KR101637445B1 - Apparatus and method for controlling single-phase induction motor - Google Patents

Abstract

A single-phase induction motor control apparatus and method are disclosed. According to the present invention, a switching device such as a triac is provided in each of a main winding and an auxiliary winding, and an input voltage is detected, a starting time is calculated based on the detected voltage, It is possible to start or operate the motor in a stable and efficient manner even in a voltage region, and to protect the motor itself from overvoltage. Accordingly, the present invention can reduce the manufacturing cost and increase the operating efficiency and the reliability by controlling the opening time of the auxiliary winding.

Single phase induction motor, input voltage, start time, switch

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single phase induction motor control apparatus and a single phase induction motor control apparatus,

The present invention relates to a single-phase induction motor, and more particularly, to a single-phase induction motor control apparatus and method which are robust against an input power source and can start or operate stably and efficiently even in a low-voltage region.

Generally, an induction motor is composed of a stator with windings, and a rotor made of permanent magnets, aluminum conductors or iron cores. Such an induction motor is a device for generating a rotational power by generating a change in a periodic current in a winding mounted on the stator and generating a torque in the rotor by a constant change of the magnetic field according to a change in current.

A single-phase induction motor is a small-sized electric motor used for household appliances generally having an output of 400 W or less, and uses a commercial power source for household use, that is, a single-phase AC power source. These single-phase induction motors are mainly used in household appliances such as electric fans, air conditioners, refrigerators, and washing machines, and provide rotational power necessary for the fans, rotary blades, and compressors.

However, in the single-phase induction motor, when an AC power is applied to the single-phase winding, an induced current flows, but the electromagnetic forces generated in the conductors in the upper and lower portions of the rotor are canceled each other and an alternating magnetic field in which the magnitude changes in the direction of the axis of the winding So that it is impossible to generate a rotational force. Accordingly, a single-phase induction motor requires a starting device for starting the single-phase induction motor. The single-phase induction motor is classified into a split starter type, a shading coil type, a condenser starter type, and a repulsive starter type.

 1 is a circuit diagram schematically showing a general condenser operation type single-phase induction motor. 1, the single-phase induction motor includes a main winding 20, an auxiliary winding 30, a positive temperature coefficient of thermally-sensitive resistors 40 connected in series to the auxiliary winding 30, And a capacitor 50 connected in parallel to the Pitti thermistor 40. In addition, the single-phase induction motor may further include an over-load protector 70 for preventing overload. The Pitty thermistor (40) is a semiconductor device whose electrical resistance increases sharply when the temperature rises, and performs a switching function. That is, when the rotational speed reaches a predetermined value of the normal speed, the auxiliary winding is opened. The capacitor 50 improves the operation efficiency of the electric power factor of the electric motor.

When a single-phase AC power source 10 is applied to the motor, an alternating magnetic field is generated in the main winding line 20, and the capacitor 50 advances the phase of the current flowing to the auxiliary winding 30 by 90 degrees. As a result, auxiliary coils having an electrical phase difference of 90 degrees are generated in the auxiliary coils 30. Therefore, the alternating magnetic field generated in the main winding line 20 and the auxiliary magnetic field generated in the auxiliary winding 30 are not canceled out because the phases of the magnetic fields are different from each other.

The single-phase induction motor according to the prior art uses a starter such as a Pittsy thermistor and rotates when the starting torque is larger than the load torque, and the starting torque is proportional to the applied voltage. In the single-phase induction motor according to the related art, if the applied voltage is low or the load is large, the single-phase induction motor can not be started, and at the same time, a current of about 10 times the rated current is generated in the motor winding. That is, the single-phase induction motor according to the prior art has a problem that the motor is damaged due to a failure in starting at a low voltage and an abnormal operation is caused in an application device in which the motor is installed.

In addition, the Pitti thermistor has a problem that the time for opening the auxiliary winding can not be controlled, and the single-phase induction motor employing the Pitti thermistor has the problems of the start failure and the abnormal operation in the low voltage region.

The present invention provides a single-phase induction motor control apparatus and method that are robust against variations in input voltage, protect the motor itself from overvoltage, and can start or operate stably and efficiently even in a low voltage region. There is a purpose in.

It is another object of the present invention to provide a single-phase induction motor control apparatus and method that can start or operate through a simple circuit configuration without using a Pitti thermistor or an overload protection device.

