KR20200008418A - 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. According to an embodiment of the present invention, the motor driving device comprises: an inverter having a plurality of switching elements and converting direct current (DC) power into alternating current (AC) power by switching of the switching element so as to supply the AC power to a master motor and a slave motor; an output current detection unit detecting output current flowing into the master motor and the slave motor; and an inverter control unit setting offset current in accordance with a phase of the slave motor in comparison with the phase of the master motor and controlling the inverter based on the offset current and magnetic flux current of the master motor detected from the output current detection unit. Accordingly, the present invention can prevent the motor from being out of phase when controlling the plurality of motors through the single inverter.

Description

Motor driving apparatus and home appliance having same {Motor driving apparatus and home appliance including the same}

The present invention relates to a motor drive device and a home appliance having the same, and more particularly, to a motor drive device and a home appliance having the same, which can prevent the motor from being dismounted when controlling a plurality of motors through a single inverter. It is about.

A home appliance is a device used for user convenience.

In addition, home appliances such as an air conditioner and a washing machine refrigerator used in a predetermined space such as a home or an office each perform unique functions and operations according to a user's operation.

On the other hand, the motor drive device is a device for driving a motor having a rotor and a coiled stator in a rotational motion, in particular can be used to drive a motor in a home appliance.

In order to drive such a motor driving device, inverter control is required, but conventionally, it was common to control one motor with one inverter. Recently, however, researches on a control method for operating a plurality of motors in parallel with one inverter have been actively conducted.

An object of the present invention, in a single inverter multi-motor control system, to provide a motor drive device and a home appliance having the same that can simultaneously control the master motor and the slave motor through the master motor control.

It is another object of the present invention to provide a motor drive device and a home appliance having the same, which can prevent desorption of a slave motor in a single inverter multiple motor control system.

Still another object of the present invention is to provide a motor drive device and a home appliance having the same, which can solve a current divergence problem due to a phase difference between a master motor and a slave motor in a single inverter multiple motor control system.

In order to achieve the above object, a motor driving apparatus according to an embodiment of the present invention includes a plurality of switching elements, and converts a DC power source into an AC power source by switching the switching element, thereby converting the AC power source into a master motor and An inverter for supplying a slave motor, an output current detector for detecting output current flowing through the master motor and the slave motor, an offset current is set according to a phase of the slave motor relative to a phase of the master motor, and the offset current and the And an inverter controller for controlling the inverter based on the flux current of the master motor detected by the output current detector.

In order to achieve the above object, a home appliance according to another embodiment of the present invention includes a plurality of switching elements, and converts DC power into AC power by switching of the switching elements, thereby converting the AC power into a master motor and An inverter for supplying a slave motor, an output current detector for detecting output current flowing through the master motor and the slave motor, an offset current is set according to a phase of the slave motor relative to a phase of the master motor, and the offset current and the And an inverter controller for controlling the inverter based on the flux current of the master motor detected by the output current detector.

The motor driving apparatus according to the embodiment of the present invention may simultaneously drive the master motor and the slave motor through the closed loop control based on the speed, phase information, etc. of the master motor.

In addition, since the motor drive device controls a plurality of motors with only one inverter, there is an advantage that the manufacturing cost is reduced and the manufacturing process is simplified.

In addition, the motor driving apparatus may vary the magnetic flux current of the master motor based on the phase information of the master motor relative to the phase of the slave motor, thereby removing the pulsation component of the slave motor reflected by the master motor. have.

In addition, when the slave motor is at a low speed, the motor driving device may add an offset current to the flux current of the master motor, and thereby prevents a drop-out phenomenon that may occur during low speed operation of the slave motor.

In addition, when the slave motor is at a low speed, the motor driving device can secure driving stability from disturbance by adding an offset current to the flux current of the master motor.

In addition, the motor driving apparatus may control the phase of the master motor relative to the phase of the slave motor to be positioned within a predetermined range, thereby solving the current divergence problem due to the phase difference between the two motors.

1 is an example of an internal block diagram of a motor drive apparatus according to an embodiment of the present invention.
FIG. 2 is an example of an internal circuit diagram of the motor drive device of FIG. 1.
3 is an internal block diagram of the inverter control unit of FIG. 2.
4 is a view for explaining a control method for removing a pulsating component of a slave motor.
5 is a diagram for explaining a phase difference between a master motor and a slave motor.
6 is a diagram for explaining a phase change and a torque change of a slave motor according to the rotational speed of the slave motor.
7 is a diagram for explaining the offset current.
8 is a perspective view illustrating a laundry treatment device as an example of a home appliance according to an exemplary embodiment of the present invention.
FIG. 9 is an internal block diagram of the laundry treatment machine of FIG. 8.
10 is a diagram illustrating a configuration of an air conditioner which is another example of a home appliance according to an embodiment of the present invention.
FIG. 11 is a schematic diagram of the outdoor unit and the indoor unit of FIG. 10.
12 is a perspective view illustrating a refrigerator that is another example of a home appliance according to an exemplary embodiment of the present invention.
FIG. 13 is a view schematically illustrating a configuration of the refrigerator of FIG. 12.

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

The suffixes "module" and "unit" for components used in the following description are merely given in consideration of ease of preparation of the present specification, and do not impart any particular meaning or role by themselves. Therefore, the "module" and "unit" may be used interchangeably.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In this application, the terms "comprises" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude, in advance, the existence or the possibility of adding numbers, steps, operations, components, parts, or combinations thereof.

The motor driving device 220 described in the present specification is a rotor less of the motor by a sensor less method, which is not provided with a position sensing unit such as a hall sensor that senses the rotor position of the motor. A motor driving device 220 capable of estimating the position. Hereinafter, the sensorless motor driving device 220 will be described.

In addition, the motor drive apparatus 220 described in this specification is a drive apparatus which can be equipped with the some motor connected in parallel with each other. Hereinafter, two motors 230a and 230b are connected in parallel to each other, and a motor driving apparatus 220 for driving two motors 230a and 230b using one inverter 420 will be described.

On the other hand, the motor drive device 220 according to an embodiment of the present invention may be referred to as a motor drive unit.

1 is an example of an internal block diagram of a motor driving apparatus according to an embodiment of the present invention, and FIG. 2 is an example of an internal circuit diagram of the motor driving apparatus of FIG.

