KR100977925B1 - Washing and drying machine - Google Patents

Abstract

The present invention provides a laundry dryer which can further shorten the drying operation time and also reduce the power consumption, and constitutes a heat pump inside the laundry dryer, and delivers the air heated by the condenser to the rotary tank. In order to dry the laundry therein and to circulate the exhaust air from the rotating tank to dehumidify in the evaporator and to heat the condenser again, the inverter circuit 83 for controlling the compressor motor 45M for driving the compressor, and the inverter circuit ( 83, the control means 56 for controlling, the drying stroke control part 70 of the control means 56 operates the field weakening of the compressor motor 45M by voltage and phase control at the initial stage of a drying operation, Thereafter, the compressor motor 45M is switched to the vector control controlled by the electric current, and the electric field operation is performed.

Description

Laundry dryer {WASHING AND DRYING MACHINE}

The present invention relates to a laundry dryer having a function of drying a dry item using a heat pump.

In the prior art, a motor for driving a compressor in a laundry dryer having a heat pump (freezing cycle) equipped with a compressor, a condenser, an evaporator, and the like to dry the dried object is provided through an inverter circuit. The structure which controls vector is disclosed (Unexamined-Japanese-Patent No. 2006-116066). By employing such a configuration, the efficiency is good and the effect of reducing the noise during the drying operation is achieved.

By the way, in the laundry dryer of the said structure, since the drying operation needs to be completed in a short time, it is calculated | required to raise the temperature in a washing tank in a very short time after starting of operation. Therefore, the rotation speed of a compressor motor is raised rapidly, and the field weakening operation is performed in order to make the rotation speed of a compressor motor higher.

However, when the field weakening operation is performed under the vector control and the speed of the motor is to be increased, the following problems occur. In vector control, if the result of the vector operation does not come out, it is not known to what level the actual driving voltage becomes. In addition, when a change occurs 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 change, the driving voltage cannot be close to 100%, and the upper limit can be lowered. It cannot be set.

As a result, the rotation speed range of the compressor motor was narrowed, and the time required for the drying operation could not be shortened sufficiently. In addition, as the drive voltage is lowered, the field must be made too weak, resulting in a decrease in motor efficiency.

This invention is made | formed in view of the said situation, and the objective is to provide the laundry dryer which can shorten drying operation time further and can also reduce power consumption.

The laundry dryer of the present invention compresses a refrigerant with a compressor, circulates the condenser in a condenser and circulates the evaporator to evaporate it, and delivers the air heated in the condenser to a drying chamber to dry an interior to be dried, from the drying chamber. An air circulation path for circulating the exhaust air of the air to dehumidify in the evaporator and then to be heated again in the condenser, an inverter circuit for controlling a compressor motor driving the compressor, and control means for controlling the inverter circuit, In the initial stage of the drying operation, the control means operates the field weakening of the compressor motor by voltage and phase control, and then operates the electric field by switching to vector control controlling the compressor motor by electric current. Starts to lower the rotational speed of the compressor motor before ending the control, In the middle of the process of lowering the number of revolutions is characterized in that for performing the transition with the vector control.

In other words, when the compressor motor is operated by voltage and phase control in the initial stage of drying operation, it becomes possible to rotate the motor at a higher speed, thereby rapidly increasing the rotation speed of the compressor to shorten the temperature in the drying chamber in a short time. Can be raised. Then, after the temperature in the drying chamber is raised to a certain level, the load fluctuation generated in the compressor can be satisfactorily suppressed when the electric field is operated by switching to the vector control for controlling the compressor motor with current.

According to the laundry dryer of the present invention, the time required for the drying operation can be shortened, and the efficiency of the compressor motor can be improved to reduce power consumption.

(First embodiment)

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 8. Fig. 2 is a vertical cross-sectional view of a drum type (dry-axis type) laundry dryer, in which a water tank 2 is installed inside the outer box 1, and a rotating tank (drum, drying chamber) 3 is installed inside the water tank 2. It is. The water tank 2 and the rotating tank 3 both have a cylindrical shape, and the front side (left side in the drawing) has respective openings 4 and 5 in the cross section, and the opening of the water tank 2 therein. 4 is connected through the bellows 7 to the laundry entrance opening 6 formed in the front part of the outer box 1. As shown in FIG. The door 8 is provided in the opening part 6 of the outer box 1 so that opening and closing is possible.

