JP2008229151A - Washing drying machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a washing drying machine by which drying operation time can be shortened and consumed power can be reduced. <P>SOLUTION: The washing drying machine has an inverter circuit 83 controlling a compressor motor 45M driving a compressor in the case a heat pump is constituted within the washing drying machine, and the inside laundry is dried by directing air heated by a condenser into a rotary tank, while the exhaust air from the rotary tank is circulated so as to reheat the same by the condenser dehumidified by an evaporator. Also, a drying step control section 70 operates the compressor motor 45M by a weak field by a voltage-phase control in an initial step of drying operation thereafter operates the compressor motor 45M by a full field shifting the control to a vector control controlling by current. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a washing / drying machine having a function of drying an object to be dried using a heat pump.

As a conventional technology, a compressor is driven in a washing and drying machine configured to use a heat pump (refrigeration cycle) including a compressor (compressor), a condenser (condenser), an evaporator (evaporator), and the like for drying an object to be dried. A configuration in which a motor is vector-controlled via an inverter circuit is disclosed (see Patent Document 1). By adopting such a configuration, there is an effect that the efficiency can be improved and the noise during the drying operation can be reduced.
JP 2006-116066 A

  By the way, in the washing / drying machine having the above-described configuration, it is necessary to complete the drying operation in a short time, and therefore, it is required to raise the temperature in the washing tub as quickly as possible after the operation is started. For this reason, the rotational speed of the compressor is rapidly increased, and at that time, the weak field operation is performed for the purpose of increasing the rotational speed of the compressor motor.

However, when weak field operation is performed in vector control to increase the rotational speed of the motor, the following problems occur. In vector control, if the result of vector calculation is not obtained, it is not known what level the actual drive voltage will be. Also, when fluctuations occur in the load torque of the motor, it is necessary to secure a margin for controlling the q-axis current so as to suppress the torque fluctuation, the drive voltage cannot be made close to 100%, and the upper limit is lower. I have to set it to a level.
As a result, the rotation speed range of the compressor motor is narrowed, and the time required for the drying operation cannot be sufficiently shortened. In addition, the field has to be weakened as much as the drive voltage is lowered, leading to a reduction in motor efficiency.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a washing / drying machine capable of further shortening the drying operation time and reducing power consumption.

The washing and drying machine of the present invention is a heat pump that compresses refrigerant with a compressor, condenses with a condenser, and circulates to evaporate with an evaporator,
An air circulation path that guides air heated by the condenser to a drying chamber to dry an object to be dried, and circulates the exhaust from the drying chamber to be dehumidified by the evaporator and then heated again by the condenser. When,
An inverter circuit for controlling a compressor motor that drives the compressor,
The initial stage of the drying operation is characterized in that the compressor motor is operated in a weak field by voltage / phase control, and then the compressor motor is switched to a vector control that is controlled by an electric current to perform a full field operation.

  That is, in the initial stage of the drying operation, if the compressor motor is operated with a weak field by voltage / phase control, the motor can be rotated at a higher speed, and the rotation speed of the compressor is rapidly increased for drying. The room temperature can be raised in a short time. Then, after raising the temperature in the drying chamber to a certain level, switching to vector control that controls the compressor motor with current and operating all-field will favorably suppress load fluctuations that occur in the compressor. Can do.

  According to the washing / drying machine of the present invention, the time required for the drying operation can be shortened, the efficiency of the compressor motor can be improved, and the power consumption can be reduced.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a longitudinal side view of a drum-type (horizontal axis) washer / dryer, in which a water tank 2 is arranged inside the outer box 1 and a rotating tank (drum, drying chamber) 3 is arranged inside the water tank 2. It is installed. The water tank 2 and the rotating tank 3 are both cylindrical, and have respective openings 4 and 5 at the front side (left side in the figure), and the opening 4 of the water tank 2 is formed as an outer box. 1 is connected through a bellows 7 to an opening 6 for loading and unloading laundry. A door 8 is provided at the opening 6 of the outer box 1 so as to be openable and closable.