Referring to the drawings, the motor driving apparatus 220 according to the embodiment of the present invention is for driving a motor in a sensorless manner, and is connected to the inverter 420 and the inverter 420 in parallel with each other. The master motor 230a, the slave motor 230b, and the inverter controller 430 may be included.

In addition, the motor driving apparatus 220 according to the embodiment of the present invention, the converter 410, the dc terminal voltage detector (B), the smoothing capacitor (C), the first output current detector (E1), the second output current detector (E2) may be included. In addition, the driver 220 may further include an input current detector A, a reactor L, and the like.

The inverter controller 430 according to the exemplary embodiment of the present invention controls the same switching control signal to be applied to the inverter 420 in order to simultaneously control the master motor 230a and the slave motor 230b.

On the other hand, when simultaneously controlling the master motor 230a and the slave motor 230b, errors in the phase, magnitude, frequency, etc. of back EMF of the master motor 230a and the slave motor 230b may occur. In addition, this error may cause harmonics and reactive circulating currents between the two motors, causing the two motors to resonate.

Accordingly, when simultaneously controlling the master motor 230a and the slave motor 230b, the flux current pulsation component of the slave motor 230b may be reflected in the flux current of the master motor 230b. This may be a deterrent to driving stability of the motor driving device 220.

In the present invention, in order to solve this problem, the magnetic flux component current of the master motor 230a may be varied based on the phase information of the slave motor 230b relative to the master motor 230a.

On the other hand, as described above, even in the case of controlling, when the low speed of the slave motor 230b, the magnetic flux current of the master motor 230a is reduced, the phase difference between the master motor 230a and the slave motor 230b excessively Can happen. This can cause outages that cannot be maintained between the two motors.

In the related art, a method of detecting and re-driving a motor when the motor driving device 220 stops due to an outage phenomenon has been proposed. However, the present invention provides a magnetic flux of the master motor 230a during a low speed operation of the slave motor 230b. The offset current is added to the divided current to prevent the outage of the motor driving device 220 in advance, and to stably drive the motor driving device 220.

Hereinafter, the operation of each component unit in the motor driving apparatus 220 of FIGS. 1 and 2 will be described.

The reactor L is disposed between the commercial AC power supplies 405 and vs and the converter 410 to perform power factor correction or boost operation. In addition, the reactor L may perform a function of limiting harmonic currents due to the high speed switching of the converter 410.

The input current detector A can detect the input current is input from the commercial AC power supply 405. To this end, a CT (current trnasformer), a shunt resistor, or the like may be used as the input current detector A. FIG. The detected input current is, as a discrete signal in the form of a pulse, may be input to the inverter controller 430.

The converter 410 converts the commercial AC power supply 405 which passed through the reactor L into DC power, and outputs it. Although the commercial AC power supply 405 is shown as a single phase AC power supply in the figure, it may be a three phase AC power supply. 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 formed of a diode 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 supply, six diodes may be used in the form of a bridge.

On the other hand, the converter 410, for example, a half-bridge type 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, the boosting operation, power factor improvement, and DC power conversion may be performed by the switching operation of the switching element.

The smoothing capacitor C smoothes the input power and stores it. In the figure, one element is illustrated as the smoothing capacitor C, but a plurality of elements may be provided to ensure device stability.

On the other hand, in the figure, but is illustrated as being connected to the output terminal of the converter 410, but is not limited to this, DC power may be directly input. For example, direct current power from a solar cell may be input directly to the smoothing capacitor (C) or may be input by direct current / direct current conversion. Hereinafter, the parts illustrated in the drawings will be mainly described.

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

The dc end voltage detector B may detect a dc end voltage Vdc that is both ends of the smoothing capacitor C. To this end, the dc terminal voltage detector B may include a resistor, 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 motor driving apparatus 220 of the present invention may simultaneously control the master motor 230a and the slave motor 230b with a single inverter 420. 1 and 2, only the master motor 230a and the slave motor 230b are illustrated as motors, but the number may be added according to an embodiment.

The inverter 420 includes a plurality of inverter switching elements, converts the smoothed DC power supply Vdc into three-phase AC power supplies va, vb, vc of a predetermined frequency by the on / off operation of the switching device, It can output to the motor 230a and the slave motor 230b.

Inverter 420 is a pair of phase arm switching elements Sa, Sb, Sc and lower arm switching elements S'a, S'b, S'c, which are 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). Diodes are 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 perform on / off operations of the respective switching elements based on the inverter switching control signal Sic from the inverter controller 430. As a result, three-phase AC power having a predetermined frequency is output to the master motor 230a and the slave motor 230b, respectively.

The inverter controller 430 may control a switching operation of the inverter 420 based on a sensorless method. In particular, for controlling the master motor 230a and the slave motor 230b, which are connected in parallel to each other, the inverter controller 430 is detected by the first output current detector E1 and the second output current detector E2. Output currents io1 and io2 can be input.

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 based on the output currents io1 and io2 detected by the first output current detector E1 and the second output current detector E2. Is generated and output.

The output current detectors E1 and E2 may include a first output current detector E1 and a second output current detector E2.

The first output current detector E1 and the second output current detector E2 detect the output currents io1 and io2 flowing through the master motor 230a and the slave motor 230b, respectively. That is, the current flowing through the master motor 230a and the slave motor 230b is detected. The first output current detector E1 and the second output current detector E2 can respectively detect the output currents ia1, ib1, ic1 and ia2, ib2, ic2 of each phase, or use three-phase equilibrium. It is also possible to detect the output current of two phases.

The first output current detector E1 and the second output current detector E2 may be located between the inverter 420 and the master motor 230a, and between the inverter 420 and the slave motor 230b, and the current. For detection, a CT (current trnasformer), a shunt resistor, or the like can be used.

When a shunt resistor is used, three shunt resistors may be located between the inverter 420 and the master motor 230a and between the inverter 420 and the slave motor 230b.

The detected output currents io1 and io2 may be applied to the inverter controller 430 as discrete signals in the form of pulses, and the inverter switching may be performed based on the detected output currents io1 and io2. The control signal Sic is generated. Hereinafter, the detected output currents io1 and io2 may be described in parallel as being the three-phase output currents ia1, ib1, ic1 and ia2, ib2, ic2.

