KR20110092058A - Refrigerator and controlling method thereof - Google Patents

Abstract

PURPOSE: A refrigerator and a control method thereof are provided to resolve the problem of an open state by performing the re-operation of a motor if the inner line of the motor is in a temporarily open state. CONSTITUTION: A refrigerator comprises a compressor, a motor(110), an inverter(130), and a control unit(120). The compressing unit is installed in the compressor and compresses refrigerant. The motor operates the compressing unit and comprises a stator and a rotor which rotates to the stator. The motor comprises a plurality of lines, to which output currents with a plurality of phases input and which are connected at single node. The control unit controls the operation of the motor by the inverter. The control unit detects the output currents according to each phase input to each line.

Description

Control method for refrigerators and freezers

The present invention relates to a refrigerator.

A refrigerator is a home appliance for storing food in a chilled or frozen state.

In general, a refrigerator is a device that can keep food fresh for a certain period of time by lowering the freezing compartment or the refrigerating compartment while repeating a refrigeration cycle in which the refrigerant is compressed, condensed, expanded, or evaporated.

Such a refrigerator includes a compressor for compressing a refrigerant into a high temperature and high pressure gas refrigerant, a condenser for condensing the refrigerant passing through the compressor into a high temperature and high pressure liquid refrigerant, and an expansion valve for reducing the refrigerant passing through the condenser into a low temperature and low pressure liquid refrigerant. And a refrigerating cycle including an evaporator as a basic component that absorbs heat inside the freezing compartment or the refrigerating compartment and keeps the temperature inside the freezing compartment or the refrigerating compartment at a low temperature while evaporating the refrigerant passing through the expansion valve to a low temperature low pressure gas refrigerant.

At this time, the compressor may be provided with a motor for providing a rotational force to provide a compression force, for the compression of the refrigerant, it may further include an inverter for controlling the current input to the motor.

The motor includes a stator and a rotor that rotates with respect to the stator. When the motor is provided with an inverter for driving the motor, the motor detects a relative position of the rotor with respect to the stator and corresponds to the relative position. The current is input.

The relative position may be detected by a hall sensor for detecting a physical position of the rotor, or the position of the rotor may be estimated based on a current value input to the motor without the sensor. The motor may be controlled based on the detected position value and the speed command for the motor.

In this case, the driving of detecting the relative position of the rotor without a separate sensor is called a sensorless driving.

On the other hand, the motor may be provided with a plurality of coils each of which a current including a plurality of phases are input, the plurality of phases having different phase values, the rotor of the motor is rotated.

However, when a current in which the plurality of phases are not normally formed is input to the motor, as the rotation of the motor is incompletely performed, the rotation of the motor is irregularly performed, or vibration and noise are generated during the rotation of the motor. This will occur.

An object of the present embodiment is to propose a refrigerator that detects an open phase even when an electric motor is driven by a sensorless drive without a separate sensor.

Another object of the present embodiment is to propose a refrigerator for eliminating the open phase when the open phase current is supplied to the electric motor.

A refrigerator according to an aspect of the present invention includes a refrigerator having a condenser, an evaporator, a compressor, and an expansion valve, the compressor being provided in the compressor and compressing a refrigerant; A motor for operating the compression mechanism, the stator and the rotor being rotated with respect to the stator, the output current including a plurality of phases being input and including a plurality of lines interconnected at a single node; An inverter including a plurality of switching elements and outputting the output current of a predetermined frequency and a predetermined magnitude by a switching operation of the switching elements to drive the electric motor; And controlling the motor driving operation of the inverter, detecting the output current according to each phase input to each line, and the magnitude of the output current input to any one line is the magnitude of the first reference current. Hereinafter, when the sum of the output currents detected in the other lines is less than or equal to the second reference current, it is determined that the output current is formed, and the restart mode of the motor is performed.

