KR102187749B1 - Motor driving apparatus and home appliance including the same - Google Patents

Abstract

The present invention relates to a motor driving device and a home appliance having the same. A motor driving apparatus according to an embodiment of the present invention and a home appliance having the same include a single-phase motor, an inverter that converts DC-stage power into AC power and outputs the converted AC power to a single-phase motor by a switching operation, It controls the inverter and includes a control unit for controlling to add an offset current to the starting current at the time of initial startup. Accordingly, the initial starting of the single-phase motor can be stably performed.

Description

Motor driving apparatus and home appliance including the same

The present invention relates to a motor driving device and a home appliance including the same, and more particularly, to a motor driving device capable of stably performing initial starting of a single-phase motor, and a home appliance having the same.

The motor driving device is a device for driving a motor having a rotor for rotational motion and a stator wound around a coil.

Motors can be classified into Samsung motors with three-phase windings and single-phase motors with single-phase windings.

In the three-phase motor, the rotation direction can be adjusted by a current applied to the three-phase or the like, but the single-phase motor cannot adjust the rotation direction.

Accordingly, when implementing a single-phase motor, there is a method of implementing a motor driving apparatus using a sensor method such as a Hall sensor, but according to this, there is a disadvantage in that additional cost is required.

Therefore, when driving a single-phase motor, a method of driving the motor in a sensorless method excluding the Hall sensor is being studied.

An object of the present invention is to provide a motor driving device capable of stably performing initial starting of a single-phase motor and a home appliance having the same.

A motor driving apparatus according to an embodiment of the present invention for achieving the above object and a home appliance including the same, a single-phase motor, and a switching operation, converting the dc-stage power into AC power, and converting the converted AC power into a single-phase motor And a control unit that controls the inverter to output to and controls the inverter to add an offset current to the starting current during initial startup.

On the other hand, the control unit of the motor driving apparatus according to an embodiment of the present invention controls to add an offset current when the first speed is less than or equal to the first speed, and controls not to apply the offset current when the first speed is exceeded.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, at the initial start, applies the current for torque and magnetic flux current to the motor, and controls to add an offset current to the current for torque.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, at the time of initial startup, to add an offset current so that the current for torque is greater than the current for magnetic flux.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention controls the applied offset current to decrease after a predetermined time.

Meanwhile, the control unit of the motor driving apparatus according to the embodiment of the present invention controls to add an offset current according to the speed of the motor.

On the other hand, the control unit of the motor driving apparatus according to an embodiment of the present invention controls to add an offset current according to the operation time of the motor.

A motor driving apparatus according to an embodiment of the present invention and a home appliance having the same include a single-phase motor, an inverter that converts DC-stage power into AC power and outputs the converted AC power to a single-phase motor by a switching operation, It controls the inverter, and includes a control unit for controlling to add an offset voltage to the starting voltage during initial startup.

Meanwhile, the control unit of the motor driving apparatus according to an embodiment of the present invention controls to add an offset voltage when the first speed is less than or equal to the first speed, and controls not to apply the offset voltage when the first speed is exceeded.

On the other hand, the control unit of the motor driving apparatus according to an embodiment of the present invention applies a voltage for torque and a voltage for magnetic flux to the motor during initial startup, and controls to add an offset voltage to the current for torque.

Meanwhile, the control unit of the motor driving apparatus according to the embodiment of the present invention controls the applied offset voltage to decrease after a predetermined time.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention controls to add an offset voltage according to the speed of the motor.

On the other hand, the control unit of the motor driving apparatus according to an embodiment of the present invention controls to add an offset voltage according to the operation time of the motor.

A motor driving apparatus according to an embodiment of the present invention and a home appliance having the same include a single-phase motor, an inverter that converts DC-stage power into AC power and outputs the converted AC power to a single-phase motor by a switching operation, It controls the inverter and includes a control unit for controlling to add an offset current to the starting current at the time of initial startup. Accordingly, it is possible to stably perform the initial starting of the single-phase motor despite the voltage drop occurring during the initial starting.

On the other hand, when the first speed is less than the first speed, the control to add an offset current, when the first speed is exceeded, by controlling the offset current not to be applied, it is possible to stably perform the initial start of the single-phase motor.

On the other hand, during the initial start-up, by applying a current for torque and a current for magnetic flux to the motor, and controlling to add an offset current to the current for torque, it is possible to stably perform the initial start of the single-phase motor.

On the other hand, at the time of initial start-up, by adding an offset current so that the current for torque is greater than the current for magnetic flux, the initial start of the single-phase motor can be stably performed.

On the other hand, after a predetermined time, by controlling the applied offset current to be small, the initial start of the single-phase motor can be stably performed.