On the other hand, the master motor 230a and the slave motor 230b are three-phase motors, each having a stator and a rotor, and having a predetermined frequency in a coil of the stator of each phase (a, b, c phase). AC power is applied to each phase of the rotor to rotate.

The master motor 230a and the slave motor 230b may be, for example, a surface-mounted permanent magnet synchronous motor (SMPMSM), an embedded permanent magnet synchronous motor (SMPMSM). IPMSM), and Synchronous Reluctance Motor (Synrm). Of these, SMPMSM and IPMSM are permanent magnet synchronous motors (PMSMs) with permanent magnets, while synrms have no permanent magnets.

In the following description, the master motor 230a and the slave motor 230b are mainly described as being a surface-attached permanent magnet synchronous motor (SPMSM) in which permanent magnets are formed symmetrically.

On the other hand, when the master motor 230a and the slave motor 230b are surface-attached permanent magnet synchronous motors (SPMSMs) in which the permanent magnets are formed symmetrically, the flux current can generally be set to zero.

FIG. 3 is an internal block diagram of the inverter controller of FIG. 2.

Referring to FIG. 3, the inverter controller 430 may include an axis converter 310, a speed calculator 320, a selector 322, a current command generator 330, a voltage command generator 340, and an axis converter. The unit 350 may include a switching control signal output unit 360.

The axis converter 310 receives the three-phase output currents ia1, ib1, and ic1 detected by the first output current detector E1, and converts the two-phase currents iα1 and iβ1 of the stationary coordinate system into a second phase. The three-phase output currents ia2, ib2 and ic2 detected by the output current detector E2 are input and converted into two-phase currents iα2 and iβ2 of the stationary coordinate system.

On the other hand, the axis conversion unit 310 converts the two-phase current iα1, iβ1 of the stationary coordinate system into the two-phase current id1, iq1 of the rotary coordinate system, and rotates the two-phase current iα2, iβ2 of the stationary coordinate system. The two-phase currents id2 and iq2 of the coordinate system can be converted.

On the other hand, according to the permanent magnetic flux synchronous motor formula, the torque of the master motor 230a can be controlled through the q-axis current which is the torque component current of the master motor 230a. In addition, in the single inverter multiple motor control system, the torque of the slave motor 230b can be controlled through the d-axis current of the master motor 230a. Therefore, even when the d-axis current of the master motor 230a is varied to control the torque of the slave motor 230b, the torque of the master motor 230a may not change.

)와 연산된 속도(

)를 출력하고, 속도 연산부(320)는, 축변환부(310)에서 축변화된 정지좌표계의 2상 전류(iα2,iβ2)에 기초하여, 슬레이브 모터(230b)의 회전자에 대한 연산된 위치(

)와 연산된 속도(

)를 출력할 수 있다.Next, the speed calculator 320 calculates the calculated position of the rotor of the master motor 230a based on the two-phase currents iα1 and iβ1 of the stationary coordinate system axially changed by the axis converter 310.

) And computed speed (

), And the speed calculator 320 calculates the calculated position of the rotor of the slave motor 230b based on the two-phase currents iα2 and iβ2 of the stationary coordinate system axially changed by the axis converter 310.

) And computed speed (

) Can be printed.

On the other hand, the motor drive device 220 of the present invention, it is possible to fix any one motor to the master motor 230a, and to fix the remaining motor to the slave motor 230b. For example, the inverter controller 430 may select, as the master motor 230a, a motor to which a larger load is applied. In addition, the master motor 230a may be changed according to the load applied to the motor.

To this end, the motor driving device 220 of the present invention may include a selector 322 for selecting the master motor 230a to be controlled.

)와 연산된 속도(

) 및 슬레이브 모터(230b)의 회전자에 대한 연산된 위치(

)와 연산된 속도(

)를 속도 연산부(320)로부터 입력 받을 수 있다. 또한, 선택부(322)는, 마스터 모터(230a)에 해당하는 연산 속도(

)를 출력할 수 있다.The selector 322 may calculate the calculated position (relative to the rotor of the master motor 230a).

) And computed speed (

) And the calculated position for the rotor of the slave motor 230b (

) And computed speed (

) May be input from the speed calculator 320. In addition, the selector 322 may include a calculation speed corresponding to the master motor 230a (

) Can be printed.

On the other hand, the selection unit 322 is a two-phase current (id1, iq1) of the rotary coordinate system to the master motor 230a from the axis conversion unit 310, and two of the rotary coordinate system to the slave motor 230b. Phase currents id2 and iq2 may be input.

Then, the selector 322, based on the phase difference or the speed difference between the master motor 230a and the slave motor 230b, the two-phase current (id1) of the rotational coordinate system for the master motor 230a selected as the control target motor , iq1 can be output to the voltage command generation unit 340.

)와 속도 지령치(

)에 기초하여, 전류 지령치(

,

)를 생성할 수 있다.On the other hand, the current command generation unit 330 calculates the operation speed of the master motor 230a to be controlled (

) And speed setpoint (

Based on the current setpoint (

,

) Can be created.

)는, 제어 대상이 아닌 슬레이브 모터(230b)의 속도 지령치인 것이 바람직하다.In particular, the speed setpoint (

) Is preferably a speed command value of the slave motor 230b which is not a control target.

)와 슬레이브 모터(230a)의 속도 지령치(

)의 차이에 기초하여, PI 제어기(335)에서 PI 제어를 수행하며, 전류 지령치(

,

)를 생성할 수 있다.Accordingly, the current command generation unit 330 calculates the calculated speed of the master motor 230a (

) And the speed command value of the slave motor 230a

Based on the difference of), the PI controller 335 performs the PI control, and the current command value (

,

) Can be created.

,

)는, 자속분 전류인 d축 전류 지령치(

)와, 토크분 전류 지령치인 q축 전류 지령치(

)를 포함할 수 있다.Current setpoint (

,

Is the d-axis current command value (the flux current)

) And q-axis current command value (the torque current command value)

) May be included.

)와, 마스터 모터(230a)의 회전 속도(

)에 기초하여, 마스터 모터(230a) 및 슬레이브 모터(230b)의 위상 차이 또는 속도 차이에 대응하는, 전류 지령치를 생성할 수 있다.The current command generation unit 330 has a speed command value for the slave motor 230b among the master motor 230a and the slave motor 230b (

) And the rotational speed of the master motor 230a (

) May generate a current command value corresponding to the phase difference or speed difference of the master motor 230a and the slave motor 230b.