A control method of a refrigerator according to an aspect of the present invention includes the steps of controlling the inverter to drive the electric motor based on the speed command and the output current; Detecting, by the control unit, the output current according to each phase input to each line; The control unit, when the magnitude of the output current input to one line is equal to or less than the predetermined first reference current, the sum of the output current detected in the other lines is less than the second reference current, the output current is Determining that it is missing; And when the output current is determined to be missing, controlling the inverter to drive the electric motor in the restart mode.

According to the proposed embodiment, when a current in which at least one phase is phased into the motor is input without an additional sensor, there is an advantage of detecting the phase state.

In addition, during the operation of the refrigerator, the current supply state to the motor of the compressor is sensed, and when the rotation state is abnormal, that is, when the internal line of the motor is temporarily lost, a restart operation of the motor is performed to perform the phase loss. The condition can be resolved.

In addition, the phase loss of the electric motor can be detected by the electric current inside the electric motor, so that the physical configuration of the electric motor drive device can be simplified, and the manufacturing cost can be reduced.

1 is a perspective view showing a refrigerator configuration according to an embodiment of the present invention.
2 and 3 are views showing the configuration of a refrigeration cycle according to an embodiment of the present invention.
4 is a view showing a driving configuration of an electric motor of a refrigerator according to the present embodiment;
5 is a diagram illustrating a configuration of a controller of FIG. 4.
6 is a view illustrating an output current input to an electric motor of a refrigerator according to the present embodiment.
7 is a view showing an output current is input to the motor of the refrigerator according to the present embodiment.
8 and 9 are views showing an aspect in which an output current and an output current are input when an imaging occurs.
10 is a flowchart illustrating a method of driving an electric motor of a refrigerator according to the present embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing a configuration of a refrigerator according to an embodiment of the present invention, Figures 2 and 3 are views showing the configuration of a refrigeration cycle according to an embodiment of the present invention.

1 to 3, the refrigerator 1 according to the exemplary embodiment of the present invention includes a main body 10 forming the refrigerating chamber 20 and the freezing chamber 30. The refrigerating compartment 20 is provided above the freezing compartment 30, and the refrigerating compartment 20 and the freezing compartment 30 are partitioned by partition walls 17.

The refrigerator 1 further includes refrigerating compartment doors 11 and 12 and a freezing compartment door 15 that selectively shield the refrigerating compartment 20 and the freezing compartment 30, respectively. The refrigerating compartment doors 11 and 12 are rotatably coupled to the main body 10, and the freezing compartment door 15 is provided to be pulled out toward the front of the freezing compartment 30.

In the lower rear part of the main body 10, the machine room 35 which accommodates the several structure which comprises a refrigeration cycle is formed.

The machine room 35 includes a compressor 60 for compressing a refrigerant at high temperature and high pressure, a condenser 70 and a condenser fan 72 for condensing the refrigerant discharged from the compressor 60, and a refrigerant passing through the condenser 70. Expansion device 80 for reducing the pressure to a low temperature low pressure refrigerant.

Then, an upper side of the machine room 35 is provided with an evaporator 90 for evaporating the refrigerant passing through the expansion device 80 to produce cold air. The evaporator 90 is disposed in the rear space of the freezer compartment 30.

On the other hand, the compressor 60 includes a compression mechanism (not shown) for compressing the refrigerant R to a predetermined pressure and an electric motor 110 (see FIG. 4) for driving the compression mechanism.

The compression mechanism according to the present embodiment may be, for example, a reciprocating mechanism such as a piston.

In addition, the motor 110 includes the stator and the rotor, and the AC power or the DC power of each phase of a predetermined frequency is applied to the coils of the stator of each phase so that the rotor rotates. The type of the motor 110 may be various forms such as a brushless DC (BLDC) motor and a synchronous reluctance motor (synRM).

Meanwhile, the refrigerator according to the present embodiment includes an electric motor driving device 100 for driving the electric motor 110. Hereinafter, the configuration of the motor drive device 100 will be described in detail.

4 is a view showing a driving configuration of the electric motor of the refrigerator according to the present embodiment.

