear duct 21, the intake port 19, the exhaust port 20, the annular duct 23, and the connecting duct 14 constitute an air circulation path 25.

  In the outer box 1, a water supply valve 26 composed of a three-way valve is disposed at the upper rear portion thereof, and a detergent feeder 26a is disposed at the upper upper portion thereof. The water supply valve 26 has a water inlet connected to a water faucet via a water supply hose, a first water outlet connected to an upper water inlet of the detergent feeder 26a via a water supply hose 26b for washing, The outlet is connected to the lower inlet of the detergent dispenser 26a via the rinsing water supply hose 26c. And the water outlet of the detergent feeder 26a is connected to the water inlet 2a formed in the upper part of the water tank 2 via the water supply hose 26d.

  A drain port 2b is formed at the rear portion of the bottom of the water tank 2, and the drain port 2b is connected to the drain hose 27 via a drain valve 27a. A part of the drain hose 27 is telescopic. And the water receiving part 13c of the casing 13 is connected to the middle part of the drainage hose 27 via the drainage hose 28 and the check valve 28a.

  An operation panel unit 29 is provided on the front upper portion of the outer box 1, and the operation panel unit 29 is provided with a display and various operation switches (not shown). Further, a control circuit (control means, current detection means, disconnection detection means, abnormality processing means, rotation abnormality determination means) 30 is provided on the back surface of the operation panel unit 29. The control circuit 30 is constituted by a microcomputer, and controls the water supply valve 26, the drum motor 11 and the drain valve 27a according to the operation of the operation switch of the operation panel unit 29, and washing, rinsing and dewatering washing operations, The drying operation is executed by controlling a compressor motor 31 (compressor motor, see FIG. 15) composed of a three-phase brushless DC motor that drives the drum motor 11 and the compressor 15.

FIG. 15 schematically shows a drive system for the drum motor 11 and the compressor motor 31. The inverter circuit (PWM control system inverter) 32 is configured by connecting six IGBTs (semiconductor switching elements) 33a to 33f in a three-phase bridge, and between the collectors and emitters of the IGBTs 33a to 33f, there is a flywheel diode. 34a-34f are connected.
The emitters of the IGBTs 33d, 33e, 33f on the lower arm side are connected to the ground through shunt resistors (current detection means) 35u, 35v, 35w. The common connection point between the emitters of the IGBTs 33d, 33e, and 33f and the shunt resistors 35u, 35v, and 35w is connected to the control circuit 30 via the level shift circuit 36, respectively. Incidentally, since a maximum of about 7 A flows through the windings 11u to 11w of the drum motor 11, the resistance values of the shunt resistors 35u to 35w are set to 0.22Ω, for example.

  The level shift circuit 36 includes an operational amplifier and the like, amplifies the terminal voltage of the shunt resistors 35u to 35w, and gives a bias so that the output range of the amplified signal is within the positive side (for example, 0 to + 3.3V). . Further, when the upper and lower arms of the inverter circuit 32 are short-circuited, the overcurrent comparison circuit 38 performs overcurrent detection in order to prevent circuit destruction.

  A driving power supply circuit 39 is connected to the input side of the inverter circuit 32. The drive power supply circuit 39 rectifies a 100V AC power supply 40 by a full-wave rectification circuit 41 composed of a diode bridge and a double voltage full-wave rectification by two capacitors 42a and 42b connected in series, and a DC voltage of about 280V. Is supplied to the inverter circuit 32. Each phase output terminal of the inverter circuit 32 is connected to each phase winding 11 u, 11 v, 11 w of the drum motor 11.

The control circuit 30 detects currents Iau to Iaw flowing through the windings 11u to 11w of the motor 11 obtained via the level shift circuit 36, and based on the current value, the phase θ and the rotational angular velocity of the secondary rotating magnetic field. In addition to estimating ω, the three-phase current is subjected to orthogonal coordinate transformation and dq (direct-quadrature) coordinate transformation to obtain an excitation current component Id and a torque current component Iq.
When a speed command is given from the outside, the control circuit 30 generates current commands Idref and Iqref based on the estimated phase θ, rotational angular velocity ω, and current components Id and Iq, and converts them into voltage commands Vd and Vq. Then, rectangular coordinate transformation and three-phase coordinate transformation are performed. Finally, a drive signal is generated as a PWM signal and output to the windings 11 u to 11 w of the motor 11 via the inverter circuit 32.