,

)가 허용 범위를 초과하지 않도록 그 레벨을 제한하는 리미터(미도시)를 더 구비할 수도 있다.On the other hand, the current command generation unit 330 is a current command value (

,

) May be further provided with a limiter (not shown) which limits the level so as not to exceed the permissible range.

Next, the voltage command generation unit 340 may receive the d-axis and q-axis currents id and iq which are converted into the two-phase rotation coordinate system by the axis transformation unit 310. In this case, the d-axis and q-axis currents id and iq may be magnetic flux current id1 and torque current iq1 on the rotational coordinate system with respect to the master motor 230a.

Meanwhile, the offset current generator 338 may generate an offset current ioff. The offset current generator 338 may add the offset current ioff to the magnetic flux current id1 on the rotational coordinate system with respect to the master motor 230a.

)와, 슬레이브 모터(230b)의 회전자에 대한 연산된 위치(

)를 기초로, 마스터 모터(230a)의 위상 대비 슬레이브 모터(230b)의 위상을 연산할 수 있다.In detail, the offset current generator 338 calculates, from the speed calculator 320, the calculated position of the rotor of the master motor 230a.

) And the calculated position for the rotor of the slave motor 230b (

), The phase of the slave motor 230b relative to the phase of the master motor 230a may be calculated.

When the phase of the slave motor 230b is slower than the phase of the master motor 230a, the offset current command generation unit 338 generates an offset current ioff to generate the flux current id1 of the master motor 230a. Can be added to

The offset current generator 338 may set the offset current ioff when the speed of the slave motor 230b is less than or equal to a preset speed. That is, the offset current generating unit 338, when the phase of the slave motor 230b is slower than the phase of the master motor 230a in a state where the speed of the slave motor 230b is less than or equal to a preset speed, the offset current ioff. May be generated and added to the flux current id1 of the master motor 230a. The addition of the offset current ioff to the flux current id1 of the master motor 230a may be referred to as flux compensation current id1 + ioff.

On the other hand, even if the speed of the slave motor is relatively slow, when a relatively large offset current (ioff) is added, the accuracy of control may be degraded. Therefore, the magnitude of the offset current ioff may be set smaller as the speed of the slave motor 230b becomes smaller.

The offset current generator 338 may not generate the offset current ioff when the phase of the slave motor 230b is earlier than the phase of the master motor 230a.

On the other hand, when the offset current ioff is excessively added to the magnetic flux current id1 of the master motor 230a, the master motor 230a and the slave motor 230b cannot be controlled accurately and stably. To this end, the offset current generator 338 may include a limiter 339 that limits the level so that the offset current ioff does not exceed the allowable range. The allowable range of the offset current ioff may be appropriately set so that the motor drive device 220 does not runaway.

,

)에 기초하여, d축, q축 전압 지령치(

,

)를 생성한다. 이때, d축 전류(id)는, 마스터 모터(230a)의 자속분 전류(id1) 또는, 자속분 보상 전류(id1+ioff)일 수 있다.The voltage command generation unit 340 is a d-axis, q-axis current (id, iq) axis-converted in the two-phase rotation coordinate system in the axis conversion unit, and the current command value (such as in the current command generation unit 330) (

,

D) and q-axis voltage command values (

,

) In this case, the d-axis current id may be a flux current id1 of the master motor 230a or a flux compensation current id1 + ioff.

)의 차이에 기초하여, PI 제어기(344)에서 PI 제어를 수행하며, q축 전압 지령치(

)를 생성할 수 있다. 또한, 전압 지령 생성부(340)는, d축 전류(id)와, d축 전류 지령치(

)의 차이에 기초하여, PI 제어기(348)에서 PI 제어를 수행하며, d축 전압 지령치(

)를 생성할 수 있다. 한편, 전압 지령 생성부(340)는, d 축, q축 전압 지령치(

,

)가 허용 범위를 초과하지 않도록 그 레벨을 제한하는 리미터(미도시)를 더 구비할 수도 있다.For example, the voltage command generation unit 340 includes a q-axis current iq and a q-axis current command value (

Based on the difference of), PI controller 344 performs PI control, and the q-axis voltage setpoint (

) Can be created. The voltage command generator 340 further includes a d-axis current id and a d-axis current command value (

Based on the difference of), the PI controller 348 performs the PI control, the d-axis voltage setpoint (

) Can be created. On the other hand, the voltage command generation unit 340 is a d-axis, q-axis voltage command value (

,

May be further provided with a limiter (not shown) which limits the level so that does not exceed the allowable range.

,

)는, 축변환부(350)에 입력된다.Meanwhile, the generated d-axis and q-axis voltage command values (

,

) Is input to the axis conversion unit 350.

)와, d축, q축 전압 지령치(

,

)를 입력받아, 축변환을 수행한다.The axis conversion unit 350 may be a position calculated by the speed calculating unit 320 (

), D-axis and q-axis voltage setpoints (

,

) Is input and axis conversion is performed.

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

) Can be used.

,

,

)를 출력하게 된다. 스위칭 제어 신호 출력부(360)는, 3상 출력 전압 지령치(

,

,

)에 기초하여 펄스폭 변조(PWM) 방식에 따른 인버터용 스위칭 제어 신호(Sic)를 생성하여 출력한다.In addition, the axis conversion unit 350 performs a conversion from the two-phase stop coordinate system to the three-phase stop coordinate system. Through this conversion, the axis conversion unit 1050, the three-phase output voltage command value (

,

,

) Will be printed. The switching control signal output unit 360 has a three-phase output voltage command value (

,

,

) Generates and outputs a switching control signal (Sic) for the inverter according to the pulse width modulation (PWM) method.

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. As a result, each of the switching elements Sa, S'a, Sb, S'b, Sc, and S'c in the inverter 420 performs a switching operation.

In this way, the inverter controller 430 sets the flux current according to the phase difference or the speed difference between the master motor 230a and the slave motor 230b, and outputs a switching control signal based on the set flux current. can do. As a result, the inverter 420 is controlled.

4 is a view for explaining a control method for removing a pulsating component of a slave motor.

Referring to the drawings, in a single inverter multi-motor control system, a phase difference or speed difference between two motors occurs, and thus, a pulsation component may appear in the slave motor 230b.

