KR20030071466A - Apparatus for controlling linear compressor and method thereof - Google Patents

Abstract

PURPOSE: An apparatus and a method are provided to achieve improved accuracy of control of operation of linear compressor by maintaining an optimum piston top clearance, while reducing power consumption. CONSTITUTION: An apparatus comprises a position sensor for detecting the position of a piston reciprocating within a cylinder of a compressor; and a compensation unit for compensating the output of the position sensor distorted by the internal temperature of the compressor and fluctuation of load. The compensation unit includes a temperature detection part(31) for detecting the internal temperature of the compressor; a resonance point travel detection part(32) for detecting the travel of the resonance point of the piston caused due to the fluctuation of load; a position calculation part(33) for compensating the maximum stroke of the piston detected by the position sensor in accordance with the internal temperature of the compressor and travel of the resonance point of the piston; and a command calculation part(35) for outputting a command for driving the compressor in accordance with the maximum stroke compensated by the position calculation part.

Description

Control device and control method of linear compressor {APPARATUS FOR CONTROLLING LINEAR COMPRESSOR AND METHOD THEREOF}

The present invention relates to a control apparatus and a control method of a linear compressor for compensating the output of the position sensor for detecting the position of the piston.

1 is a block diagram illustrating a control apparatus of a conventional linear compressor.

Referring to FIG. 1, a core 10 of a magnetic material that operates in conjunction with a mechanism (a piston in a compressor) to detect a position, a first coil 12 and a first coil 12 symmetrically wound on an outer side of the core 10. It consists of two coils 13 and a signal processor 20 for detecting and outputting a position change of the core 10 in accordance with voltages induced in the first coil 12 and the second coil 13.

The signal processing unit 20 includes a first rectifying unit 21 for full-wave rectifying a voltage induced in the first coil 12 and a second rectifying unit 22 for full-wave rectifying a voltage induced in the second coil 13. And a differential amplifier 23 for amplifying the difference between the full-wave rectified voltages by the first rectifier 21 and the second rectifier 22, and a filter unit for removing high frequency components from the output signal of the differential amplifier 23. And a peak detector 25 for detecting the highest and lowest values of the signals output from the filter unit 24 and transmitting them to the microcomputer 30.

Operation according to the conventional configuration described above is as follows.

The position of the core 10 is changed by the positional change of the mechanism to detect the position in the state where the AC power source AC having a frequency of several kHz from the outside is applied to the first coil 12 and the second coil 13. When fluctuating, a voltage proportional to the positional change of the core 10 is induced in the first coil 12 and the second coil 13. Voltages respectively induced in the first coil 12 and the second coil 13 are full-wave rectified by the first rectifying unit 21 and the second rectifying unit 22 and input to the input terminals of the differential amplifier 23, respectively.

The differential amplifier 23 amplifies the difference between the full-wave rectified voltage by the first full-wave rectifier 21 and the second full-wave rectifier 22 and outputs the difference to the filter unit 24. The filter unit 24 removes and amplifies high frequency components from the output signal of the differential amplifier 23 and outputs the amplified components to the peak detector 25. The peak detector 25 detects the peak, i.e., the maximum stroke, of the signal output from the filter unit 24 and outputs it to the microcomputer 26. The microcomputer 26 controls the stroke of the linear compressor according to the maximum stroke.

In the prior art, the output control of the linear compressor is controlled depending on the voltage value detected by the first coil 12 and the second coil 13 to control the position of the piston. However, as the resistance of the coil increases with temperature, the output value increases. In addition, the center of the piston resonance point is moved in accordance with the load fluctuations, the output decreases when moving away from the valve as compared to the initial assembly position, and the output increases when near.

That is, the first coil 12 and the second coil 13 serve to detect the position of the piston, and the output voltage varies according to the internal temperature of the compressor. In addition, when the load changes unstable, the output voltage changes as the center of the piston resonance point moves.

As such, when controlling the position of the piston with the detection signal of the conventional sensor, as the center of the resonance point due to the internal temperature of the compressor or the load fluctuation is moved, the sensor output at the same top clearance is distorted, thereby providing the optimum top clearance. I can't keep it. In the worst case, an abnormality such as a piston of the compressor colliding with the valve is caused.