  The first power supply circuit 43 steps down the drive power supply of about 280V supplied to the inverter circuit 32 to generate a control power supply of 15V and supplies it to the control circuit 30 and the drive circuit 44. The second power supply circuit 45 is a three-terminal regulator that generates 3.3V power from the 15V power generated by the first power circuit 43 and supplies the 3.3V power to the control circuit 30. The high voltage driver circuit 46 is arranged to drive the IGBTs 33 a to 33 c on the upper arm side in the inverter circuit 32.

  The rotor of the motor 11 is provided with a rotational position sensor 82 for use at startup, and a rotor position signal output from the rotational position sensor 82 is given to the control circuit 30. That is, when the motor 11 is started, vector control is performed using the rotational position sensor 82 until the rotational speed at which the rotor position can be estimated (for example, about 30 rpm), and after reaching the rotational speed, Switch to sensorless vector control without using the rotational position sensor 82.

  And about the compressor motor 31, the structure symmetrical with the drive system of the drum motor 11 is arrange | positioned. That is, the compressor motor 31 is driven by an inverter circuit (PWM control type inverter) 47, and shunt resistors (current detection means) 48u to 48w are inserted on the lower arm side thereof. The terminal voltages of these shunt resistors 48u to 48w are supplied to the control circuit 30 through the level shift circuit 49, and the overcurrent comparison circuit 50 performs comparison for detecting overcurrent. The control circuit 30 drives the inverter circuit 47 via the drive circuit 51 and the high voltage driver circuit 52. However, since the current flowing through the windings 31u to 31w of the compressor motor 31 is as small as about 2A at the maximum compared to the drum motor 11, the resistance values of the shunt resistors 48a to 48c are set to 0.033Ω, for example.

  A series circuit of resistance elements 83 a and 83 b is connected between the output terminal of the power supply circuit 39 and the ground, and the common connection point is connected to the input terminal of the control circuit 30. The control circuit 30 reads the input voltages of the inverter circuits 32 and 47 divided by the resistance elements 83a and 83b and uses them as a reference for determining the PWM signal duty.

  FIG. 16 is a diagram showing functional blocks of sensorless vector control performed by the control circuit 30 for the drum motor 11 and the compressor motor 31 (however, only the drum motor 11 side is shown). This configuration is the same as that disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-181187, and will be schematically described here. In FIG. 16, (α, β) indicates an orthogonal coordinate system obtained by orthogonally transforming a three-phase (UVW) coordinate system having an electrical angle interval of 120 degrees corresponding to each phase of the motor 11, and (d, q) is The coordinate system of the secondary magnetic flux which is rotating with rotation of the rotor of the motor 11 is shown.

  The subtracter 62 is supplied with the target speed command ωref from the speed command output unit 60 as a subtracted value and the detected speed ω of the motor 11 detected by the estimator 63 as a subtracted value. The result is given to a speed PI (Proportional-Integral) control unit 65. The speed PI control unit 65 performs PI (proportional integration) control based on the difference between the target speed command ωref and the detected speed ω, and generates and subtracts the q-axis current command value Iqref and the d-axis current command value Idref. Are output as subtracted values to the devices 66q and 66d, respectively.

  When vector control is performed, the d-axis current command value Idref is basically set to “0” and the motor 11 is driven by full field control. However, in the high-speed rotation region during the dehydration operation, the rotation speed is further increased. For this reason, the command value Idref is set to a negative value to perform weak disclosure control. The subtractors 66q and 66d are respectively provided with the q-axis current value Iq and the d-axis current value Id output from the αβ / dq conversion unit 67 as subtraction values, and the subtraction results are respectively supplied to the current PI control units 68q and 68d. Given. The control period in the speed PI control unit 65 is set to 1 msec.

  The current PI controllers 68q and 68d perform PI control based on the difference amount between the q-axis current command value Iqref and the d-axis current command value Idref, and generate the q-axis voltage command value Vq and the d-axis voltage command value Vd. And output to the dq / αβ conversion unit 69. The dq / αβ conversion unit 69 is given a rotational phase angle (rotor position angle) θ of the secondary magnetic flux detected by the estimator 63, and voltage command values Vd and Vq are converted into voltage commands based on the rotational phase angle θ. Convert to values Vα and Vβ.