A hole 9 is formed in a substantially entire region of the peripheral side portion (body portion) of the rotating tub 3 (only a part is shown), and this hole 9 functions as a water passage hole during washing and dehydration, and during drying. Functions as a vent hole. In the water tank 2, a hot air outlet 10 is formed at the upper part of the front end face (a part above the opening 4), and a hot air inlet 11 is formed at the upper part of the rear end face part. In addition, a drain port 12 is formed at the rearmost part of the bottom of the water tank 2, a drain valve 13 is connected to the drain port 12 outside the water tank 2, and a drain hose 14 is further connected to the drain valve 13, The water in the water tank 2 is discharged out of the machine.
A reinforcing member 15 is attached to the rear surface (rear surface) of the end surface portion on the rear side of the rotating tub 3, and the rotating shaft 16 protrudes rearward from the central portion of the reinforcing member 15. A large number of hot air introduction holes 17 are formed around the center of the rear end surface portion of the rotating tub 3.

A bearing housing 18 is attached to the center of the rear end surface of the water tank 2, and the rotating shaft 16 is inserted into the center of the bearing housing 18 and is rotatably supported by bearings 19 and 20. . Thereby, the rotation tank 3 is supported coaxially with the water tank 2 so as to be rotatable. The water tank 2 is elastically supported by the outer case 1 by a suspension (not shown), and the support form is a horizontal axis shape in which the axial direction of the water tank 2 is front and rear, and an upwardly inclined shape. The rotating tank 3 supported as described above has the same configuration.
A stator 22 of a motor 21 is attached to the outer periphery of the bearing housing 18, and a rotor 23 attached to the rear end portion of the rotating shaft 16 is opposed to the stator 22 from the outside. Therefore, the motor 21 is an outer rotor type brushless DC motor, and rotates the rotating tub 3 around the rotating shaft 16 by a direct drive system.

A warm air cover 24 is attached to the inside of the rear end surface portion of the water tank 2. On the other hand, the reinforcing member 15 is formed with a plurality of relatively large hot air inlets 25 around a central portion where the rotating shaft 16 is attached, and a seal member 26 is attached to the outer periphery of this portion. By bringing the seal member 26 into pressure contact with the front surface of the hot air cover 24, a hot air passage 27 is formed that communicates airtightly from the hot air inlet 11 to the hot air inlet 25.
A base plate 29 is disposed below the water tank 2 (on the bottom surface of the outer box 1) via a plurality of cushions 28, and a ventilation duct 30 is disposed on the base plate 29. The ventilation duct 30 has an air inlet 31 at the top of the front end, and the hot air outlet 10 of the water tank 2 is connected to the air inlet 31 via a return air duct 32 and a connection hose 33. . The return air duct 32 is piped so as to bypass the left side of the bellows 7.

On the other hand, a casing 35 of a circulation fan 34 is connected to the rear end portion of the ventilation duct 30, and an outlet 36 of the casing 35 is connected to the hot air of the water tank 2 via a connection hose 37 and an air supply duct 38. Connected to the inlet 11. The air supply duct 38 is piped so as to bypass the left side of the motor 21.
The warm air outlet 10 and the warm air inlet 11 of the water tank 2 are connected by the return air duct 32, the connection hose 33, the ventilation duct 30, the casing 35, the connection hose 37, and the air supply duct 38. Is provided. The circulation fan 34 circulates the air in the rotary tank 3 out of the rotary tank 3 through the ventilation path 39 and returns the air to the rotary tank 3 again. The ventilation fan 39 and the circulation fan 34 A circulation device 40 that circulates the air in the rotating tub 3 is configured.

  The circulation fan 34 is, for example, a centrifugal fan, and includes a centrifugal impeller 34 a inside the casing 35, and a motor 34 b that rotates the centrifugal impeller 34 a outside the casing 35.

  In the ventilation path 39, the filter 41, the evaporator 42, and the condenser 43 are arrange | positioned in the inside of the ventilation duct 30 in order from the front part to the rear part. Among these, the filter 41 captures lint (waste thread) carried by the air in the rotating tub 3 flowing into the ventilation duct 30 from the hot air outlet 10 of the water tub 2 through the return air duct 32 and the connection hose 33. is there. The evaporator 42 is formed by mounting a large number of heat transfer fins made of aluminum, for example, on a copper refrigerant circulation pipe having a meandering shape, and the condenser 43 has the same configuration. The air in the rotary tub 3 flowing through the ventilation duct 30 passes between them.