The present invention provides a single-phase induction motor control apparatus and method for detecting an input voltage, calculating and starting a start time based on the detected input voltage, and operating the motor based on the detected input voltage after a start time has elapsed There is another purpose in.

According to an aspect of the present invention, there is provided a single-phase induction motor control apparatus including a main winding line switch connected in series to a main winding line and for interrupting power to be applied to or applied to the main winding line, An auxiliary winding switch connected in series to supply power to the auxiliary winding or to cut off power to be applied; a voltage detecting unit for detecting an input voltage applied from an external power supply; and a control unit for calculating a starting time based on the detected voltage A control unit for opening and closing the main winding line switch and the auxiliary winding switch, and a power supply unit for converting the input voltage into a driving voltage of the control unit and outputting the driving voltage.

In the single-phase induction motor control apparatus according to the embodiment of the present invention, the power supply unit includes: a rectification unit for rectifying the input voltage; a smoothing unit for smoothing the rectified voltage; And a transforming unit for converting the voltage to a voltage.

In the single-phase induction motor control apparatus according to the embodiment of the present invention, the voltage detection unit directly detects the AC voltage of the external power supply or detects the smoothed DC voltage.

In the single-phase induction motor control apparatus according to the embodiment of the present invention, when the detected voltage is equal to or higher than a preset reference voltage, the control unit opens the auxiliary winding switch, operates the motor through the main winding line, When the detected voltage is smaller than the reference voltage, the main power line switch is opened and the motor is operated through the auxiliary winding.

Further, in the single-phase induction motor control apparatus according to the embodiment of the present invention, the control unit may be configured such that a first reference voltage and a second reference voltage greater than the first reference voltage are preset, And when the detection voltage is lower than the first reference voltage, opening the main power line switch and opening the main winding line switch through the auxiliary winding, Operate the motor.

According to another aspect of the present invention, there is provided a method of controlling a single-phase induction motor, including the steps of: applying power to a single-phase induction motor through a primary winding switch and a secondary winding switch; Phase induction motor based on the detected start time, calculating a start time based on the detected voltage, starting the single-phase induction motor based on the calculated start time, and, when the start time elapses, And operating the single-phase induction motor by opening or closing the line switch or the auxiliary winding switch. Wherein the step of operating the single-phase induction motor includes the steps of: setting a reference voltage; comparing the detected voltage with the reference voltage; and when the detected voltage is equal to or greater than the reference voltage, And a process of opening. If the detected voltage is smaller than the reference voltage as a result of the comparison, the step of opening the main line switch may further include the step of opening the main line switch. The step of operating the single-phase induction motor may include the steps of: setting a first reference voltage and a second reference voltage greater than the first reference voltage; comparing the detected voltage with the second reference voltage; And opening the auxiliary winding switch when the detected voltage is equal to or greater than the second reference voltage. The step of operating the motor further includes the step of comparing the detected voltage with the first reference voltage and opening the main power line switch when the detected voltage is equal to or less than the first reference voltage.

The method for controlling a single phase induction motor according to an embodiment of the present invention includes the steps of: applying power to a single phase induction motor through a main winding line switch and a secondary winding switch; detecting a voltage applied to the single phase induction motor; And operating the single-phase induction motor by opening and closing the main winding line switch or the auxiliary winding switch.

Phase induction motor control method according to an embodiment of the present invention includes the steps of applying power to a single-phase induction motor through a main winding line switch and a secondary winding switch, detecting a voltage applied to the single-phase induction motor, Calculating a start time on the basis of the detected voltage when the detected voltage is within the operation range, and determining whether the voltage is within a predetermined operation range; Phase induction motor to start the single-phase induction motor.

According to the apparatus and method for controlling a single-phase induction motor according to the present invention, a single-phase induction motor is robust against variations in input voltage and can be stably and efficiently operated or operated even in a low voltage region. Further, the single-phase induction motor according to the present invention can protect the motor itself from overvoltage.

The present invention can start or operate the electric motor through a simple circuit configuration including a switch without using a Pitti thermistor or an overload protection device. Accordingly, the present invention can reduce the manufacturing cost and increase the operating efficiency and the reliability by controlling the opening time of the auxiliary winding.

An apparatus and method for controlling a single-phase induction motor according to the present invention detect an input voltage, calculate a start time based on the detected input voltage, start the motor with the calculated start time, So that it can be stably driven even in a low voltage or an overvoltage state.