  The voltage command values Vα and Vβ output from the dq / αβ conversion unit 69 are converted into three-phase voltage command values Vu, Vv and Vw by the αβ / UVW conversion unit 70 and output. The voltage command values Vu, Vv, Vw are given to one fixed contact 71ua, 71va, 71wa of the changeover switches 71u, 71v, 71w, and are output from the initial pattern output unit 76 to the other fixed contact 71ub, 71vb, 71wb. Voltage command values Vus, Vvs, and Vws are given. The movable contacts 71uc, 71vc, 71wc of the changeover switches 71u, 71v, 71w are connected to the input terminal of the PWM forming unit 73.

  The PWM forming unit 73 modulates a 15.6 kHz carrier (triangular wave) based on the voltage command values Vus, Vvs, Vws or Vu, Vv, Vw, and outputs PWM signals Vup (+,-), Vvp (+, -), Vwp (+,-) is output to the inverter circuit 32. The PWM signals Vup to Vwp are output as signals having a pulse width corresponding to the voltage amplitude based on the sine wave so that, for example, a sine wave current is passed through the phase windings 11u, 11v, and 11w of the motor 11.

The A / D converter 74 outputs current data Iau, Iav, and Iaw obtained by A / D converting voltage signals appearing at the emitters of the IGBTs 33 d to 33 f to the UVW / αβ converter 75. The UVW / αβ conversion unit 75 converts the three-phase current data Iau, Iav, Iaw into biaxial current data Iα, Iβ in an orthogonal coordinate system according to a predetermined arithmetic expression. Then, the biaxial current data Iα and Iβ are output to the αβ / dq converter 67.
The αβ / dq converter 67 obtains the rotor position angle θ of the motor 11 from the estimator 63 at the time of vector control, thereby obtaining the biaxial current data Iα, Iβ on the rotational coordinate system (d, q) according to a predetermined arithmetic expression. When converted into the d-axis current value Id and the q-axis current value Iq, they are output to the estimator 63 and the subtractors 66d and 66q as described above.

  The estimator 63 estimates the rotor position angle θ and the rotational speed ω based on the q-axis voltage command value Vq, the d-axis voltage command value Vd, the q-axis current value Iq, and the d-axis current value Id, and outputs them to each unit. . Here, when the motor 11 is started, a startup pattern is applied by the initial pattern output unit 76 and forced commutation is performed. After the start of vector control, the estimator 63 is activated to estimate the rotor position angle θ and rotational speed ω of the drum motor 11.

  The switching control unit 78 controls switching of the selector switch 71 based on the duty information of the PMW signal given from the PWM forming unit 73. In the above configuration, the configuration excluding the inverter circuit 32 is a block of functions realized by the software of the control circuit 30. The current control period in the vector control is set to 128 μsec, for example.

  FIG. 17 is a block diagram showing other peripheral circuits controlled by the control circuit 30. The door control circuit 84 locks the door 9 when a door lock command is given. In addition, a signal indicating the open / closed state of the door 9 is output to the control circuit 30. The fan motor 85 for drying operation drives the blower fan 18 according to the operation command and the rotation speed command, and outputs a rotation speed signal to the control circuit 30. Although not shown in FIG. 15, the power factor correction circuit 86 includes a step-up chopper circuit arranged on the input side of the full-wave rectifier circuit 41, and the current waveform so that the current waveform of the power supply circuit 39 approaches a sine wave. The switching operation is performed in accordance with the drive pulse given with reference to the zero cross point.

  The board cooling fan motor 87 drives a fan that blows and cools the circuit board on which the control circuit 30 and the like are mounted. The water level sensor 88 detects the water level of the rotating drum 4 and outputs a pulse signal to the control circuit 30. The drain pump drive circuit 89 drives a drain pump for discharging condensed water during a drying operation in accordance with a given drive command, and outputs a water level detection signal during drainage to the control circuit 30. The commercial frequency generation circuit 90 outputs the frequency (50/60 Hz) extracted from the commercial AC power supply to the control circuit 30 as an AC pulse in order to obtain the triac drive timing.

The dry filter presence / absence detection circuit 91 detects whether or not a filter for removing lint or the like disposed in the air circulation path 25 is set at a predetermined position, and sends a signal corresponding to the presence or absence of the filter to the control circuit 30. Output. The input current detection circuit 92 outputs a voltage corresponding to the input current in order to protect when the input of the inverter circuit 47 on the compressor 15 side becomes excessive.
The temperature detection circuit 93 for the refrigerant system includes a detector for detecting the temperatures of the inlet and outlet of the condenser (condenser) 16 and the evaporator (evaporator) 17, and a thermistor disposed in the discharge pipe. In addition, the air system temperature detection circuit 94 detects the temperature of the outside air temperature or the temperature of the circulating air at the entrance to the drum 4 and the temperature at the exit from the drum 4. Detection signals from these temperature detection circuits 93 and 94 are output to the control circuit 30.