Referring to FIG. 4, the motor driving apparatus 100 of FIG. 2 according to an exemplary embodiment of the present invention may include a converter 140, an inverter 130, a controller 120, an input current detector n1, and an output current detector. and (n2 to n4). In addition, the motor driving apparatus 200 of FIG. 2 may further include a reactor L, a smoothing capacitor C, a dc terminal voltage detector B, and the like.

The reactor L is disposed between, for example, the power supply unit 150 to which an AC power source of 130 V to 60 Hz is input and the converter 140 to perform power factor correction or step-up operation. In addition, the reactor L may perform a function of limiting harmonic currents due to the high speed switching of the converter 140.

The output current supplied to the electric motor 110 according to the present embodiment is formed as a sine wave including a plurality of phases having a predetermined phase difference from each other, and is supplied for a period of 180 °.

Then, the supply period of the current supplied to one phase and the current supplied to the other phase is controlled in a 180 ° energizing manner in which at least a part thereof overlaps.

On the other hand, the motor 110 is provided with a plurality of lines each of which the output current (i _o ) of the plurality of phases are input, the coil (L) is provided on the line.

The input current detector n ₁ may detect the input current i _s input from the power supply unit 150. To this end, a current sensor, CT (current trnasformer), shunt resistor, or the like can be used.

The detected input current i _s is a discrete signal in the form of a pulse and is input to the controller 120 to estimate the input voltage v _s and generate the converter switching control signal S ₁ . Can be.

The converter 140 converts the power supply unit 150 which has passed through the reactor L into DC power and outputs the DC power. In the drawing, the power supply unit 150 is illustrated as a single-phase AC power source, but may be a three-phase AC power source.

The internal structure of the converter 140 also varies according to the type of the power supply 150. For example, in the case of a single phase AC power supply, 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.

The converter 140 includes a switching element to perform a boost operation, a power factor improvement, and a DC power conversion by a switching operation. On the other hand, the converter 140 may be made of a diode or the like to perform rectification without a separate switching operation.

The smoothing capacitor C is connected to the output terminal of the converter 140. The converted DC power output from the converter 140 is smoothed.

Hereinafter, the output terminal of the converter 140 is called a dc terminal or a dc link terminal. The DC voltage smoothed in the dc stage is applied to the inverter 130.

The dc terminal voltage detector n ₅ may detect a dc terminal voltage V _{dc that} is both ends of the smoothing capacitor C. To this end, the dc terminal voltage detector n ₅ may include a resistor, an amplifier, and the like. The detected dc terminal voltage (V _dc ) is detected, the dc terminal voltage (Vdc) is a discrete signal in the form of a pulse, the estimation of the input voltage (v _s ) of the converter switching control signal (S ₂ ) For generation, it may be input to the controller 120.

The inverter 130 includes a plurality of inverter switching elements, converts a smoothed DC power source into a three-phase AC power source having a predetermined frequency by on / off operation of the switching element, and outputs the same to the electric motor 110.

At this time, the motor 110 may be provided with a three-phase electric motor Y-wired three coils (L) for inputting the three-phase AC power.

4 schematically shows the configuration of the configuration of the motor 110, the parameters corresponding to the electromotive force by the rotational drive of the motor 110.

That is, the resistance value R1 of the coil L1 having the constant inductance λ1 and the counter electromotive force E1 according to the rotation driving are shown in the first phase, for example, among the three phases provided in the electric motor 110. have.

The inverter 130 is configured by connecting a pair of upper arm switching elements Sa, Sb, Sc, and lower arm switching elements S'a, S'b, and S'c, which are connected to each other in series. A total of three upper and lower arm switching elements are connected in parallel with each other (Sa, S'a, Sb, S'b, Sc, and 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 plurality of switching elements Sa, S'a, Sb, S'b, Sc, and S'c included in the inverter 130 are based on the inverter switching control signal S ₁ from the controller 120. , Perform an on / off operation, and outputs a three-phase power source having a predetermined frequency to the motor (110).