The evaporator 42 and the condenser 43 constitute a heat pump 47 together with the compressor 45 and the throttle 46 shown in FIG. In the heat pump 47, the compressor 45, the condenser 43, the throttle 46, and the evaporator 42 are cycle-connected in this order by the connection pipe 48 (refrigeration cycle). Circulate the enclosed refrigerant. For example, R134a, which is a high-temperature refrigerant, is used as the refrigerant.
Refrigerant R134a is a refrigerant that is suitable for high temperatures compared to refrigerant R410a and the like, and therefore, the initial rotational speed during the drying operation is set to 100 rps, as will be described later, and a rapid temperature rise is achieved in a short time, thereby shortening the drying operation time. Can help. The compressor 45 is arranged in parallel outside the ventilation duct 30 as shown in FIG. In this case, the restrictor 46 is composed of an expansion valve (in particular, an electronic expansion valve [PMV: Pulse Motor Valve]) and has an opening degree adjusting function.

  A dehumidified water discharge port 49 is formed in a portion facing the bottom surface 30 a in the side surface portion of the ventilation duct 30 between the air suction port 31 and the evaporator 42, and the dehumidified water discharge port 49 is formed on the side surface of the outer box 1. A drain pipe 50 formed in the lower part is connected by a connection pipe 51. The ventilation duct 30 has an inclined surface that descends toward the dehumidified water discharge port 49 at a portion 30 b located immediately below the evaporator 42 in the bottom surface portion.

  On the other hand, a water supply valve 52 is arranged at the rear upper part in the outer box 1. The water supply valve 52 has a plurality of outlet portions, and these are connected to a water supply box 53 disposed at the upper part of the front side in the outer box 1 by connecting pipes 54 and 55. Further, although not shown in detail, the water supply box 53 has a detergent charging part and a softening agent charging part. The water supply valve 52 is selected from the connection pipe 54 at the time of washing by selecting the opening of the outlet part. Water is supplied into the water tank 2 through the detergent charging part 53, and is also supplied into the water tank 2 from the connection pipe 55 through the softening agent charging part of the water supply box 53 at the time of final rinsing.

  In addition, a control device 56 is disposed on the back side of the upper portion of the front portion of the outer box 1. The control device 56 is composed of a microcomputer, for example, and functions as control means for controlling the overall operation of the washing / drying machine. As shown in FIG. 4, various operation signals are input to the control device 56 from an operation input unit 57 including various operation switches provided on an operation panel (not shown), and the water level in the water tank 2 is detected. A water level detection signal is input from a water level sensor 58 provided in the.

  Furthermore, the control device 56 receives temperature detection signals from temperature sensors 59 to 62 that are means for detecting the temperatures of the inlet and outlet of the evaporator 42, the condenser 43, and the refrigerant discharge portion of the compressor 45, respectively. In addition, a current value detection signal is input from an A / D converter 86 described later. The control device 56 detects the temperatures of the inlet and outlet of the evaporator 42 via the temperature sensors 59 and 61 so that the inlet temperature is slightly lower than the outlet temperature (for example, the difference is about 5 ° C.). The diaphragm 46 is controlled.

  Based on the input of the above various signals and the control program stored in advance, the control device 56 supplies the water supply valve 52, the motor 21, the drain valve 13, the compressor 45, the throttle 46, the motor 34b of the circulation fan 34, and the heater 44. The compressor cooling blower 64 is controlled via a drive circuit 65. The compressor cooling blower 64 is provided so as to cool the compressor 45, although not shown other than FIG.

  FIG. 1 is a diagram showing functional blocks of sensorless vector control performed by the control device 56 for the motor 21 and the compressor motor 45M (however, only the compressor motor 45M side is shown). Since this configuration is the same as that disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-181187, it will be schematically described here. Here, (α, β) are coordinates obtained by orthogonally transforming a three-phase (UVW) coordinate system with an electrical angle interval of 120 degrees corresponding to each phase of a compressor motor 45M, which is a three-phase IPM (Interior Permanent Magnet) motor, for example. (D, q) indicates the coordinate system of the secondary magnetic flux rotating with the rotation of the rotor of the compressor motor 45M.