On the other hand, by adding an offset current according to the speed of the motor, it is possible to stably perform the initial start of the single-phase motor.

On the other hand, by adding an offset current according to the operation time of the motor, the initial start of the single-phase motor can be stably performed.

A motor driving apparatus according to an embodiment of the present invention and a home appliance having the same include a single-phase motor, an inverter that converts DC-stage power into AC power and outputs the converted AC power to a single-phase motor by a switching operation, It controls the inverter, and includes a control unit for controlling to add an offset voltage to the starting voltage during initial startup. Accordingly, it is possible to stably perform the initial starting of the single-phase motor despite the voltage drop occurring during the initial starting.

On the other hand, the control unit of the motor driving apparatus according to an embodiment of the present invention controls to add an offset voltage when the first speed is less than or equal to the first speed, and controls not to apply the offset voltage when the first speed is exceeded. Maneuvering can be performed stably.

On the other hand, at the initial start-up, by applying a voltage for torque and a voltage for magnetic flux to the motor and controlling to add an offset voltage to the current for torque, the initial start of the single-phase motor can be stably performed.

On the other hand, after a predetermined time, by controlling the applied offset voltage to decrease, it is possible to stably perform the initial start of the single-phase motor.

On the other hand, by controlling to add an offset voltage according to the speed of the motor, the initial start of the single-phase motor can be stably performed.

On the other hand, by controlling to add an offset voltage according to the operation time of the motor, the initial start of the single-phase motor can be stably performed.

1 is a side elevation view showing a state of use of a cleaner according to an embodiment of the present invention.
FIG. 2 is a perspective view of a cleaner from which the nozzle module is removed from FIG. 1.
3 is a side elevation view of the cleaner of FIG. 2.
4 is a view showing the suction motor of FIG. 3.
5 illustrates an example of an internal block diagram of a motor driving apparatus according to an embodiment of the present invention.
6 is an example of an internal circuit diagram of the motor driving apparatus of FIG. 5.
7 is an internal block diagram of the inverter controller of FIG. 6.
8A to 8F are views referenced for explaining the operation of the inverter.
9 is a diagram showing an initial starting waveform.
10 is a diagram showing an initial starting waveform according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The suffixes "module" and "unit" for the constituent elements used in the following description are given in consideration of only the ease of writing in the present specification, and do not impart a particularly important meaning or role by themselves. Therefore, the "module" and "unit" may be used interchangeably with each other.

The home appliance described herein refers to a home appliance that includes a single-phase motor and is driven according to an operation of the single-phase motor. For example, the home appliance may be variously exemplified such as a vacuum cleaner, a hair dryer, an electric fan, a washing machine, an air purifier, an air conditioner, a water purifier, a refrigerator, and a vehicle. Hereinafter, a vacuum cleaner among home appliances will be described.

1 is a side elevational view showing a state of use of a cleaner according to an embodiment of the present invention, FIG. 2 is a perspective view of a cleaner with a nozzle module removed from FIG. 1, and FIG. 3 is a side elevation view of the cleaner of FIG. 2.

1 to 3, the cleaner 100 according to an embodiment of the present invention includes a main body 10 and a main body 10 forming a flow path P for guiding suctioned air to be discharged to the outside. ), the handle 30 coupled to the rear side of the main body 10, the nozzle module 70 detachably connected to the suction unit 11 of the main body 10, a battery Bt for supplying power, and a battery Bt. A fan module 50 disposed on the battery housing 40 and the flow path P to move air in the flow path may be provided.

The nozzle module 70 may include a nozzle unit 71 provided to suck in external air and an extension pipe 73 extending from the nozzle unit 71.

The extension pipe 73 connects the nozzle part 71 and the suction part 11. The extension pipe 73 guides the air sucked in from the nozzle part 71 to flow into the suction flow path P. One end of the extension pipe 73 may be detachably coupled to the suction part 11 of the main body 10. The user can clean while holding the handle 30 and moving the nozzle 71 while placing the nozzle 71 on the floor.

The main body 10 includes an exhaust cover 12 forming an exhaust port 10a, a dust collecting unit 13 for storing separated dust, and a fan module housing 14 accommodating the fan module 50 therein. It may include.

The discharge cover 12 may form an upper surface of the main body 10. The exhaust cover 12 covers the upper side of the fan module housing 14.

The dust collection part 13 may be formed in a cylindrical shape. The dust collecting part 13 may be disposed under the fan module housing 14. Accordingly, a storage space for dust may be formed inside the dust collection unit 13.

The fan module housing 14 may be formed to extend upward from the dust collection unit 13. The fan module housing 14 is formed in a cylindrical shape. The extended portion 31 of the handle 30 may be disposed on the rear side of the fan module housing 14.