In this case, between the first to third phase arm switching elements Sa, Sb, and Sc and the first to third lower arm switching elements S'a, S'b, and S'c, respectively, the first to third phase arm switching elements S'a, S'b, and S'c. First to third connection nodes n6, n7, n8 connected to the coil L of the third phase are provided, and the switching elements Sa, S'a, Sb, S'b, Sc, and S'c are provided. The three-phase power is input to the motor 110 by a switching on / off operation.

The controller 120 controls an inverter switching control signal S ₁ for controlling on / off operations of the switching elements Sa, S'a, Sb, S'b, Sc, and S'c with respect to the inverter 130. )

In this case, the controller 120 outputs a plurality of inverter switching control signals S ₁ according to a plurality of driving stages according to the driving state of the motor 110.

The first to third shunt resistors R s ₁ , R s ₂ , and R _{s 3} are provided on the other side of the first to third arm arm switching elements S'a, S'b, and S'c, respectively.

The output current detectors n ₂ , n ₃ , and n ₄ may be located between the inverter 130 and the motor 110. For the current detection, a current sensor, a current trnasformer (CT), a shunt resistor, or the like may be used. have. For example, one end of the shunt resistor may be connected to three lower arm switching elements S'a, S'b, and S'c of the inverter 130, respectively.

The detected output current i _o , as a discrete signal in the form of a pulse, may be applied to the controller 120, and based on the detected output current i _o , to estimate the input current. Can be used. In addition, the detected output current i _o may be used to generate the inverter switching control signal S ₁ .

The controller 120 estimates the position of the motor 110, that is, the position of the rotor of the motor 110, based on the output current i _o detected by the output current detectors n ₂ , n ₃ , n ₄ . In addition, the rotation speed of the electric motor 110 can be calculated. In addition, based on the estimated position and rotation speed, various control operations are performed to drive the motor 110 according to the speed command, thereby generating and outputting an inverter switching control signal S ₁ having a variable pulse width. do.

In this way, the output current is detected without using a separate motor position detecting element or the like, the position and speed of the motor 110 are estimated according to the output current, and the feedback control is performed so that the estimated speed follows the speed command. This is called control by a sensorless algorithm.

The control operation by the sensorless algorithm, that is, the driving by the second driving step, is not performed at the initial startup of the motor 110, but is performed when the rotation speed of the motor 110 is greater than or equal to a predetermined value. It is possible.

In addition, the controller 120 controls the switching operation of the inverter 130. To this end, the controller 120 receives the output current i _o detected by the output current detector E, generates an inverter switching control signal S1, and outputs it to the inverter 130. The inverter switching control signal S1 may be a switching control signal for pulse width modulation (PWM).

A detailed operation of the output of the inverter switching control signal S1 in the controller 120 will be described later with reference to FIG. 3.

The controller 120 may also control the switching operation of the converter 140. To this end, the controller 120 may receive the dc terminal voltage Vdc detected by the dc terminal voltage detector B, generate a converter switching control signal S2, and output the converter switching control signal S2 to the converter 140. The converter switching control signal S2 may be a switching control signal for PWM.

In addition, the controller 120 may control a switching operation of the converter 140. To this end, the controller 120 may receive the dc terminal voltage Vdc detected by the dc terminal voltage detector B, generate a converter switching control signal S2, and output the converter switching control signal S2 to the converter 140. The converter switching control signal S2 may be a switching control signal for PWM.

In addition, the control unit 120, when the rotor of the motor 110 is interfered or constrained by the restraint factors such as the internal contact or the magnetic flux direction with the stator in the motor 110, the rotation Detects the restraint of the electrons and performs a restart operation to solve the restraint or deceleration of the rotor.

Hereinafter, the configuration of the control unit 120 will be described in detail.

5 is a diagram illustrating a configuration of the controller of FIG. 4. 6 is a view illustrating an output current input to an electric motor of a refrigerator according to the present embodiment, and FIG. 7 is a view illustrating an output current input to an electric motor of the refrigerator according to the present embodiment.

