JP2011110133A - Washing and drying machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an electric current to an induction motor, by specifying more adequately the drive conditions of the induction motor and securing torque particularly required for a drying process. <P>SOLUTION: A washing and drying machine includes: a drum 31 for accommodating clothes 30 to be washed and dried; an induction motor 33 for rotating the drum 31; an inverter circuit 34 for supplying electric power to the induction motor 33; and a heater 35 provided inside the drum 31, for heating air for drying. During a washing process, the inverter circuit 34 drives the induction motor 33. Meanwhile, during a drying process, not only does the inverter circuit 34 drive the induction motor 33, but the heater 35 operates, too. The inverter circuit 34 supplies to the induction motor 33, the electric power having an equal slip frequency during both processes of washing and drying, thereby suppressing the electric current to the induction motor 33, while increasing the efficiency, as well. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a washing / drying machine used in general households.

  Conventionally, this type of washing and drying machine is provided with a three-phase induction motor that rotationally drives a drum for putting laundry and a heater for drying, and the average value of the supply voltage of the three-phase induction motor is determined in the washing process. Thus, the rotational torque of the induction motor is reduced (see, for example, Patent Document 1).

  FIG. 8 shows a conventional washing and drying machine described in Patent Document 1. In FIG. As shown in FIG. 8, a drum 3 for putting the laundry 2 is provided in the outer tub 1, and a three-phase induction motor 5 that rotationally drives the drum 3 via a belt 4, a drying heater 6, and a blower fan motor 7 and the three-phase induction motor 5 is supplied with electric power from the inverter circuit 8.

  The AC power supply 9 supplies power to the fan drive circuit 10, the heater drive circuit 11, and the rectifier circuit 12, and the output of the rectifier circuit 12 is supplied to the inverter circuit 8.

  Furthermore, the fan drive circuit 10, the heater drive circuit 11, and the inverter circuit 8 are controlled by the control unit 13, and the control unit 13 receives a signal from the input key circuit 14.

  FIG. 9 shows a control flowchart in the controller 12 of the conventional washer / dryer. After processing in the order of start (step S1) and input key operation (step S2), a modulation degree set for each frequency (step S3) is performed, and then whether or not washing (step S4) is NO is determined. The process proceeds to the determination of whether or not it is dry (step S5). If YES here, the modulation factor X coefficient (1 or less) (step S6) is executed, and the determination of whether or not it is dry (step S5) is NO. In that case, the process proceeds to another process (step S7).

  Therefore, at the time of starting the electric motor (step S8), it is determined whether it is a washing process or a drying process, and if it is a drying process, the degree of modulation is multiplied by a coefficient (1 or less), Compared with the washing process, the degree of modulation is lower, and thus a state in which the supply voltage to the three-phase induction motor 5 is lower is realized. This results in an operation in which the rotational torque is lower than that in the washing process. This reduces wasteful power consumption during drying.

  After the motor is started (step S8), the process proceeds to the motor stop (step S9), and if the determination of whether or not the drying is finished (step S10) is YES, the process proceeds to the end (step S11) and the operation is finished. If the determination of whether or not to end (step S10) is NO, the process returns to the determination of whether or not to wash (step S4), and the operation is continued until the end of drying.

JP-A-4-152971

However, in the conventional configuration, only the supply voltage to the three-phase induction motor 5 is used to suppress the rotational torque in the drying process to be lower than that in the washing process, thereby suppressing the waste of electric power in the drying process. However, since the operating conditions of the induction motor are not determined only by the supply voltage, the generated torque may vary depending on other factors that generally determine the generated torque of the induction motor, such as the primary frequency or the slip frequency. As a result, it is not possible to confirm whether or not what is necessary for driving 1 can be obtained. As a result, sufficient rotational torque cannot be obtained, resulting in instability. However, there is a problem that a sufficient reduction effect of wasted electric power in the drying process may not be obtained even if the amount is sufficient.

  The present invention solves the above-mentioned conventional problems, and by more accurately defining the driving conditions of the induction motor, it ensures the necessary torque especially during drying, suppresses the supply current to the induction motor, and is useless. An object of the present invention is to provide a washing / drying machine capable of reliably suppressing power consumption.

  In order to solve the above-described conventional problems, a washing and drying machine of the present invention includes a drum that stores clothes to be washed and dried, an induction motor that rotates the drum, and an inverter circuit that supplies electric power to the induction motor. And heating means for heating the drying air in the drum, the inverter circuit drives the induction motor during washing, and the inverter circuit drives the induction motor during drying and the heating means operates during drying. The inverter circuit supplies a current of the same slip frequency to the induction motor during washing and drying.

