KR102278219B1 - 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 device and a home appliance having the same according to an embodiment of the present invention include a motor, an inverter that converts DC power to AC power by a switching operation, and outputs the converted AC power to the motor, and the motor an output current detection unit detecting a flowing output current, and a control unit controlling the inverter based on the detected output current, wherein the control unit includes: a first number of times during one rotation of the motor when the speed of the motor is less than the first speed by performing output current sampling of , and controlling the inverter based on the first number of output current sampling, and when the speed of the motor is equal to or greater than the first speed, during one rotation of the motor, outputting a second number of times less than the first number Current sampling is performed to control the inverter based on the second number of output current sampling. Accordingly, it is possible to maintain the same phase of the counter electromotive force and the phase of the current when the motor is driven.

Description

Motor driving apparatus and home appliance including the same

The present invention relates to a motor driving device and a home appliance having the same, and more particularly, to a motor driving device capable of maintaining the same phase of a counter electromotive force and a current phase when driving a motor, and a home appliance having the same.

A motor driving device is a device for driving a motor including a rotor that rotates and a stator around which a coil is wound.

The motor may be classified into a Samsung motor in which a three-phase winding is wound, a motor in which a single-phase winding is wound, and the like.

On the other hand, when a high-speed motor is used for high-speed rotation of the motor, such as a vacuum cleaner or a hair dryer, it is difficult to increase the inductance due to limitations in motor design.

As such, when a motor having a small inductance is driven, the current quality is not good, and thus, a separate inductor filter is required.

On the other hand, when a high-speed motor is driven, there is a frequency restriction during sampling and switching, and accordingly, current quality is deteriorated when a low switching frequency is used.

In addition, since the ratio of the sampling frequency to the driving frequency is low, it is difficult to synthesize a sine wave through switching, and as a result, the current quality is deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor driving device capable of improving motor efficiency while reducing harmonics of an inverter current, and a home appliance having the same.

Another object of the present invention is to provide a motor driving device capable of driving a motor at high speed by reducing the number of sampling times required for inverter switching control, and a home appliance having the same.

Another object of the present invention is to provide a motor driving device capable of improving inverter efficiency by reducing inverter switching and a home appliance having the same.

Another object of the present invention is to provide a motor driving device capable of reducing torque ripple of a motor and a home appliance having the same.

A motor driving apparatus and a home appliance having the same according to an embodiment of the present invention for achieving the above object, converts dc terminal power to AC power by a motor and a switching operation, and outputs the converted AC power to the motor an inverter, an output current detector for detecting an output current flowing through the motor, and a controller for controlling the inverter based on the detected output current, wherein the controller includes: During the rotation, the output current sampling is performed a first number of times, and based on the output current sampling of the first number of times, the inverter is controlled, and when the speed of the motor is equal to or greater than the first speed, during one rotation of the motor, more than the first number of times A small second number of output current sampling is performed to control the inverter based on the second number of output current sampling times.

Meanwhile, the controller of the motor driving apparatus according to an embodiment of the present invention may control the inverter to be driven at a switching frequency that is an integer multiple of the rotation frequency of the motor.

Meanwhile, the controller of the motor driving apparatus according to the embodiment of the present invention may control the switching frequency of the inverter to be variable according to the speed of the motor.

Meanwhile, the controller of the motor driving apparatus according to the embodiment of the present invention may control the sampling frequency for the output current to be varied according to the speed of the motor.

On the other hand, the controller of the motor driving apparatus according to the embodiment of the present invention may control the number of sampling times to be sampled in each sector area of the space vector area in the space vector modulation method to decrease as the speed of the motor increases. .

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, when a plurality of sampling is performed in one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the center of the sector, It can be controlled to be different from the sampling period of other sampling.

Meanwhile, the controller of the motor driving apparatus according to the embodiment of the present invention may control the sampling period of the sampling corresponding to the center of the sector to be smaller than the sampling period of other sampling as the speed of the motor increases.

Meanwhile, the controller of the motor driving apparatus according to the embodiment of the present invention may control the inverter to be switched 7 times or 9 times during one rotation of the motor.

Meanwhile, the controller of the motor driving apparatus according to an embodiment of the present invention may control 7 or 9 pulses to be applied to the inverter during one rotation of the motor.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention performs a plurality of sampling in one sector area of the space vector area in the space vector modulation method, and when the voltage utilization ratio is equal to or greater than the first reference value, the center of the sector is The sampling period of the corresponding sampling may be controlled to be smaller than the sampling period of the other sampling.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, when a plurality of sampling is performed in one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the center of the sector, It can be controlled to be smaller than the sampling period of other sampling.

On the other hand, it is preferable that the maximum rotation speed of the motor of the motor driving apparatus according to the embodiment of the present invention is 100,000 rpm or more.

A motor driving device and a home appliance having the same according to another embodiment of the present invention for achieving the above object converts dc terminal power to AC power by a motor and a switching operation, and applies the converted AC power to the motor An inverter for outputting an output, an output current detection unit for detecting an output current flowing through the motor, and a control unit for controlling the inverter based on the detected output current, wherein the control unit includes a switching frequency that is an integer multiple of the rotation frequency of the motor, the inverter is controlled to be driven, and when a plurality of samplings are performed within one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the sector center is controlled to be different from the sampling period of other sampling. can

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, 7 pulses are applied to the inverter during one rotation of the motor, and when the voltage utilization ratio is equal to or greater than the first reference value, the sampling period of the sampling corresponding to the center of the sector is , can be controlled to be smaller than the sampling period of other sampling.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, when nine pulses are applied to the inverter during one rotation of the motor, the sampling period of the sampling corresponding to the center of the sector is longer than the sampling period of other sampling It can be controlled to be small.