  The flash writing communication terminal 95 is a terminal for writing to the flash ROM (program memory) built in the control circuit 30 from the outside by serial communication. The nonvolatile memory 96 is, for example, an EEPROM or FRAM (registered trademark), and the control circuit 30 performs reading and writing by serial communication. The circulation pump drive circuit 97 drives a circulation pump that pumps up the washing water in accordance with a given drive command in order to sprinkle the washing water on the laundry in the rotating drum 4 during the washing operation.

  The water supply valve drive circuit 98, the drain valve drive circuit 99, and the softer valve drive circuit 100 open and close the water supply valve 26, the drain valve 27a, and the softer valve for supplying a softener (not shown), respectively, in response to an applied opening / closing command. To do. The bath water pump pump driving circuit 101 drives a bath water pumping DC motor according to a given drive command, and the refrigerant flow valve drive circuit 102 drives a flow rate adjusting valve 80 according to a given flow command.

  Next, the operation of this embodiment will be described with reference to FIGS. The basic control contents such as the washing operation and the drying operation are disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-116066, and thus will be omitted. Below, the disconnection detection process which is the gist of the present invention will be described separately for the drum motor 11 side and the compressor motor 31.

<Drum motor 11 side disconnection detection processing>
First, processing on the drum motor 11 side will be described with reference to FIGS. FIG. 6 shows a three-phase current waveform observed when the wiring between the inverter circuit 32 and the drum motor (washing / drying motor) 11 is disconnected only by the V phase (0.38 A / DIV). ). As is apparent from this figure, even when the wire is disconnected, the current value does not indicate “0” due to the influence of noise from other phases. Moreover, FIG. 7 shows the waveform which took the moving average of 0.3 second per three-phase current about the same state (0.15A / DIV). Thus, it is clear that the average value of the V-phase current does not become “0”. In the present invention, the disconnection is detected by capturing such a phenomenon that appears in the output current of the inverter circuit 32 when the disconnection occurs.

1 to 5 are flowcharts showing a disconnection detection process by the control circuit 30. FIG. FIG. 1 shows a main routine executed at a cycle of 1 msec, and FIG. 2 shows a current detection process executed at the time of interruption occurring every 128 μsec. In FIG. 2, since the current is detected while the lower arm side IGBTs 33d to 33f of the inverter circuit 32 are ON, the phase not showing the maximum output value is the U, V phase (step A16) or the V, W phase. (Step A18), if it is determined as (YES) in step A16, U / V phase current values are A / D converted and read (step A17), and if it is determined as (YES) in step A18, V, W The phase current value is A / D converted and read (step A19). If “NO” is determined in step A18, the phase indicating the maximum output value is the V phase, so the U and W phase current values are A / D converted and read (step A20).
In vector control, the phase currents that are not subject to A / D conversion are calculated from the relationship where the sum of the three-phase currents is “0”. Since this is not established, only the two-phase current that is actually A / D converted is used in this processing.

FIG. 1 is intended to detect that a disconnection has occurred while the motor 11 is rotating. First, in step A1, the average value of each phase current is calculated, and details of the processing are shown in FIG. In steps A21 to A23, the average value of the currents in the U, V, and W phases is calculated as a moving average of 0.3 seconds of the absolute value of the current (smoothing process).
Here, the moving average period of 0.3 seconds is set as a period longer than the current change period. As the current change period, the electrical angle period when the motor 11 rotates, the load and the number of rotations, and the like. There are things that accompany fluctuations. As the output current or PWM output voltage of the inverter circuit 32 increases, the noise generation level also increases. However, by smoothing the detected current value by moving average, an appropriate value corresponding to the noise generation state can be obtained. , Misjudgment can be prevented.

In the last step A24, the average value of the three-phase currents is calculated by adding the average values of the U, V, and W phase currents obtained in steps A21 to A23 to 1/3.
In step A2 of FIG. 1, it is determined whether an appropriate condition for determining a disconnection (open phase) is satisfied. The above judgment conditions are:
(1) The rotation speed of the motor 11 is 30 rpm or more. (2) The brake operation of the motor 11 is not in progress.
(3) The average value of the three-phase current obtained in step A24 is 0.15 A or more, and if all these three conditions are satisfied, it is determined as “YES”. Further, if any one of these is not established, “NO”, an error counter corresponding to each of U, V, and W phases described later is cleared to zero (step A14), and the process is terminated.