First, referring to FIG. 5, the controller 120 includes an estimator 121, a current command generator 122, a voltage command generator 124, a torque compensator 123, and a switching control signal output unit 125. ) And a comparator 126.

On the other hand, although not shown in the drawings, the three-phase output current (i _o ) may be further included an axis conversion unit for converting the d-axis, q-axis current or the d-axis, q-axis current to three-phase current.

The estimator 121 estimates the position information v of the rotor according to the phase of the electric angle or the mechanical angle based on the detected output current i _o . For example, the mechanical equations of the electric motor 110 and the electric equations may be compared with each other, whereby the positional information v of the rotor and the rotational speed of the electric motor 110 may be estimated. That is, by estimating the positional information v of the rotor, it is possible to estimate the rotational speed of the motor 110 in accordance with the positional change of the positional information v.

At this time, the rotational speed and position information v of the electric motor estimated by the estimating unit 121 are referred to as estimated position information v.

The electric angle or the mechanical angle of the electric motor 110 may be estimated using the position of the rotor. In general, the relationship between the mechanical angle and the electrical angle is such that the period of the mechanical angle is twice the number of poles of the electric motor 110 compared to the electrical angle.

Where θ _Me represents a mechanical angle and θ _e represents an electrical angle. For example, when the number of poles of the motor 110 is six poles, the relationship is θ _Me = 3θ _e , and when the number of poles of the motor 110 is four poles, the relationship is θ _Me = 2θ _e .

That is, when the number of poles of the motor 110 is six poles, three electric angles θ _e of 120-degree cycles correspond to each other within 360 degrees of the machine angle θ _Me , and the number of poles of the motor 110 is four poles. In this case, within the machine angle θ _Me 360 degrees, two electric angles θ _e of 180 ° periods correspond to each other.

In the sensorless control step, the current command generation unit 122 generates a current command value i ^* _d , i ^* _q based on the estimated rotation speed v2 and the speed command value v ^* .

For example, the current command generation unit 122 performs PI control on the basis of the difference between the estimated speed and the speed command value v ^* according to the estimated position information v, so that the current command value i ^* _d , i ^* _q ) can be generated. To this end, the current command generation unit 122 may include a PI controller (not shown). Further, a limiter (not shown) may be further provided to limit the level so that the current command value i ^* _d , i ^* _q does not exceed the allowable range.

Voltage command generation section 124 is a voltage command value based on the in sensorless control step, the detected output current (i _o) and the calculated current command value (i ^* _d, i ^* _q), (v ^* _d, v ^* _q) Create

For example, the voltage command generation unit 124 performs the PI control based on the difference between the detected output current i _o and the calculated current command value i ^* _d , i ^* _q to perform the voltage command value v. ^* _d , v ^* _q ) To this end, the voltage command generation unit 124 may include a PI controller (not shown). Further, a limiter (not shown) may be further provided to limit the level so that the voltage command value v ^* _d , v ^* _q does not exceed the allowable range.

The torque compensator 123 generates and outputs a compensation current command value i ^* _c according to the calculated maximum speed machine angle θ _M to compensate for the speed ripple during constant speed operation due to the load torque, thereby outputting the speed ripple. Ripple can be compensated.

On the other hand, the output current i _o is input to the comparator 126, and the comparator 126 compares the output current i _o and a reference current formed with a predetermined magnitude, and supplies a restart signal S3 to the current. The command generator 122 outputs the command.

Hereinafter, the configuration in which the comparator 126 compares the output current i _o and the reference current will be described in detail.

Referring to FIG. 6, the output currents i _s according to the present exemplary embodiment have a phase difference of a predetermined magnitude from each other, and the first to third phase output currents i _{o , 1} , and i _o according to three phases. _{, 2} , i _{o , 3} ).

As described above, the first, second and third phase output currents i _{o , 1} , i _{o , 2} , i _{o , 3} are sinusoidal and overlap each other by a certain area, i.e., a phase. It is supplied to the electric motor 110.

In addition, the controller 120 detects the first to third phase output currents i _{o , 1} , i _{o , 2} , i _{o , 3} from the first to third connection nodes n6, n7 and n8. .