Hereinafter, a single phase induction motor control apparatus and a control method according to the present invention will be described in detail with reference to the accompanying drawings.

2, a single-phase induction motor control apparatus according to an exemplary embodiment of the present invention includes a main winding line 210 connected in series to a main winding line 210, A switch 230 and an auxiliary winding switch 240 connected in series to the auxiliary winding 220 to cut off the power applied or applied to the auxiliary winding 220, A control unit (300) for calculating a starting time based on the detected voltage and opening and closing the main winding line switch and the auxiliary winding switch, and a control unit And a power supply unit 400 for converting the driving voltage into a driving voltage of the unit and outputting it.

In addition, the control device may further include a driving capacitor 250 connected in parallel to the auxiliary winding switch 240 and compensating for a power factor. The control device can increase the operation efficiency of the single-phase induction motor through the operation capacitor 250. Of course, the driving capacitor 250 may be connected to the main line switch 230 in parallel, if necessary.

Relay, TRIAC, or other mechanical or electronic semiconductor devices may be used as the main winding line switch 230 and the auxiliary winding switch 240, respectively. In particular, the triac is a bidirectional thyristor that performs the same function as that of two silicon controlled rectifiers (SCRs) connected in parallel, is an electronic device, and is reliable because it can perform a large number of switching operations.

Referring to FIG. 2, in the single-phase induction motor control apparatus according to an embodiment of the present invention, the voltage detecting unit 500 is constituted by a circuit including an OP-AMP, The AC voltage is directly detected and transmitted to the control unit 300. The external power source 100 is a domestic commercial AC power source, for example, in the case of Korea, an AC power source of 220 V and 50 Hz is used.

Referring to FIG. 3, in the single-phase induction motor control apparatus according to the embodiment of the present invention, the power supply unit 400 includes a rectification unit 410 for rectifying the input voltage, a smoothing unit 410 for smoothing the rectified voltage, And a transformer unit 430 for transforming the smoothed voltage to a drive voltage of the control unit 300. [

The power supply unit 400 receives the external power supply 100, that is, commercial AC power, and outputs a DC voltage for driving a single-phase induction motor and a circuit, a unit, and the like constituting the controller. In general, the power supply unit 400 uses a Switched-Mode Power Supply (SMPS). Of course, other types of AC-DC converters other than SMPS can be used. The switch mode power supply rectifies and smoothes the AC voltage of the external power supply 100 and converts the DC voltage into a DC voltage. The DC voltage is converted to a single-phase induction motor and a single-phase induction motor control device using a transformer unit such as a high frequency transformer and a regulator And generates necessary driving voltages. The voltage detection unit (500) detects the smoothed DC voltage.

The control unit 300 sets the initial start time to be short to prevent the overvoltage when the detection voltage is high and to set the initial start time to be long in inverse proportion to the detection voltage when the detection voltage is low.

Referring to FIG. 4, there is a graph showing a change in start time calculated according to a change in input voltage. Here, the main winding line switch and the auxiliary winding switch are connected to generate a rotating magnetic field in the single-phase induction motor through the main winding line and the auxiliary winding, and the starting time means the time limit. In FIG. 4, the starting time may be calculated through experimentation in consideration of the allowable range of the temperature of the windings after the rotation of the motor. For example, the control unit 300 sets the rated voltage 220V to V2 and sets the low voltage limit V1. Of course, V2 can be set to an overvoltage limit value larger than the rated voltage.

If the detected voltage is equal to or higher than V2, the control unit 300 sets the startup time to T2, for example, 0.3 seconds, and if the detected voltage is V1, the startup time is T1, . Accordingly, the control unit 300 can set the start time according to the detection voltage as shown in FIG. 4 using V1, V2, T1, and T2. Then, the control unit 300 can calculate the start time according to the detected voltage based on the detected voltage. That is, if the detected voltage is between the low voltage limit value and the rated voltage, the control unit 300 sets the start time in inverse proportion to the detected voltage.