  As a result, the operating conditions of the induction motor are determined while having a very simple configuration, and the supply current to the induction motor is suppressed while reliably obtaining the necessary torque for drum rotation as the generated torque, thereby reducing the burden on the inverter circuit. This will reduce wasteful power consumption especially during drying.

  The washing and drying machine according to the present invention includes a drum for storing clothes to be washed and dried, an induction motor for rotating the drum, an inverter circuit for supplying power to the induction motor, and a dryer for drying in the drum. Heating means for heating air, the inverter circuit drives the induction motor at the time of washing, the inverter circuit drives the induction motor at the time of drying and the heating means operates, and the inverter circuit is at the time of washing A current having a higher sliding frequency than that during drying is supplied to the induction motor.

  As a result, although the operation condition of the induction motor is determined with a relatively simple configuration, the required torque for drum rotation can be reliably obtained as the generated torque, and the induction motor has characteristics such as non-linearity due to magnetic saturation or the like. Even if it has, the thing which suppresses the input current of the induction motor at the time of washing and drying, and has high efficiency can be obtained.

  The washing and drying machine according to the present invention includes a drum for storing clothes to be washed and dried, an induction motor for rotating the drum, an inverter circuit for supplying power to the induction motor, and a dryer for drying in the drum. Heating means for heating air, the inverter circuit drives the induction motor at the time of washing, the inverter circuit drives the induction motor at the time of drying and the heating means operates, and the inverter circuit is at the time of washing A current having a frequency in the vicinity of the slip frequency at which the highest motor efficiency is obtained is supplied to the induction motor during drying and drying.

  As a result, although the operation condition of the induction motor is determined with a relatively simple configuration, the required torque for drum rotation can be reliably obtained as the generated torque, and the induction motor has characteristics such as non-linearity due to magnetic saturation or the like. Even if it has, the efficiency of the induction motor at the time of washing and drying is extremely high, and a particularly remarkable energy saving effect can be obtained.

  The washing / drying machine of the present invention can increase the energy saving effect while suppressing wasteful power during drying.

Cross-sectional view of the main body including a block diagram of the washing and drying machine in the first embodiment of the present invention Graph of current and primary inductance L1 of the induction motor of the washer / dryer A graph showing the conditions under which the current of the induction motor of the washer / dryer is minimized Cross-sectional view of the main body including a block diagram of the washing and drying machine in the second embodiment of the present invention Control block diagram of washing and drying machine in Embodiment 3 of the present invention Control block diagram of washing and drying machine in Embodiment 4 of the present invention (A) Graph showing the waveform of the output signal S1 of the start signal generating means at the start of the washing and drying machine (b) The output signal S2 of the start signal generating means at the start of the washing and drying machine Graph showing waveform (c) Graph showing change in sliding frequency at the start of washing and drying machine (d) Graph showing change in current value at the start of washing and drying machine Cross-sectional view of the main body including a block diagram of a conventional washing and drying machine Control flow chart of the washer / dryer

  The first invention is a drum for storing clothes to be washed and dried, an induction motor for rotating the drum, an inverter circuit for supplying power to the induction motor, and heating air for drying in the drum. Heating means, the inverter circuit drives the induction motor at the time of washing, the inverter circuit drives the induction motor at the time of drying and the heating means operates, and the inverter circuit is the same at the time of washing and drying By adopting a washing / drying machine that supplies the current of the slip frequency to the induction motor, the operating conditions of the induction motor are determined and the required torque for the drum rotation is ensured while having a very simple configuration. In addition, it can reduce the current supplied to the induction motor during washing and drying, and increase the efficiency of the induction motor especially during drying. Becomes wasteful power consumption is suppressed by.

  The second invention is a drum for storing clothes to be washed and dried, an induction motor for rotating the drum, an inverter circuit for supplying electric power to the induction motor, and heating air for drying in the drum. Heating means, the inverter circuit drives the induction motor at the time of washing, the inverter circuit drives the induction motor at the time of drying and the heating means operates, and the inverter circuit is more dry than at the time of washing By adopting a washing / drying machine that supplies a high slip frequency current to the induction motor, the operating conditions of the induction motor are determined and the required torque for drum rotation is ensured while having a relatively simple configuration. Even if the induction motor has non-linearity due to magnetic saturation or the like in its characteristics, it can be used during washing and drying. Suppressing the input current of the induction motor that, the those that efficiency is high can be obtained.