Meanwhile, the first to third phase output currents i _{o , 1} , i _{o , 2} , i _{o , 3} are respectively supplied to the motor 110, and the first coil L1 and the second coil L2, respectively. ) And the first line, the second line and the third line are provided with a third coil (L3).

Next, referring to FIG. 7, first to third phase output currents i _{o , 1} , i _{o , 2} , i _o are respectively provided in the first line, the second line, and the third line of the motor 110. _{And 3} ) are supplied respectively.

The output current i _o supplied to any one of the first line, the second line, and the third line is output through two other lines, or the first line, the second line, and the third line. The output current i _o supplied through any two of the lines may be output through the other line.

Accordingly, the comparator 126 is configured such that the first, second, and third phase output currents i _{o , 1} , i _{o , 2} , i _{o , 3} according to the present embodiment are overlapped by a predetermined phase so that the motor ( According to the output current i _{o of} this embodiment supplied to 110, the first, second and third phase output currents i _{o , 1} , i _{o , 2} , i _{o , 3} and the The reference current is compared to determine whether the first to third lines are missing, and a restart signal S3 is output.

At this time, the imaging of the output current is a phase of a predetermined size is not formed during the driving process of the motor 110, it may be generated by a predetermined event inside or outside the motor driving device (100).

Hereinafter, when the imaging of the output current occurs, the input aspect of the output current will be described in detail.

8 and 9 are views showing an aspect in which an output current and an output current are input when an imaging occurs.

8 and 9, when an image is generated in an output current input to any one line of the motor 110 according to the present embodiment, for example, the first line, the first phase output current i _{o , 1} ) phase is not formed or flows, and the output current i _o is input or output only to the other two lines.

As shown in the present embodiment, in the state in which the output current i _{o of the} three phases is input, when an image is formed in one phase, the output currents of the other two phases are input to the line in a phase inverted phase, or the Is output from the line.

When the imaging occurs in the line, the torque generated by the motor 110 may be reduced, or rotational driving of the motor 110 may not be performed.

Hereinafter, a process of performing the restart mode of the motor 110 by determining whether the line is missing in the motor 110 will be described in detail.

10 is a flowchart illustrating a method of driving an electric motor of a refrigerator according to the present embodiment.

Referring to FIG. 10, it is determined whether the motor driving start signal is input (S100), and when the driving start signal is input, the control unit 120 based on the speed command v ^* and the output current i _o . The inverter 130 for driving the electric motor 110 is controlled (S200).

The control unit 120 controls the inverter 130 for driving the motor 110 based on the speed command v ^* and the output current i _o (S200) by the estimating unit of the control unit 120. 121, estimating the position of the rotor of the motor 110 based on the speed command v ^* and the output current i _o , and the control unit 120 estimates the position and speed command of the rotor. Based on (v ^* ), it may be a sensorless drive including controlling the inverter 130.

Next, the controller 120 determines which of the plurality of lines provided in the motor 110 is missing based on the output current i _o .

In detail, the controller 120 detects an output current i _o of each phase input to the first to third lines of the motor 110 (S300).

The controller 120 compares the magnitudes of the detected first, second, and third phase output currents i _{o , 1} , i _{o , 2} , i _{o , 3} with the magnitudes of the reference currents.

Then, the control unit 120 of the first-phase, second-phase and third-phase output current (i _{o, 1,} i _{o, 2,} i _{o, 3)} any one of the output current (i _o) of an output When the magnitude of the current i _o is smaller than the magnitude of the reference current, it is determined that any one line corresponding to the output current i _{o is} formed (S400).

At this time, the control part 120 includes a first phase, second phase and third-phase output current (i _{o, 1,} i _{o, 2,} i _{o, 3)} any one of the output current (i _o) of an output From the time when the magnitude of the current i _o is smaller than the magnitude of the reference current, the magnitude of the output current i _o of one phase is smaller than the magnitude of the first reference current, and the output current i of the other two phases. _When the state in which the sum of the magnitudes of _o ) is smaller than the magnitude of the second reference current lasts for a reference time of a predetermined magnitude, it is determined that the output current i _o that is smaller than the reference current is formed. do.