In addition, in a single inverter multi-motor control system, there is a possibility that two motors may resonate due to the error in the phase, magnitude, frequency, etc. of back EMF of the master motor 230a and the slave motor 230b. Accordingly, as illustrated in FIG. 4A, the pulsation component of the slave motor 230b may be reflected in the magnetic flux component idm1 of the master motor 230b. This may hinder driving stability of the motor driving device 220.

On the other hand, in the single inverter plural motor control system, the master motor 230a is capable of torque control via the q-axis current, which is the torque component current, and the slave motor 230b is the magnetic flux component current of the master motor 230a. Through d-axis current, torque control is possible.

The motor drive apparatus 220 of the present invention can remove the pulsation component by controlling the d-axis current of the master motor 230a.

Specifically, when the phase of the slave motor 230b is earlier than the phase of the master motor 230a, the inverter controller 430 controls the magnetic flux component current of the master motor 230a to be reduced, and the slave motor 230b. If the phase is slower than the phase of the master motor 230a, the magnetic flux component current of the master motor 230a may be controlled to increase.

Accordingly, it can be seen that the magnetic flux current pulsation component of the master motor 230a is removed as shown in FIG. 4B.

However, even in the case of controlling as shown in FIG. 4, in the low speed operation of the slave motor 230b, the torque of the slave motor 230b becomes small, and there is a possibility of the stepping out of the slave motor 230b. In order to solve this problem, the motor driving apparatus 220 of the present invention may add an offset current to the flux current of the master motor 230a. This will be described in more detail below with reference to FIG. 5.

FIG. 5 is a diagram for explaining the phase difference between the master motor and the slave motor, FIG. 6 is a diagram for explaining the phase change and the torque change of the slave motor according to the rotational speed of the slave motor, and FIG. It is a figure for demonstrating the offset current.

Referring to the drawings, in FIG. 5, S51 represents an output current of the master motor 230a, and S52 represents an output current of the slave motor 230b.

In a single inverter multiple motor control system, despite the same switching control signal output of the inverter 420, the phase of the slave motor 230b may be slower than the phase of the master motor 230a, as in FIG. 5A. Alternatively, as shown in FIG. 5B, the phase of the slave motor 230b may be faster than the phase of the master motor 230b.

In particular, when the phase difference between the master motor 230a and the slave motor 230b is greater than or equal to the predetermined phase difference, a motor outage may occur.

When the rotation speed of the slave motor 230b is small, since the torque of the slave motor 230b is small, such a possibility of this step out increases. Therefore, when the rotation speed of the slave motor 230b is small, the normal operating range of the single inverter multiple motor control system can be reduced. The normal driving range may be a phase difference allowable range between the master motor 230a and the slave motor 230b for the motor driving device 220 to operate normally.

Specifically, in FIG. 6A, S71 represents a relationship between the phase difference between the master motor 230a and the slave motor 230b and the torque of the slave motor 230b when the rotation speed of the slave motor 230b is 800 rpm. S72 represents the relationship between the phase difference between the master motor 230a and the slave motor 230b and the torque of the slave motor 230b when the rotation speed of the slave motor 230b is 600 rpm, and S73 represents the slave motor. When the rotation speed of the 230b is 400 rpm, the relationship between the phase difference between the master motor 230a and the slave motor 230b and the torque of the slave motor 230b is shown, and S74 indicates the rotation speed of the slave motor 230b. , 200rpm, the relationship between the phase difference between the master motor 230a and the slave motor 230b and the torque of the slave motor 230b.

In FIG. 6A, when the phase of the slave motor 230b is slower than the phase of the master motor 230a, it can be seen that the torque of the slave motor 230b gradually decreases over a predetermined phase difference.

In particular, depending on the number of revolutions of the slave motor 230b, the normal driving range in which the motor driving device 220 does not cause outage is changed.

That is, as shown in FIG. 6A, when the rotation speed of the slave motor 230b is 800 rpm, the normal driving range of the motor driving device 220 is about 61.7 degrees, while when the rotation speed of the slave motor 230b is 600 rpm, 55.2 degrees In case of 400rpm, it is gradually decreased to 42.3 degrees, and to 200rpm to 28.1 degrees.

In order to solve this problem, the motor driving apparatus 220 of the present invention adds an offset current to the flux current of the master motor 230a to increase the torque of the slave motor 230b and to increase the range of normal operation. Can be extended

In detail, the inverter controller 430 may determine whether the speed of the slave motor 230b is less than or equal to a preset speed. For example, when the slave motor 230b operates in the range of 0 to 1000 rpm, the preset speed may be 200 rpm.

The inverter controller 430 may calculate whether to perform offset compensation control when the slave motor 230b is below a preset speed.

The inverter controller 430 may calculate the phase of the slave motor 230b with respect to the phase of the master motor 230a while the speed of the slave motor 230b is equal to or less than a preset speed.

The inverter controller 430 may set the offset current ioff when the phase of the slave motor 230b is slower than the phase of the master motor 230a. The offset current ioff may be set such that the magnitude of the offset current is smaller as the speed of the slave motor 230b is smaller.

As illustrated in FIG. 7, the inverter controller 430 may generate the magnetic flux compensation current by adding an offset current ioff to the magnetic flux current idm3 on the rotational coordinate system with respect to the master motor 230a. . In addition, the inverter controller 430 may control the inverter 420 based on the magnetic flux compensation current.

On the other hand, S75 of FIG. 6B shows the relationship between the phase difference between the master motor 230a and the slave motor 230b and the torque of the slave motor 230b when the magnetic flux current of the master motor 230a is 1A, S76 represents a relationship between the phase difference between the master motor 230a and the slave motor 230b and the torque of the slave motor 230b when the flux current of the master motor 230a is 0A, and S77 represents the master motor. When the magnetic flux component current of 230a is -1A, the relationship between the phase difference between the master motor 230a and the slave motor 230b and the torque of the slave motor 230b is shown.

In FIG. 6A, when the phase of the slave motor 230b is slower than the phase of the master motor 230a, it can be seen that as the flux current of the master motor 230a increases, the normal operating range of the motor increases.

That is, when the phase of the slave motor 230b is slower than the phase of the master motor 230a, the normal operating range of the motor is expanded by adding an offset current ioff to the flux current idm3 of the master motor 230a. In addition, it becomes possible to prevent the motor out of step and to drive stably.