A motor driving device and a home appliance having the same according to an embodiment of the present invention include a motor, an inverter that converts DC power to AC power by a switching operation, and outputs the converted AC power to the motor, and the motor an output current detection unit detecting a flowing output current, and a control unit controlling the inverter based on the detected output current, wherein the control unit includes: a first number of times during one rotation of the motor when the speed of the motor is less than the first speed by performing output current sampling of , and controlling the inverter based on the first number of output current sampling, and when the speed of the motor is equal to or greater than the first speed, during one rotation of the motor, outputting a second number of times less than the first number Current sampling is performed to control the inverter based on the second number of output current sampling. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current. In addition, it is possible to drive the motor at high speed by reducing the number of sampling times required for inverter switching control. Meanwhile, inverter efficiency can be improved by reducing inverter switching, and torque ripple of the motor can be reduced.

Meanwhile, the controller of the motor driving apparatus according to an embodiment of the present invention may control the inverter to be driven at a switching frequency that is an integer multiple of the rotation frequency of the motor. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

Meanwhile, the controller of the motor driving apparatus according to the embodiment of the present invention may control the switching frequency of the inverter to be variable according to the speed of the motor. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

Meanwhile, the controller of the motor driving apparatus according to the embodiment of the present invention may control the sampling frequency for the output current to be varied according to the speed of the motor. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

On the other hand, the controller of the motor driving apparatus according to the embodiment of the present invention may control the number of sampling times to be sampled in each sector area of the space vector area in the space vector modulation method to decrease as the speed of the motor increases. . Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current. In addition, it is possible to drive the motor at high speed by reducing the number of sampling times required for inverter switching control.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, when a plurality of sampling is performed in one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the center of the sector, It can be controlled to be different from the sampling period of other sampling. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

Meanwhile, the controller of the motor driving apparatus according to the embodiment of the present invention may control the sampling period of the sampling corresponding to the center of the sector to be smaller than the sampling period of other sampling as the speed of the motor increases. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

Meanwhile, the controller of the motor driving apparatus according to the embodiment of the present invention may control the inverter to be switched 7 times or 9 times during one rotation of the motor. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

Meanwhile, the controller of the motor driving apparatus according to an embodiment of the present invention may control 7 or 9 pulses to be applied to the inverter during one rotation of the motor.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention performs a plurality of sampling in one sector area of the space vector area in the space vector modulation method, and when the voltage utilization ratio is equal to or greater than the first reference value, the center of the sector is The sampling period of the corresponding sampling may be controlled to be smaller than the sampling period of the other sampling.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, when a plurality of sampling is performed in one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the center of the sector, It can be controlled to be smaller than the sampling period of other sampling. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

On the other hand, it is preferable that the maximum rotation speed of the motor of the motor driving apparatus according to the embodiment of the present invention is 100,000 rpm or more. Accordingly, it is possible to drive the motor at high speed while reducing the harmonics of the inverter current.

A motor driving device and a home appliance having the same according to another embodiment of the present invention include a motor, an inverter that converts DC power to AC power by a switching operation, and outputs the converted AC power to the motor; An output current detection unit for detecting an output current flowing in the , and a control unit for controlling the inverter based on the detected output current, wherein the control unit controls the inverter to be driven at a switching frequency that is an integer multiple of the rotation frequency of the motor, When a plurality of sampling is performed in one sector area of the space vector area in the space vector modulation method, it is possible to control the sampling period of the sampling corresponding to the sector center to be different from the sampling period of other sampling. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current. In addition, it is possible to drive the motor at high speed by reducing the number of sampling times required for inverter switching control. Meanwhile, inverter efficiency can be improved by reducing inverter switching, and torque ripple of the motor can be reduced.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, 7 pulses are applied to the inverter during one rotation of the motor, and when the voltage utilization ratio is equal to or greater than the first reference value, the sampling period of the sampling corresponding to the center of the sector is , can be controlled to be smaller than the sampling period of other sampling. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

On the other hand, the control unit of the motor driving apparatus according to the embodiment of the present invention, when nine pulses are applied to the inverter during one rotation of the motor, the sampling period of the sampling corresponding to the center of the sector is longer than the sampling period of other sampling It can be controlled to be small. Accordingly, it is possible to improve the motor efficiency while reducing the harmonics of the inverter current.

1A is a side elevation view of a vacuum cleaner which is an example of a home appliance according to an embodiment of the present invention.
1B is a perspective view of the cleaner from which the nozzle module is removed in FIG. 1A ;
1C is a side view of the cleaner of FIG. 1B.
2 is a perspective view of a dryer that is another example of a home appliance according to an embodiment of the present invention.
3 is an example of an internal block diagram of a home appliance according to an embodiment of the present invention.
FIG. 4 illustrates an example of an internal block diagram of the motor driving apparatus of FIG. 3 .
FIG. 5 is an example of an internal circuit diagram of the motor driving apparatus of FIG. 4 .
6 is an internal block diagram of the inverter control unit of FIG. 5 .
6 is an example of a motor driving apparatus according to an embodiment of the present invention.
7 is a flowchart illustrating a method of operating a motor driving apparatus according to an embodiment of the present invention.
8 to 14B are diagrams referred to in the description of the operation method of FIG. 7 .