In order to avoid such a piston collision, if the top clearance is set to be larger, the compressor is required to increase the size of the compressor as the top clearance is increased so that the cooling force (output) of the desired size can be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control apparatus and a control method of a linear compressor that can compensate for a sensor output that is distorted by a compressor internal temperature or a load change.

1 is a block diagram illustrating a control apparatus of a conventional linear compressor.

2 is a block diagram illustrating a control device of a linear compressor according to the present invention.

3 is a circuit diagram when the position of the piston is detected by receiving AC power according to the present invention.

4 is a circuit diagram of detecting a compressor internal temperature by receiving a DC power supply according to the present invention.

5 is a circuit diagram of a resonance point movement detection unit according to the present invention.

6 is a view for explaining the error of the sensor output according to the compressor internal temperature.

7 is a view for explaining a stroke compensated according to the amount of resonance point movement for each condition of the compressor.

8 is a flowchart for explaining a temperature detection routine according to the present invention.

9 is a flowchart for explaining a position calculation routine according to the present invention.

10 is a flowchart for explaining a load calculation routine according to the present invention.

11 is a block diagram of a control device of a linear compressor according to another embodiment of the present invention.

FIG. 12 is a diagram for describing an operation of compensating position information according to temperature information input by the command value calculating unit according to the modified example of FIG. 11.

Explanation of symbols on the main parts of the drawings

31: temperature detector 32: resonance point movement detector

33: position calculation unit 34: load calculation unit

35: Command value calculation unit 35: Compressor drive unit

37: linear compressor

In order to achieve the above object, the present invention provides a control apparatus of a linear compressor, comprising: a position sensor for detecting a position of a piston reciprocating in a cylinder of the compressor; And a compensator for compensating the output of the position sensor distorted by the variation of the internal temperature and the load of the compressor.

The present invention for achieving the above object is a control method of a linear compressor having a position sensor for detecting the position of the piston of the compressor, supplying AC power to the position sensor and the output of the position sensor according to the output of the position sensor Detecting a position and detecting a load according to the detected position of the piston; Supplying DC power to the position sensor and detecting an internal temperature of the compressor according to the output of the position sensor; And compensating for the output of the position sensor according to the detected compressor internal temperature and load.

According to an aspect of the present invention, there is provided a method of controlling a linear compressor having a position sensor for detecting a position of a piston of a compressor, the method comprising: detecting an internal temperature of the compressor; Detecting a movement amount of the piston resonance point; Compensating for the maximum stroke of the piston detected by the position sensor according to the compressor internal temperature and the piston resonance point movement amount; And driving the compressor in accordance with the maximum stroke to be compensated for.

In order to achieve the above object, the present invention provides a control apparatus of a linear compressor, comprising: a position sensor for detecting a position of a piston reciprocating in a cylinder of the compressor; A power supply unit supplying driving power to the position sensor; And a compensator for compensating the output of the position detector, which is distorted by the internal temperature of the compressor.

In order to achieve the above object, the present invention provides a control apparatus of a linear compressor, comprising: a position sensor for detecting a position of a piston reciprocating in a cylinder of the compressor; A power supply unit supplying driving power to the position sensor; And a compensator for calculating the piston resonance point movement amount and the load from the position of the piston and compensating the output of the position sensor which is distorted according to the calculated load.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings, where the first embodiment compensates in consideration of both the compressor internal temperature and the load, and the second embodiment compensates in consideration of the compressor internal temperature. Explain.

[First Embodiment]

FIG. 2 is a block diagram illustrating the control apparatus of the linear compressor according to the present invention, and the same components performing the same functions as in the related art will be described with reference to the same reference numerals.

Referring to FIG. 2, a control apparatus of a linear compressor according to the present invention includes a core 10 of a magnetic material operating in conjunction with a mechanism for detecting a position, and a first symmetrically wound on an outer side of the core 10. A position sensor including a coil 12 and a second coil 13 is provided.