  The drying process control unit 70 outputs the target speed command ωref to the movable contact 71a of the changeover switch 71 and outputs it as a subtracted value to the subtracters 72 and 73 via the fixed contacts 71b and 71c. Further, the subtracters 72 and 73 are provided with the detection speed ω of the motor 45M detected by the angular speed / rotor position estimation unit 74 as a subtraction value. The subtraction result of the subtracter 72 is given to a (current control) speed PI (Proportional-Integral) control unit 75.

  The speed PI control unit 75 performs PI (proportional integration) control based on the difference between the target speed command ωref and the detected speed ω, and performs q (quadrature) axis current command value Iqref and d (direct) axis current command value Idref. And output as subtracted values to the subtracters 76q and 76d, respectively. When performing vector control, the d-axis current command value Idref is set to a minus side slightly below “0”, so that the reluctance force of the iron core existing around the magnet of the motor 45M, which is an IPM motor, is also used. The motor 45M is driven by field control. The subtracters 76q and 76d are respectively provided with the q-axis current value Iq and the d-axis current value Id output from the d / q-axis current conversion unit 77 as subtraction values, and the subtraction results are the current PI control units 78q and 78d. To each.

  The current PI controllers 78q and 78d perform PI control based on the difference 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 converter 79. The dq / αβ conversion unit 79 is given the rotational phase angle (rotor position angle) θ of the secondary magnetic flux in the compressor motor 45M detected by the angular velocity / rotor position estimation unit 74, and based on the rotational phase angle θ. The voltage command values Vd and Vq are converted into voltage command values Vα and Vβ.

The voltage command values Vα and Vβ output from the dq / αβ conversion unit 79 are given to the UVW output conversion unit 80. The UVW output conversion unit 80 converts the voltage command values Vα and Vβ into three-phase voltage command values Vu, Vv, Convert to Vw and output. The voltage command value is given to one fixed contact 81ua, 81va, 81wa of the changeover switches 81u, 81v, 81w, and the other fixed contact 81ub, 81vb, 81wb has a UVW output waveform generator on the voltage control side. The voltage command value output by 89 is given. The movable contacts 81uc, 81vc, 81wc of the changeover switches 81u, 81v, 81w are connected to the input terminal of the PWM forming unit 82.
The PWM forming unit 82 outputs PWM signals Vup (+, −), Vvp (+, −), Vwp (+, −) of each phase obtained by modulating the carrier (triangular wave) based on the voltage command values Vu, Vv, Vw. Output to inverter circuit 83. 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 each phase winding of the motor 45M.

  Shunt resistors 85u, 85v, and 85n are inserted in the emitters of the lower arm side IGBTs 84un, 84vn, and 84wn (only one phase is shown in FIG. 1) constituting the inverter circuit 83, and the A / D conversion unit 86 includes: The terminal voltage of the shunt resistor 85 is A / D converted, and current data Iu, Iv, Iw are output to the three-phase / two-phase converter 87. The three-phase / two-phase conversion unit 87 converts the three-phase current data Iu, Iv, Iw into two-axis 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 d / q axis current converter 77.

  The d / q-axis current conversion unit 77 obtains the rotor position angle θ of the motor 45M from the angular velocity / rotor position estimation unit 74 at the time of vector control, and thereby obtains the biaxial current data Iα and Iβ in accordance with a predetermined arithmetic expression. d, q) are converted into a d-axis current value Id and a q-axis current value Iq. Then, the d-axis current value Id and the q-axis current value Iq are output to the angular velocity / rotor position estimation unit 74 and the subtractors 76d and 76q as described above.

  The angular velocity / rotor position estimation unit 74 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, Output to each part. Here, at the time of startup, the motor 45M is subjected to forced commutation by applying a startup pattern by the speed PI control unit 75, and after the rotational speed has increased to some extent to start vector control, the angular speed / rotor position is estimated. The unit 74 is activated to estimate the rotor position angle θ and rotational speed ω of the compressor motor 45M.

  On the other hand, the result of subtraction by the subtracter 73 is given to the (voltage control) speed PI control unit 88. The speed PI control unit 88 generates a voltage command (DUTY) and a phase command (PHASE) based on the subtraction result and outputs the voltage command (DUASE) and the UVW output conversion unit 89. The UVW output conversion unit 89 converts the command value output from the speed PI control unit 88 into a three-phase voltage command value of U, V, and W, and outputs it to the changeover switch 81 as described above.