Holes 9 are formed in almost all regions of the circumferential side (body portion) in the rotating tub 3 (only a part of them), and the holes 9 function as water holes during washing and dehydration, and are dried. At the time, it functions as a ventilation hole. In the water tank 2, the hot air outlet 10 is formed in the upper part of the front end surface part (upper part than the said opening part 4), and the hot air inlet 11 is formed in the upper part of the rear end part. Moreover, the drain port 12 is formed in the last part of the bottom part of the water tank 2, The drain valve 13 is connected to the said drain port 12 from the water tank 2 outside, and the drain valve 13 is drained. By connecting the hose 14, the water in the water tank 2 is discharged | emitted to the exterior of a washing machine.

The reinforcing member 15 is attached to the rear surface (back side) of the cross section of the rear side of the rotating tank 3, and the rotating shaft 16 is attached to the center part of the said reinforcing member 15, and protrudes rearwardly. A plurality of warm air introduction holes 17 are formed around the center of the rear end face of the rotary tub 3.

The bearing housing 18 is attached to the center of the rear end surface of the water tank 2, and the said rotating shaft 16 is inserted through the center of the said bearing housing 18, and can be rotated by the bearings 19 and 20. FIG. Is supported. Moreover, the rotating tank 3 is rotatably supported by the water tank 2 coaxially by this. In addition, the water tank 2 is elastically supported by the outer box 1 by the suspension which is not shown in figure, The support form is the inclination shape which goes up to the front also in the horizontal axis shape in which the axial direction of the water tank 2 becomes back and front, and the said The rotating tank 3 supported by the water tank 2 as mentioned above also becomes the same form.

The stator 22 of the motor 21 is attached to the bearing housing 18 on the outer circumference thereof, and the rotor 23 attached to the rear end of the rotation shaft 16 is opposed to the stator 22 from the outside. have. Therefore, the motor 21 is an outer rotor type brushless DC motor, and drives the rotating tub 3 to the rotation shaft 16 by the direct drive system.

The warm air cover 24 is attached inside the rear end surface of the water tank 2. On the other hand, the reinforcement member 15 is formed with a plurality of relatively large hot air inlet 25 at the periphery of the central portion to which the rotation shaft 16 is attached, and the seal member 26 is attached to the outer peripheral portion of the portion. The hot air passage 27, which is hermetically passed from the hot air inlet 11 to the hot air inlet 25, is formed by pressing the seal member 26 to the front face of the hot air cover 24.

The base plate 29 is arrange | positioned below the water tank 2 (on the bottom face of the outer box 1) through the some cushion 28, and the ventilation duct 30 is carried out on the said base plate 29. Is arranged. The ventilation duct 30 has an air intake 31 at the upper end of the front end portion, and the hot air outlet 10 of the water tank 2 is provided with an air intake duct 32 and a connection hose 33 in the air intake 31. Is connected via In addition, the ventilation duct 32 is piped so as to bypass the left side of the bellows 7.

On the other hand, the casing 35 of the circulation blower 34 is connected to the rear end of the ventilation duct 30, and the outlet part 36 of the casing 35 is connected to the connection hose 37 and the air blowing duct 38. It is connected to the warm air inlet 11 of the water tank 2 through the through. In addition, the blowing air duct 38 is piped so as to bypass the left side of the motor 21.

The ventilation duct 32, the connection hose 33, the ventilation duct 30, and the casing 35 are connected to the hot air outlet 10 of the water tank 2 by the connection hose 37 and the air blowing duct 38. The hot air inlet 11 is connected, and a ventilation path 39 is provided. The circulation blower 34 discharges the air in the rotary tank 3 out of the rotary tank 3 through the ventilation path 39, and circulates it back to the rotary tank 3 so as to circulate it back to the rotary tank 3. By the circulation blower 34, the circulation device 40 which circulates the air in the rotating tank 3 is comprised.

Moreover, the circulation blower 34 is a centrifugal fan, for example, is provided with the centrifugal vane wheel 34a in the inside of the casing 35, and the casing (the motor 34b which rotates the centrifugal vane wheel 34a) is carried out. It is provided outside 35).