  If “YES” is determined in step A2, it is determined in steps A3, A5, and A7 whether or not the average value of the U, V, and W phase currents is smaller than 30% of the average value of the three-phase currents. . If “YES” is determined in each of these steps, the error counter corresponding to each phase is incremented (steps A11, A12, A13). If “NO” is determined, the error counter is cleared to zero (steps A4, A6, A6). A8).

  Then, in step A9, it is determined whether any one of the error counters corresponding to the U, V, and W phases has reached a count value (5000 counts) corresponding to 5 seconds or more. If it is determined, the process is terminated. On the other hand, if “YES” is determined, the state in which the current value of the corresponding phase has decreased compared to the current value of the other phase has continued for a predetermined time, and it is determined that the corresponding phase has been lost and the motor 11 The drive is stopped (OFF) (step A10). That is, when “YES” is determined in step A9, it corresponds to the state of the current waveform shown in FIG. 7 (the V phase is open), and the average value of the open phase current is the three-phase current. It is clearly smaller than the average value.

  FIG. 4 shows a process for detecting disconnection while the motor 11 is stopped. This process is executed every time the main routine of FIG. 1 is executed 20 times, that is, at a cycle of 20 milliseconds. First, it is determined whether any error such as start failure, overcurrent, overvoltage, phase loss (according to step A10), or rotation stop has occurred in the motor 11 (step A31). If any error has occurred (YES), the motor 11 is in a state where the rotation is stopped, so that a restart process (retry) is executed in step A37 described later.

In the next step A32, it is determined whether or not the number of retries has reached 24 or more. If it is less than 24 (NO), the error state is canceled and the motor 11 is set to the brake mode (mode 1). (Step A33) and return. Then, at the next execution, “NO” is determined in step A31 and “YES” is determined in step A35. If the brake operation is finished (YES in step A36), the motor 11 is restarted and the number of retries is determined. The counter is incremented (step A37) and the process returns.
In step A32, if the number of retries reaches 24 or more (YES), mode 2 is set, d-axis current command Idref is set to a fixed value of 5A (step A34), and the process returns. Then, at the next execution, “NO” is determined in steps A31 and A35, and “YES” is determined in step A38, and disconnection reconfirmation operation is performed (step A39).

  FIG. 5 shows details of step A39. The processing of steps A44 to A49 and A54 to A56 here is performed in the same manner as the processing of steps A3 to A8 and A11 to A13 in FIG. 1, but the error counter for each phase is different (error 2 counter). ing. After execution of steps A49 and A56, it is determined whether or not the average current value of the three phases is less than 1A (step A50). If it is 1A or more (NO), the all-phase error 2 counter is cleared to zero (step A51) If less than 1A (YES), the all-phase error 2 counter is incremented (step A57).

  In the subsequent step A52, whether or not any one or more of the count values of the U, V and W phase currents and the three-phase current error 2 counter has reached a value corresponding to 2.5 seconds or more (125 counts). If not reached, return. If it has reached 2.5 seconds or more (YES), it is determined that the three-phase current is in an unbalanced state or all of the three-phase currents are in a low state (step A53). Here, the rotation of the motor 11 is stopped, an error display corresponding to the operation panel 29 is performed, and information indicating that a phase failure has occurred is written and stored in the nonvolatile memory 96. When the washing and drying machine is turned on again without performing repairs or the like, the control circuit 30 reads the nonvolatile memory 96 to determine whether or not the information on occurrence of phase loss is stored. . When the above information is stored, subsequent washing operation is prohibited.

  Refer to FIG. 4 again. After execution of step A39, the motor 11 is energized at the same energization angle (step A40), and when 5 seconds have elapsed in this state (YES), energization at three types of angles with the energization angle shifted by 120 degrees is performed. It is determined whether or not the process is finished (step A41). If energization with the three types of angles has not been completed (NO), the energization angle is set to be shifted by +12 degrees in the next step A42, and the process returns.

  That is, when the cause of the error of the motor 11 is, for example, a temporary stop of rotation caused by the imbalance of the laundry inside the rotating drum 4, the motor 11 may be restarted by executing a retry. There is. However, if two or more phases are missing, the motor 11 cannot be restarted. Therefore, “YES” is determined in Step A41, and it is determined that a disconnection has occurred at this point (Step S41). A43).