Voltage command (DUTY) and phase command (PHASE) and q-axis and d-axis voltage command values Vq and Vd are input to the drying process control unit 70, and the drying process control unit 70 receives these command values. With reference to this, the change-over switches 71 and 81 are changed over.
In the above configuration, the configuration excluding the inverter circuit 83 is a block of functions realized by software of the control device (control means) 56.

  Next, the operation of the present embodiment will be described with reference to FIGS. FIG. 5 is a flowchart showing the contents of control by the drying process control unit 70. FIG. 6 is a timing chart showing the number of rotations of the motor 45M corresponding to the control contents, the temperature of the outlet (drum outlet temperature) at which hot air is sent into the rotary tub 3, and the change in input power. . When the drying operation of the washing / drying machine is started, the drying process control unit 70 starts the motor 45M by setting the target rotation speed of the compressor 45 to 100 rps in order to increase the temperature in the rotary tub 3 (step S1). ). Further, as an initial state, the changeover switches 71 and 81 have their movable contacts on the current control side.

  First, the energization phase is fixed by the current command output from the speed PI controller 75, and the rotor is positioned by gradually increasing the current value to 8A (step S2), and then the current value is fixed at 8A. Then, the energization phase is rotated to forcibly commutate the motor 45M (step S3). Then, the drying process control unit 70 determines whether or not the rotational speed of the motor 45M is 6 rps or more based on the command frequency of forced commutation (step S4), and when it is 6 rps or more (YES), the vector of the motor 45M. Control is started (step S5). Thereafter, the angular speed / rotor position estimating unit 74 estimates the rotor position angle θ and the rotational speed ω of the compressor motor 45M, and controls the output torque by obtaining the d-axis and q-axis currents Id and Iq based on the estimation results. To do.

  In the configuration disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-181187, the motor starting process corresponding to steps S1 to S4 is performed on the voltage control side. This is because the driving target is a washing machine motor arranged in a relatively open space, and therefore it is necessary to suppress the generation of noise as much as possible, so it is necessary to avoid the generation of noise due to current control. Is based. On the other hand, in the case of the present embodiment, the compressor motor 45M disposed in the sealed case is also driven in the outer box 1 of the washing machine, and around the case. Since the sound insulating material is also disposed, the driving sound of the motor 45M does not become a problem as noise, and is activated by current control. Thus, it is possible to reduce the variation in the starting torque when the motor 45M is started by current control.

  When the vector control is started, the drying process control unit 70 synthesizes the voltage command values Vq and Vd, and the output voltage of the inverter circuit 83 is a DC power supply voltage (for example, about 220V to 280V) supplied to the inverter circuit 83. ) As a reference, it is determined whether or not it has risen to a level (about 180 V to 240 V) that is equal to or higher than −40 V (step S6). The above level is a level at which it is determined that there is no margin for suppressing torque fluctuation in the output voltage control range by vector control. If it is determined that the level is equal to or higher than the above level (YES), the movable contacts of the changeover switches 71 and 81 are both switched to the voltage control side, and the voltage / phase control is performed by the speed PI control unit 88 (step S7). In this case, in order to make the rotation speed of the motor 45M higher, the weak field operation is performed by the advance angle control.

  That is, as shown in FIG. 7, when (b) is the energization timing (full field) at which the efficiency of the motor 45M is maximized, the energization timing is advanced by the phase command PHASE as shown in (c). By shifting to, the field is weakened while the applied voltage to the motor 45M is maintained at the level based on the voltage command DUTY output by the speed PI control unit 88. (A) shows the positional relationship (phases P0 to P5) between the stator winding and the rotor magnet when the motor 45M rotates. Then, the energization advance angle is set to increase as the speed command value ωref increases, and the induced voltage generated in the winding of the motor 45M is suppressed.

  In subsequent step S <b> 7, the drying process control unit 70 monitors the discharge temperature from the compressor 45 by the compressor discharge unit temperature sensor 62. Then, when the temperature becomes 110 ° C. or higher, the temperature increase period is ended, the number of rotations of the motor 45M is decreased, the temperature is shifted to the stable period, and the discharge temperature is controlled to be maintained at 110 ° C.