In the ventilation path 39, the filter 41, the evaporator 42, and the condenser 43 are disposed in order from the front part to the rear part of the ventilation duct 30. Among them, the filter 41 is caused by the air in the rotary tank 3 flowing into the ventilation duct 30 from the hot air outlet 10 of the water tank 2 through the ventilation duct 32 and the connection hose 33. This is to capture the lint that is transported. The evaporator 42 is formed by attaching, for example, a plurality of heat transfer fins made of, for example, aluminum to a copper refrigerant distribution pipe having a meandering shape, and the condenser 43 also has the same configuration. It is comprised so that the air in the rotating tank 3 which flows through the ventilation duct 30 may pass between each of the.

The evaporator 42 and the condenser 43 constitute the heat pump 47 together with the compressor 45 and the throttle 46 shown in FIG. In the heat pump 47, the connection pipe 48 cycles these in the order of the compressor 45, the condenser 43, the throttle 46, and the evaporator 42 (refrigeration cycle), and the compressor 45 Is operated to circulate the refrigerant enclosed in the cycle. As the refrigerant, for example, R134a, which is a high temperature refrigerant, is used.

Since the refrigerant R134a is a refrigerant suitable for high temperature in comparison with the refrigerant R410a or the like, the initial rotational speed during the drying operation is set to 100 rpm as described later, and thus, a rapid temperature rise in a short time can be contributed to shortening the drying operation time. In addition, the compressor 45 is provided in the outside of the ventilation duct 30 as shown in FIG. In this case, the throttle 46 consists of an expansion valve (especially an electronic expansion valve [PMV: Pulse Motor Valve]), and has a function of opening degree adjustment.

A dehumidifying water outlet 49 is formed at a portion of the side face of the ventilation duct 30 between the air intake port 31 and the evaporator 42 toward the bottom surface 30a, and the dehumidifying water outlet 49 is formed in an outer box. The connection pipe 51 is connected to the drain port 50 formed in the lower part of the side surface of (1). Moreover, the ventilation duct 30 makes the part 30b which is located just below the evaporator 42 in the bottom face part as the inclined surface which descend | falls toward the said dehumidification water discharge port 49. As shown in FIG.

On the other hand, the water supply valve 52 is arrange | positioned at the upper back side in the outer box 1. The water supply valve 52 is provided with a plurality of outlet portions, and they are connected to the water supply box 53 disposed at the upper part of the front side in the outer box 1 by connecting pipes 54 and 55. In addition, although not shown in detail, the water supply box 53 is equipped with the detergent input part and the flexible finishing agent input part, The said water supply valve 52 connects the pipe 54 at the time of washing | cleaning by selection of opening of an exit part. Water supply in the water tank 2 via the detergent inlet of the water supply box 53, and from the connection pipe 55 through the flexible finishing agent inlet of the water supply box 53 at the time of final rinsing. I am trying to.

In addition, the control apparatus 56 is arrange | positioned inside the upper part of the front part of the outer box 1. The control device 56 is made of, for example, a microcomputer and functions as a control means for controlling the overall operation of the laundry dryer. As shown in FIG. 4, the control apparatus 56 is provided so that various operation signals may be input from the operation input part 57 which consists of various operation switches which have an operation panel (not shown), and will detect the water level in the water tank 2, respectively. The water level detection signal is input from one water level sensor 58.

Further, the control device 56 has a temperature detection signal from the temperature sensors 59 to 62, which are means for detecting respective temperatures of the inlet and the outlet of the evaporator 42, the refrigerant discharge portion of the condenser 43, and the compressor 45. Further, the current value detection signal is input from the A / D converter 86 described later. In addition, the control device 56 detects the temperatures of the inlet and the outlet of the evaporator 42 through 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.). ) Controls the throttle 46.

The control device 56 circulates the water feed valve 52, the motor 21, the drain valve 13, the compressor 45, the throttle 46, and the circulation based on the input of the various signals and the previously stored control program. The motor 34b of the blower 34, the heater 44, and the compressor cooling blower 64 are controlled through the drive circuit 65. As shown in FIG. In addition, although the compressor cooling blower 64 is not shown other than FIG. 4, it is provided so that the compressor 45 may be cooled.

FIG. 1 is a diagram showing a functional block of sensorless vector control performed by the control device 56 for the motor 21 and the compressor motor 45M (but only for the compressor motor 45M side). Since the configuration is the same as that disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-181187 or the like, it will be described schematically here. In addition, ((alpha), (beta)) is the coordinate system which orthogonally converted the three-phase (UVW) coordinate system of 120 degrees of electrical angles corresponding to each phase of the compressor motor 45M which is a 3-phase Interior Permanent Magnet (IPM) motor, for example. (D, q) shows the coordinate system of the secondary magnetic flux which is rotating with the rotation of the rotor of the compressor motor 45M.