  According to a third aspect of the present invention, there is provided a drum for storing clothes to be washed and dried, an induction motor for rotating the drum, an inverter circuit for supplying electric power to the induction motor, and heating air for drying in the drum. Heating means, the inverter circuit drives the induction motor at the time of washing, the inverter circuit drives the induction motor at the time of drying and the heating means operates, the inverter circuit is at the time of washing and drying In each case, by making the washing and drying machine that supplies the induction motor with a current having a frequency in the vicinity of the slip frequency at which the highest motor efficiency is obtained, the operating conditions of the induction motor are determined while having a relatively simple configuration, The required torque for drum rotation can be reliably obtained as the generated torque, and the induction motor has non-linearity due to magnetic saturation and other characteristics. Be those having a washing time of the extremely high efficiency of the induction motor during the drying, it is possible to obtain particularly those marked as energy-saving effect.

  In a fourth aspect of the invention, in particular, the inverter circuit according to any one of the first to third aspects of the invention is a washing and drying machine that outputs a voltage at which the speed of the induction motor is equal to a predetermined value during washing and drying. With a simple configuration, the speed can be maintained at a predetermined value by adjusting the voltage against the change in torque during washing and drying, so that the surroundings of the cloth is good, excellent washing performance, and drying The performance can be improved.

  According to a fifth aspect of the invention, in particular, the inverter circuit according to any one of the first to third aspects of the invention is a washing and drying machine that outputs a current at which the speed of the induction motor is equal to a predetermined value during washing and drying. With a relatively simple configuration, the speed can be maintained at a predetermined value by adjusting the current with respect to the torque change during washing and drying, so the surroundings of the cloth becomes good, and excellent washing performance, And can improve the drying performance.

  In the sixth aspect of the invention, in particular, the inverter circuit of the fifth aspect of the invention is a washing / drying machine having a current detection means for detecting the input current of the induction motor. Since the speed can be kept at a predetermined value by adjusting the current with respect to the change in torque at the time, the surroundings of the cloth become good, and the excellent washing performance and drying performance can be improved.

  In the seventh aspect of the invention, in particular, when the inverter circuit of the sixth aspect of the invention is a washing / drying machine having current control means for controlling the output of the current detection means by dividing it into a magnetic flux component and a component orthogonal to the magnetic flux component, It is possible to realize a highly responsive reaction by changing the current of the orthogonal component with respect to fluctuations in the load torque, and it is possible to obtain higher washing performance and drying performance by suppressing fluctuations in the drum speed.

  According to an eighth aspect of the invention, in particular, the inverter circuit according to any one of the first to seventh aspects is a washing / drying machine that supplies a current having a larger sliding frequency to the induction motor when starting up during washing. In particular, it is possible to obtain the large starting torque required with a large amount of cloth in a smaller current while using a small and low-cost induction motor whose inductance is significantly reduced due to magnetic saturation. Even if the peak current is suppressed from a low-cost inverter circuit, sufficient start-up performance can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a cross-sectional view of a main body including a block diagram of the washing and drying machine according to Embodiment 1 of the present invention, FIG. 2 is a graph of the current and primary inductance L1 of the induction motor of the washing and drying machine, and FIG. The graph which showed the conditions which the electric current of the induction motor of a dryer becomes the minimum is shown.

  In FIG. 1, a drum 31 for storing clothes 30 to be washed and dried, an induction motor 33 for rotating the drum 31 via a belt 32, an inverter circuit 34 for supplying power of variable frequency to the induction motor 33, and a drum 31 Heating means 35 for heating the air for drying is provided.

  The specific configuration of the heating means 35 may be a so-called heat pump cycle using a compressor or a heat exchanger, in addition to an electric heater that has been widely used since ancient times. The heat exchanger serves as the heating means 35.

Here, the induction motor 33 is operated at a considerably high speed of 10,000 revolutions per minute, and is designed to have two poles (the number of pole pairs = 1) in order to reduce iron loss. Although equal, it is not always necessary to have two poles, and four poles (number of pole pairs = 2) may be used.

  The inverter circuit 34 is an inverter module 36 in which a three-phase six-stone IGBT and a drive circuit are housed in one package, and receives three-phase voltage command signals by pulse width modulation (PWM) using a triangular carrier wave of 15 kHz. A PWM circuit 37 that outputs an ON / OFF signal of each IGBT to the inverter module 36; a rotation distribution means 38 that receives the magnitude Va and phase θ of the voltage vector, converts them into a three-phase instantaneous modulation degree, and outputs them to the PWM circuit 37; A speed detection means 40 for detecting the speed of the electric motor 33, a speed setting means 41 for outputting a speed set value, a difference between outputs of the speed setting means 41 and the speed detection means 40, that is, a speed error, is obtained and is expressed as PI (proportional, Integration) calculation, speed error amplification means 42 for outputting to rotation distribution means 38, and slip frequency setting means 43 for setting the slip frequency. The sum of the output value of the slip frequency setting means 43 and the speed detection means 40 is calculated, the adding means 44 for outputting the primary frequency of the induction motor 33, the output of the adding means 44 is time integrated, and the instantaneous value of the phase θ is calculated. Then, an integration means 45 for outputting to the rotation distribution means 38 is provided.