That is, when the output current i _{o , 1 of} the first phase is imaged, the output current output current i _{o , 1 of} the first phase is formed to be equal to or less than the first reference current value. As the output current i _{o , 1 of} the first phase is phased, for example, the second phase output current i _{o , 2} input to the second line and the third phase output output from the third line. The sum of the currents i _{o , 3} is formed to be equal to or less than the second reference current value. In the first to third lines interconnected at one node, when the phase is not formed in the first line, the output current i _o is input to one of the other two lines, and the rest is performed. This is because it is output on one line.

In this case, the reference current value according to the present embodiment may be 0.05 A, for example, and the first reference time and the second reference time may be any one of a range of 50 ms to 1 s. For example, in the present embodiment, the first reference time and the second reference time are set to 70 ms.

If it is determined that the output current i _o input to the motor 110 is missing, the controller 120 controls the inverter 130 to drive the motor 110 in the restart mode (S500, S600, S700). ).

In more detail, when it is determined that the motor 110 is in an open phase, the control unit 120 blocks the operation of the motor 110, that is, stops the operation, and blocks the speed command (S500).

Next, it is determined whether a restart time of a predetermined size has elapsed (S600), and when the restart time has elapsed, the controller 120 controls the inverter 130 to operate the electric motor 110 in an initial driving mode. .

In this case, the restart time may be 120 seconds, for example.

In the initial driving mode, the control unit 120 supplies a DC current having a predetermined magnitude to the motor 110 such that the rotor of the motor 110 is aligned in an initial state, and then is fixed regardless of the speed command. Inverter 130 is controlled to rotate the rotor at a speed.

Next, it is determined whether the motor drive end signal is input (S800), and when the drive end signal is input, control is terminated. When the drive end signal is not input, the controller 120 receives the speed command (v). ^* ) And controlling the inverter 130 for driving the motor 110 based on the output current (i _o ) (S200).

On the other hand, in step S100 of determining whether the driving start signal is input, when the driving start signal is not input, the control ends.

In addition, when the magnitude of the output current i _o is smaller than the magnitude of the reference current, in operation S400, it is determined that any one line corresponding to the output current i _{o is} formed. When the magnitude of the output current i _o is greater than or equal to the magnitude of the reference current, a step (S800) of determining whether the motor driving stop signal is input is performed.

And, in step S600 of determining whether the reference time has elapsed, when the restart time has not elapsed, the control unit 120 stops the operation of the motor 110 and blocks the speed command. Perform (S500).

According to the proposed embodiment, while the refrigerator 1 is driven, the current supply state to the electric motor 110 of the compressor 10 is sensed so that the rotation state is abnormal, that is, the internal line of the electric motor 110. When the phase is temporarily lost, the restart state of the motor 110 may be performed to eliminate the phase loss.

In addition, the imaging state of the motor 110 can be detected by the current inside the motor, so that the physical configuration of the motor driving apparatus 100 can be simplified, and the manufacturing cost can be reduced.

1: refrigerator
10: Body
60: compressor
100: electric motor drive device
110: electric motor
120: control unit
130: inverter
140: converter

Claims (17)