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

The suffixes "module" and "part" for the components used in the following description are given simply in consideration of the ease of writing the present specification, and do not give a particularly important meaning or role by themselves. Accordingly, the terms “module” and “unit” may be used interchangeably.

The home appliance described in this specification means a home appliance that has a motor and is driven according to the operation of the motor. For example, the home appliance may be exemplified in various ways, such as a cleaner, a hair dryer, a fan, a washing machine, an air purifier, an air conditioner, a water purifier, a refrigerator, a vehicle, and the like. Hereinafter, a cleaner among home appliances will be mainly described.

1A is a side elevation view of a cleaner which is an example of a home appliance according to an embodiment of the present invention, FIG. 1B is a perspective view of the cleaner with the nozzle module removed in FIG. 1A, and FIG. 1C is a side view of the cleaner of FIG. 1B.

1A to 1C , a cleaner 100a, which is an example of a home appliance 100 according to an embodiment of the present invention, has a main body that forms a flow path P for guiding sucked air to be discharged to the outside. (10), a handle 30 coupled to the rear side of the main body 10, a nozzle module 70 detachably connected to the suction unit 11 of the main body 10, and a battery (Bt) for supplying power , a battery housing 40 in which the battery Bt is accommodated, and a fan module 50 disposed on 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 long 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 be introduced into the suction passage P. One end of the extension pipe 73 may be detachably coupled to the suction unit 11 of the main body 10 . The user can clean the nozzle part 71 while holding the handle 30 while moving the nozzle part 71 while placing the nozzle part 71 on the floor.

The main body 10 includes a discharge 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. may include.

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

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

The fan module housing 14 may be formed to extend upwardly from the dust collector 13 . The fan module housing 14 is formed in a cylindrical shape. The extension part 31 of the handle 30 may be disposed on the rear side of the fan module housing 14 .

Within 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 below the suction motor 230 . The impeller 51 is coupled to 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 100a 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 a circuit element 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. A user may use the cleaner 100a while holding the additional extension 32 . The upper end of the additional extension part 32 is connected to the rear end of the extension part 31 . The lower end of the additional extension 32 is connected to the battery housing 40 .

The additional extension part 32 has a movement limiting part 32a for preventing the user's 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 vertically spaced apart from the extension part 31 . In a state in which the user holds the additional extension part 32 , some fingers of the user's gripped hand are positioned above the movement limiting part 32a , and the remaining fingers are positioned 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 on the rear surface of the extension part 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 below 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, an upward direction). The plurality of exhaust ports 10a may be divided into each other in the circumferential direction by the plurality of exhaust guides 12a. The plurality of exhaust ports 10a may be arranged to be spaced apart from each other by a predetermined distance along the circumferential direction.

2 is a perspective view of a dryer that is another example of a home appliance according to an embodiment of the present invention.

Referring to the drawings, the dryer 100b according to an embodiment of the present invention includes a main body CAS that forms a flow path for guiding sucked air to be discharged to the outside, and a cable connected to the rear side of the main body CAS. (CAB), which is detachably coupled to the front of the main body (CAS), may be provided with a front case (CASb) in which air in the flow path is discharged through the exhaust port (OTa).

On the other hand, the main body (CAS) of the dryer (100b), the suction port (INa) formed with an opening for sucking in the external air may be formed.

The dryer 100b is disposed inside the suction port INa, is disposed on the furnace P and rotates to move the air in the flow path, and a motor driving unit for driving the fan (FAN) (FIG. 3 of 220) may be provided.

On the other hand, the dryer (100b) is formed on the handle portion of the main body (CAS), the operation key (117a) operated to set the operation of the dryer (100b), the power key (117b) operated to set the power on / off ), and may be provided with a display 118 for displaying the operating state of the dryer (100b).

3 is an example of an internal block diagram of a home appliance according to an embodiment of the present invention.

Referring to the drawings, the home appliance 100 includes a motor 230 for rotating the fan FAN, a driving unit 220 for driving the motor 230 , and a power supply unit 270 for supplying power; , an operation key 117 , a display 118 , and a control unit 210 for controlling each unit in the home appliance 100 may be provided.

In particular, the control unit 210 may control the motor driving unit 220 .

The home appliance 100 may be controlled by the control operation of the controller 210 . In particular, the control unit 210 may control the motor driving unit 220 .

The motor driving unit 220 drives the motor 230 . Accordingly, the fan FAN is rotated by the motor 230 .

The control unit 210 operates by receiving an operation signal from the operation key 117 .

The operation key 117 may include an operation key 117a operated for setting the operation of the home appliance 100 and a power key 117b operated for setting the power on/off.

The control unit 210 may control the speed of the motor or the operating period of the motor in the home appliance 100 to vary according to the operation of the operation key 117a.