Also, the control unit 300 can protect both the single phase induction motor by opening both the main winding line switch 230 and the auxiliary winding switch 240 when the detected voltage is equal to or greater than a predetermined overvoltage limit value. That is, the control unit 300 opens both the main winding line switch 230 and the auxiliary winding switch 240 to cut off the power input to the single-phase induction motor to prevent breakage of the single-phase induction motor from overvoltage. The control unit 300 also opens both the main winding line switch 230 and the auxiliary winding switch 240 to cut off the power input to the single phase induction motor even when the detection voltage is lower than a predetermined low voltage limit value . The control unit 300 opens both the main winding line switch 230 and the auxiliary winding switch 240 to cut off the power supplied to the single phase induction motor to thereby cause the start failure due to the low voltage and cause the overcurrent Thereby preventing the abnormal operation from being performed. The control device may further include a separate storage unit (not shown), and the overvoltage limit value and the low voltage limit value may be set and stored in the storage unit. The overvoltage limit value and the low voltage limit value are set differently according to the voltage condition of the area using the single-phase induction motor, the type and the form of the single-phase induction motor, the load condition, etc., and may be set to a predetermined ratio of the input voltage of the external power source.

Phase induction motor, the control unit (300) sets a blocking region for shutting off the power input to the single-phase induction motor when the detected voltage is equal to or higher than the overvoltage limit value or equal to or less than the low-voltage limit value. On the other hand, if the detected voltage is smaller than the overvoltage limit value Set the case to the operation area. That is, the control unit 300 connects both the main winding line switch 230 and the auxiliary winding switch 240 in the operation region to start the single-phase induction motor. At this time, the control unit 300 starts the single-phase induction motor for the startup time calculated according to the detection voltage. The control unit 300 applies power to the main winding line 210 and the auxiliary winding 220 to generate an alternating magnetic field generated in the main winding line 210 and an auxiliary magnetic field generated in the auxiliary winding 220, And generates a rotating magnetic field to rotate the single-phase induction motor.

Then, the control unit 300 sets a reference voltage in an operation region between the overvoltage limit value and the low voltage limit value, and when the detection voltage is equal to or higher than a preset reference voltage, the auxiliary winding switch 240 is opened Phase induction motor is operated through the main winding line 210. When the detected voltage is smaller than the reference voltage, the control unit 300 opens the main winding line switch 230 and operates the single-phase induction motor through the auxiliary winding 240. The reference voltage is set differently according to the voltage of the region where the single-phase induction motor is used, the type and the form of the single-phase induction motor, the load condition, etc., and may be set to a predetermined ratio of the input voltage of the external power source.

Also, the control unit 300 may preset and store a first reference voltage and a second reference voltage that is larger than the first reference voltage. The control unit 300 opens the auxiliary winding switch 240 and operates the single phase induction motor through the main winding line 210 when the detection voltage is equal to or higher than the second reference voltage, Phase induction motor is operated through the auxiliary winding 220 when the first reference voltage is lower than the first reference voltage. The first reference voltage V1 and the second reference voltage V2 are set differently depending on the voltage of the region using the single-phase induction motor, the type and the form of the single-phase induction motor, the load condition, As shown in FIG. The first reference voltage V1 and the second reference voltage V2 have a difference of about 10 V, for example, and perform a hysteresis operation to prevent the breakdown of the motor due to a sudden change in the input voltage.

5, a method of controlling a single-phase induction motor according to an exemplary embodiment of the present invention includes steps S111 and S112 of applying power to a single-phase induction motor through a main winding line switch and a secondary winding switch, (S140) of starting the single-phase induction motor through a main winding line and an auxiliary winding, calculating a start time based on the detected voltage (S140) (Step S150), and operating the single-phase induction motor by opening and closing the main winding line switch or the auxiliary winding switch based on the detection voltage (step S160). The configuration of the apparatus is described below with reference to Figs.

The start time is set to be short in order to prevent overvoltage when the detection voltage is large and the initial start time is set to be long so as to be in inverse proportion to the detection voltage when the detection voltage is low.

Here, the main winding line switch and the auxiliary winding switch are connected to generate a rotating magnetic field in the single-phase induction motor through the main winding line and the auxiliary winding, and the starting time means the time limit. In FIG. 4, the starting time may be calculated through experimentation in consideration of the allowable range of the temperature of the windings after the rotation of the motor. For example, the control unit 300 sets the rated voltage 220V to V2 and sets the low voltage limit V1. Of course, V2 can be set to an overvoltage limit value larger than the rated voltage.

If the detected voltage is equal to or greater than V2, the start time is set to T2, for example, 0.3 seconds, and if the detected voltage is the lower limit voltage V1, the start time is set to T1, for example, 1.5 seconds. If the detected voltage is between the low voltage limit value and the rated voltage, the start time is set in inverse proportion to the detected voltage.