In the fan module housing 14, a fan module 50 may be disposed.

The fan module 50 includes a suction motor 230 that rotates the impeller 51. The suction motor 230 may be located above the dust separation unit 20.

The impeller 51 may be disposed under the suction motor 230. The impeller 51 is coupled with the suction motor 230 and rotates by the rotational force of the suction motor 230.

Meanwhile, the impeller 510 may pressurize the air by rotation so that the air in the flow path P is discharged through the exhaust port 10a.

Meanwhile, the cleaner 100 may include a motor driving unit 220 for controlling the suction motor 230. The motor driving unit 220 may be disposed between the suction motor 230 and the dust collecting unit 13. Meanwhile, the motor driving unit 220 may include circuit elements disposed on a PCB circuit board.

The handle 30 extends in the vertical direction and includes an additional extension 32. The additional extension part 32 may be spaced apart from the main body 10 in the front-rear direction. The user can use the vacuum cleaner 100 while holding the additional extension 32. The upper end of the additional extension 32 is connected to the rear end of the extension 31. The lower end of the additional extension 32 is connected to the battery housing 40.

The additional extension part 32 is provided with a movement limiting part 32a to prevent the hand from moving in the longitudinal direction (up and down direction) of the additional extension part 32 while the user holds the additional extension part 32 Can be. The movement limiting part 32a may protrude forward from the additional extension part 32.

The movement limiting part 32a is disposed to be spaced apart from the extension part 31 vertically. While the user holds the additional extension part 32, some fingers of the user's hand are positioned above the movement limiting part 32a, and the other fingers are provided to be located below the movement limiting part 32a.

The handle 30 may include an inclined surface 33 facing the direction between the upper side and the rear side. The inclined surface 33 may be positioned at the rear of the extension 31. The input unit 3 may be disposed on the inclined surface 33.

The battery Bt may supply power to the fan module 50. The battery Bt may supply power to the noise control module. The battery Bt may be detachably disposed inside the battery housing 40.

The battery housing 40 is coupled to the rear side of the main body 10. The battery housing 40 is disposed under the handle 30. The battery Bt is accommodated in the battery housing 40. A heat dissipation hole for discharging heat generated from the battery Bt to the outside may be formed in the battery housing 40.

Meanwhile, the exhaust port 10a may be disposed to face a specific direction (eg, upward direction). The plurality of exhaust ports 10a may be divided from each other in the circumferential direction by a plurality of exhaust guides 12a. The plurality of exhaust ports 10a may be arranged at predetermined intervals apart from each other along the circumferential direction.

4 is a view showing the suction motor of FIG. 3.

Referring to the drawings, the suction motor 230 according to the embodiment of the present invention may include a rotor (ROT) and a stator (STA).

The rotor ROT may include a rotor core PCO and a magnet PM formed on the outer periphery of the rotor core PCO. The magnet (PM) is formed in a circular shape, and may be provided with an S pole (PMS) and an N pole (PMN), respectively. In the drawing, it is illustrated that the S pole (PMS) faces upward.

The stator STA may include a stator frame SFR formed on one side of the rotor ROT, and coils Cla and Clb respectively wound on the upper and lower sides of the stator frame SFR.

On the other hand, since the stator frame (SFR) is disposed on one side of the magnet (PM) of the rotor (ROT), an asymmetrical air gap (ARG) between the magnet (PM) of the rotor (ROT) and the stator frame (SFR) Can be formed.

As described above, the suction motor 230 according to an embodiment of the present invention may be a brushless DC (BLDC) single-phase motor in which an asymmetric air gap (ARG) is formed.

The motor driving apparatus described in this specification is capable of estimating the rotor position of the motor by a sensorless method, which does not include a position detection unit such as a hall sensor for sensing the rotor position of the motor. It is a possible motor drive. Hereinafter, a sensorless motor driving device will be described.

5 illustrates an example of an internal block diagram of a motor driving apparatus according to an embodiment of the present invention, and FIG. 6 is an example of an internal circuit diagram of the motor driving apparatus of FIG. 5.

Referring to the drawings, the motor driving apparatus 220 according to an embodiment of the present invention is for driving the single-phase motor 230 and may include an inverter 420 and an inverter control unit 430.

In addition, the motor driving apparatus 220 according to an embodiment of the present invention may include a converter 410, a dc terminal voltage detection unit (B), a dc terminal capacitor (C), and an output current detection unit (E). In addition, the driving unit 220 may further include an input current detection unit A and the like.

Hereinafter, operations of each of the constituent units in the motor driving apparatus 220 of FIGS. 5 and 6 will be described.

The input current detection unit A may detect an input current i _s input from the battery BT. To this end, as the input current detection unit A, a current trnasformer (CT), a shunt resistor, or the like may be used. The detected input current i _s is a pulsed discrete signal and may be input to the inverter controller 430.