The position detecting unit 20 includes a first rectifying unit 21 for full-wave rectifying a voltage induced in the first coil 12, a second rectifying unit 22 for full-wave rectifying a voltage induced in the second coil 13, and A differential amplifier 23 for amplifying the difference between the full-wave rectified voltages by the first rectifier 21 and the second rectifier 22, and a filter for removing high frequency components from the output signal of the differential amplifier 23 ( 24) and a peak detection section 25 for detecting the maximum stroke from the signal output from the filter section 24.

The control apparatus of the linear compressor according to the present invention includes a compensation means 30 for compensating for the output distortion of the position sensor according to the compressor internal temperature and the load fluctuation.

The compensation means includes a temperature detector 30, a resonance point movement detector 32, a position calculator 33, a load calculator 33 and a command value calculator 35.

The power supply unit 14 serves to selectively supply AC power for detecting the position of the piston or DC power for detecting the internal temperature of the compressor. The power supply unit 14 supplies any one of AC power and DC power by the command of the temperature detector 31.

The temperature detector 31 determines a change in the load according to the resonance point movement change rate (△ resonance point movement data), and when the load is unstable, provides an AC supply command to the power supply unit 14 and the power supply unit 14 as shown in FIG. 3. ) Supplies AC power, and provides a DC supply command to the power supply unit 14 when the load is stable, and the power supply unit 14 supplies DC power as shown in FIG. 4.

The case of supplying AC power from the power supply unit 14 may be represented by the circuit of FIG. 3. AC power supply Vac is supplied to both ends of the first coil 12 and the second coil 13. As the inductance L1 of the first coil 12 and the inductance L2 of the second coil 13 change due to the positional change of the core 10 interlocking with the piston, a voltage proportional to the resistances R1, Output is via R2), rectifier diode (D1), and capacitor (C). The output voltage is induced in the first coil 12 and the second coil 13, and the induced voltage is information for detecting the position of the piston. The first rectifier 21, the second rectifier 22, and the temperature detector Provided at 31.

Modeling a case in which the DC power supply is supplied from the power supply unit 14 may be represented by the circuit of FIG. 4. DC power supply Vdc is supplied to both ends of the first coil 12 and the second coil 13. As the inductance L1 of the first coil 12 and the inductance L2 of the second coil 13 change according to the compressor temperature (compressor internal temperature), a voltage proportional thereto is rectified with the resistors R1 and R2. It is output through the diode D1 and the capacitor C. That is, the output voltage is induced in the first coil 12 and the second coil 13, and the induced voltage is the first rectifier 12, the second rectifier 13, and the temperature detector as information for detecting the compressor temperature. Are provided at 31.

The temperature detector 31 digitally converts a temperature detection signal corresponding to the provided induced voltage and outputs the converted temperature data to the position calculator 33.

When AC power is supplied from the power supply unit 14, a voltage proportional to the positional change of the core 10 is induced to the first coil 12 and the second coil 13, and the induced voltage is supplied to the first rectifier 21. ) And the second rectifier 22 are full-wave rectified and input to the input terminal of the differential amplifier 23, and amplify the difference of the voltage input from the differential amplifier 23 to the filter unit 24. The filter unit 24 removes a high frequency component from the amplified output signal and outputs the high frequency component to the resonance point movement detector 32 and the peak detector 25. The peak detection unit 25 detects the maximum stroke of the piston and outputs the detected maximum stroke data to the position calculation unit 33.

5 is a circuit diagram of a resonance point movement detection unit, and includes an operational amplifier OP, resistors Ra, Rb, and Rc, and a capacitor Ca.

The resonance point movement detector 32 outputs the resonance point movement data indicating the state in which the center of the resonance point is moved from the signal provided from the filter unit 24 to the position calculator 33 and the load calculator 34.

As shown in FIG. 6, as the compressor internal temperature increases, the compensated sensor output S1, that is, the voltage induced in the first coil 12 and the second coil 13 appears larger than the uncompensated sensor output S2. . Therefore, the higher the compressor internal temperature, the greater the error of the sensor output, so it is necessary to cope with it.