  In FIG. 2, the primary inductance L1 with respect to the current of the induction motor 33 in the present embodiment is indicated by a solid line, and has a constant L1 value regardless of the current. In FIG. 2, the current value is indicated by the absolute value of the primary current vector. When a sine wave current is used, it is equivalent to √3 times the effective value of the line current. By the way, when the influence of magnetic saturation is observed, the characteristic is shown by a broken line, and the L1 value is almost constant in the range where the current value is low, but in the large current region, the L1 value decreases as the current increases. ing.

  In the above configuration, in the washing and drying machine of the present embodiment, the inverter circuit 34 drives only the induction motor 33 during washing, and the inverter circuit 34 drives the induction motor 33 and also the heating means 35 during drying, By reducing the relative humidity of the air in the drum 31, an operation for effectively leading the clothes 30 to drying is performed.

  Since the speed error amplifying means 42 operates in accordance with the difference between the output of the speed setting means 41 and the speed detecting means 40, the voltage command value to be input to the rotation distributing means 38 is adjusted, so that the inverter circuit 34 Outputs a voltage at which the speed of the induction motor 33 is substantially a predetermined value, both during washing and drying.

  In particular, in a configuration in which the rotation axis of the drum 31 is horizontal or provided with a rotation axis with an inclination of about 30 degrees from the horizontal, the rotation speed of the drum 31 during washing and drying is substantially the same value. In addition, the inventors have found that the best washing performance and drying performance can be obtained, and the speed is determined by the diameter of the drum 31 and the acceleration of gravity of the earth, and is several tens of times that is a household size. In the drum 31 of cm, the value is about 50 to 60 revolutions per minute.

  In particular, in the present embodiment, the inverter circuit 34 induces the current of the same slip frequency at the time of washing and drying because the slip frequency setting means 43 outputs the same value at the time of drying and washing. It is supplied to the electric motor 33, and can be configured without distinction between drying and washing as in the prior art.

  FIG. 3 shows torque on the horizontal axis and sliding frequency on the vertical axis. Also in FIG. 3, the characteristics of the induction motor 33 used in the present embodiment are such that the minimum current can be obtained at a constant slip frequency regardless of the torque, as indicated by the solid line. ing.

The slip frequency condition in which the current (primary current) supplied from the inverter circuit 34 to the induction motor 33 is the minimum is a condition in which the excitation current (magnetization current) component and the current component orthogonal thereto are almost equal. The absolute value of the current vector Ia [A] is expressed by Equation 1 with respect to the torque T [Nm], the primary inductance L1 [H], the coupling coefficient k, and the number of pole pairs Np, and the sliding frequency fs [Hz] at this time ] Is expressed by Equation 2 as the secondary resistance R2 [Ω].

  The above is the condition that the induction motor 33 is linear. If the values of R2 and L1 are constant, fs is a constant value. In the case of the induction motor 33 used in this embodiment, since R2 = 1.0 [Ω] and L1 = 0.1 [H], fs = 1.59 [Hz]. However, this is the minimum primary current condition.

  Therefore, in this embodiment, by controlling the slip frequency at the same value during drying and washing, the operating condition of the induction motor 33 is determined, and the current supplied from the inverter circuit 34 to the induction motor 33 is always supplied. Therefore, even if the current rating of the components of the inverter circuit 34 (for example, IGBT) is small and low cost, it is possible to operate with minimal loss, Also for the induction motor 33, at least the primary copper loss can be minimized.

  Incidentally, the efficiency of the induction motor 33 is slightly different from the minimum primary current condition described in the present embodiment because of secondary copper loss and iron loss.

  However, according to the experiments by the inventors, the effect of iron loss is almost negligible in low speed conditions during washing and drying, and in the case of drying with a relatively small torque, the primary current is minimum. The operation at the maximum efficiency point of the induction motor 33 is made possible by this operation. In particular, in the washing / drying machine, the operation time at the time of drying is longer than at the time of washing, and considering the effect of energy saving, the induction motor 33 is at the time of drying. However, it can be said that the merit of driving with high efficiency is remarkably large.

  At the time of washing, the output current of the inverter circuit 34 is suppressed as much as possible, and the effect of being able to reduce the load is great, and the limited inverter, such as when the cloth is hardened and the load torque suddenly increases The point that the maximum torque can be realized within the rated output current of the circuit 34 is a great advantage in ensuring the washing performance.