The converter 410 may convert the level of the battery power Vs from the battery BT to output the level-converted DC power. To this end, the converter 410 may include a switching element. Meanwhile, the converter 410 may be omitted.

The dc terminal capacitor C may store input power. In addition, the input power can be smoothed.

Meanwhile, since DC power is stored at both ends of the DC terminal capacitor C, this may be referred to as a dc terminal or a dc link terminal.

The dc terminal voltage detector B may detect the dc terminal voltage Vdc, which is both ends of the dc terminal capacitor C. To this end, the dc terminal voltage detection unit B may include a resistance element, an amplifier, and the like. The detected dc voltage Vdc may be input to the inverter controller 430 as a discrete signal in the form of a pulse.

The inverter 420 includes a plurality of inverter switching elements, and converts the DC power supply (Vdc) of the dc stage into a single phase AC power supply (va) of a predetermined frequency by an on/off operation of the switching element, and a single phase synchronous motor It can be output to 230.

In the inverter 420, a pair of upper-arm switching elements (Sa, Sb) and lower-arm switching elements (S'a, S'b) connected in series with each other, respectively, and a total of two pairs of upper and lower arm switching elements are parallel to each other ( It is connected to Sa&S'a,Sb&S'b). Diodes are connected in reverse parallel to each of the switching elements Sa, S'a, Sb, S'b.

The switching elements in the inverter 420 perform on/off operations of each switching element based on the inverter switching control signal Sic from the inverter controller 430. As a result, single-phase AC power having a predetermined frequency is output to the single-phase synchronous motor 230.

The inverter controller 430 may control a switching operation of the inverter 420 based on a sensorless method. To this end, the inverter control unit 430 may receive an output current i _o detected by the output current detection unit E.

The inverter controller 430 outputs an inverter switching control signal Sic to the inverter 420 in order to control the switching operation of the inverter 420. The inverter switching control signal Sic is a switching control signal of the pulse width modulation method (PWM), and is generated and output based on the output current i _o detected by the output current detection unit E. A detailed operation of the output of the inverter switching control signal Sic in the inverter control unit 430 will be described later with reference to FIG. 7.

The output current detection unit E detects an output current i _o flowing between the inverter 420 and the single-phase motor 230. That is, the current flowing through the motor 230 is detected.

The output current detection unit E may be located between the inverter 420 and the motor 230, and for current detection, a current trnasformer (CT), a shunt resistor, or the like may be used. Alternatively, the output current detection unit E may include a shunt resistor disposed between the dc terminal capacitor C and the inverter 420.

The detected output current i _o may be applied to the inverter control unit 430 as a discrete signal in the form of a pulse, and the inverter switching control signal Sic based on the detected output current i _o Is created. Hereinafter, it may be described in parallel that the detected output current i _o is the single-phase output current io.

Meanwhile, the single-phase motor 230 includes a stator and a rotor, and single-phase AC power having a predetermined frequency is applied to the coil of the single-phase stator, so that the rotor rotates.

Such a single-phase motor 230 is, for example, a surface-mounted permanent magnet synchronous motor (Surface-Mounted Permanent-Magnet Synchronous Motor; SMPMSM), a built-in permanent magnet synchronous motor (Interior Permanent Magnet Synchronous Motor; IPMSM), and synchronous It may include a reluctance motor (Synchronous Reluctance Motor; Synrm) or the like. Among them, SMPMSM and IPMSM are Permanent Magnet Synchronous Motor (PMSM), and Synrm is characterized by no permanent magnet.

7 is an internal block diagram of the inverter controller of FIG. 6.

Referring to FIG. 7, the inverter control unit 430 includes an axis conversion unit 310, a speed calculation unit 320, a current command generation unit 330, a voltage command generation unit 340, an axis conversion unit 350, and A switching control signal output unit 360 may be included.

The axis conversion unit 310 receives the single-phase output current io or ia detected by the output current detection unit E and converts it into two-phase currents iα and iβ of the stationary coordinate system.

Meanwhile, the axis conversion unit 310 may convert the two-phase currents iα and iβ of the stationary coordinate system into the two-phase currents id and iq of the rotational coordinate system.

)와 연산된 속도(

)를 출력할 수 있다.The speed calculation unit 320 is based on the two-phase current (iα, iβ) of the stationary coordinate system axis-changed by the axis conversion unit 310,

) And calculated speed (

) Can be printed.