For example, the controller 210 may change the rotation speed of the motor 230 or control the heater (not shown) to operate according to the operation of the operation key 117a.

Also, the controller 210 may control the display 118 to display speed information of the motor, operation information of the motor, and the like.

Meanwhile, the control unit 210 controls the motor driving unit 220 , and the motor driving unit 220 controls the motor 230 to operate. At this time, a position sensing unit is not provided inside or outside the motor 230 to detect the position of the rotor of the motor. That is, the motor driving unit 220 may control the motor 230 by a sensorless method.

The motor driving unit 220 is for driving the motor 230 , and an inverter (not shown), an inverter control unit (not shown), and an output current detection unit (E of FIG. 5 ) for detecting an output current flowing through the motor 230 . ) can be provided. In addition, the motor driving unit 220 may be a concept that further includes a converter, etc. for supplying DC power input to an inverter (not shown).

For example, the inverter control unit ( 430 in FIG. 5 ) in the motor driving unit 220 estimates the rotor position of the motor 230 based on the output current io. Then, based on the estimated rotor position, the motor 230 is controlled to rotate.

Specifically, the inverter controller ( 430 in FIG. 5 ) generates a pulse width modulation (PWM) switching control signal (Sic in FIG. 5 ) based on the output current io and outputs it to an inverter (not shown). Then, the inverter (not shown) performs a high-speed switching operation to supply AC power of a predetermined frequency to the motor 230 . Then, the motor 230 is rotated by AC power having a predetermined frequency.

The motor driving unit 220 will be described later with reference to FIG. 4 .

FIG. 4 illustrates an example of an internal block diagram of the motor driving apparatus of FIG. 3 , and FIG. 5 is an example of an internal circuit diagram of the motor driving apparatus of FIG. 4 .

Referring to the drawings, the motor driving device 220 according to the embodiment of the present invention is for driving the motor in a sensorless manner, and may include an inverter 420 and an inverter controller 430 . have.

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

Hereinafter, operations of the respective constituent units in the motor driving apparatus 220 of FIGS. 4 and 5 will be described.

The reactor L is disposed between the commercial AC power source 405, v _s and the converter 410, and performs a power factor correction or a step-up operation. In addition, the reactor L may perform a function of limiting the harmonic current caused by the high-speed switching of the converter 410 .

Input current detection section (A), it is possible to detect the input current (i _s) to be inputted from the commercial AC power source 405. To this end, as the input current detection unit A, a current transformer (CT), a shunt resistor, or the like may be used. The detected input current i _s may be input to the inverter controller 430 as a discrete signal in the form of a pulse.

The converter 410 converts the commercial AC power 405 through the reactor L into a DC power and outputs it. Although the figure shows the commercial AC power source 405 as a single-phase AC power source, it may be a three-phase AC power source. The internal structure of the converter 410 also varies according to the type of the commercial AC power source 405 .

Meanwhile, the converter 410 may be made of a diode or the like without a switching element, and may perform a rectification operation without a separate switching operation.

For example, in the case of a single-phase AC power supply, four diodes may be used in the form of a bridge, and in the case of a three-phase AC power, six diodes may be used in the form of a bridge.

Meanwhile, as the converter 410, for example, a half-bridge converter in which two switching elements and four diodes are connected may be used, and in the case of a three-phase AC power supply, six switching elements and six diodes may be used. .

When the converter 410 includes a switching element, a step-up operation, a power factor improvement, and a DC power conversion may be performed by a switching operation of the corresponding switching element.

The dc terminal capacitor C may store input DC power. In the drawings, one element is exemplified as a dc terminal capacitor (C), but a plurality of elements may be provided to ensure element stability.

Meanwhile, in the drawings, it is illustrated as being connected to the output terminal of the converter 410 , but the present invention is not limited thereto, and DC power may be directly inputted. For example, direct current power from the battery BT may be directly input to the dc terminal capacitor C, or may be input after being converted to direct current/direct current. Hereinafter, the parts illustrated in the drawings will be mainly described.

On the other hand, 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 detection unit B may detect the dc terminal voltage Vdc that 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 terminal 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 a DC power supply (Vdc) smoothed by an on/off operation of the switching elements into a three-phase AC power supply (va, vb, vc) of a predetermined frequency, three-phase output to the synchronous motor 230 .

Inverter 420 is a pair of upper-arm switching elements (Sa, Sb, Sc) and lower-arm switching elements (S'a, S'b, S'c) connected in series with each other, and a total of three pairs of upper and lower arms The switching elements are connected in parallel with each other (Sa&S'a, Sb&S'b, Sc&S'c). A diode is connected in anti-parallel to each of the switching elements Sa, S'a, Sb, S'b, Sc, and S'c.

The switching elements in the inverter 420 turn on/off the respective switching elements based on the inverter switching control signal Sic from the inverter controller 430 . Accordingly, the three-phase AC power having a predetermined frequency is output to the three-phase synchronous motor 230 .

The inverter controller 430 may control the switching operation of the inverter 420 based on the 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 control unit 430 outputs the 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 pulse width modulation (PWM) switching control signal, 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 controller 430 will be described later with reference to FIG. 6 .

The output current detection unit E may detect a phase current flowing between the three-phase motors 230 , that is, the output current io.

The output current detection unit E may be disposed in the inverter 420 and the motor 230 to detect a current flowing through the motor 230 as shown in the drawing.