  As described above, in the present embodiment, the inverter circuit supplies the same slip frequency power to the induction motor at the time of washing and drying, so that the operation of the induction motor is very simple. The conditions are fixed and the necessary torque for drum rotation is obtained as the generated torque, while reducing the supply current to the induction motor, reducing the burden on the inverter circuit, and reducing unnecessary power consumption especially during drying. Become.

As a control block configuration, for example, a configuration in which control is performed by dividing into a current component in the direction of (secondary) magnetic flux and a current component orthogonal thereto as in vector control is often used. The configuration may not be used, and as long as the primary frequency is determined so that the sliding frequency becomes a predetermined value, the components inside the inverter circuit 34 may have any configuration. Needless to say, if it is desired to control the speed so that the actual speed becomes equal to the set value, a component capable of adjusting the voltage or current supplied from the inverter circuit 34 to the induction motor 33 may be appropriately provided. Regardless of the internal configuration of the inverter circuit 34, the same effect can be obtained.

(Embodiment 2)
FIG. 4 is a cross-sectional view of the main body including a block diagram of the washing / drying machine according to Embodiment 2 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the second embodiment, only the configurations of the induction motor 49 and the inverter circuit 50 are different from those of the first embodiment, but other components are the same as those in the first embodiment. Used.

  In FIG. 4, the induction motor 49 has a slightly different design than that of the first embodiment, and the primary inductance L1 is likely to decrease due to magnetic saturation, and has the characteristics shown by the broken line in FIG.

  The inverter circuit 50 amplifies the difference between the current detection circuit 51 that detects the input current of the induction motor 49 and the set speed that is a signal from the speed setting means 41 and the speed detection means 40, and converts it into a current set value. A speed error amplifying means 52, a current error amplifying means 53 for amplifying the difference between the speed error amplifying means 52 and the current detection circuit 51 by including a PI element are provided, and a current control means 54 is configured.

  In the second embodiment, the current detection means 51 includes one resistor 55 inserted in a portion to which the three switching elements on the low potential side of the inverter module 36 having a three-phase six-stone configuration are connected, The peak hold circuit 56 is configured to detect and output a current value corresponding to the peak value of the current supplied to the induction motor 49 by performing peak hold of the voltage generated between the terminals of the resistor 55. .

  Since the voltage generated at both ends of the resistor 55 is as low as 1 V or less, it is effective that the peak hold circuit 56 has an operational amplifier inside and outputs an analog voltage corresponding to the peak value while amplifying the voltage. is there.

  Further, as for the slip frequency setting means 60, the slip frequency setting means 61 for washing that outputs 2.2 Hz, the slip frequency setting means 62 for drying that outputs 1.6 Hz, and the washing frequency and the drying time respectively. There is provided a switching means 63 for switching the outputs of the hourly slip frequency setting means 61 and the drying slip frequency setting means 62 and outputting them to the adding means 44.

  In the above configuration, the washing and drying machine of the second embodiment is such that the induction motor 49 rotates and drives the drum 31 to perform the washing and drying operations as in the first embodiment. Particularly in this embodiment, the output signal of the slip frequency setting means 60 is 2.2 Hz during washing and 1.6 Hz during drying.

  In the second embodiment, the current detection means 51 outputs a signal corresponding to the current corresponding to the peak value of the three-phase line current from the peak hold circuit 56, which is the magnitude of the current vector. It is proportional to

  Depending on the actual rotational speed detected by the speed detecting means 40 and the error of the speed setting means 41, the speed error amplifying means 52 outputs a current value set value, and the difference from the current detecting means 51, that is, the current error is A current set value is input to the rotation distribution unit 38 by the current error amplification unit 53.

  The set value of the current value output by the speed error amplifying means 52 has an upper limit of 10A as the absolute value of the current vector Ia so as not to exceed the current rated capacity of the inverter module 36, and exceeds it. In some cases, it is limited to 10A. As for the phase θ, the output from the integrating means 45 is used as in the first embodiment.

  As a result, during washing and drying, the adjusted electric current is output to the induction motor 49 so that the speed of the induction motor 49 is almost the predetermined value set by the speed setting means 41, and At the time of washing, a current having a higher slip frequency than that at the time of drying is supplied to the induction motor 49.

  Regarding the characteristics of the induction motor 49 affected by magnetic saturation, as shown by the broken line in FIG. 2 of the first embodiment, the primary inductance value decreases as the current increases, and the slip frequency condition where the minimum current is obtained. Increases as the torque increases, as shown by the broken line in FIG.

  In this case, when the magnetic flux Φ [Wb] is saturated, the primary inductance L1 [H] is obtained by the calculation formula of Formula 3 with respect to the excitation current Im1 [A]. As for the internal magnetic flux, when the magnetic flux density of the iron core reaches about 1.5 T, magnetic saturation becomes noticeable, and the value of the inductance L1 obtained by dividing the magnetic flux value by the current value tends to decrease. There is.