<Disconnection detection processing on the compressor motor 31 side>
Next, processing on the compressor motor 31 side will be described with reference to FIGS. FIG. 13 shows a three-phase current waveform observed when the wiring between the inverter circuit 32 and the compressor motor 31 is disconnected only in the U phase (5 A / DIV). In the case of the compressor motor 31, since the level of the detected current value is higher than that in the case of the drum motor 11, the S / N ratio is high, and the reduced state of the current value is observed relatively clearly.

FIG. 14 shows the three-phase combined output voltage waveform (110 V / DIV) and the three-phase combined output current waveform (0.75 A / DIV) when the U and V phases of the compressor motor 31 are disconnected. It is shown. If the two phases are lost, the rotation of the compressor motor 31 stops and the three-phase combined current decreases. In response to the decrease in the current, the control circuit 30 gives a voltage command to increase the output voltage of the compressor motor 31. At this time, the control circuit 30 is near the maximum voltage detected by the resistance elements 83a and 83b. To reach.
In the case of the compressor motor 31, since a sensor such as the rotation sensor 82 cannot be arranged inside like the drum motor 11, even if the rotation of the compressor motor 31 is stopped due to disconnection, the stop state is detected by the sensor. It cannot be detected directly. Therefore, in this embodiment, the disconnection of the compressor motor 31 is detected by capturing the phenomenon shown in FIGS.

  FIGS. 8 to 12 are flowcharts showing disconnection detection processing by the control circuit 30 and correspond to FIGS. 1 and 3 to 5 showing processing of the drum motor 11. The current detection process is performed every 128 μs as in FIG. FIG. 8 shows a main routine executed at a cycle of 1 msec. Steps B1 to B14 are processes (processes during speed control) basically corresponding to steps A1 to A14 of FIG. The details of step B1 are disclosed in FIG. 9, but in steps B21 to B23, the average value of the U, V, W phase current is calculated as a moving average of 0.1 seconds of the absolute value of the current. In Step B24, the average value of the three-phase currents is calculated by adding the average values of the respective phase currents obtained in Steps B21 to B23 to 1/3.

  In the subsequent step B25, the average value of the three-phase voltages is calculated. Here, the moving average of 0.1 seconds is calculated for the effective values of the voltage commands Vdref and Vqref. Note that what is calculated here is the same as the three-phase composite voltage waveform shown in FIG. 14, and the waveform in FIG. 14 is D / A converted and output to the outside as a result of calculation by the control circuit 30. The waveform is observed.

The determination condition in step B2 in FIG.
(1) The rotation speed of the motor 31 is 30 rps or more. (2) The average value of the three-phase current obtained in step B24 is two, 0.5 A or more. And after execution of step B10, B14, two or more phase-loss determination processing is performed in step B15.

  FIG. 10 shows details of Step B15. First, by dividing the average value of the three-phase voltage by the average value of the three-phase current to calculate the resistance value including the winding of the motor 31 as viewed from the output terminal of the inverter circuit 47 (step B31), step B2 and Similar determination is performed again (step B32). If both conditions are not satisfied (NO), the all-phase error counter is cleared to zero (step B37) and the process returns.

  On the other hand, if both conditions are satisfied (step B32, YES), it is determined whether or not the resistance value calculated in step B31 is 5Ω or more. If it is less than 5Ω (NO), the process proceeds to step B37. If the resistance value is 5Ω or more (YES), the all-phase error counter is incremented (step B34), and when the counter value becomes a value corresponding to 5 seconds or more (step B35, YES), it is determined that the phase is missing and the motor The rotation of 31 is stopped (step B36). That is, if “YES” is determined in step B35, it corresponds to the voltage and current waveform states shown in FIG.

  FIG. 11 shows a process performed every 1 msec during the “positioning” → “forced commutation” period when the compressor motor 31 is started from a stopped state (“speed control” corresponding to FIG. Performed after “commutation”). First, it is determined whether or not forced commutation is being executed (step B41). If it is a stage before execution (NO), the error 2 counter for each phase of U, V, and W is cleared to zero (step B53). If the forced commutation is being executed (YES), whether or not the average value of the U, V, and W phase currents is smaller than 30% of the d-axis current command value Idref is determined in steps B42, B44, and B46. Judge each. If “YES” is determined in each of these steps, the error 2 counter corresponding to each phase is incremented (steps B50, B51, B52). If “NO” is determined, the error 2 counter is cleared to zero (steps B43, B43). B45, B47).