As shown in the figure, the output current detection unit E may include three resistance elements. Through the three resistor elements, it is possible to detect a phase current (ia, ib, ic) that is an output current (io) flowing through the motor 230 . The detected output current (ia, ib, ic) may be applied to the inverter controller 430 as a discrete signal in the form of a pulse, and based on the detected output current (ia, ib, ic), the inverter A switching control signal Sic is generated.

Meanwhile, in this specification, ia, ib, ic, or io are used interchangeably as the output current.

Meanwhile, unlike the drawing, the output current detection unit E may include two resistance elements. The phase current of the other phase can be calculated using the three-phase balance.

On the other hand, unlike the figure, the output current detection unit (E) is disposed between the dc terminal capacitor (C) and the inverter (420), and includes one shunt resistor (Rs), the current flowing through the motor (230) can also be detected. This method may be referred to as a one-shunt method.

According to the 1 shunt method, the output current detection unit (E) uses one shunt resistor element (Rs) to turn on the lower arm switching element of the inverter 420, time-divisionally, the output current flowing through the motor 230 ( idc), a phase current may be detected.

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 based on the detected output current i o} , the inverter switching control signal Sic is created Hereinafter, the detected output current (i _o ) may be described in parallel as the three-phase output current (ia, ib, ic).

Meanwhile, the three-phase motor 230 includes a stator and a rotor, and each phase AC power of a predetermined frequency is applied to the coils of the stators of each phase (a, b, c phase), and the rotor rotates. will do

The motor 230 includes, for example, a Surface-Mounted Permanent-Magnet Synchronous Motor (SMPMSM), an Interior Permanent Magnet Synchronous Motor (IPMSM), and a synchronous relay. It may include a Synchronous Reluctance Motor (Synrm) and the like. Among them, SMPMSM and IPMSM are Permanent Magnet Synchronous Motor (PMSM) applied with permanent magnet, and Synrm is characterized by no permanent magnet.

6 is an internal block diagram of the inverter control unit of FIG. 5 .

Referring to FIG. 6 , the inverter control unit 430 includes an axis converting unit 310 , a speed calculating unit 320 , a current command generating unit 330 , a voltage command generating unit 340 , an axis converting unit 350 , and A switching control signal output unit 360 may be included.

The axis conversion unit 310 may convert the three-phase output current (ia, ib, ic) or the estimated current detected by the output current detection unit (E) into a two-phase current (iα, iβ) of a stationary coordinate system. have.

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

)와 연산된 속도(

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

) and the 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 ), a current command value (i ^* _q ) is generated. For example, the current command generation unit 330 may set the calculation speed (

) and the speed command value (ω ^* _r ) based on the difference, the PI controller 335 may perform PI control and generate a ^{current command value (i *} _{q ).} In the drawing, the q-axis current command value (i ^* _q ) is exemplified as the current command value, but unlike the drawing, it is also possible to generate the ^{d-axis current command value (i *} _{d ) together.} On the other hand, the value of the d-axis current command value (i ^* _d ) may be set to 0.

On the other hand, the current command generation unit 330, the current command value (i ^* _q ) may further include a limiter (not shown) for limiting the level so as not to exceed the allowable range.

Next, the voltage command generation unit 340 includes the d-axis and q-axis currents (i _d ,i _q ) that are axis-transformed into the two-phase rotational coordinate system by the axis transformation unit, and the current command values ( Based on i ^* _d ,i ^* _q ), 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 ), q} A shaft voltage setpoint (v ^* _q ) can be generated. 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} A setpoint (v ^* _d ) can be generated. On the other hand, the voltage command generation unit 340, the d-axis, q-axis voltage command value (v ^* _d , v ^* _q ) may further include a limiter (not shown) for limiting the level so as not to exceed the allowable range. .

On the other hand, the generated d-axis and q-axis voltage command values (v ^* _d , 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, the position calculated by the speed calculating unit 320 (

) and d-axis and q-axis voltage command values (v ^* _d ,v ^* _q ) are received and axis transformation is performed.

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

) can be used.

Then, the axis transformation unit 350 performs transformation from the two-phase stationary coordinate system to the three-phase stationary coordinate system. Through this conversion, the shaft conversion unit 1050 outputs a three-phase output voltage command value (v ^* a, v ^* b, v ^* c).

The switching control signal output unit 360 generates a switching control signal (Sic) for an inverter according to a pulse width modulation (PWM) method based on the three-phase output voltage command value (v ^* a, v ^* b, v ^{* c)} to output

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

Meanwhile, the motor driving device 100 may drive a high-speed motor 230 capable of high-speed rotation. The high-speed motor 230 at this time preferably has a maximum speed of 100,000 rpm or more.

On the other hand, in the case of the high-speed motor 230, it is difficult to increase the inductance due to the limitation of the motor design. In particular, due to space constraints of the high-speed motor 230, it is difficult to increase the inductance.

As such, when a motor having a small inductance is driven, the current quality is not good, and thus, a separate inductor filter is required.

On the other hand, when the high-speed motor 230 is driven, there is a frequency constraint during sampling and switching by using a high voltage, and accordingly, current quality is deteriorated when a low switching frequency is used.