As shown in Fig. 7, the compensated stroke according to the movement amount of the resonance point becomes large. Here, the difference between the suction pressure and the discharge pressure of the compressor has a relationship of G1> G2> G3> G4.

The position calculator 33 digitally converts the maximum stroke data obtained by digitally converting the maximum stroke calculated by the highest value and the lowest value of the signal output from the filter unit 24 and the temperature detection signal output from the temperature detection unit 31. The top clearance is compensated for using the temperature data and the resonance point movement data obtained by digitally converting the resonance point movement signal output from the resonance point movement detection unit 32, and the compensated top clearance information is output to the command value calculator 35.

The load calculator 34 outputs a command value determined according to the resonance point movement signal output from the resonance point movement detection unit 32 and a preset setting value to the command value calculator 35.

The command value calculator 35 outputs a drive signal for driving the linear compressor to the compressor driver 36 according to the top clearance output from the position calculator 33 and the command value output from the command value calculator 35.

The compressor driver 36 drives the linear compressor 37 according to the drive signal output from the command value calculator 35.

A control method of the linear compressor according to the present invention having the above configuration will be described.

8 is a temperature detection routine performed by the temperature detection unit. First, the temperature detector 31 calculates the resonance point movement change rate (Δ resonance point movement data) from the signal output from the circuit of FIG. 3 when AC power is supplied from the power supply unit 14 (S10). Here, the resonance change rate is calculated as follows.

△ resonance point movement data = previous resonance point movement data-current resonance point movement data

The temperature detector 31 determines whether the compressor start time counted using the first counter (not shown) has passed the set time A (S11), and moves the resonance point when the compressor start time has elapsed. It is determined whether the change rate (△ resonance point movement data) is smaller than the set change rate B (S12), and from this time, the time is counted using a second counter (not shown).

As a result of the determination in step S12, if the resonance point movement change rate is smaller than the set change rate B, it is determined whether the time counted using the second counter reaches the set time D (S13), and as a result, the time D is set. ), The DC power supply 14 provides a DC signal to the power supply 14 to supply DC power, and as the DC power is supplied, the first coil 12 and the second coil 13 are supplied. In operation S14, an operation of providing temperature detection data obtained by digitally converting a signal proportional to the voltage induced by the position calculation unit 33 to the position calculator 33 is performed.

When the compressor start time has not elapsed at the set time A in step S11, when the resonance point movement change rate (△ resonance point movement data) is not smaller than the set change rate B in step S12, and when the time is set in step S13 ( If it does not reach D), the AC signal is provided to the power supply unit 14 so that the AC power is supplied from the power supply unit 14.

9 is a position calculation routine performed by the position calculation unit. First, the position calculation unit 33 receives the temperature data from the temperature detector 31 and the resonance point movement data from the resonance point movement detector 32, and the peak detector 25 when the AC power is supplied from the power supply unit 14. Piston position information that is provided that is provided with the maximum stroke data (S20).

The position calculation unit 33 searches for the maximum stroke corresponding to the temperature data and the resonance point movement data in the look up table (S21), and compensates the maximum stroke compensated according to the searched maximum stroke, that is, the compressor internal temperature and the amount of movement of the resonance point. Is output to the command value calculator 35 (S22). This means that when the linear compressor is driven with the compensated maximum stroke, the error of the sensor output due to the internal temperature of the compressor and the amount of movement of the resonance point is corrected, which is semantically equivalent to compensating the error of the top clearance.

Since the linear compressor has superior characteristics as compared to the general AC motor in terms of varying the capacity, the linear compressor can appropriately vary the capacity of the linear compressor according to the load information calculated by the load calculation unit 34.

10 is a load calculation routine performed by the load calculation unit. First, the load calculation unit 34 determines whether the compressor start time has elapsed from the set time C (S30), and as a result of the determination, when the compressor start time has elapsed from the set time C, the resonance point movement information, that is, the resonance point movement detecting unit ( By comparing the resonance point movement data provided from 32) with the set value, a command value suitable for the load condition is determined and output to the command value calculator 35 (S31). As a result of the determination, the compressor start time has not passed the set time (C). In the case of initial operation of the compressor, the command value is determined for the normal load condition and output to the command value calculator 35 (S32).

