KR950007065B1 - Motor control method and inverter driver - Google Patents

Abstract

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Description

Direct drive washing machine motor control method and inverter drive device

1 is a circuit diagram of an inverter drive device of the present invention.

Figure 2a is a flow chart when washing and dehydration in the method of the present invention, Figure b is a flow chart showing the washing tank rotation prevention program when the lid is opened when dehydration in the method of the present invention.

3A to 3G are waveform diagrams of output voltages by pulse width modulation control.

* Explanation of symbols for main parts of the drawings

1: Micom 2 ~ 4: ROM

5 ~ 7: D / A converter 8 ~ 10: Current transformer

11 ~ 13: comparator 14 ~ 16: driving part

17-19: Arm 20: Rectification part

21: power generation braking unit 170: power conversion unit

The present invention relates to a control method and an inverter driving apparatus for a direct washing machine motor capable of driving the power of a motor to a pulsator and a washing tank by direct driving in washing / dehydration, which is a basic function of an automatic washing machine. .

The triac driving method, which is a motor driving method of a conventional automatic washing machine, is intended to classify the washing force (eg, standard washing high, low, etc.) by controlling the energization time of the power applied to a constant motor power supplied to the customer. (Zero-cross method) and a certain range of effective power supply adjustment can be made, but this is limited due to the change in the number of revolutions and the output torque due to the synchronization of the induction motor by the applied power frequency and the number of poles of the motor. Also has a problem that can not fall.

Accordingly, an object of the present invention is to provide a control method and an inverter drive device capable of controlling the motor by configuring a direct drive system in the form of a geared motor in which a motor and a differential reduction gear are integrated in order to solve this problem. .

The present invention will be described in detail with reference to the accompanying drawings as follows.

As shown in FIG. 1, the apparatus of the present invention receives the speed pulse and the dehydration cover opening signal from the pulse generator PG according to the rotation of the three-phase inverter direct motor IM to perform the overall control function of the automatic washing machine. (1) and; A plurality of ROMs 2 to 4 which are controlled by the microcomputer 1 and store sine wave data having different phases (120 °); D / A converters 5-7 for converting predetermined digital signals outputted to said ROMs 2-4 into analog signals, respectively; Output signals (ia *, ob *, ic *) of the D / A converters 5-7 and the output currents (ia, ib, ic) of the current transformers 8-10 installed on the U, V, and W three-phase lines Comparators (11 to 13) for detecting error signals (iae, ibe, ice) by comparison with each other (A phase, A 'phase, B phase, B' phase, C phase output from the comparators 11 to 13) A driving unit 14 to 16 to prevent the arm short by giving a time difference between the phases C '); A power conversion unit 170 composed of three arms 17 to 19 amplifies the output signal of the driving unit 14, and converts a DC voltage into an AC voltage to be applied to an inverter direct motor IM. )Wow ; A rectifier 20 for rectifying the AC voltage into a DC voltage; When the brake signal is output from the microcomputer (1) is provided with a power generation braking unit 21 for braking the power generation of the motor (IM).

In addition, according to the method of the present invention, the washing function subroutine in the washing machine subroutine, the dewatering subroutine, and the washing machine rotation prevention interrupt subroutine when the lid is opened when dewatering, as shown in FIGS. The routine determines the water level by detecting the weight of the laundry through the weight sensor, detects the temperature of the water through the temperature sensor, determines the amount of detergent, adds the detergent amount, and determines the speed and acceleration time according to the washing conditions. The process of increasing the voltage and frequency gradually and increasing the proportionately until a certain time has elapsed. Then, the motor power is turned “off” to reduce the rising temperature of the motor. After repeating the above process by developing the driving direction of the motor, left and right for a predetermined number of times The dehydration function subroutine sets the speed and stage according to the dehydration condition and performs proportional acceleration by increasing the voltage and frequency until the speed of the dehydration tank reaches the set speed. When the speed is reached, it consists of the process of blocking the operation of the motor. The interrupt subroutine for preventing rotation of the washing tank due to the opening of the lid during dehydration is an alarm for a certain time while decelerating the motor when the lid is opened for a predetermined time (about 0.4 seconds) in the dehydration mode. If a certain time elapses after the sound is generated, the current speed is detected, and if it is not “0”, the rotation of the dehydration tank is braked through the power generation brake unit, and then the process returns to just before the interruption.