  Then, the drying process control unit 70 refers to the output voltage of the inverter circuit 83 again, and determines whether or not the DC power supply voltage supplied to the inverter circuit 83 has decreased to a level (160V to 220V) that is −60V or less. Is determined (step S9). The reason why the determination voltage in step S6 is set lower than that in step S6 is to prevent chattering. Then, when the level is lowered to the above level (YES), both the movable contacts of the changeover switches 71 and 81 are switched to the current control side, and the motor 45M is again operated all over the field by vector control (step S10). The process until the switching to vector control again corresponds to the “initial stage” of the drying operation. Thereafter, the rotation speed of the motor 45M is maintained substantially constant, and the drying operation is continued until the time set by the user or until the laundry is dried by the sensor (step S11: YES). .

Even after the discharge temperature from the compressor 45 is maintained at 110 ° C., the drum outlet temperature shown in FIG. 6 continues to rise.
FIG. 6 shows a change in input power to the inverter circuit 83 when the above control is performed, and a change in input power when the same control pattern is all subjected to current control (vector control) (left side). X1000 W) for the vertical axis index. As in this embodiment, when the number of rotations of the motor 45M is being increased during the temperature increase period and when the weak field operation is performed by switching to the voltage control, the power consumption is reduced as compared with the case where all the currents are controlled. I understand.

  FIG. 8 compares the control of the present embodiment with the case where everything is performed by current control as in the prior art. FIG. 8A shows the effect of improving the input power to the inverter circuit 83, and FIG. This shows the effect of improving the maximum rotational speed of the compressor motor. In addition, A and B are the types of compressors, and B has a configuration in which the compressor motor corresponds to a higher speed rotation than A (the number of turns of the stator coil is small).

  FIG. 8A shows the case where the operating conditions are set to 100 rps / 1.5 N · m at startup and 70 rps / 1.7 N · m at stable time for each compressor. In the case of the compressor A, the input power at startup is improved by -3.4% from the conventional 1025 W to 990 W, and the input power at the time of stabilization is improved by -0.8% from the conventional 816 W to 809 W. Is seen. In the case of the compressor B, the input power at the time of start-up is improved by -3.4% from the conventional 1020 W to 990 W as in the case of A, and the input power at the stable time is changed from the conventional 820 W to 821 W. It is worse by + 0.6% than the standard. About this deterioration, it is guessed that it originates in a compressor motor being high-speed rotation direction rather than A.

  FIG. 8B shows a case where the load torque at startup is constant at 1.5 N · m and 1.7 N · m. In the case of the compressor A, the maximum rotational speed at 1.5 N · m is improved by + 24% from the conventional 115 rps to 143 rps, and the maximum rotational speed at 1.7 N · m is 102 rp + 25% improvement is seen from 127 to 127 rps. In the case of the compressor B, the maximum rotational speed at 1.5 N · m is improved by + 52% from the conventional 118 rps to 175 rps (data not obtained at 1.7 N · m is not acquired). Note that the output voltage range of the inverter circuit when the data of FIG. 8 is acquired is different from that shown in the flowchart of FIG.

  As described above, according to the present embodiment, the heat pump 47 is configured inside the washing / drying machine, the air heated by the condenser 43 is guided to the rotating tub 3 to dry the laundry inside, and the laundry from the rotating tub 3 is dried. When the exhaust gas is heated again by the condenser 43 dehumidified by the evaporator 42 and circulated, the inverter circuit 83 that controls the compressor motor 45M that drives the compressor 45 is provided, and the drying process control unit 70 performs the drying operation. In the initial stage, the compressor motor 45M is operated by weak field by voltage / phase control, and then the compressor motor 45M is switched to vector control that is controlled by current to perform full field operation.

  Therefore, in the initial stage of the drying operation, the compressor motor 45M can be rotated at a higher speed than before, and the temperature in the rotary tank 3 is increased in a short time by rapidly increasing the number of rotations of the compressor 45. Thus, the time required for the drying operation can be shortened. And after raising the temperature in the rotary tank 3 to a certain level, the load fluctuation generated in the compressor 45 can be suppressed well, the efficiency of the compressor motor 45M is improved, and the power consumption is reduced. Can be reduced.