The drying stroke control unit 70 outputs the target speed command ωref to the movable contact 71a of the changeover switch 71 as a subtracted value to the subtractors 72 and 73 via the fixed contacts 71b and 71c. Output In addition, the subtractors 72 and 73 are provided with the detection speed? Of the motor 45M detected by the angular speed / rotor position estimating unit 74 as a subtracted value. The subtraction result of the subtractor 72 is given to the (current control) speed PI (Proportional-Integral) control unit 75.

The speed PI control unit 75 performs PI (comparison integration) control based on the difference between the target speed command ω ref and the detection speed ω, and performs the q (quadrature) axis current command value I qref and d ( direct) A shaft current command value I dref is generated and output to the subtractors 76q and 76d as subtracted values, respectively. In addition, when performing vector control, d-axis current command value I dref is set to the negative side slightly below "0", and the magnetoresistive force of the iron core which exists around the magnet of the motor 45M which is an IPM motor is also used. While driving, the motor 45M is driven by the electric field control. The subtractors 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 converter 77 as subtraction values. 78q and 78d), respectively.

The current PI control units 78q and 78d perform PI control based on the difference amount between the q-axis current command value I qref and the d-axis current command value I dref, and the q-axis voltage command value Vq and d The axial voltage command value Vd is generated and output to the dq / αβ conversion unit 79. The dq / αβ conversion unit 79 is provided with a rotation phase angle (rotor position angle) θ of the secondary magnetic flux in the compressor motor 45M detected by the angular velocity / rotor position estimating unit 74, and the rotation thereof. The voltage command values Vd and Vq are converted into the voltage command values Vα and Vβ based on the phase angle θ.

The voltage command values Vα and Vβ output by the dq / αβ conversion unit 79 are given to the UVW output conversion unit 80, and the UVW output conversion unit 80 sets the voltage command values Vα and Vβ in three phases. The voltage command is converted into the voltage command values Vu, Vv, and Vw and output. The voltage command value is applied to one of the fixed contacts 81ua, 81va, 81wa of the switching switches 81u, 81v, 81w, and UVW of the voltage control side to the other fixed contacts 81ub, 81vb, 81wb. The voltage command value output by the output waveform generator 89 is given. The movable contacts 81uc, 81vc, 81wc of the changeover switches 81u, 81v, 81w are connected to the input terminals of the PWM forming unit 82.

The PWM forming unit 82 modulates the PWM signals Vup (+,-), Vvp (+,-), Vwp (+,-of each phase in which the carrier (triangle wave) is modulated based on the voltage command values Vu, Vv, and Vw. ) Is output to the inverter circuit 83. The PWM signals Vup to Vwp are output as, for example, signals of a pulse width corresponding to the voltage amplitude based on the sinusoidal wave so that a sinusoidal current is energized through each phase winding of the motor 45M.

The shunt resistors 85u, 85v, 85n are inserted into the emitters of the lower arm IGBTs 84un, 84vn, 84wn (only one phase in Fig. 1) constituting the inverter circuit 83, and the A / D converter 86 performs A / D conversion on the terminal voltage of the shunt resistor 85 and outputs the current data Iu, Iv, and Iw to the three-phase and two-phase conversion unit 87. The three-phase / two-phase conversion unit 87 converts the three-phase current data Iu, Iv, and Iw into biaxial current data Iα and Iβ of the rectangular coordinate system according to a predetermined calculation formula. The biaxial current data Iα and Iβ are then output to the dq axis current converter 77.

 The d-q-axis current converter 77 obtains the rotor position angle θ of the motor 45M from the angular velocity / rotor position estimator 74 during vector control, thereby making the biaxial current data in accordance with a predetermined equation. (Iα, Iβ) are converted into d-axis current values Id and q-axis current values Iq on the rotation coordinate systems d and q. Then, the d-axis current value Id and the q-axis current value Iq are output to the angular velocity / rotor position estimating unit 74 and the subtractors 76d and 76q as described above.

The angular velocity / rotor position estimating unit 74 determines the position angle of the rotor 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. (theta) and the rotational speed (ω) are estimated and output to each part. Here, the motor 45M is applied with a starting pattern by the speed (PI) control unit 75 at the time of starting, and a forced current is applied, and after the rotation speed is increased to some extent and the vector control is started, the angular speed and rotor position weight is added. The step 74 is started to estimate the position angle θ and the rotational speed ω of the rotor of the compressor motor 45M.