In addition, since the ratio of the sampling frequency to the driving frequency is low, it is difficult to synthesize a sine wave through switching, and consequently, the current quality is deteriorated.

Accordingly, the present invention proposes a method for improving the efficiency of the motor 230 while reducing the harmonics of the inverter current.

In addition, the present invention proposes a method capable of driving a motor at high speed by reducing the number of sampling times required for inverter switching control.

In addition, the present invention proposes a method capable of reducing the torque ripple of the motor while improving inverter efficiency by reducing inverter switching. This will be described with reference to FIG. 7 and below.

7 is a flowchart illustrating an operation method of a motor driving apparatus according to an embodiment of the present invention, and FIGS. 8 to 14B are diagrams referenced in the description of the operation method of FIG. 7 .

First, the output current detection unit E of the motor driving apparatus 220 according to the embodiment of the present invention may detect the output current io flowing through the motor 230 ( S710 ).

In addition, the inverter control unit 430 may vary the switching frequency based on the output current io detected by the output current detection unit E ( S720 ).

Then, the inverter control unit 430 may output the switching control signal Sic based on the switching frequency (S730).

Meanwhile, the inverter controller 430 according to an embodiment of the present invention may control the inverter 420 to be driven at a switching frequency that is an integer multiple of the rotation frequency of the motor 230 . That is, the inverter 420 may be controlled to be driven in synchronization with the rotation frequency of the motor 230 . Accordingly, as the rotational speed of the motor 230 increases, the rotational frequency increases, and accordingly, the switching frequency of the inverter 420 may also increase. Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

On the other hand, when the speed of the motor 230 is less than the first speed, the inverter control unit 430 according to the embodiment of the present invention performs output current sampling a first number of times during one rotation of the motor 230, The inverter 420 is controlled based on the sampling of the output current one number of times, and when the speed of the motor 230 is equal to or greater than the first speed, the second number of times less than the first number of outputs during one rotation of the motor 230 Current sampling is performed to control the inverter 420 based on the second number of output current sampling. Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current. In addition, it is possible to drive the motor 230 at high speed by reducing the number of sampling times required for the inverter 420 switching control. Meanwhile, the efficiency of the inverter 420 may be improved by reducing the switching of the inverter 420 , and the torque ripple of the motor 230 may be reduced.

Meanwhile, the inverter control unit 430 according to an embodiment of the present invention may control the switching frequency of the inverter 420 to vary according to the speed of the motor 230 . Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

Meanwhile, the inverter control unit 430 according to an embodiment of the present invention may control the sampling frequency for the output current to vary according to the speed of the motor 230 . Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

FIG. 8 is a diagram illustrating sampling time points in a plurality of sector areas based on a space vector.

Referring to the drawing, a sampling time corresponding to SPa corresponds to a sampling time corresponding to the sector center, and a sampling time corresponding to SPb indicates a sampling time of sampling other than the sector center.

In the drawing, there are a total of 18 sampling points in a space vector-based six sector area, and a sampling point corresponding to the center of one sector and two different sampling points may be arranged in one sector.

On the other hand, the inverter control unit 430 according to the embodiment of the present invention, when a plurality of sampling is performed within one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the center of the sector is: It can be controlled to be different from the sampling period of other sampling.

For example, a sampling period corresponding to SPa may be different from a sampling period corresponding to SPb.

Meanwhile, as the speed of the motor 230 increases, the inverter controller 430 according to an embodiment of the present invention may control the sampling period of the sampling corresponding to the center of the sector to be smaller than the sampling period of other sampling. Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

For example, the inverter controller 430 may control the sampling period corresponding to SPa to be smaller than the sampling period corresponding to SPb as the speed of the motor 230 increases. Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

Meanwhile, FIG. 9A exemplifies a total of 18 sampling points in 6 sector regions based on a space vector, similar to FIG. 8 . That is, during one electrical rotation of the motor 230 , 18 output current sampling may be performed.

Next, unlike FIG. 9A, FIG. 9B illustrates a total of nine sampling points in six sector regions based on a space vector. That is, during one electrical rotation of the motor 230 , nine output current sampling may be performed.

That is, as the speed of the motor 230 increases, the inverter controller 430 according to the embodiment of the present invention controls the number of sampling times to be sampled in each sector area of the space vector area in the space vector modulation method to be smaller. can do. Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current. In addition, it is possible to drive the motor 230 at high speed by reducing the number of sampling times required for switching control of the inverter 420 .

In addition, the inverter control unit 430 according to an embodiment of the present invention may control the inverter 420 to be switched 7 times or 9 times during one rotation of the motor 230 . Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

That is, the inverter controller 430 according to an embodiment of the present invention may control 7 or 9 pulses to be applied to the inverter 420 during one rotation of the motor 230 .

As such, when the inverter 420 is switched 7 times or 9 times, or when 7 or 9 pulses are applied to the inverter 420 , symmetric switching is performed based on the space vector modulation method, so that the inverter 420 ) It is possible to improve the efficiency of the motor 230 while reducing the harmonics of the current. On the other hand, as the sampling interval is reduced, the current ripple can be reduced.

10A illustrates that the sampling period is Psfa when the inverter is switched, and FIG. 10B illustrates that the sampling period is Psfb that is smaller than that of FIG. 10A.