Referring to the effect of the present invention made of such a method and configuration as follows.

First, when an AC voltage is supplied to a washing machine provided with the apparatus of the present invention, the rectifying unit 20 configured as a bridge rectifying diode rectifies the AC voltage to a predetermined DC voltage and supplies it to each part of the washing machine.

At this time, when the washing switch is pressed, the weight sensor determines the amount of water required for washing by measuring the amount of washing contained in the washing tank, and then detects the temperature of the water introduced into the washing tank through the temperature sensor.

Subsequently, the detergent input amount is determined by using the data according to the washing water level and the water temperature, and then a predetermined amount of detergent is added, and then the driving speed and acceleration time of the inverter direct motor (IM) are set according to the washing conditions according to the type of laundry. Thus, the acceleration of the motor IM is achieved.

At this time, the acceleration of the motor is increased proportionally by gradually increasing the voltage (0 ~ 220V) and the frequency (0 ~ 45Hz) applied to the motor. The acceleration time and acceleration speed of the motor are set by the conditions of the laundry. And speed.

After that, when the motor accelerates to a predetermined speed for a predetermined time, the washing tank is stopped by stopping the power voltage for a predetermined time, which lowers the rising temperature of the motor generated by driving the motor to a predetermined temperature or less. It is to prevent burnout.

After the motor is shut off for a predetermined time as described above, the motor is again driven in the opposite direction as described above to accelerate the motor for a predetermined time, and then stops. This operation is performed as many times as necessary to clean the laundry. After repeated execution, the washing operation is completed.

In addition, after the user operates the dehydration switch to wash the laundry or after the washing is completed, the dehydration tank is accelerated by setting the driving speed and the acceleration stage of the motor according to the dehydration conditions in consideration of the amount of washing in the microcomputer (1).

Acceleration at this time is carried out in proportional acceleration while increasing the voltage (0 ~ 220V) and the frequency (0 ~ 200Hz) applied to the motor as in the washing, the process of the motor speed is driven for a predetermined time at a set speed This is repeated several times until the final speed is reached, and when the final target speed is reached, the power supply voltage applied to the motor is cut off and dehydration is completed.

However, when the lid of the washing machine is opened while dehydration is being performed as described above, the user may detect the time when the lid is opened to determine whether the lid is opened by mistake.

If the lid is closed again within a predetermined time (approximately 0.4 seconds) when the result of the opening time of the washing machine lid is checked, the dehydration operation will continue, but if the lid is opened for more than the set time, alarm will be generated while reducing the motor (IM). Let's go.

As described above, if the lid is closed before the time for decelerating the driving of the motor is over for a predetermined time (about 10 seconds), the driving speed is detected and returned to the dehydration mode corresponding to the current speed. Nevertheless, if the driving speed of the motor IM does not become “0”, the motor is braked through the power generation brake 21, thereby preventing the user from being injured by the rotation of the dehydration tank.

In addition, the brake brake is applied at a speed reduced to the minimum speed, so that the capacity of the braking resistor can be made small.

On the other hand, when a predetermined pulse is generated according to the speed set in the microcomputer 1 which performs the overall control function of the automatic washing machine (see triangular wave in FIG. 3a) and is inputted as the address value of the ROM 2-4, the ROM 2-4. ) Outputs three-phase data stored in each, as shown in FIGS. 3b to d.