  The slip frequency fs [Hz] at this time is a correct value as a direction even if it is understood as a mechanism that the slip frequency fs increases if L1 decreases in Equation 4 as the secondary resistance R2 [Ω].

  In particular, since the required torque is large during washing, there are many cases where it is desired to suppress the output current from the inverter circuit 50 as much as possible to reduce the burden on the inverter circuit 50. As a result, it is possible to suppress the current to the minimum condition by creating a condition by switching the slip frequency even during washing while suppressing the current during drying as much as possible for the induction motor 49 in which saturation, that is, nonlinearity exists. The output current of the inverter circuit 50 can be suppressed, and the efficiency of the induction motor 49 during washing can be improved.

  In general, when an induction motor is designed so that low magnetic flux is sufficient in any case so that saturation of magnetic flux does not become a problem, the induction motor becomes heavy and large, and the cost becomes high.

  For this reason, the induction motor 49 reaches the saturation magnetic flux density almost at the magnetic flux density of the internal magnetic path under a condition that requires a considerably large torque, although it is a short time especially when the washing / drying machine is started. It is economical to raise the degree to the extent, and in this embodiment, even if the induction motor 49 having such characteristics is used, a good operation can be obtained.

  As described above, in the second embodiment, the inverter circuit 50 supplies the induction motor 49 with a higher frequency of sliding frequency than when drying during washing, so that the induction motor 49 has a relatively simple configuration. As a result, the necessary torque for drum rotation can be reliably obtained as the generated torque, and even if the induction motor 49 has non-linearity due to magnetic saturation or the like in its characteristics, it can be used during washing and drying. It is possible to suppress the input current of the induction motor 49 and obtain high efficiency.

  In particular, when efficiency is more important than the current reduction effect, the set values of the washing frequency setting means 61 for washing and the sliding frequency setting means 62 for drying become the maximum conditions for the efficiency of the induction motor 49. If a value is entered, it can be realized.

  In the second embodiment, the current detection circuit has a very simple configuration using one resistor 55 and a peak hold circuit 56. However, the current detection circuit is not limited to such a configuration, and DCCT and A magnetic sensor that can detect a direct current or a current having a very low frequency component, and a low potential side of each of the three low potential side switching elements in the inverter module 36. The resistors may be provided with a total of three resistors one by one, and the absolute value of the input current vector to the induction motor 49 is detected not from the peak hold but from the instantaneous current value of each of the three phases. It may also be one that detects it by dividing it into two axis components orthogonal to each other. In short, the current of the induction motor 49 is controlled as a result. It can be supplied to the induction motor 49 a current value as a predetermined value.

(Embodiment 3)
FIG. 5 is a control block diagram of the washing / drying machine according to Embodiment 3 of the present invention. About the same structure as Embodiment 1 and 2, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  In FIG. 5, three resistors 72, 73, 74, current control means 71, which is a component in the inverter circuit 70, are connected to each of the three switching elements on the low potential side of the inverter module 36. An amplifier 75 for outputting an analog voltage corresponding to the instantaneous value of the current of each of the three phases from the both-end voltages is provided. Then, the line current of each phase of the three phases is input from the current detection unit 71 to the rotation distribution unit 80. While receiving the phase θ, the rotation distribution means 80 also performs conversion from three phases to two phases, distributes the current components to two orthogonal axes (M axis and T axis), and outputs them.

  The current setting means 81 and 82 output the set values of the M-axis component and the T-axis component of the primary current of the induction motor 49, respectively. The current error amplifying means 83 and 84 both cause the primary error from the setting error. The current control unit 86 is configured to output the voltage M-axis component Vm1 and the T-axis component Vt1.

  Therefore, in the third embodiment, the inverter circuit 70 includes a current control unit 86 that controls the output of the current detection unit 71 by dividing it into a magnetic flux component (secondary magnetic flux component) Im1 and a component It1 orthogonal thereto. Become.

  The rotational distribution means 88 is slightly different from the first embodiment in that the voltage for two phases is inputted, but the three-phase (referred to as U, V, W, etc.) while receiving the signal of the phase θ. It distributes to each voltage.

Incidentally, the current setting means 81 for setting the M-axis primary current is obtained from the signal Φ2 * from the secondary magnetic flux setting means 90 by Φ2 * / (k · L1), and particularly the L1 value is shown in FIG. The magnetic saturation due to the described current is changed as a function of the current Im1, and the secondary magnetic flux setting means 90 has a characteristic that avoids a large temporal change (dΦ2 * / dt) of the output Φ2 *. ing.