On the other hand, as shown in Figs. 6A to 6B, when the phase of the slave motor 230b is faster than the phase of the master motor 230a, the torque required for synchronizing the phases of the two motors is almost negative (-) torque, so that the inverter controller 430 may control the inverter as shown in FIG. 4.

Specifically, when the phase of the slave motor 230b is faster than the phase of the master motor 230a, the inverter controller 430 does not set the offset current ioff, but instead sets the magnetic flux current of the master motor 230b. On the basis, the inverter 420 can be controlled.

When the phase of the slave motor 230b is earlier than the phase of the master motor 230a, the inverter controller 430 may control the magnetic flux current of the master motor 230a to be reduced. Accordingly, the magnetic flux current pulsation component of the master motor 230a can be removed.

8 is a perspective view showing a laundry treatment machine according to an embodiment of the present invention.

Referring to the drawings, the laundry treatment machine 100a according to an embodiment of the present invention is a laundry machine of a front load type in which a cloth is inserted into a washing tank in a front direction. The laundry treatment apparatus of the front type is a concept including a washing machine in which a cloth is inserted to perform washing, rinsing and dehydration, or a dryer in which a wet cloth is inserted to perform drying. Hereinafter, a washing machine will be described.

The laundry treatment apparatus 100a of FIG. 8 is a laundry tub laundry treatment apparatus, and includes a cabinet 110 forming an exterior of the laundry treatment apparatus 100a and a cabinet 110 and supported by the cabinet 110. The tub 120 to be disposed, the washing tub 122 disposed inside the tub 120, the motor 130 driving the washing tub 122, and the cabinet body 111 are disposed outside the cabinet 110. It includes a washing water supply device (not shown) for supplying the wash water therein, and a drainage device (not shown) formed under the tub 120 to discharge the wash water to the outside.

A plurality of through holes 122A are formed in the washing tub 122 to allow the washing water to pass therethrough, and when the washing tub 122 is rotated, the laundry is lifted to a certain height and then lifted on the inner side of the washing tub 112 so as to fall by gravity. 124 may be deployed.

The cabinet 110 includes a cabinet main body 111, a cabinet cover 112 disposed at the front of the cabinet main body 111 and coupled thereto, and a control disposed at the upper side of the cabinet cover 112 and coupled with the cabinet main body 111. The panel 115 and a top plate 116 disposed above the control panel 115 and coupled to the cabinet body 111 are included.

The cabinet cover 112 includes a cloth entry hole 114 formed to allow entry and exit of the gun, and a door 113 disposed to be rotatable from side to side to enable opening and closing of the gun entry hole 114.

The control panel 115 is provided with operation keys 117 for operating the operating state of the laundry processing apparatus 100a and a display device disposed on one side of the operation keys 117 and displaying an operating state of the laundry processing apparatus 100a ( 118).

The operation keys 117 and the display device 118 in the control panel 115 are electrically connected to a control unit (not shown), and the control unit (not shown) electrically controls each component of the laundry processing apparatus 100a. do. The operation of the controller (not shown) will be described later.

On the other hand, the washing tank 122 may be provided with an auto balance (not shown). Auto balance (not shown) is to reduce the vibration caused by the eccentric amount of the laundry contained in the washing tank 122, it may be implemented as a liquid balance, ball balance and the like.

On the other hand, although not shown in the figure, the laundry treatment apparatus 100a may further include a vibration sensor for measuring the vibration amount of the washing tank 122 or the vibration amount of the cabinet 110.

FIG. 9 is an internal block diagram of the laundry treatment machine of FIG. 8.

Referring to the drawings, in the laundry treatment apparatus 100a, the driving unit 220 is controlled by the control operation of the control unit 210, and the driving unit 220 includes the master motor 230a and the slave motor 230b. Will be driven. Meanwhile, in the drawing, the washing tub 122 is connected to the master motor 230a and rotates by the master motor 230a. Alternatively, a separate washing tub (not shown) is connected to the slave motor 230b. It is also possible to rotate by the slave motor 230b.

That is, the laundry treatment apparatus 100a may include two washing tanks, and may be driven by the master motor 230a and the slave motor 230b, respectively.

The control unit 210 receives an operation signal from the operation key 1017 and operates. Accordingly, washing, rinsing, and dehydration strokes can be performed.

In addition, the controller 210 may control the display 18 to display a washing course, a washing time, a dehydration time, a rinsing time, or a current operation state.

On the other hand, the control unit 210 controls the drive unit 220, and the drive unit 220 controls the master motor 230a and the slave motor 230b to operate. At this time, inside or outside the master motor 230a and the slave motor 230b, a position sensing unit for sensing the rotor position of the motor is not provided. That is, the driving unit 220 controls the master motor 230a and the slave motor 230b by a sensorless method.

For example, the inverter control unit 430 in FIG. 2 in the drive unit 220 estimates the rotor positions of the master motor 230a and the slave motor 230b based on the output currents io1 and io2. Then, based on the estimated rotor position, the master motor 230a and the slave motor 230b are controlled to rotate.

Meanwhile, the driving unit 220 may correspond to the motor driving device 220 of FIG. 1.

On the other hand, the control unit 210, based on the output current (io1) and the like flowing in the master motor 230a, it can detect the amount of quantity. For example, while the washing tub 122 rotates, the amount of quantity can be sensed based on the current value io1 of the master motor 230a.

In particular, the control unit 210, when detecting the amount of capacity, by using the stator resistance and inductance value of the motor measured in the motor alignment section, it is possible to accurately detect the amount of quantity.

On the other hand, the control unit 210 may detect the unbalance (UB) of the washing tank 122, that is, the unbalance (UB) of the washing tank 122. The eccentricity detection may be performed based on the ripple component of the output current io1 flowing in the master motor 230a or the rotation speed change amount of the washing tub 122.

In particular, the control unit 210, by detecting the amount of capacity, by using the stator resistance and inductance value of the motor measured in the motor alignment section, it is possible to accurately detect the eccentric amount.

10 is a diagram illustrating a configuration of an air conditioner which is another example of a home appliance according to an embodiment of the present invention.

As shown in FIG. 10, the air conditioner 100b according to the present invention may include an indoor unit 31b and an outdoor unit 21b connected to the indoor unit 31b.