Referring to FIG. 5, the step of operating the single-phase induction motor includes the steps of setting a reference voltage (step S60), comparing the detected voltage with the reference voltage (step S160) And a step S161 of opening the auxiliary winding switch and operating the motor through the main winding line when the voltage is equal to or higher than the reference voltage. If the detected voltage is smaller than the reference voltage as a result of the comparison, the main winding line switch is opened and the motor is operated through the auxiliary winding (S162).

First, in the control method, power is applied to the single phase induction motor by connecting both the main winding line switch and the auxiliary winding switch (S110), and the AC voltage input from the external power source is directly detected using the OP-AMP, Alternatively, the external power supply is connected to a smoothing capacitor of a power supply unit for converting a single-phase AC motor and a single-phase AC motor control device into a drive voltage for a circuit, a unit or the like, and detects a DC voltage to detect a voltage input to the motor S120). Then, the control method calculates the start time as described above based on the detected voltage (S130).

In addition, the control method determines whether the detected voltage is within a predetermined operating range (not shown). The operation region is set differently according to the voltage of the region where the single-phase induction motor is used, the type and form of the single-phase induction motor, the load condition, and the like, and may be set to a certain ratio of the input voltage of the external power source. The control method controls the main winding line switch and the auxiliary winding switch according to the determination result. When the detection voltage is outside the operation range, the main winding line switch and the auxiliary winding switch are opened to supply power to the single phase induction motor (Not shown). If the detected voltage is within the operating range, the main power switch and the auxiliary winding switch are connected to start the motor (S140). In the control method, after starting the single-phase induction motor, when the start time calculated in step S130 has elapsed, the single-phase induction motor is operated by opening or closing the primary winding switch or the secondary winding switch based on the detected voltage (S160 and below). If the detected voltage is equal to or higher than a preset reference voltage, the control method is to open the auxiliary winding switch to cut off the power applied to the auxiliary winding circuit, and operate the motor through the main winding wire (S161). On the other hand, if the detected voltage is smaller than a predetermined reference voltage, the control method is to turn off the main winding line switch to cut off the power applied to the main winding line circuit, and operate the motor through the auxiliary winding (S162). The reference voltage is set differently according to the voltage of the region where the single-phase induction motor is used, the type and the form of the single-phase induction motor, the load condition, etc., and may be set to a predetermined ratio of the input voltage of the external power source.

Referring to FIG. 6, a method of controlling a single-phase induction motor according to another embodiment of the present invention includes steps S211 and S212 of applying power to a single-phase induction motor through a main winding line switch and an auxiliary winding switch, (S230) of calculating the starting time based on the detected voltage and operating the single-phase induction motor by opening or closing the main-line switch or the auxiliary winding switch .

The operation of the single-phase induction motor includes a process (not shown) of calculating a start time based on the detected voltage, a process of setting a reference voltage (not shown), and a process of comparing the detected voltage and the reference voltage (S230), if the detected voltage is equal to or higher than the reference voltage, the step S231 of starting the power supply for the start time through the main winding line and the auxiliary winding (S231) (S233). ≪ / RTI >

Also, the step of operating the single-phase induction motor may include a step (S241) of extending the start-up time when the detection voltage is lower than the reference voltage as a result of the comparison, (S242) for activating the elapsed start time through the elapsed start time, and opening the main line switch (S244) after elapse of the extended start time.

First, in the control method, power is applied to the single-phase induction motor by connecting both the main winding line switch and the auxiliary winding switch (S210), and the AC voltage input from the external power source is directly detected using OP-AMP or the like The external power supply is connected to a smoothing capacitor of a power supply unit that converts a single-phase AC motor and a single-phase AC motor control device into a driving voltage of a circuit, a unit or the like, and detects a DC voltage to detect a voltage input to the motor ). Then, the control method calculates the starting time as described above on the basis of the detected voltage. Phase induction motor is started for the calculated starting time if the detected voltage is equal to or higher than a preset reference voltage and the auxiliary winding switch is opened for auxiliary The electric power applied to the winding circuit is cut off, and the electric motor is operated through the main winding line (S231 to S234). On the contrary, in the control method, if the detected voltage is smaller than a preset reference voltage, the calculated start time is extended to start the single phase induction motor for an extended start time, And the electric motor is operated through the auxiliary winding (S241 to S245). The reference voltage is set differently according to the voltage of the region where the single-phase induction motor is used, the type and the form of the single-phase induction motor, the load condition, etc., and may be set to a predetermined ratio of the input voltage of the external power source.