In addition, the current data of the digital output from the ROMs 2 to 4 are respectively converted into predetermined analog signals through the D / A converters 5 to 7 and input to the comparators 11 to 13. 13), the current flowing through the motor is fed back through the current transformers 8 to 10 in order to maintain the motor speed at a constant speed despite the load variation, and compare the current with the reference currents (ia *, ib *, ic *). do.

Error signals (iae, ibe, and ice) output as the result of comparison by the comparators 11 to 13 are added to the original signals (ia *, ib *, ic *) and are driven through three driving units 14-16. Since it is applied to the power conversion unit 170 composed of arms (17 ~ 19) it is possible to accelerate and decelerate the drive speed in accordance with the load of the inverter direct motor (IM) in the power conversion unit 170 according to the variation of the load The speed change can be compensated for, thus enabling constant speed operation.

That is, the power converter 170 may output a signal as shown in FIG.

At this time, the driving unit 14 to 16 generate a predetermined driving signal to the power conversion unit 170 composed of a transistor, a resistor, and a photocoupler before operating the error signal output from the comparators 11 to 13. It is input to and separated into control signal and power.

On the other hand, the power generation braking part 21 is driven when a predetermined brake signal is output from the microcomputer 1 due to the opening of the lid when dewatering to brake the rotational force of the motor IM.

As described above, according to the present invention, the drive speed of the washing machine drive motor and the differential gear are integrated, and the drive speed of the inverter direct motor is detected and compensated for by an error signal, and the voltage and frequency are increased to accelerate gradually. The washing efficiency can be further improved.

Claims (2)

In the control method of the automatic washing machine comprising a washing function subroutine, a dehydration function subroutine and an interrupt subroutine for preventing the rotation of the washing tank when the lid is opened during dehydration. After determining the temperature of the water through the temperature sensor, determine the amount of detergent, add the detergent amount, determine the speed and acceleration time according to the washing conditions, and gradually increase the voltage and frequency until reaching a predetermined set temperature. After the predetermined time has elapsed, turn off the power of the motor, and if the rotation of the washing tank stops, after the predetermined time, reverse the driving direction of the motor and repeat the above process. Process, and dehydration subroutine rate and stage according to dehydration conditions It is set to set the speed of the dehydration tank until the speed reaches the set speed and then increase the voltage and frequency. The interrupt subroutine for preventing rotation of the washing tank due to the opening of the alarm generates an alarm sound for a certain time while decelerating the motor when the lid is opened for a predetermined time (approximately 0.4 seconds) in the dehydration mode, and then detects the current speed after a certain time has elapsed. If it is not "0" control method of the direct drive washing machine motor comprising the step of braking the rotation of the dehydration tank through the power generation braking part and returning to the immediately before interruption. A microcomputer (1) which receives the speed pulse and the dehydration cover opening signal according to the rotation of the three-phase inverter direct motor (IM) from the pulse generator (PG) to perform the overall control function of the automatic washing machine; A plurality of ROMs 2 to 4 which are controlled by the microcomputer 1 and store sine wave data having different phases (120 °); D / A converters 5 to 7 for converting predetermined digital signals output from the ROMs 2 to 4 into analog signals, respectively; Output signals (ia *, ib *, ic *) of the D / A converter 5/7 and output currents (ia, ib, ic) of the current transformers 8 to 10 installed on three-phase lines of U, V, and W Comparators (11 to 13) for detecting the error signal (iae, ibe, ice) by comparing with each other; A driving unit 14 to 16 which prevents an arm short by giving a time difference between each phase (A phase, A 'phase, B phase, B' phase, C phase, C 'phase) output from the comparators 11 to 13; ; It is composed of three arms 17 to 19 respectively driven by the output signal of the drive unit 14 to amplify the output signal immediately and convert the DC voltage into AC voltage and apply it to the inverter direct motor IM. The power converter 170 and the giving; A rectifier 20 for rectifying with an AC voltage; Inverter drive device for a direct drive washing machine motor characterized in that it comprises a power generation brake (21) for braking the power generation of the motor (IM) when the brake signal is output from the microcomputer (1).