  As a result, the M-axis current Im2 on the secondary side is suppressed as much as possible, and a characteristic in which the secondary magnetic flux Φ2 is substantially determined by Im1 is realized, and a transient loss when changing the secondary magnetic flux is reduced.

  Further, the current setting means 82 for setting the T-axis primary current outputs a value calculated by T * / (Φ2 * · k) from the torque setting value T * and the aforementioned Φ2 *. The smooth frequency setting means 93 outputs a value calculated by R2 · It1 · k / (2π · Φ2 *).

  In the third embodiment, the torque set value T * is a value obtained by converting an error (speed error) between the speed setting means 41 and the speed detection means 40 into a torque value by the speed error amplifying means 95, and is thus equal to the set speed. The torque is constantly adjusted so that the speed can be obtained. Since such torque control is performed almost without delay from the change of It1, it becomes possible to realize torque control with very high responsiveness. Even when the load fluctuation is large due to the way the garment 30 is rotated, the speed control is possible. It is possible to suppress fluctuations.

  In particular, in the third embodiment, the secondary magnetic flux setting means 90 is a function of the torque setting value T * so that the slip frequency condition where the efficiency of the induction motor 49 is the highest is obtained under any torque condition. The secondary magnetic flux set value Φ2 * is changed. Therefore, a current having a frequency in the vicinity of the slip frequency that automatically obtains the highest motor efficiency is automatically supplied to the induction motor 49 even under operating conditions with different load torque conditions such as during washing and drying. Will be.

  Therefore, even when the required torque changes due to changes in the conditions such as the amount of clothing 30, the highly efficient induction motor 49 can be driven, and a washing / drying machine with a high energy-saving effect can be realized. Will be able to.

  In particular, in a condition where the required torque is large, such as immediately after start-up, the setting of Φ2 * is set so that the current value can be reduced more effectively than the high efficiency, for example, such that Im1 = It1. You can also determine the value.

  In any case, the condition of the slip frequency is determined from Φ2 * and T *, the operating condition of the induction motor 49 is determined, and the efficiency, current, etc. are all determined.

  It is not essential that the L1 value be a nonlinear function corresponding to the current Im1 and that Φ2 * be a function of the torque setting value T *, and sufficient efficiency can be ensured with only one of them, or the current can be reduced. If an effect can be obtained, the configuration can be omitted as appropriate.

  As described above, in the present embodiment, the inverter circuit 70 supplies the induction motor 49 with the smooth frequency power that provides the highest motor efficiency during washing and drying, thereby achieving the highest energy saving effect. I can give you.

  Further, by controlling the output of the current detection means 71 separately for the magnetic flux component Im1 and the component It1 orthogonal thereto, highly responsive torque control is possible, and speed fluctuations during washing and drying can be suppressed. As a result, extremely high washing performance and drying performance can be obtained.

(Embodiment 4)
FIG. 6 is a control block diagram of the washing / drying machine according to Embodiment 4 of the present invention, and FIG. 7 (a) shows a waveform of the output signal S1 of the activation signal generating means at the time of starting the washing / drying machine at the time of washing. FIG. 7B is a graph showing the waveform of the output signal S2 of the activation signal generating means at the time of activation of the washing / drying machine, and FIG. 7C is the activation of the washing / drying machine at the time of washing. FIG. 7D is a graph showing a change in current value at the time of starting the washing / drying machine. The same components as those in the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 6, the inverter circuit 100 includes a startup slip frequency setting unit 101, a switching unit 102, and a startup signal generation unit 103. When the induction motor 49 is started during washing, the startup signal generation unit 103 is The signal S1 is output to the starting slip frequency setting means 101 and the speed setting means 41, and the signal S2 is output to the switching means 102. Regarding the other components, the same components as in FIG. 4 described in the second embodiment are used.

  In the above configuration, the washing and drying machine of the present embodiment operates as follows.

  At t1, as shown in FIG. 7 (a), S1 is turned on and the startup sliding frequency setting means 101 receives this, but the sliding frequency output from the startup sliding frequency setting means 101 is shown in FIG. ), The period from t1 to Td is maintained at 0 [Hz] and becomes 3.5 [Hz] at the time point t2.

  On the other hand, the speed setting means 41 outputs 50 revolutions per minute from the time t1 in the drum 31 which is a steady speed, and since the set speed is higher than the actual speed (= 0), the current setting is automatically increased. Then, Ia = 10A which is a limit value inside the speed error amplifying means 52 is reached. In the Td period, since the frequency is in a zero state, no torque is generated at all, and the current supplied to the induction motor 49 with Ia = 10 A is all Im1.