Referring to FIG. 7, the single-phase induction motor control method according to still another embodiment of the present invention includes the steps of (S310) applying power to a single-phase induction motor through a main-line switch and a sub- A step (S320) of detecting an applied voltage, a step (S331 to S332) of judging whether or not the detected voltage is within a predetermined operating range, and if the detected voltage is within the operating range, A step S340 of calculating a starting time based on the voltage, and a step S350 of starting the single-phase induction motor based on the calculated starting time.

The control method further includes a step (S333) of opening the main winding line switch and the auxiliary winding switch when the detection voltage is out of the operation range as a result of the determination. Further, the control method further includes a step (S370) of operating the single-phase induction motor by opening and closing the main winding line switch or the auxiliary winding switch based on the detection voltage.

The step of operating the single-phase induction motor includes the steps of setting a first reference voltage and a second reference voltage that is greater than the first reference voltage, comparing the detected voltage with the second reference voltage, (S370); and opening the auxiliary winding switch if the detected voltage is equal to or greater than the second reference voltage (S371). Also, the step of operating the single-phase induction motor may include comparing the detected voltage with the first reference voltage (S372), and if the detected voltage is equal to or less than the first reference voltage, (S380).

First, in the control method, power is applied to the single phase induction motor by connecting both the main winding line switch and the auxiliary winding switch (S310), and the AC voltage input from the external power source is directly detected using the OP-AMP, Alternatively, the external power supply is connected to a smoothing capacitor of a power supply unit for converting a single-phase AC motor and a single-phase AC motor control device into a drive voltage for a circuit, a unit or the like, and detects a DC voltage to detect a voltage input to the motor S320). The control method determines whether or not the detected voltage is within a predetermined operating range (S331, S332). The operation region is set differently according to the voltage of the region where the single-phase induction motor is used, the type and form of the single-phase induction motor, the load condition, and the like, and may be set to a certain ratio of the input voltage of the external power source. The control method controls the main winding line switch and the auxiliary winding switch according to the determination result. When the detection voltage is outside the operation range, the main winding line switch and the auxiliary winding switch are opened to supply power to the single phase induction motor (S333). If the detected voltage is within the operating range, the starting time is calculated according to the detected voltage, and the main power line switch and the auxiliary winding switch are connected during the calculated starting time to start the motor S340 or later). The start time may be set as shown in FIG. 4. When the detection voltage is high, it is set short to prevent overvoltage. When the detection voltage is low, the initial start time is set to be long Respectively.

The control method may further include setting a first reference voltage V1 and a second reference voltage V2 in advance and if the detected voltage is equal to or higher than the second reference voltage V2 at S370, , And operates the electric motor through the main power line (S371). If the detected voltage is lower than the first reference voltage V1 (S372), the control method opens the main power line switch and operates the motor through the auxiliary winding (S381). The first reference voltage V1 and the second reference voltage V2 have a difference of about 10 V, for example, and perform a hysteresis operation to prevent the breakdown of the motor due to a sudden change in the input voltage.

As described above, the apparatus and method for controlling a single-phase induction motor according to the present invention include a switching device such as a triac in each of a main winding and an auxiliary winding, detecting an input voltage, calculating a starting time based on the detected voltage, By controlling the switching elements, it is robust against variations in the input voltage, and can be stably and efficiently started or operated even in a low voltage region, and the motor itself can be protected from overvoltage.

1 is a circuit diagram schematically showing a general condenser operation type single-phase induction motor;

FIG. 2 or FIG. 3 is a block diagram schematically showing a configuration of a single-phase induction motor according to embodiments of the present invention; FIG.

4 is a graph showing a change in start-up time calculated according to a change in an input voltage in a single-phase induction motor according to the present invention;

5 to 7 are flowcharts schematically illustrating a method of controlling a single-phase induction motor according to embodiments of the present invention.