On the other hand, the subtraction result by the subtractor 73 is given to the (voltage control) speed PI control part 88. As shown in FIG. The speed PI control unit 88 generates a voltage command DUTY and a phase command PHASE based on the result of the subtraction, and outputs the voltage command DUTY and the phase command PHASE to the UVW output converter 89. The UVW output converting unit 89 converts the command value output by the speed PI control unit 88 into voltage command values of three phases of U, V, and W, and outputs it to the switching switch 81 as described above.

A voltage command DUTY and a phase command PHASE and q-axis and d-axis voltage command values Vq and Vd are input to the drying stroke control unit 70, and the drying stroke control unit 70 refers to these command values. The switching switches 71 and 81 are configured to be switched.

In addition, the structure except the inverter circuit 83 in the above structure blocks the function realized by the software of the control apparatus (control means) 56. As shown in FIG.

Next, the operation of the present embodiment will be described with reference to Figs. 5 is a flowchart showing the control contents by the drying stroke control unit 70. 6 is a timing chart showing changes in the rotational speed of the motor 45M corresponding to the control contents, the temperature of the outlet (drum outlet temperature) at which the warm air is blown out inside the rotating tank 3, and the change of the input power. to be. When the drying operation of the laundry dryer is started, the drying stroke control unit 70 raises the temperature in the rotating tank 3, and thus starts the motor 45M with the target rotational speed of the compressor 45 at 100 rpm. (S1)). In addition, as the initial state, the changeover switches 71 and 81 have the movable contact as the current control side.

First, by the current command output from the speed PI control unit 75, the energization phase is fixed, and the rotor position of the motor 45M is performed by gradually increasing the current value to 8A (step S2), and the current therefrom. The value is fixed to 8A, and the energized phase is rotated to force the motor 45M (step S3). And the drying stroke control part 70 judges whether the rotation speed of the motor 45M became 6 rpm or more based on the command frequency of the forced current (step S4), and when it becomes 6 rpm or more (Yes), the motor 45M Start vector control (step S5). Subsequently, the angular velocity and rotor position estimating unit 74 estimates the position angle θ and the rotational speed ω of the rotor of the compressor motor 45M, and the d-axis and q-axis currents Id based on the estimation result. , Iq) to control the output torque.

For example, in the structure disclosed by Unexamined-Japanese-Patent No. 2003-181187 etc., the starting process of the motor corresponding to steps S1-S4 is made to be performed by the voltage control side. This is based on the need to avoid the generation of noise due to the current control, since it is necessary to minimize the generation of noise since the washing machine motor is arranged in a relatively open space. In contrast, in the case of the present embodiment, the compressor motor 45M, which is disposed in the outer box 1 of the washing machine and also inside the sealed case, is the driving target, and the sound insulating material is also disposed around the case. The driving sound of 45M is not a problem as a noise and is started by current control. In this way, it is possible to reduce the variation in the starting torque by starting the motor 45M with current control.

When the vector control is started, the drying stroke control unit 70 synthesizes the voltage command values Vq and Vd, and the DC power supply voltage (for example, the output voltage of the inverter circuit 83 is supplied to the inverter circuit 83). On the basis of approximately 220V to 280V, it is determined whether or not it has risen to a level (about 180V to 240V) that is -40V or more (step S6). The above level is a level at which it is judged that the margin for suppressing the torque fluctuation disappears with respect to the control range of the output voltage by the vector control. If it is determined that the level is equal to or greater than the above level (Yes), the movable contacts of the changeover switches 71 and 81 are all switched to the voltage control side, and the voltage and phase control by the speed PI control unit 88 is performed (step ( S7)). In this case, in order to make the rotation speed of the motor 45M higher, weak field operation is performed by advancing angle control.

That is, as shown in FIG. 7, when (b) is an energization timing (an electric field) in which the efficiency of the motor 45M becomes the maximum, electricity supply timing advances by phase command PHASE as shown in (c). By shifting to the phase side, the field is weakened while the voltage applied to the motor 45M is maintained at a level based on the voltage command DUTY output by the speed PI control unit 88. In addition, (a) shows the positional relationship (phases P0 to P5) between the stator winding and the rotor magnet when the motor 45M rotates. Then, as the speed command value ω ref rises, the energizing propagation angle is set to be large, and the induced voltage generated in the winding of the motor 45M is suppressed.