In a refrigerator having a condenser, an evaporator, a compressor and an expansion valve,
A compression mechanism provided in the compressor, for compressing a refrigerant;
A motor for operating the compression mechanism, the stator and the rotor being rotated with respect to the stator, the output current including a plurality of phases being input and including a plurality of lines interconnected at a single node;
An inverter including a plurality of switching elements and outputting the output current of a predetermined frequency and a predetermined magnitude by a switching operation of the switching elements to drive the electric motor; And
Controlling the motor driving operation of the inverter, detecting the output current according to each phase input to each line, and the magnitude of the output current input to any one line is equal to or less than a predetermined first reference current. And when the sum of the output currents detected in other lines is equal to or less than a second reference current, determining that the output current is missing and performing the restart mode of the electric motor. The method of claim 1,
And a first reference current and a second reference current have the same magnitude. The method of claim 2,
And a magnitude of the first reference current and the second reference current is 0.05 A. 3. The method of claim 1,
The state in which the magnitude of the output current input to one line is equal to or less than a preset first reference current, and the sum of the output currents detected in other lines is equal to or less than a second reference current is maintained for a preset reference time. If it is, the refrigerator characterized in that it is determined that the output current is missing. The method of claim 4, wherein
The said reference time is a refrigerator in any one of the ranges of 50 ms or more and 1 s or less. The method of claim 1,
And the restart mode stops the motor for a preset restart time and then performs an initial driving mode for performing alignment of the rotor of the motor. The method of claim 1,
The output current includes three phases having different phase angles, and the plurality of lines include a first line, a second line, and a third line to which respective phases are input. The method of claim 1,
The control unit,
An estimator for estimating estimated position information of the rotor with respect to the stator of the motor, based on the output current input to the motor;
A current command generation unit that generates a current command value based on the estimated position information and the speed command;
A voltage command generator for generating a voltage command value based on the current command value and the output current; And
And a switching control signal output unit configured to generate the inverter switching control signal based on the voltage command value and output the generated inverter switching control signal to the inverter. The method of claim 1,
The output current of one of the plurality of phases included in the output current, wherein the output current of one of the phases overlaps with the output current of the other phase in at least a portion of the refrigerator, characterized in that input to the motor. A compressor for compressing a refrigerant for supplying cold air to the storage chamber, an electric motor having a stator and a rotor rotating about the stator, and an inverter for supplying an output current including a plurality of phases to the electric motor; And a control unit for controlling the inverter, wherein the electric motor is provided with a plurality of lines to which respective phases of the output current are input.
Controlling the inverter to drive the electric motor based on the speed command and the output current;
Detecting, by the control unit, the output current according to each phase input to each line;
The control unit, when the magnitude of the output current input to one line is equal to or less than the predetermined first reference current, the sum of the output current detected in the other lines is less than the second reference current, the output current is Determining that it is missing; And
And if the output current is determined to be missing, controlling the inverter to drive the electric motor in a restart mode. The method of claim 10,
In the step of the control unit determines that the output current is formed,
When the magnitude of the output current is equal to or less than a preset first reference current and the sum of the output currents detected in other lines is equal to or less than a second reference current is maintained for a reference time of a predetermined magnitude, And the control unit determines that the line corresponding to the output current of one of the phases is missing. The method of claim 11,
The reference time is a refrigeration control method, characterized in that any time in the range of 50 ms or more and 90 ms or less. The method of claim 10,
The control method of the refrigerator, characterized in that the magnitude of the first reference current and the second reference current is 0.05 A. The method of claim 10,
If it is determined that at least one line of the plurality of lines provided in the motor is missing, the step of controlling the inverter so that the motor is driven in the restart mode may include:
Controlling, by the controller, the inverter so that the operation of the motor is stopped for a restart time of a predetermined size; And
And controlling the inverter to operate in an initial driving mode in which the rotor and the stator of the electric motor are aligned after the restarting time has elapsed. The method of claim 14,
In the initial driving mode, the control unit supplies a DC current of a predetermined magnitude to the motor so that the rotor of the motor is aligned in an initial state, and rotates the rotor at a constant speed regardless of the speed command. The control method of the refrigerator characterized in that. The method of claim 10,
The controlling of the inverter supplying the output current to the motor according to the speed command and the output current input to the motor,
Estimating by the control unit estimating the position of the rotor of the electric motor based on the output current and the speed command; And
And controlling, by the controller, the inverter based on the estimated position of the rotor and the speed command. The method of claim 10,
The output current of any one of the plurality of phases included in the output current, the output current of any one of the phases overlapping the output current of the other phase in at least a portion of the control method of the refrigerator characterized in that it is input to the electric motor.

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