  Then, the drying process control unit 70 starts to reduce the rotational speed of the compressor motor 45M before the voltage / phase control is finished, and switches to vector control in the course of reducing the rotational speed. Can be done smoothly. Further, in the initial stage of the drying operation, the compressor motor 45M is first switched to the weak field operation by the voltage / phase control after the full field operation by the vector control. Therefore, the compressor motor 45M is increased in the process of increasing the rotation speed. Torque fluctuation can be suppressed as much as possible.

(Second embodiment)
9 to 11 show a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. Hereinafter, different parts will be described. In FIG. 9 corresponding to FIG. 1, the drying process control unit 70 is replaced with a drying process control unit 90 and a modulation rate control unit 91 and a DUTY / PHASE_Vd, Vq conversion unit 92 are added from the configuration of the first embodiment. Yes. In the second embodiment, amplitude modulation is performed so that the output voltage waveform of the inverter circuit 83 has a sine wave shape, and when the compressor motor 45M is operated in the weak field operation by voltage / phase control in the initial stage of the drying operation, Control is performed so that the output voltage is overmodulated.

  The modulation rate control unit 91 receives the d-axis current command Idref and the d-axis current Id. The modulation rate control unit 91 determines the modulation rate command based on these, and the voltage control speed PI control unit 88. Output to. The DUTY / PHASE_Vd, Vq conversion unit 92 is inserted between the voltage control speed PI control unit 88 and the output waveform generation unit 89, and converts the DUTY / PHASE command output from the PI control unit 88 into the d-axis voltage Vd. , Q-axis voltage Vq, and output to output waveform generation unit 89 and angular velocity / rotor position estimation unit 74.

  Next, the operation of the second embodiment will be described with reference to FIGS. FIG. 10 corresponds to FIG. In step S21 instead of step S6, the drying process control unit 90 determines whether or not the output voltage of the inverter circuit 83 has increased to a level that is 70% or more of the lower limit value of the DC power supply voltage. If it is determined that the level has reached the above level (YES), voltage / phase control is performed by the speed PI control unit 88 (step S22). However, unlike the first embodiment, the field weakening control is not performed at this point, and the entire field control is performed by supplying an exciting current for canceling only the reluctance torque generated by the motor 45M. The amplitude modulation rate is given in the range of 1.0 or less.

  Subsequently, the drying process control unit 90 waits until the output voltage of the inverter circuit 83 reaches 100% with respect to the lower limit value of the DC power supply voltage (step S23), and when it reaches 100% (YES), the output voltage In addition to performing voltage / phase control overmodulating, the field-weakening control is performed by increasing the excitation current to the negative side (step S24). Here, FIG. 11 shows that when the inverter circuit 83 outputs a sinusoidal voltage by two-phase modulation (a), when the amplitude modulation rate is less than 1.0 (a), and when the amplitude modulation rate is 1. FIG. 11 shows the waveform when it exceeds 0 (that is, overmodulation state) (b) (however, FIG. 11 shows only the envelope, and is actually a waveform that is interrupted by the PWM signal).

  In the case of normal voltage / phase control, the amplitude modulation rate is 1.0 at the maximum, and a sinusoidal voltage is output within a range in which the voltage waveform is not distorted. On the other hand, in step S24, by setting the amplitude modulation factor to be larger than 1.0, the voltage waveform is output in a state distorted from the sine wave. Note that the modulation rate control unit 91 determines the modulation rate command based on the d-axis current command Idref and the d-axis current Id as described above. In this case, since the rotational speed command ωref is not given to the current vector control side, it does not function as a whole. However, for the d-axis current command Idref, a value to be applied may be set in advance for both the case of the whole field and the case of the field weakening. The control of the d-axis current Id is also performed when the control is switched in step S7. In addition, the angular velocity / rotor position estimator 74 can be obtained by continuing the operation.

In other words, the field weakening control is performed by causing the excitation current to flow more on the negative side of the negative side (than the balance with the reluctance torque) for the purpose of further increasing the rotational speed of the motor 45M. It is a current that does not contribute, and if it flows more, the copper loss increases and the efficiency decreases. Therefore, when overmodulation control is performed as described above, the execution output voltage becomes higher due to waveform distortion, so that the timing for starting field-weakening control can be delayed and efficiency can be increased.
Thereafter, step S8 is executed in the same manner as in the first embodiment, and when the output voltage of the inverter circuit 83 falls below 70% with respect to the lower limit value of the DC power supply voltage (step S25, YES), the vector control side Switch.