In subsequent step S8, the drying stroke control part 70 monitors the discharge temperature from the compressor 45 by the temperature sensor 62 for compressor discharge parts. And when the temperature becomes 110 degreeC or more, a temperature raising period is complete | finished, the rotation speed of the motor 45M is reduced, it transfers to a temperature stability period, and it controls so that discharge temperature is maintained at 110 degreeC.

Then, the drying stroke control unit 70 refers to the output voltage of the inverter circuit 83 again, and has fallen from the DC power supply voltage supplied to the inverter circuit 83 to a level (160V to 220V) which becomes -60V or less. It is determined whether or not (step S9). In addition, setting the determination voltage of step S6 lower than step S6 is for preventing chattering. Then, when the level is lowered to the above level (Yes), the movable contacts of the changeover switches 71 and 81 are all switched to the current control side, and the motor 45M is driven again by vector control (step S10). From this point onward, switching to vector control again corresponds to the "initial stage" of the drying operation. Thereafter, the rotation speed of the motor 45M is kept 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). do.

Further, 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.

6 shows the change of the input power to the inverter circuit 83 when the above control is performed, and the change of the input power when the current control (vector control) is performed for all the same control patterns (left side). X1000W for the longitudinal axis index). As shown in the present embodiment, when the number of revolutions of the motor 45M is increased during the temperature increase period, when the field weakening operation is performed by switching to the voltage control, it is understood that the power consumption is lower than when the current is controlled by all of them. have.

FIG. 8 compares the control of the present embodiment with a case where all of them are performed by current control as in the prior art, (a) shows an effect of improving the input power to the inverter circuit 83, and (b) shows the effect of the compressor motor. The improvement effect of the highest rotation speed is shown. In addition, A and B are types of a compressor, and B is a thing whose structure of a compressor motor respond | corresponds to high speed rotation rather than A (the number of turns of a stator coil is few).

Fig. 8 (a) shows a case where operating conditions are set at 100 rpm / 1.5 N · m at start time and 70 rpm / 1.7 N · m at stable time for each compressor. In the case of compressor A, the input power at startup is improved by -3.4% from 1025W to 990W, and the stable input power is improved by -0.8% from 816W to 809W. In the case of compressor B, the input power at startup is improved from -1020W to 990W in the same way as A, and the improvement of -3.4% is seen, and the stable input power is from conventional 820W to 821W, +0.6 than the standard. It's getting worse by%. This deterioration is estimated to be due to the tendency of the compressor motor to rotate faster than A.

FIG. 8B shows the case where the load torque at the start is made constant at 1.5 N · m and 1.7 N · m. In the case of compressor A, the maximum rotational speed in the case of 1.5 N · m is improved by + 24% from 115 rpm to 143 rpm, and the maximum rotational speed in the case of 1.7N · m is + 25% from conventional 102 rpm to 127 rpm. Of improvement is seen. In the case of the compressor B, the maximum rotational speed in the case of 1.5 N · m shows a + 52% improvement from the conventional 118 rpm to 175 rpm (data for 1.7 N · m is not obtained). In addition, the output voltage range of the inverter circuit at the time of acquiring the data of FIG. 8 differs from what was shown to the flowchart of FIG.

According to the present embodiment as described above, the heat pump 47 is configured inside the laundry dryer, the air heated in the condenser 43 is led to the rotary tank 3 to dry the laundry inside the rotary tank ( In the case where the exhaust air from 3) is dehumidified in the evaporator 42 and heated and circulated again in the condenser 43, an inverter circuit 83 for controlling the compressor motor 45M for driving the compressor 45 is provided. The drying stroke control unit 70 weakly operates the compressor motor 45M by the voltage and phase control at the initial stage of the drying operation, and then switches to the vector control which controls the compressor motor 45M by the electric current and then the electric field. Let's drive.

Therefore, in the initial stage of the drying operation, the compressor motor 45M can be rotated at a higher speed than the conventional one, and the rotation speed of the compressor 45 is rapidly increased to raise the temperature in the rotating tank 3 in a short time, The time required for the drying operation can be shortened. And after raising the temperature in the rotating tank 3 to some level, the load fluctuation which generate | occur | produces in the compressor 45 can be suppressed favorably, the efficiency of the compressor motor 45M is improved, and power consumption is reduced. You can.