Then, in step B48, it is determined whether any one of the error 2 counters corresponding to the U, V, W phases has reached a count value corresponding to 5 seconds or more, and “NO” is determined. Then, the process ends. On the other hand, if “YES” is determined, it is determined that the corresponding phase is missing, and the drive of the motor 31 is stopped (step B49). That is, if “YES” is determined in step B48, this corresponds to the state of the current waveform shown in FIG. 13 (the U phase is missing).
When the disconnection is determined in either step B10 of FIG. 8 or step B49 of FIG. 11 and the motor 31 is stopped, for example, after an interval of about 1 minute, “positioning” → “forced commutation” Retry (Retry).

FIG. 12 shows the final disconnection determination process, which is executed every 20 milliseconds. In the first step B54, it is determined whether or not the disconnection determination is made in any of the above steps B10 and B49. If there is a disconnection determination (YES), the determination number counter is incremented (step B55).
If the count value of the counter is three times or more (step B56, YES), the phase loss determination is confirmed, an error display corresponding to the operation panel 29 is performed, and phase loss has occurred in the nonvolatile memory 96. Is written and stored (step B57). Also in this case, as in the case of the drum motor 11, when the washing / drying machine is turned on again without performing repair or the like, the control circuit 30 reads out the non-volatile memory 96 and information on occurrence of phase loss. Is stored, and if the above information is stored, the subsequent washing operation is prohibited.

  As described above, according to this embodiment, the washing / drying machine control circuit 30 has the three-phase current output from the inverter circuit 32 to the drum motor 11 and the inverter circuit 47 outputs the three-phase current to the compressor motor 31. Among the phase currents, the disconnection is detected when a state where the current value of one phase is equal to or less than a predetermined value compared to the current values of the other two phases continues for a predetermined time. In other words, the current of the phase in which the disconnection occurred continues to decrease from the current of the other healthy phases, so the current between each phase is relatively compared to ensure that the disconnection is not affected by noise. Can be detected.

  Then, the control circuit 30 calculates the resistance value in step B31 of FIG. 10, so that the PWM output voltage of the inverter circuit 47 (moving average value of the effective values of the voltage commands Vdref and Vqref) is equal to or greater than a predetermined value, and Since the disconnection is detected when the current values of all three phases are equal to or less than the predetermined value, the disconnection of two or more phases can be reliably detected for the compressor motor 31 that cannot structurally incorporate the sensor.

  Further, the control circuit 30 stores the abnormality occurrence information in the nonvolatile memory 96 when the disconnection is detected and the abnormality is notified, and when the power is supplied to the washing / drying machine again, the nonvolatile memory 96 is first used. Is read out, and when the abnormality occurrence information is stored, the subsequent operation is prohibited. In other words, when an electric device does not operate normally, the user tends to turn on the power again to see the situation, but even if such a situation occurs after disconnection, operation is definitely prohibited can do.

  Furthermore, since the control circuit 30 performs the smoothing process over a longer time than the current change period accompanying the rotation of the motor 11 or 31, the detected current value is determined. Disconnection determination can be performed after eliminating the influence as much as possible. In addition, when the rotation of the drum motor 11 is stopped, the control circuit 30 tries to start the motor 11 a plurality of times, and as a result, when the rotation abnormality is determined, the disconnection is detected. The disconnection can be detected by eliminating the case where the motor 11 is temporarily constrained by the load condition or the like and the rotation is stopped.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following modifications or expansions are possible.
It is not always necessary to compare the current values with the average values of the three phases, and the current values may be compared with the other two-phase current values.
What is necessary is just to change suitably the period which calculates | requires a moving average value about an electric current and a voltage according to each design.
What is necessary is just to change suitably about determination threshold values, such as an electric current, rotation speed, and resistance value, and the predetermined time for determination.
For the compressor motor 31, instead of evaluating with a resistance value, each value of voltage and current is compared with a predetermined threshold value, and whether or not the voltage is at a predetermined position or more and all of the three-phase currents are at or below a predetermined value. The determination may be made depending on the situation. The current may be determined by determining whether the sum of the three-phase currents is equal to or less than a predetermined value.

When determining the rotation abnormality (error) of the motor 11 in step A31 or the like, it may be determined that the induced voltage of the motor 11 is lower than the rotation speed, or the rotation detected by the rotation sensor 82. The rotation stop may be determined based on the number.
Similarly to the compressor motor 31, the resistance value of the drum motor 11 is calculated as shown in FIG. 10, and the PWM output voltage of the inverter circuit 32 is equal to or higher than a predetermined value, and the current values of all three phases are equal to or lower than the predetermined value. In some cases, disconnection may be detected.
In the case of drum-type washing, the rotation axis of the drum does not necessarily have to be horizontal, and it may be arranged to have an elevation angle of several tens to several tens of degrees.
You may apply not only to a washing dryer but to either a washing machine or a dryer.
The washing machine or the washing and drying machine is not limited to the drum type, but may be applied to a so-called vertical washing machine that rotationally drives the pulsator.