Referring to FIG. 10A , in order to apply 7 or 9 pulses during one electrical rotation of the motor 230 , 18 output current samplings are required. Accordingly, the maximum speed of the motor 230 may be limited to approximately 130,000 rpm.

Meanwhile, according to FIG. 10B , 9 output current samplings are required to apply 7 or 9 pulses during one electrical rotation of the motor 230 . Accordingly, the maximum speed of the motor 230 may be limited to approximately 260,000 rpm.

That is, compared to FIG. 10A , as shown in FIG. 10B , when the sampling period is reduced, the maximum speed of the motor 230 can be increased, so that high-speed driving can be performed.

Meanwhile, as shown in FIG. 11 , when a total of 18 output currents are sampled in the space vector-based 6 sector regions, the actual rotor position of the motor 230 may be different from the sampling time, so the inverter control unit 430 may , it is preferable to calculate T1, T2, and T0 related to the turn-on time of the three-phase switching element by applying a compensation value according to the position of the rotor of the motor 230 .

For example, the inverter controller 430 may calculate the turn-on period of the three-phase switching elements Sa, Sb, and Sc of the inverter 420 according to T1, T2, and T0 as shown in FIG. 12 .

Meanwhile, T1 denotes a case in which only one phase switching element among the three-phase switching elements Sa, Sb, and Sc is turned on, and T2 denotes a case in which only two phase switching elements among the three-phase switching elements Sa, Sb, Sc are turned on. , and T0 represents a case in which all of the three-phase switching elements Sa, Sb, and Sc are turned on or off.

12B illustrates that output current sampling is performed at a position Sp1 corresponding to an electrical angle of 20 degrees to implement switching of positions 1 and 2.

The inverter control unit 430 may calculate the above-described T1, T2, and T0, respectively, according to the information Ts of the sampling time at the Sp1 position, the dc terminal voltage Vdc, and the magnitude of the voltage command value.

12C is a three-phase switching element of the inverter 420 according to T1, T2, T0 calculated according to the information (Ts) of the sampling time at the Sp1 position, the dc terminal voltage (Vdc), and the magnitude of the voltage command value. The turn-on period of (Sa, Sb, Sc) is illustrated.

13A illustrates the turn-on timing of the three-phase switching elements Sa, Sb, and Sc according to effective vectors in two sampling periods Tsb in which a sector change occurs in Tcs.

Meanwhile, FIG. 13B illustrates a sector change interval (SSP).

As shown in FIG. 13B , among six sector areas based on a space vector, when a sector is changed from a first sector to a second sector, when a sector is changed from a third sector to a fourth sector, when a sector is changed from a fifth sector to a sixth sector , when the sector is changed from the sixth sector to the first sector, when the sector is changed from the second sector to the third sector, when the sector is changed from the fourth sector to the fifth sector, in the two sampling periods Tsb shown in FIG. 13A . The sampling time and the effective vector time (T1, T2) may be the same.

13C illustrates a curve CVa related to a modulation index, an angle, and a harmonic (THD) of a motor when 7 pulses are applied to the inverter 420 .

Referring to the drawings, as the utilization rate of the motor increases, the harmonic component is lowered, and the angle can be lowered.

FIG. 13D illustrates a curve CVb related to the motor utilization, angle, and harmonics (THD) when nine pulses are applied to the inverter 420 .

Referring to the drawings, as the utilization rate of the motor increases, the harmonic component is lowered, and the angle can be lowered.

On the other hand, the inverter control unit 430 according to the embodiment of the present invention performs a plurality of sampling in one sector area of the space vector area in the space vector modulation method, and when the voltage utilization ratio is equal to or greater than the first reference value, The sampling period of the corresponding sampling may be controlled to be smaller than the sampling period of the other sampling.

Here, the first reference value may correspond to approximately 0.8.

On the other hand, the inverter control unit 430 according to the embodiment of the present invention, when a plurality of sampling is performed within one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the center of the sector is: It can be controlled to be smaller than the sampling period of other sampling. Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

Meanwhile, the maximum rotation speed of the motor 230 of the motor driving device 220 according to the embodiment of the present invention is preferably 100,000 rpm or more. Accordingly, it is possible to drive the motor 230 at high speed while reducing the harmonics of the current of the inverter 420 .

Meanwhile, the inverter controller 430 according to the embodiment of the present invention applies seven pulses to the inverter 420 during one rotation of the motor 230 , and when the voltage utilization ratio is equal to or greater than the first reference value, it corresponds to the center of the sector The sampling period of the sampling to be performed may be controlled to be smaller than the sampling period of the other sampling. Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

On the other hand, the inverter control unit 430 according to the embodiment of the present invention, when nine pulses are applied to the inverter 420 during one rotation of the motor 230 , the sampling period of the sampling corresponding to the center of the sector is different. It can be controlled to be smaller than the sampling period of the sampling. Accordingly, it is possible to improve the efficiency of the motor 230 while reducing the harmonics of the inverter 420 current.

14A illustrates curves CVa1 and CVa2 related to the modulation index and contrast harmonics (THD) of the motor when 7 pulses are applied to the inverter 420 .

In particular, according to the CVa2 by the sampling variable according to the synchronous switching according to the embodiment of the present invention, compared to the CVa1 in which only the synchronous switching is performed, it can be seen that the harmonic (THD) component is significantly reduced when the voltage utilization is low. have.