In this way, the command value calculating section 35 generates a drive command for driving the compressor with the maximum stroke compensated from the position calculating section 33 and the command value determined according to the load information calculated by the load calculating section 34. 36).

Second Embodiment

In the first embodiment, the sensor output is compensated in consideration of the compressor internal temperature and the load amount, and AC power or DC power should be alternately supplied from the power supply according to the load condition.

However, if the supply cycle is short (for example, 120Hz), the process of compensating for temperature and load becomes complicated, and thus the implementation in hardware is limited. Accordingly, in an embodiment to be described later, in order to perform both a position detection operation of the piston and a detection operation of the internal temperature of the compressor, driving power in which a high frequency signal is superimposed on a DC voltage is supplied to the position sensor, and a high frequency is output from the signal output through the position sensor. After separating the signal and the direct current signal, the separated high frequency signal is used as the position detection signal and the separated direct current signal is used as the temperature detection signal to simultaneously take the position information and the temperature information.

11 is a block diagram of a control device of a linear compressor according to another embodiment of the present invention. The control apparatus of the linear compressor according to the present invention uses a method of superimposing a position detecting signal (a high frequency signal of several KHz or more) and a temperature detecting signal (constant DC voltage).

As shown in FIG. 11, the control apparatus of the linear compressor according to the present invention includes a high frequency signal generator 61, a DC voltage generator 63, and an adder 65 for supplying power to the position sensor 67. Equipped.

The position sensor 67 includes a core of a magnetic material and first and second coils symmetrically wound on an outer side of the core. Resistors R1 and R2 are connected to the position sensor 67, and are connected to the adder 65 through the resistor R1.

The high frequency signal generator 61 supplies a high frequency signal (several KHz) to the adder 65, and the DC voltage generator 63 supplies a constant DC voltage to the adder 65. The adder 65 superimposes a high frequency signal on a constant DC voltage, and this superimposed power is supplied to the position sensor 67.

One output via the position sensor 67 is input to the differential amplifier 69 via a rectifier 68. The differential amplifier 69 compares the sensor output signal rectified by the rectifier 68 with a preset reference value. As a result of the comparison, the difference signal between the two input signals is output to the low frequency filter 71. The signal passing through is used as location information. This position information is provided to the position calculation unit 79 via the peak detection unit 73 as a signal for detecting the position of the piston (for example, 60 Hz).

The other output passing through the position sensor 67 has a characteristic that the output value decreases when the ambient temperature rises, and is provided to the low frequency filter 75 for temperature detection, and the high frequency signal of the output value varies according to the position of the piston. do. Therefore, a low frequency filter 75 having a cut-off frequency of several Hz is used, and only the DC signal is separated using the low frequency filter 75. The separated signal is separated from the amplifier 77 for signal processing. After amplified to an appropriate level, the position calculation unit 79 provides the position information.

The position calculator 79 compensates the position information according to the received temperature information and provides the temperature compensated position information to the command value calculator 81. The command value calculator 81 digitally converts temperature-compensated position information and outputs a control signal for driving the compressor to the compressor driver 83 based on the digitally converted position information, whereby the compressor driver 83 A drive signal for driving the compressor is output to the compressor.

However, the location information increases as the temperature increases, while the temperature information decreases. In order to apply a method of adding position information to the temperature information amplified by the position calculating unit 79 and compensating the temperature information, the temperature information and the position information should have linearity.

Therefore, the modified example as shown in FIG. 12 is applied in case the temperature information and the position information do not have linearity.

FIG. 12 is a view for explaining an operation of compensating position information according to temperature information input by the command value calculating unit according to the present invention in FIG. 11.

12, the position detecting signal (high frequency signal of several KHz or more) generated by the high frequency signal generator 61 and the temperature detecting signal (constant DC voltage) generated by the DC voltage generator 63 are added ( The method of supplying to the position sensor 67 by overlapping at 65) is applied. One output of the position sensor 67 passes through the rectifier 68, the differential amplifier 69, the low frequency filter 71, and the peak detector 73, and is then provided to the command value calculator 81a as position information. The other output of the position sensor 67 passes through the low frequency filter 75 and is then provided to the command value calculator 81a as temperature information.