And the drying stroke control part 70 starts to reduce the rotation speed of the compressor motor 45M before ending voltage-phase control, and switches to vector control in the middle of the process of reducing the rotation speed. We can perform change over smoothly. In the initial stage of the drying operation, the compressor motor 45M is first operated by an electric field under vector control, and then switched to a field weakening operation by voltage and phase control, so that the compressor motor 45M is in the process of increasing the rotation speed. The vector variation of can be suppressed extremely.

(Second embodiment)

9 to 11 show a second embodiment of the present invention. The same parts as those of the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted. In FIG. 9, which corresponds to FIG. 1, the drying stroke control unit 70 is replaced with the drying stroke control unit 90 from the configuration of the first embodiment, and the modulation rate control unit 91, DUTY PHASE_Vd, and Vq conversion unit 92 are replaced. Adding. In the second embodiment, the output voltage waveform of the inverter circuit 83 is amplitude modulated so as to have a sine wave shape, and the output voltage is reduced when the compressor motor 45M is operated by voltage and phase control in the initial stage of the drying operation. Control to be overmodulated.

The d-axis current command Idref and the d-axis current Id are input to the modulation rate control unit 91, and the modulation rate control unit 91 determines the modulation rate command based on these and sets the voltage control speed PI. ) Is output to the control unit 88. The DUTY / PHASE_Vd and Vq modulators 92 are inserted between the voltage control speed (PI) control unit 88 and the output waveform generation unit 89 and receive the DUTY and PHASE commands output from the PI control unit 88. It converts into axial voltage Vd and q-axis voltage Vq, and outputs them to the output waveform generation part 89 and the angular velocity and rotor position estimation part 74. As shown in FIG.

Next, the operation of the second embodiment will be described with reference to FIGS. 10 and 11. 10 is a diagram corresponding to FIG. 5. In step S21 instead of step S6, the drying stroke control unit 90 determines whether or not the output voltage of the inverter circuit 83 has risen to a level of 70% or more with respect to the lower limit of the DC power supply voltage. When it is determined that the level is equal to or higher than the level (Yes), the voltage and phase control by the speed (PI) control unit 88 is performed (step S22). Unlike the first embodiment, however, field weakening control is not performed at this point, and the electric field control is performed by allowing the excitation current to flow as much as the rejected portion of the magnetoresistive torque generated by the motor 45M. In addition, an amplitude modulation rate is given in 1.0 or less range.

Subsequently, the drying stroke control unit 90 waits until the output voltage of the inverter circuit 83 reaches 100% with respect to the lower limit of the DC power supply voltage (step S23), and when it reaches 100% (YES) ), The voltage and phase control which overmodulated the output voltage is performed, and the field weakening control is performed by increasing the excitation current to the cathode side (step S24). Here, in FIG. 11, when the inverter circuit 83 outputs a sine wave shape voltage by two-phase modulation, (a) when the amplitude modulation rate is less than 1.0, and when the amplitude modulation rate exceeds 1.0 (that is, (Overmodulation state) (b) shows a waveform (However, FIG. 11 shows only an envelope, and is actually a waveform interrupted by a PWM signal).

In the case of normal voltage / phase control, the amplitude modulation rate is at most 1.0, and a sinusoidal voltage is output in a range in which the voltage waveform is not distorted. In contrast, in step S24, the amplitude modulation rate is set to be larger than 1.0, so that the voltage waveform is output in a state in which the voltage waveform is distorted than the sine wave. As described above, the modulation rate controller 91 determines the modulation rate command based on the d-axis current command I dref and the d-axis current Id. In this case, since the rotation speed command? Ref is not given to the current vector control side, it does not function as a whole. However, the d-axis current command I dref may be set in advance in the case of an electric field and in the case of an weak field, and the angular velocity when the d-axis current Id is also controlled in step S7. This can be obtained by continuously operating the rotor position estimating unit 74.

That is, the field weakening control causes the excitation current to flow more (than the state where the magnetoresistance balance is balanced) by the cathode positive side for the purpose of further increasing the rotation speed of the motor 45M. However, the excitation current is a current which does not contribute to the generation of torque, and if more flows, copper damage is increased, so efficiency is lowered. Therefore, when the overmodulation control is performed as described above, the execution output voltage is higher due to the distortion of the waveform, so that the time for starting the field weakening control can be delayed and the 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 of the DC power supply voltage (step S25, YES), the vector The control is converted.