)와 속도 지령치(ω^* _r)에 기초하여, 전류 지령치(i^* _q)를 생성한다. 예를 들어, 전류 지령 생성부(330)는, 연산 속도(

)와 속도 지령치(ω^* _r)의 차이에 기초하여, PI 제어기(335)에서 PI 제어를 수행하며, 전류 지령치(i^* _q)를 생성할 수 있다. 도면에서는, 전류 지령치로, q축 전류 지령치(i^* _q)를 예시하나, 도면과 달리, d축 전류 지령치(i^* _d)를 함께 생성하는 것도 가능하다. 한편, d축 전류 지령치(i^* _d)의 값은 0으로 설정될 수도 있다. On the other hand, the current command generation unit 330, the calculation speed (

) And the speed command value (ω ^* _r ), the current command value (i ^* _q ) is generated. For example, the current command generation unit 330, the calculation speed (

) And the speed command value (ω ^* _r ), the PI controller 335 performs PI control, and a current command value (i ^* _q ) can be generated. In the drawing, the q-axis current command value (i ^* _q ) is illustrated as the current command value, but unlike the drawing, it is also possible to generate the d-axis current command value (i ^* _d ) together. Meanwhile, the value of the d-axis current command value (i ^* _d ) may be set to 0.

Meanwhile, the current command generation unit 330 may further include a limiter (not shown) that limits the level so that the current command value i ^* _q does not exceed the allowable range.

Next, the voltage command generation unit 340 includes the d-axis and q-axis currents (i _d , i _q ) that have been axially transformed from the axis conversion unit into a two-phase rotational coordinate system, and a current command value in the current command generation unit 330, etc. Based on i ^* _d ,i ^* _q ), the d-axis and q-axis voltage command values (v ^* _d ,v ^* _q ) are generated. For example, the voltage command generation unit 340 performs PI control in the PI controller 344 based on the difference between the q-axis current (i _q ) and the q-axis current command value (i ^* _q ), and q It is possible to generate the axis voltage command value (v ^* _q ). In addition, the voltage command generation unit 340 performs PI control in the PI controller 348 based on the difference between the d-axis current (i _d ) and the d-axis current command value (i ^* _d ), and the d-axis voltage You can create a setpoint (v ^* _d ). Meanwhile, the voltage command generation unit 340 may further include a limiter (not shown) that limits the level of the d-axis and q-axis voltage command values (v ^* _d , v ^* _q ) to not exceed the allowable range. .

On the other hand, the generated d-axis and q-axis voltage command values (v ^* _d and v ^* _q ) are input to the axis conversion unit 350.

)와, d축, q축 전압 지령치(v^* _d,v^* _q)를 입력받아, 축변환을 수행한다.The axis conversion unit 350 is a position calculated by the speed calculation unit 320 (

) And the d-axis and q-axis voltage command values (v ^* _d ,v ^* _q ) and perform axis transformation.

)가 사용될 수 있다.First, the axis conversion unit 350 converts from a two-phase rotation coordinate system to a two-phase stationary coordinate system. At this time, the position calculated by the speed calculating unit 320 (

) Can be used.

In addition, the axis conversion unit 350 converts from a two-phase stationary coordinate system to a single-phase stationary coordinate system. Through this conversion, the axis conversion unit 1050 outputs a single-phase output voltage command value (v ^* a).

The switching control signal output unit 360 generates and outputs a switching control signal Sic for an inverter according to a pulse width modulation (PWM) method based on a single-phase output voltage command value (v ^* a).

The output inverter switching control signal Sic may be converted into a gate driving signal by a gate driver (not shown) and may be input to the gate of each switching element in the inverter 420. Accordingly, each of the switching elements Sa, S'a, Sb, S'b in the inverter 420 performs a switching operation.

8A to 8F are views referenced for explaining the operation of the inverter.

First, FIG. 8A illustrates that a current flows according to a first current path (path1) in the regenerative mode. At this time, all the switching elements Sa, Sb, S'a, S'b may be turned off.

Here, the positive current according to the first current path path1 flows through the motor 230, the second upper arm diode Db, the capacitor C, and the first lower arm diode D'a.

At this time, the voltage Vm of both ends of the motor 230 is the voltage Vdb of the second upper arm diode Db and the voltage Vd'a of the first lower arm diode D'a at the dc voltage Vdc. Corresponds to subtracting ).

Ideally, the voltage (Vm) at both ends of the motor 230 should correspond to the voltage at the dc end (Vdc), but in the actual regenerative mode, the voltage (Vdb) of the second upper arm diode (Db) and the first lower arm diode A voltage drop occurs due to the voltage Vd'a of (D'a).

Next, FIG. 8B illustrates that, in the regenerative mode, current flows according to the second current path pbth2. At this time, all the switching elements Sb, Sb, S'b, S'b may be turned off.

Here, the negative current according to the second current path pbth2 flows through the motor 230, the first upper-arm diode Da, the capacitor C, and the second lower-arm diode D'b.