  The secondary magnetic flux Φ2 is stabilized in a form in which a secondary time constant of about 100 ms (= L2 / R2) is applied, and the slip frequency output from the start-time slip frequency setting means 101 at t2 is 3.5 Hz. Then, a starting torque is generated.

  However, in the period until S2 is turned on at t3, 3.5 Hz output from the startup sliding frequency setting means 101 becomes the primary frequency, and as indicated by the solid line as the speed of the induction motor 49 increases. The slip frequency gradually decreases. Incidentally, the broken line indicates the output of the startup sliding frequency setting means 101 that outputs a constant value of 3.5 Hz.

  At time t3, when S2 is turned on, the switching means 102 is switched to the normal state, and instead of the output of the starting sliding frequency setting means 101, the operation is performed with the output of the adding means 44. As a result, the output of the washing frequency setting means 61 for washing becomes 2.2 Hz, and the subsequent operation is continued. The current shown in FIG. 7D also gradually approaches the steady value at the time of washing after t3.

  As described above, in the fourth embodiment, a period for supplying a current having a sliding frequency larger than 2.2 Hz in the steady state of 3.5 Hz to the induction motor 49 at the time of starting at the time of washing is provided.

  In general, during washing, a cloth that contains a large amount of moisture is often hardened and stored under the drum 31. To start from this state, for example, the torque at the drum 31 is about 25 Nm. Often big things are needed.

  In such a case, if an attempt is made to suppress the supply current from the inverter circuit 100 to the induction motor 49 as much as possible, a condition is used in which the effect of magnetic saturation becomes even more pronounced than during washing as described in FIG. The value of the slip frequency that minimizes the current for realizing the necessary starting torque needs to be higher than that during washing.

  Therefore, as in the fourth embodiment, the current reduction with a certain degree of magnetic saturation can be realized, so that the drum 31 can be reliably started within the limited output current rating of the inverter circuit 100, and the washing and drying machine As a result, the necessary operation can be performed.

  As described above, in the fourth embodiment, the inverter circuit 100 supplies the induction motor with a current having a higher frequency than the rated frequency at the time of start-up at the time of washing, so that the effect of magnetic saturation is large. A reliable drum start-up is possible, and high washing performance can be ensured.

  As described above, the washing / drying machine according to the present invention can increase the energy saving effect while suppressing wasteful power during drying, and therefore can be applied to the use of a washing / drying machine used in general households.

30 Clothing 31 Drum 33, 49 Induction motor 34, 50, 70, 100 Inverter circuit 35 Heating means 51, 71 Current detection means 54, 86 Current control means

Claims (8)

A drum for storing clothes to be washed and dried, an induction motor for rotating the drum, an inverter circuit for supplying power to the induction motor, and a heating means for heating the drying air in the drum, The inverter circuit drives the induction motor at the time of washing, the inverter circuit drives the induction motor at the time of drying and the heating means operates, and the inverter circuit generates a current having a smooth frequency equivalent to that at the time of washing and drying. A washing and drying machine for supplying to the induction motor. A drum for storing clothes to be washed and dried, an induction motor for rotating the drum, an inverter circuit for supplying power to the induction motor, and a heating means for heating the drying air in the drum, The inverter circuit drives the induction motor at the time of washing, the inverter circuit drives the induction motor at the time of drying and the heating means operates, and the inverter circuit generates a current having a higher slip frequency than at the time of drying at the time of washing. A washing and drying machine for supplying to the induction motor. A drum for storing clothes to be washed and dried, an induction motor for rotating the drum, an inverter circuit for supplying power to the induction motor, and a heating means for heating the drying air in the drum, The inverter circuit drives the induction motor at the time of washing, the inverter circuit drives the induction motor at the time of drying, and the heating means operates. The inverter circuit is the best motor for both washing and drying. A washing / drying machine that supplies a current having a frequency near the slip frequency to obtain efficiency to the induction motor. The laundry dryer according to any one of claims 1 to 3, wherein the inverter circuit outputs a voltage at which the speed of the induction motor is equal to a predetermined value during washing and drying. The laundry dryer according to any one of claims 1 to 3, wherein the inverter circuit outputs a current at which the speed of the induction motor is equal to a predetermined value during washing and drying. The washing / drying machine according to claim 5, wherein the inverter circuit includes a current detection unit that detects an input current of the induction motor. The washing / drying machine according to claim 6, wherein the inverter circuit includes current control means for controlling the output of the current detection means by dividing it into a magnetic flux component and a component orthogonal thereto. The washing / drying machine according to any one of claims 1 to 7, wherein the inverter circuit supplies a current having a higher sliding frequency than that in a steady state to the induction motor at the time of starting at the time of washing.

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