FIG. 12 shows the case where the overmodulation control is combined with the voltage control in the second embodiment, together with FIG. 8 of the first embodiment. In the case of compressor A in Fig. 12 (a), the input power at startup is improved by -4% from 1025W to 985W, and the stable input power is improved by -0.7% from 816W to 810W. see. In the case of the compressor B, the input power at start-up is improved from -1020W to 985W, which is -4%, similar to A, and the stable input power is the same as the conventional 820W, +0.5 from the comparison standard. It's getting worse by%. The reason for this is the same as that described in the first embodiment.

In the case of compressor A, the maximum rotational speed in the case of 1.5 N · m shows a + 37% improvement from the conventional 115 rpm to 157 rpm, and the highest rotational speed in the case of 1.7 N · m is shown in Fig. 12 (b). A + 34% improvement is seen from 102 rpm to 137 rpm. In addition, the data for compressor B is unacquired. In sum, the improvement effect is higher than that of the first embodiment.

As described above, according to the second embodiment, when amplitude modulation is performed so that the output voltage of the inverter circuit 83 becomes a sine wave shape, and the field weakening operation is performed by the voltage / phase control 88 in the initial stage of the drying stroke, The amplitude modulation rate of the output voltage was made larger than 1.0 to control the overmodulation state. Therefore, efficiency can be raised by making the execution voltage applied to the motor 45M higher and making the weak field control start time later.

This invention is not limited only to the Example mentioned above and shown in drawing, The following deformation | transformation or expansion is possible.

The voltage and phase control may be terminated to switch to vector control, and the speed of the compressor motor 45M may be lowered.

What is necessary is just to change the level setting of the output voltage which switches vector control and voltage phase control suitably according to an individual design.

You may start the motor 45M by voltage control from the beginning.

1 is a functional block diagram of sensorless vector control performed by a control device of a laundry dryer on a compressor motor in a first embodiment of the present invention;

2 is a longitudinal sectional side view showing the entire configuration of a drum type laundry dryer;

3 is a view showing the configuration of a heat pump;

4 is a functional block diagram showing a control system of the laundry dryer;

5 is a flowchart showing the control contents by the drying stroke control unit;

6 is a timing chart showing changes in the rotational speed of the motor, the warm air outlet temperature of the rotating tank (drum), and the input power corresponding to the control contents of FIG. 5;

7 is a view for explaining field weakening operation in voltage and phase control;

FIG. 8 compares the control of the present embodiment with a case where all of them are performed by current control, (a) shows an effect of improving the input power, (b) shows an effect of improving the maximum rotational speed of the compressor motor,

9 is a view corresponding to FIG. 1 showing a second embodiment of the present invention;

10 is equivalent to FIG. 5,

11 is an output voltage waveform of an inverter circuit, (a) shows a case where the modulation rate is less than 1.0, (b) shows a case where the modulation rate is above 1.0, and

12 is a diagram corresponding to FIG. 8.

* Explanation of symbols for the main parts of the drawings

3: rotating tank (drying chamber) 42: evaporator

43: condenser 45: compressor

45M: compressor motor 47: heat pump

70: drying stroke control unit 83: binder circuit

Claims (4)

A heat pump that compresses the refrigerant in the compressor, condenses in the condenser, and circulates to evaporate in the evaporator, An air circulation path for guiding the air heated by the condenser to a drying chamber to dry the dry matter therein, and circulating the exhaust air from the drying chamber to be dehumidified in the evaporator and then heated again in the condenser; An inverter circuit for controlling a compressor motor driving the compressor, and And control means for controlling the inverter circuit, The control means In the initial stage of the drying operation, the field weakening of the compressor motor is driven by voltage and phase control, and then the electric field is driven by switching to the vector control which controls the compressor motor by current, and the voltage and phase control is terminated. And before starting to lower the rotational speed of the compressor motor, and switching to the vector control in the middle of the lowering of the rotational speed. The method of claim 1, The control means And in the initial stage of the drying operation, the compressor motor is operated by the vector control, and then the field is switched to the field weakening operation by the voltage and phase control. The method according to claim 1 or 2, The control means When the output voltage of the inverter circuit is amplitude modulated to have a sinusoidal shape and the field weakening operation is performed by the voltage and phase control, controlling the output voltage to an overmodulation state by setting the amplitude modulation rate of the output voltage to greater than 1.0. A laundry dryer characterized by the above. delete

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