At this time, the voltage Vm of both ends of the motor 230 is the voltage Vda of the first upper arm diode Da and the voltage Vd'b of the second lower arm diode D'b at the dc end voltage Vdc. Corresponds to the addition of ).

Ideally, the voltage (Vm) at both ends of the motor 230 should correspond to the voltage at the dc end (Vdc), but in the actual regenerative mode, the voltage (Vdb) of the second upper arm diode (Db) and the first lower arm diode A voltage increase occurs due to the voltage Vd'a of (D'a).

Next, FIG. 8C illustrates that, in the power supply mode, current flows according to the third current path (path3). At this time, the first upper arm switching element Sa and the second lower arm switching element S'b may be turned on, and the second upper arm switching element Sb and the first lower arm switching element S'a may be turned off.

Here, the positive current according to the third current path path3 flows through the capacitor C, the first upper arm switching element Sa, the motor 230, and the second lower arm switching element S'b.

At this time, the voltage Vm of both ends of the motor 230 is the voltage Vsa of the first upper arm switching element Sa and the voltage Vs of the second lower arm switching element S'b at the dc voltage Vdc. It corresponds to subtracting'b).

Ideally, the voltage (Vm) at both ends of the motor 230 should correspond to the voltage at the dc end (Vdc), but in the power supply mode, the voltage (Vsa) of the first phase-arm switching element (Sa) and the second A voltage drop occurs due to the voltage Vs'b of the lower arm switching element S'b.

Next, FIG. 8D illustrates that, in the power supply mode, current flows according to the fourth current path pbth4. In this case, the first upper arm switching element Sa and the second lower arm switching element S'b may be turned off, and the second upper arm switching element Sb and the first lower arm switching element S'a may be turned on.

Here, the negative current according to the fourth current path pbth4 flows through the capacitor C, the second upper arm switching element Sb, the motor 230, and the first lower arm switching element S'a. .

At this time, the voltage (Vm) of both ends of the motor 230 is the voltage (Vsb) of the second upper arm switching element (Sb) and the voltage (Vs) of the first lower arm switching element (S'a) at the dc end voltage (Vdc). It corresponds to the addition of'a).

Ideally, the voltage (Vm) at both ends of the motor 230 should correspond to the voltage at the dc end (Vdc), but in the power supply mode, the voltage (Vsb) of the second phase-arm switching element (Sb) and the first A voltage increase occurs due to the voltage Vs'a of the lower arm switching element S'a.

Next, FIG. 8E illustrates that current flows according to the fifth current path (path5) in the reflux mode. At this time, the first upper arm switching element Sa is turned on, and the second lower arm switching element S'b, the second upper arm switching element Sb, and the first lower arm switching element S'a may be turned off. .

Here, the positive current according to the fifth current path path5 flows through the motor 230, the second phase-arm diode Db, and the first phase-arm switching element Sa.

At this time, the voltage (Vm) of both ends of the motor 230 is subtracted from the voltage (Vdc) of the first phase-arm switching element (Sa) and the voltage (Vdb) of the second phase-arm diode (Db) from the dc-terminal voltage (Vdc). Corresponds to what was done.

Ideally, the voltage (Vm) of both ends of the motor 230 should correspond to the voltage of the dc end (Vdc), but in fact, in the reflux mode, the voltage (Vsa) of the first phase-arm switching element (Sa) and the second phase-arm A voltage drop occurs due to the voltage Vdb of the diode Db.

Next, FIG. 8F illustrates that current flows according to the sixth current path pbth6 in the reflux mode. At this time, the first lower arm switching element S'a is turned on, and the second lower arm switching element S'b, the second upper arm switching element Sb, and the first upper arm switching element Sa may be turned off. .

Here, the negative current according to the sixth current path pbth6 flows through the motor 230, the first lower arm switching element S'a, and the second lower arm diode D'b.

At this time, the voltage Vm across the motor 230 is between the voltage Vs'a of the first lower arm switching element S'a and the second lower arm diode D'b at the dc voltage Vdc. It corresponds to the addition of the voltage Vd'b.

Ideally, the voltage (Vm) at both ends of the motor 230 should correspond to the voltage at the dc end (Vdc), but in fact, in the reflux mode, the voltage (Vs'a) of the first lower arm switching element S'a and , A voltage increase occurs due to the voltage Vd'b of the second lower arm diode D'b.

8A to 8F, in the regenerative mode, the power supply mode, and the reflux mode, switching elements Sa, Sb, S'a, S'b and switching elements Sa, Sb, respectively of the inverter 420 Due to the diodes (Da, Db, D'a, D'b) connected in antiparallel to S'a, S'b), a voltage drop or voltage rise occurs.