14B illustrates curves CVb1 , CVb2 , and CVb3 related to a motor modulation index and contrast harmonic THD when nine pulses are applied to the inverter 420 .

In particular, according to CVb3 by sampling variable sampling according to synchronous switching according to an embodiment of the present invention, compared to CVb2 in which only synchronous switching is performed or CVb1 in which synchronous switching is not performed, the harmonic (THD) component is significantly reduced Able to know.

In particular, it can be seen that even when the voltage utilization ratio is low or high, the harmonic (THD) component is significantly reduced according to the CVb3 due to the sampling variable according to the synchronous switching according to the embodiment of the present invention.

In addition, it can be seen that the difference in the harmonic (THD) component becomes larger according to CVb3 as compared to CVb2 or CVb1 as the voltage utilization rate increases.

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

On the other hand, the motor driving method or the home appliance operating method of the present invention can be implemented as a processor-readable code on a processor-readable recording medium provided in the motor driving device or the home appliance. The processor-readable recording medium includes all types of recording devices in which data readable by the processor is stored.

In addition, although 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 as claimed in the claims 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 (18)

motor;
an inverter that converts dc power supply into AC power by a switching operation and outputs the converted AC power to the motor;
an output current detection unit detecting an output current flowing through the motor;
Based on the detected output current, a control unit for controlling the inverter; includes,
The control unit is
When the speed of the motor is less than the first speed, the sampling of the output current flowing through the motor during one rotation of the motor is performed a first number of times, and the inverter is controlled based on the sampling of the first number of times,
When the speed of the motor is equal to or greater than the first speed, sampling of the output current flowing through the motor during one rotation of the motor is performed a second number of times less than the first number of times, and based on the second number of sampling, the inverter Motor driving device, characterized in that for controlling. According to claim 1,
The control unit is
A motor driving apparatus, characterized in that the inverter is controlled to be driven at a switching frequency of an integer multiple of the rotation frequency of the motor. According to claim 1,
The control unit is
The motor driving apparatus, characterized in that the control so that the switching frequency of the inverter is variable according to the speed of the motor. According to claim 1,
The control unit is
The motor driving apparatus, characterized in that the control so as to vary the sampling frequency for the output current according to the speed of the motor. According to claim 1,
The control unit is
The motor driving apparatus according to claim 1, wherein as the speed of the motor increases, the number of times of sampling in each sector area of the space vector area in the space vector modulation method is controlled to decrease. According to claim 1,
The control unit is
Motor driving, characterized in that when a plurality of sampling is performed within one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the sector center is controlled to be different from the sampling period of other sampling Device. 7. The method of claim 6,
The control unit is
and controlling a sampling period of the sampling corresponding to the center of the sector to be smaller than a sampling period of other sampling as the speed of the motor increases. According to claim 1,
The control unit is
A motor driving apparatus, characterized in that during one rotation of the motor, the inverter is controlled to be switched 7 times or 9 times. According to claim 1,
The control unit is
During one rotation of the motor, 7 pulses or 9 pulses are controlled to be applied to the inverter. 10. The method of claim 9,
The control unit is
In the space vector modulation method, when a plurality of sampling is performed within one sector area of the space vector area and the voltage utilization ratio is equal to or greater than the first reference value, the sampling period of the sampling corresponding to the center of the sector is longer than the sampling period of other sampling. A motor driving device, characterized in that it is controlled to be small. 10. The method of claim 9,
The control unit is
Motor characterized in that when a plurality of sampling is performed within one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the sector center is controlled to be smaller than the sampling period of the other sampling. drive device. According to claim 1,
The maximum rotation speed of the motor is a motor driving device, characterized in that 100,000 rpm or more. motor;
an inverter that converts dc power supply into AC power by a switching operation and outputs the converted AC power to the motor;
an output current detection unit detecting an output current flowing through the motor;
Based on the detected output current, a control unit for controlling the inverter; includes,
The control unit is
Controlling the inverter to be driven at a switching frequency that is an integer multiple of the rotation frequency of the motor,
Motor driving, characterized in that when a plurality of sampling is performed within one sector area of the space vector area in the space vector modulation method, the sampling period of the sampling corresponding to the sector center is controlled to be different from the sampling period of other sampling Device. 14. The method of claim 13,
The control unit is
and controlling a sampling period of the sampling corresponding to the center of the sector to be smaller than a sampling period of other sampling as the speed of the motor increases. 14. The method of claim 13,
The control unit is
and controlling a sampling period of the sampling corresponding to the center of the sector to be smaller than a sampling period of other sampling as the speed of the motor increases. 14. The method of claim 13,
The control unit is
During one rotation of the motor, when seven pulses are applied to the inverter and the voltage utilization rate is equal to or greater than the first reference value, controlling the sampling period of the sampling corresponding to the sector center to be smaller than the sampling period of other sampling Characterized by the motor drive. 14. The method of claim 13,
The control unit is
The motor driving apparatus according to claim 1, wherein when nine pulses are applied to the inverter during one rotation of the motor, a sampling period of a sampling corresponding to a sector center is controlled to be smaller than a sampling period of other sampling. 18. A home appliance comprising the motor driving device of any one of claims 1 to 17.

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