The indoor unit 31b of the air conditioner can be any of a stand type air conditioner, a wall-mounted air conditioner, and a ceiling type air conditioner, but the drawing illustrates the stand type indoor unit 31b.

Meanwhile, the air conditioner 100b may further include at least one of a ventilation device, an air cleaning device, a humidifier, and a heater, and may operate in conjunction with the operation of the indoor unit and the outdoor unit.

The outdoor unit 21b includes a compressor (not shown) for receiving and compressing a refrigerant, an outdoor heat exchanger (not shown) for exchanging refrigerant and outdoor air, and an accumulator for extracting and supplying a gas refrigerant to the compressor. And a four-way valve (not shown) for selecting a flow path of the refrigerant according to the heating operation. In addition, although a plurality of sensors, valves and oil recovery device, etc. are further included, the description of the configuration will be omitted below.

The outdoor unit 21b operates the compressor and the outdoor heat exchanger, and compresses or heat exchanges the refrigerant according to a setting to supply the refrigerant to the indoor unit 31b. The outdoor unit 21b may be driven by the demand of the remote controller (not shown) or the indoor unit 31b. In this case, as the cooling / heating capacity is changed corresponding to the indoor unit being driven, the number of operation of the outdoor unit and the number of operation of the compressor installed in the outdoor unit may be changed.

At this time, the outdoor unit 21b supplies the compressed refrigerant to the connected indoor unit 310b.

The indoor unit 31b receives a coolant from the outdoor unit 21b and discharges cold air into the room. The indoor unit 31b includes an indoor heat exchanger (not shown), an indoor fan (not shown), an expansion valve (not shown) in which the refrigerant supplied is expanded, and a plurality of sensors (not shown).

At this time, the outdoor unit 21b and the indoor unit 31b are connected by a communication line to transmit and receive data to each other, and the outdoor unit and the indoor unit are connected to a remote controller (not shown) by wire or wirelessly and operate under the control of a remote controller (not shown). can do.

The remote controller (not shown) may be connected to the indoor unit 31b to input a user's control command to the indoor unit, and receive and display state information of the indoor unit. At this time, the remote control may communicate by wire or wirelessly according to the connection form with the indoor unit.

FIG. 11 is a schematic diagram of the outdoor unit and the indoor unit of FIG. 10.

Referring to the drawings, the air conditioner 100b is largely divided into an indoor unit 31b and an outdoor unit 21b.

The outdoor unit 21b includes a compressor 102b that serves to compress the refrigerant, a compressor electric motor 102bb that drives the compressor, an outdoor side heat exchanger 104b that serves to radiate the compressed refrigerant, and an outdoor unit. An outdoor blower 105b disposed on one side of the heat exchanger 104b and configured to include an outdoor fan 105ab for promoting heat dissipation of the refrigerant and an electric motor 105bb for rotating the outdoor fan 105ab, and an expansion for expanding the condensed refrigerant; The mechanism 106b, the cooling / heating switching valve 110b for changing the flow path of the compressed refrigerant, and the accumulator 103b for temporarily storing the gasified refrigerant to remove moisture and foreign matter and then supplying a refrigerant of a constant pressure to the compressor. And the like.

The indoor unit 31b is disposed in the room to perform a cooling / heating function, the indoor side heat exchanger 109b, and the indoor fan 109ab and the room disposed at one side of the indoor heat exchanger 109b to promote heat dissipation of the refrigerant. The indoor blower 109b etc. which consist of the electric motor 109bb which rotates the fan 109ab are included.

At least one indoor side heat exchanger (109b) may be installed. The compressor 102b may be at least one of an inverter compressor and a constant speed compressor.

In addition, the air conditioner 100b may be configured as a cooler for cooling the room, or may be configured as a heat pump for cooling or heating the room.

On the other hand, the outdoor unit 21b of FIG. 10 can be provided with the some outdoor fan. In particular, two outdoor fans may be provided.

In this case, the two outdoor fans may be driven by the motor driving device 220, as shown in FIG.

12 is a perspective view illustrating a refrigerator that is another example of a home appliance according to an exemplary embodiment of the present invention.

Referring to the drawings, the refrigerator 100c according to the present invention, although not shown, has a case 110c having an internal space partitioned into a freezer compartment and a refrigerator compartment, a freezer compartment door 120c that shields the freezer compartment, and a refrigerator compartment. A rough appearance is formed by the refrigerating compartment door 140c.

In addition, the front surface of the freezing compartment door 120c and the refrigerating compartment door 140c is further provided with a door handle 121c protruding forward, so that the user easily grips and rotates the freezing compartment door 120c and the refrigerating compartment door 140c. Make it work.

On the other hand, the front of the refrigerator compartment door 140c may be further provided with a home bar 180c, which is a convenient means for allowing a user to take out a storage such as a beverage contained therein without opening the refrigerator compartment door 140c.

In addition, the front of the freezer compartment door 120c may be provided with a dispenser 160c, which is a convenient means for allowing the user to easily take out ice or drinking water without opening the freezer compartment door 120c, such a dispenser 160c. An upper side of the control panel 210c may be further provided to control the driving operation of the refrigerator 100c and to show a state of the refrigerator 100c in operation on the screen.

Meanwhile, although the dispenser 160c is illustrated as being disposed on the front surface of the freezer compartment door 120c, the present invention is not limited thereto, and the dispenser 160c may be disposed on the front side of the refrigerator compartment door 140c.

Meanwhile, an ice maker 190c for ice-making water supplied using cold air in the freezer compartment and an ice bank mounted inside the freezer compartment (not shown) are included in the freezer compartment (not shown). 195c may be further provided. In addition, although not shown in the drawing, an ice chute (not shown) may be further provided to guide the ice contained in the ice bank 195c to fall into the dispenser 160c.

The control panel 210c may include an input unit 220c including a plurality of buttons, and a display unit 230c for displaying a control screen and an operation state.

The display unit 230c displays information such as a control screen, an operating state, and a temperature inside the refrigerator. For example, the display unit 230c may display a service type of the dispenser (ice ice, water, flake ice), a set temperature of the freezer compartment, and a set temperature of the refrigerator compartment.