FIG. 12 shows a case where overmodulation control is combined with voltage control in the second embodiment together with FIG. 8 of the first embodiment. In the case of the compressor A in FIG. 12A, the input power at start-up is improved by −4% from the conventional 1025 W to 985 W, and the input power at the stable time is −0. There is a 7% improvement. In the case of the compressor B, the input power at the time of start-up is improved by -4% from the conventional 1020 W to 985 W as in the case of A, and the input power at the time of stability is the same as that of the conventional 820 W. It is worse by + 0.5% from the standard. The reason is the same as that described in the first embodiment.
12B, in the case of the compressor A, the maximum rotational speed at 1.5 N · m is improved by + 37% from the conventional 115 rps to 157 rps, and is 1.7 N · m. The maximum rotational speed is improved by + 34% from the conventional 102 rps to 137 rps. Moreover, the data about the compressor B is not acquired. In general, the improvement effect is higher than in the first embodiment.

  As described above, according to the second embodiment, when the output voltage of the inverter circuit 83 is amplitude-modulated so as to have a sine wave shape, and the weak field operation is performed by the voltage / phase control 88 in the initial stage of the drying process, The amplitude modulation rate of the output voltage is set to be larger than 1.0 and the overmodulation state is controlled. Therefore, the efficiency can be increased by increasing the execution voltage applied to the motor 45M and delaying the start time of the field weakening control.

The present invention is not limited to the embodiments described above or shown in the drawings, and the following modifications or expansions are possible.
The voltage / phase control may be terminated and switched to vector control, and at the same time, the rotation speed of the compressor motor 45M may be started to decrease.
What is necessary is just to change suitably the level setting of the output voltage which switches vector control and voltage phase control according to each design.
The motor 45M may be activated by voltage control from the beginning.

Functional block diagram of sensorless vector control which is a first embodiment of the present invention and is performed on a compressor motor by a control device of a washing and drying machine Longitudinal side view showing the overall structure of the drum-type washer / dryer Diagram showing the configuration of the heat pump Functional block diagram showing the control system of the washer / dryer Flow chart showing the control contents by the drying process control unit Timing chart showing changes in motor rotation speed, hot air outlet temperature of the rotating tub (drum), and input power corresponding to the control contents of FIG. Diagram explaining weak field operation in voltage / phase control The control of the present embodiment is compared with the case where all are controlled by current control. (A) shows the improvement effect of the input power, (b) shows the improvement effect of the maximum rotational speed of the compressor motor. FIG. 1 equivalent view showing a second embodiment of the present invention. Figure equivalent to FIG. It is an output voltage waveform of an inverter circuit, (a) shows a case where the modulation factor is less than 1.0, and (b) shows a case where the modulation factor is more than 1.0. Equivalent to FIG.

Explanation of symbols

  In the drawings, 3 is a rotating tank (drying chamber), 42 is an evaporator, 43 is a condenser, 45 is a compressor, 45M is a compressor motor, 47 is a heat pump, 70 is a drying process control unit, and 83 is an inverter circuit. .

Claims (4)

A heat pump that compresses the refrigerant with a compressor, condenses it with a condenser, and circulates it to evaporate with an evaporator;
An air circulation path that guides air heated by the condenser to a drying chamber to dry an object to be dried, and circulates the exhaust from the drying chamber to be dehumidified by the evaporator and then heated again by the condenser. When,
An inverter circuit for controlling a compressor motor that drives the compressor,
The initial stage of the drying operation is a washing operation characterized in that the compressor motor is operated in a weak field by voltage / phase control, and then the compressor motor is switched to a vector control that is controlled by an electric current to perform a full field operation. Dryer.   2. The vector control is started in the process of starting to reduce the rotational speed of the compressor motor before the voltage / phase control is finished, and reducing the rotational speed. Laundry dryer.   3. The washing / drying machine according to claim 1, wherein, in the initial stage of the drying operation, the compressor motor is switched to the weak field operation by the voltage / phase control after the compressor motor is operated by the vector control. . The output voltage of the inverter circuit is amplitude-modulated to have a sine wave shape,
4. When performing a weak field operation by the voltage / phase control, the amplitude modulation rate of the output voltage is set to be larger than 1.0 and controlled to an overmodulation state. The washing dryer described.

Images