In particular, as shown in Fig. 7c, as a power supply mode, for rotation of the motor 230, when the motor is driven, the voltage Vsa of the first upper arm switching element Sa and the second lower arm switching element S'b A voltage drop occurs due to the voltage Vs'b of.

On the other hand, when the motor 230 is initially started, due to a voltage drop due to the voltage Vsa of the first upper arm switching element Sa and the voltage Vs'b of the second lower arm switching element S'b, It is often not possible to perform stably during initial start-up. This will be described with reference to FIG. 9.

9 is a diagram showing an initial starting waveform.

Referring to the drawings, T1x denotes a stop period of the motor 230, T2x denotes a start period of the motor 230, i ^* qx is a q-axis current command value, i ^* dx is a d-axis current command value, and iax is a motor 230 Shows the current waveform flowing in.

As shown in Fig. 7c, as a power supply mode, for rotation of the motor 230, when the motor is started, as shown in Fig. 9, i ^* qx is the q-axis current command value, i ^* dx is the level of the d-axis current command value. When set to be, as described above in the description of FIG. 7C, the voltage due to the voltage Vsa of the first upper-arm switching element Sa and the voltage Vs'b of the second lower-arm switching element S'b A drop occurs.

Accordingly, the current iax flowing through the motor 230 is not a smooth sinusoidal wave, but an unstable sinusoidal wave as shown in the figure is input. Accordingly, the start-up cannot be stably performed during initial start-up.

In order to solve this point, an embodiment of the present invention proposes a method of adding an offset current (OFS) to the starting current during initial startup. This will be described with reference to FIG. 10 below.

10 is a diagram showing an initial starting waveform according to an embodiment of the present invention.

Referring to the drawing, T1 represents the stop period of the motor 230, T2 represents the start period of the motor 230, i ^* q represents the q-axis current command value or the torque equivalent current command value, and i ^* d is the d-axis current command value or magnetic flux. The minute current command value, ia1, represents a current waveform flowing through the motor 230.

As shown in Fig. 7c, as a power supply mode, for rotation of the motor 230, when the motor is started, the voltage Vsa of the first upper arm switching element Sa and the voltage of the second lower arm switching element S'b Voltage drop occurs due to (Vs'b).

In order to compensate for this voltage drop, the inverter controller 430 according to an embodiment of the present invention may control to add an offset current OFS to the starting current.

In particular, the inverter control unit 430 according to an embodiment of the present invention, as shown in the drawing, on the other hand, at the initial start, the motor 230, the torque portion current (i ^* q) and the magnetic flux current (i ^* d) Is applied and the offset current (OFS) is added to the torque current (i ^* q).

That is, the inverter control unit 430 according to an embodiment of the present invention may add an offset current (OFS) so that the torque current (i ^* q) is greater than the magnetic flux current (i ^* d) during initial startup. I can.

According to this, the torque portion current (i ^* q) in charge of rotation according to the application of the electric signal is greater than the magnetic flux portion current (i ^* d) in charge of rotation by the magnet, so that the initial start of the single-phase motor 230 It becomes possible to perform stably.

On the other hand, the inverter control unit 430 according to an embodiment of the present invention may control to add an offset current OFS when the first speed is less than or equal to the first speed, and control not to apply the offset voltage when the first speed is exceeded. . At this time, the first speed may correspond to the speed until completion of the initial start-up.

The inverter controller 430 according to an embodiment of the present invention may control not to separately apply an offset voltage when the first speed is exceeded, that is, after completion of the initial start.

On the other hand, in the drawing, the initial start-up period is shown as a constant level of the offset current OFS during the T2 period, but may be modified differently.

That is, the inverter control unit 430 according to an embodiment of the present invention may control the added offset current OFS to decrease during initial startup and after a predetermined time. Accordingly, the initial start of the single-phase motor 230 can be stably performed.

Meanwhile, the inverter control unit 430 according to an embodiment of the present invention may add an offset current OFS according to the speed of the motor 230. For example, if it is less than the first speed, it may be controlled to add an offset current OFS.

Meanwhile, the inverter control unit 430 according to an embodiment of the present invention may add an offset current OFS according to the operation time of the motor 230. For example, an offset current OFS may be added from the motor operation time point for about 10 seconds, or for about 10 seconds when initially starting. Accordingly, the initial start of the single-phase motor 230 can be stably performed.

Meanwhile, in FIG. 10, it is exemplified that the current ia flowing through the motor 230 appears as a smooth sinusoidal wave with the addition of the offset current OFS.

Meanwhile, in another embodiment of the present invention, a method of adding an offset voltage to the starting voltage during initial startup is proposed.