Claims (19)

A mains line switch connected in series to a mains line and for interrupting power supplied to or applied to the mains line; An auxiliary winding switch connected in series to the auxiliary winding and for applying power to the auxiliary winding or for interrupting the applied power; A voltage detection unit for detecting an input voltage applied from an external power supply; A control unit for calculating a starting time based on the detected voltage and opening / closing the main winding line switch and the auxiliary winding switch; And And a power supply unit for converting the input voltage into a driving voltage of the control unit and outputting the driving voltage, Wherein the control unit comprises: Wherein the auxiliary winding switch is opened when the detected voltage is equal to or higher than a preset reference voltage, and the motor is operated through the main winding line. The voltage detection circuit according to claim 1, And directly detects the AC voltage of the external power supply. The power supply apparatus according to claim 1, A rectifying unit for rectifying the input voltage; A smoothing unit for smoothing the rectified voltage; And A transforming unit for transforming the smoothed voltage into a driving voltage of the control unit; Phase induction motor control device. The voltage detection circuit according to claim 3, And detects the smoothed direct current voltage. delete The apparatus according to claim 1, Wherein when the detected voltage is smaller than the reference voltage, the main power line switch is opened and the motor is operated through the auxiliary winding. A mains line switch connected in series to a mains line and for interrupting power supplied to or applied to the mains line; An auxiliary winding switch connected in series to the auxiliary winding and for applying power to the auxiliary winding or for interrupting the applied power; A voltage detection unit for detecting an input voltage applied from an external power supply; A control unit for calculating a starting time based on the detected voltage and opening / closing the main winding line switch and the auxiliary winding switch; And And a power supply unit for converting the input voltage into a driving voltage of the control unit and outputting the driving voltage, Wherein the control unit comprises: A first reference voltage and a second reference voltage greater than the first reference voltage are preset, Wherein when the detection voltage is equal to or higher than the second reference voltage, the auxiliary winding switch is opened and the motor is operated through the main winding line. 8. The apparatus according to claim 7, Wherein when the detected voltage is equal to or lower than the first reference voltage, the main power line switch is opened and the motor is operated through the auxiliary winding. Applying power to the single phase induction motor through the main winding line switch and the auxiliary winding switch; Detecting a voltage applied to the single-phase induction motor; Calculating a start time based on the detected voltage; Driving the single-phase induction motor based on the calculated start time; And And operating the single-phase induction motor by opening and closing the primary winding switch or the secondary winding switch based on the detection voltage when the startup time elapses, The step of operating the single-phase induction motor includes: A step of setting a reference voltage; Comparing the detected voltage with the reference voltage; And And opening the auxiliary winding switch when the detected voltage is equal to or greater than the reference voltage as a result of the comparison. delete 10. The method of driving a single-phase induction motor according to claim 9, Further comprising the step of: if the detected voltage is smaller than the reference voltage, opening the main line switch. Applying power to the single phase induction motor through the main winding line switch and the auxiliary winding switch; Detecting a voltage applied to the single-phase induction motor; And Calculating a start time based on the detected voltage, and operating the single-phase induction motor by opening and closing the main winding line switch or the auxiliary winding switch, The step of operating the single-phase induction motor includes: Calculating a start time based on the detected voltage; A step of setting a reference voltage; Comparing the detected voltage with the reference voltage; If the detected voltage is equal to or greater than the reference voltage, starting the power supply for the start time through the main winding line and the auxiliary winding; And And opening the auxiliary winding switch after the start time elapses. delete The method as claimed in claim 12, wherein the step of operating the single- If the detected voltage is lower than the reference voltage as a result of the comparison, extending the startup time; Starting over the extended start time through the main winding line and the auxiliary winding; And opening the main line switch after the elapse of the extended start time. Applying power to the single phase induction motor through the main winding line switch and the auxiliary winding switch; Detecting a voltage applied to the single-phase induction motor; Determining whether the detected voltage is within a predetermined operation range; Calculating a start time based on the detected voltage when the detected voltage is within the operation range; Driving the single-phase induction motor based on the calculated start time; And And operating the single-phase induction motor by opening and closing the primary winding switch or the secondary winding switch based on the detected voltage, The step of operating the single-phase induction motor includes: Setting a first reference voltage and a second reference voltage that is greater than the first reference voltage; Comparing the detected voltage with the second reference voltage; And And opening the auxiliary winding switch when the detected voltage is equal to or greater than the second reference voltage. 16. The method of claim 15, And opening the main winding line switch and the auxiliary winding switch when the detected voltage is out of the operating range as a result of the determination. delete delete 16. The method of claim 15, wherein the step of operating the single- Comparing the detected voltage with the first reference voltage; And And opening the main power line switch when the detected voltage is lower than the first reference voltage.

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