The flowchart which shows one Example at the time of applying this invention to a washing-drying machine, and shows the disconnection detection process by the side of the drum motor by a control circuit. Flow chart of current detection process Flow chart showing details of step A1 Flow chart showing disconnection detection processing in motor stop state Flow chart showing details of step A39 The figure which shows the three-phase current waveform observed when the wiring of the drum motor is disconnected only in the V phase FIG. 6 is a diagram showing a waveform obtained by taking a moving average per three-phase current in the state of FIG. 1 equivalent diagram of compressor motor Flow chart showing details of step B1 Flow chart showing details of Step B15 The flowchart which shows the process performed when starting a compressor motor from a stop state Flow chart showing final disconnection determination processing The figure which shows the three-phase current waveform observed when the wiring of the compressor motor is disconnected only in the U phase The figure which shows the three-phase synthetic output voltage waveform at the time of disconnecting the U and V phases of the compressor motor, and the three-phase synthetic output current waveform A diagram schematically showing a drive system of a drum motor and a compressor motor Functional block diagram of sensorless vector control Block diagram showing other peripheral circuits controlled by the control circuit Longitudinal side view of washer / dryer Diagram showing the configuration of the heat pump

Explanation of symbols

  In the drawings, 4 is a rotating drum, 11 is a drum motor (three-phase brushless DC motor), 14 is a heat pump, 15 is a compressor, 30 is a control circuit (control means, current detection means, disconnection detection means, abnormality processing means, rotation) Abnormality determination means, PWM control system inverter), 31 is a compressor motor (three-phase brushless DC motor), 32 is an inverter circuit (PWM control system inverter), 35 is a shunt resistor (current detection means), 47 is an inverter circuit (PWM) Control type inverter), 48 is a shunt resistor (current detection means), and 96 is a nonvolatile memory.

Claims (6)

A three-phase brushless DC motor that generates a rotational driving force for performing a driving operation related to washing, a PWM control type inverter, current detection means for individually detecting the three-phase current of the motor, and vector control of the motor An abnormal process for stopping the rotation of the motor when the disconnection is detected by the disconnection detecting means, and for notifying the abnormality when a predetermined condition is satisfied. In a laundry machine comprising means,
The disconnection detecting means detects disconnection when a state in which a current value of one phase is equal to or less than a predetermined value compared to other two-phase current values among the three-phase currents continues for a predetermined time. And laundry equipment.   2. The laundry according to claim 1, wherein the disconnection detecting means detects a disconnection when the PWM output voltage of the inverter is equal to or higher than a predetermined value and the current values of all three phases are equal to or lower than a predetermined value. machine. A three-phase brushless DC motor that generates a rotational driving force for performing a driving operation related to washing, a PWM control type inverter, current detection means for individually detecting the three-phase current of the motor, and vector control of the motor An abnormal process for stopping the rotation of the motor when the disconnection is detected by the disconnection detecting means, and for notifying the abnormality when a predetermined condition is satisfied. In a laundry machine comprising means,
The disconnection detecting means is configured to detect a state in which a current value of one phase of the three-phase current is equal to or lower than a predetermined value compared to other two-phase current values for a predetermined time, or a PWM output voltage of the inverter A laundry device that detects disconnection when the current value of all three phases is equal to or less than a predetermined value. The abnormality processing means is
When the abnormality notification is performed, the abnormality occurrence information is stored in a nonvolatile memory,
4. When the power is turned on again, the non-volatile memory is first read, and when the abnormality occurrence information is stored, the subsequent operation is prohibited. The laundry equipment described.   The disconnection detecting means performs a determination after performing a smoothing process over a time longer than a current change period accompanying the rotation of the motor with respect to a current value detected by the current detecting means. The laundry machine according to any one of claims 1 to 4. When rotation of the motor is stopped, a rotation abnormality determination means for performing rotation abnormality determination of the motor is provided,
The laundry machine according to any one of claims 1 to 5, wherein the disconnection detection unit performs disconnection detection when a rotation abnormality is determined by the rotation abnormality determination unit.

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