The display unit 230c may be implemented in various ways, such as a liquid crystal display (LCD), a light emitting diode (LED), and an organic light emitting diode (OLED). In addition, the display unit 230c may be implemented as a touch screen capable of performing the function of the input unit 220c.

The input unit 220c may include a plurality of operation buttons. For example, the input unit 220c may include a dispenser setting button (not shown) for setting a service type of the dispenser (ice, water, ice, etc.), and a freezer temperature setting button (not shown) for setting a freezer temperature. And, it may include a refrigerator compartment temperature setting button (not shown) for setting the freezer compartment temperature. The input unit 220c may be implemented as a touch screen that can also perform the function of the display unit 230c.

Meanwhile, the refrigerator according to the embodiment of the present invention is not limited to the double door type illustrated in the drawings, but is a one door type, a sliding door type, a curtain door type. It may be any type such as (Curtain Door Type).

FIG. 13 is a view schematically illustrating a configuration of the refrigerator of FIG. 12.

Referring to the drawings, the refrigerator 100c receives the compressor 112c, the condenser 116c condensing the refrigerant compressed by the compressor 112c, and the refrigerant condensed by the condenser 116c, and evaporates it. A freezer compartment evaporator 124c disposed in a freezer compartment (not shown) and a freezer compartment expansion valve 134c for expanding a refrigerant supplied to the freezer compartment evaporator 124c may be included.

On the other hand, in the figure, but illustrated as using one evaporator, it is also possible to use each evaporator in the refrigerating chamber and freezing chamber.

That is, the refrigerator 100c is a three-way valve for supplying a refrigerator evaporator (not shown) arranged in the refrigerator compartment (not shown) and the refrigerant condensed in the condenser 116c to the refrigerator compartment evaporator (not shown) or the freezer compartment evaporator 124c. (Not shown) and a refrigerator compartment expansion valve (not shown) for expanding the refrigerant supplied to the refrigerator compartment evaporator (not shown).

In addition, the refrigerator 100c may further include a gas-liquid separator (not shown) in which the refrigerant passing through the evaporator 124c is separated into a liquid and a gas.

In addition, the refrigerator 100c further includes a refrigerator compartment fan (not shown) and a freezer compartment fan 144c that suck cold air that has passed through the freezer compartment evaporator 124c and blow it into a refrigerator compartment (not shown) and a freezer compartment (not shown), respectively. can do.

In addition, the compressor driving unit 113c for driving the compressor 112c, a refrigerator compartment fan driver (not shown) and a freezer compartment fan driver 145c for driving the refrigerator compartment fan (not shown) and the freezer compartment fan 144c may be further included. have.

Meanwhile, according to the drawing, since a common evaporator 124c is used in the refrigerating compartment and the freezing compartment, in this case, a damper (not shown) may be installed between the refrigerating compartment and the freezing compartment, and the fan (not shown) is one evaporator. The cold air generated in the air may be forced to be supplied to the freezing compartment and the refrigerating compartment.

Meanwhile, the refrigerator 100c may be driven by using one inverter 420 when driving the refrigerator compartment fan (not shown) and the freezer compartment fan 144c.

In this case, the refrigerating compartment fan (not shown) and the freezer compartment fan 144c may be driven by the motor driving device 220, as shown in FIG. 1.

The accompanying drawings are only for easily understanding the embodiments disclosed in the present specification, and the technical idea disclosed in the present specification is not limited by the accompanying drawings, and all modifications and equivalents included in the spirit and scope of the present invention are provided. It should be understood to include water or substitutes.

Likewise, although the operations are depicted in the drawings in a specific order, it should not be understood that such operations must be performed in the specific order or sequential order shown in order to obtain desirable results, or that all illustrated operations must be performed. . In certain cases, multitasking and parallel processing may be advantageous.

On the other hand, the motor driving method or the operation method of the home appliance of the present invention, it is possible to implement as a processor readable code in a processor-readable recording medium provided in the motor drive device or home appliance. The processor-readable recording medium includes all kinds of recording devices that store data that can be read by the processor.

In addition, while the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

230a: master motor
230b: slave motor
338: offset current generator
420: inverter
430: inverter control unit

Claims (10)

An inverter having a plurality of switching elements, converting a DC power source into an AC power source by switching the switching element, and supplying the AC power source to a master motor and a slave motor;
An output current detector for detecting an output current flowing in the master motor and the slave motor; And
An inverter controller which sets an offset current according to the phase of the slave motor relative to the phase of the master motor, and controls the inverter based on the offset current and the flux current of the master motor detected by the output current detector; Motor drive device comprising a.
The method of claim 1,
The inverter control unit,
When the phase of the slave motor is faster than the phase of the master motor, the magnetic flux component current of the master motor is controlled to be reduced, and when the phase of the slave motor is slower than the phase of the master motor, the magnetic flux of the master motor A motor drive, characterized in that the control to increase the minute current.
The method of claim 1,
The inverter controller
When the phase of the slave motor is slower than the phase of the master motor, the offset current is added to the flux current of the master motor to generate a flux compensation current, and based on the flux compensation current, the inverter Motor drive, characterized in that for controlling.
The method of claim 3,
The inverter control unit,
And the offset current is set when the speed of the slave motor is less than or equal to a preset speed.
The method of claim 4, wherein
The inverter control unit,
The motor driving apparatus, characterized in that the control is controlled so that the magnitude of the offset current is smaller as the speed of the slave motor is smaller.
The method of claim 5,
The inverter control unit,
And a limiter for limiting the magnitude of the offset current.
The method of claim 1,
The inverter control unit,
And when the phase of the slave motor is faster than the phase of the master motor, the inverter is controlled based on the flux current of the master motor without setting the offset current.
The method of claim 1,
The output current detector,
A first output current detector configured to detect an output current flowing through the master motor; And
And a second output current detector configured to detect an output current flowing through the slave motor.
The inverter control unit,
And calculating a phase of the slave motor relative to the master motor based on the first output current and the second output current.
The method of claim 8,
The inverter control unit,
A speed calculator configured to calculate speeds of the master motor and the slave motor based on the first output current and the second output current;
A current command generation unit that generates a current command value based on a rotation speed of the master motor and a speed command value; And
A voltage command generator that generates a voltage command value based on the current command value from the current command generator;
And a switching control signal output unit configured to output an inverter switching control signal based on the voltage command value.
A home appliance comprising the motor drive device according to claim 1.

Images