For example, the inverter control unit 430 according to another embodiment of the present invention applies a torque voltage (v ^* q) and a magnetic flux voltage (v ^* d) to the motor 230 at initial startup, It can be controlled to add an offset voltage to the torque voltage (v ^* q).

That is, the inverter control unit 430 according to another embodiment of the present invention may add an offset voltage such that the torque voltage (v ^* q) is greater than the magnetic flux voltage (v ^* d) during initial startup. .

According to this, since the voltage for torque (v ^* q) responsible for rotation according to the application of the electric signal is greater than the voltage for magnetic flux (v ^* d) responsible for rotation by the magnet, the initial start of the single-phase motor 230 It becomes possible to perform stably.

Meanwhile, the inverter controller 430 according to another embodiment of the present invention may control to add an offset voltage when the first speed is less than or equal to the first speed, and control not to apply the offset voltage when the first speed is exceeded. At this time, the first speed may correspond to the speed until completion of the initial start-up.

The inverter control unit 430 according to another embodiment of the present invention may control not to separately apply an offset voltage when the first speed is exceeded, that is, after completion of the initial start-up.

Meanwhile, the inverter control unit 430 according to another embodiment of the present invention may control the applied offset voltage to decrease after a predetermined time during initial startup. Accordingly, the initial start of the single-phase motor 230 can be stably performed.

Meanwhile, the inverter controller 430 according to another embodiment of the present invention may add an offset voltage according to the speed of the motor 230. For example, if it is less than the first speed, it may be controlled to add an offset voltage.

Meanwhile, the inverter controller 430 according to another embodiment of the present invention may add an offset voltage according to the operation time of the motor 230. For example, an offset voltage may be added from the motor operation time point for about 10 seconds, or for about 10 seconds when initially starting. Accordingly, the initial start of the single-phase motor 230 can be stably performed.

The motor driving device and the home appliance having the same according to an embodiment of the present invention are not limited to the configuration and method of the embodiments described as described above, but the above embodiments are each so that various modifications can be made. All or some of the embodiments may be selectively combined and configured.

Meanwhile, the motor driving method or the home appliance operating method of the present invention may be implemented as a code readable by the processor on a recording medium readable by a processor provided in the motor driving apparatus or the home appliance. The processor-readable recording medium includes all types of recording devices that store data that can be read by the processor.

In addition, although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

Claims (15)

Single-phase motor;
An inverter converting a dc terminal power into an AC power source by a switching operation and outputting the converted AC power to the single-phase motor;
Includes; a control unit that controls the inverter and controls to add an offset current to the starting current during initial startup,
The control unit,
After a predetermined time, the motor driving apparatus, characterized in that the control so that the added offset current decreases. The method of claim 1,
The control unit,
When the speed of the single-phase motor is less than or equal to a first speed, the offset current is controlled, and when the speed of the single-phase motor exceeds the first speed, the offset current is not applied. The method of claim 1,
The control unit,
During the initial start-up, a torque-based current and a magnetic flux-based current are applied to the motor, and control is performed to add the offset current to the torque-based current. The method of claim 1,
The control unit,
At the time of the initial starting, the offset current is added so that the current for torque is greater than the current for magnetic flux. delete The method of claim 1,
The control unit,
A motor driving apparatus, characterized in that controlling to add the offset current according to the speed of the motor. The method of claim 1,
The control unit,
The motor driving apparatus, characterized in that controlling to add the offset current according to the operation time of the motor. Single-phase motor;
An inverter converting a dc terminal power into an AC power source by a switching operation and outputting the converted AC power to the single-phase motor;
Includes; a control unit that controls the inverter and controls to add an offset voltage to the starting voltage during initial startup,
The control unit,
After a predetermined time, the motor driving apparatus, characterized in that the control so that the added offset voltage decreases. The method of claim 8,
The control unit,
When the speed of the single-phase motor is less than or equal to a first speed, the offset voltage is controlled to be added, and when the speed of the single-phase motor is greater than the first speed, the offset voltage is not applied. The method of claim 8,
The control unit,
During the initial start-up, a torque voltage and a magnetic flux voltage are applied to the motor, and the motor driving apparatus is controlled to add the offset voltage to the torque voltage. The method of claim 8,
The control unit,
The motor driving apparatus, characterized in that the offset voltage is added so that a voltage for torque is greater than a voltage for magnetic flux at the initial start-up. delete The method of claim 8,
The control unit,
The motor driving apparatus, characterized in that controlling to add the offset voltage according to the speed of the motor. The method of claim 8,
The control unit,
The motor driving apparatus, characterized in that controlling to add the offset voltage according to the operation time of the motor. A home appliance comprising the motor drive device of any one of claims 1 to 4, 6 to 11, and 13 to 14.

Images