The command value calculation unit 81a digitally converts the received position information and temperature information, and compensates the position information according to the digitally converted temperature information. In order to compensate for the temperature information and the position information having a nonlinear relationship in advance, Use the created look up table. The temperature compensated position information is provided to the compressor driver 83, and the compressor driver 83 outputs a drive signal for driving the compressor to the compressor.

Although not mentioned in the above embodiment, the output of the position sensor may be compensated for by considering only load variation, which will be easily understood by those skilled in the art from the first embodiment.

As described above, the present invention compensates the distortion of the sensor output as the center of the resonance point according to the internal temperature of the compressor and the load fluctuation in driving the linear compressor in accordance with the position of the piston can be controlled with the optimum top clearance to control the control accuracy. Can be improved. In addition, since the capacity of the compressor is appropriately changed based on the load information obtained according to the resonance point movement data, it is possible to actively cope with load fluctuations on its own, thereby reducing power consumption.

Also, the present invention superimposes a high frequency signal and a DC voltage and supplies the position sensor and separates the high frequency signal and the DC signal from the output of the position sensor, and then separates the separated high frequency signal and the DC signal into the position detection signal and the temperature detection signal, respectively. By doing so, position detection and temperature detection can be performed simultaneously, and the hardware can be easily implemented.

Claims (17)

In the control device of the linear compressor, A position sensor for detecting a position of a piston reciprocating in the cylinder of the compressor; And And a compensator for compensating the output of the position sensor distorted by a change in the internal temperature and the load of the compressor. The method of claim 1, The position sensor detects the position of the piston when AC power is supplied, and the control device of the linear compressor, characterized in that for detecting the internal temperature of the compressor when DC power is supplied. The method of claim 2, And a power supply for supplying AC power or DC power to the position sensor. The method of claim 3, And the power supply unit supplies AC power to the position sensor when the load is unstable and supplies DC power to the position sensor when the load is stable. The method of claim 1, The compensator includes a temperature detector for detecting the internal temperature of the compressor, a resonant point moving detector for detecting a displacement amount of the piston resonance point according to a load change, and a piston detected by the position sensor according to the compressor internal temperature and the piston resonant point movement amount. And a command value calculating unit for outputting a driving command for driving the compressor according to the maximum stroke compensated by the position calculating unit. The method of claim 5, The compensation unit further comprises a load calculation unit for calculating a load amount according to the resonance point movement amount of the piston, the command value calculation unit driving the compressor in consideration of the calculated load amount. In the control method of the linear compressor having a position sensor for detecting the position of the piston of the compressor, Supplying AC power to the position sensor, detecting a position of the piston according to the output of the position sensor, and detecting a load according to the detected position of the piston; Supplying DC power to the position sensor and detecting an internal temperature of the compressor according to the output of the position sensor; And Compensating the output of the position sensor according to the detected compressor internal temperature and load. The method of claim 7, wherein And counting the compressor starting time and detecting the internal temperature of the compressor when the counted starting time elapses. In the control method of the linear compressor having a position sensor for detecting the position of the piston of the compressor, Detecting an internal temperature of the compressor; Detecting a movement amount of the piston resonance point; Compensating for the maximum stroke of the piston detected by the position sensor according to the compressor internal temperature and the piston resonance point movement amount; And Driving the compressor according to the maximum stroke being compensated for. In the control device of the linear compressor, A position sensor for detecting a position of a piston reciprocating in the cylinder of the compressor; A power supply unit supplying driving power to the position sensor; And And a compensator for compensating the output of the position detector, which is distorted by the internal temperature of the compressor. The method of claim 10, The power supply control unit of the linear compressor, characterized in that for supplying a drive power made by superimposing a high-frequency signal for detecting the position of the piston and a DC voltage for detecting the internal temperature of the compressor. The method of claim 11, The power supply unit includes a high frequency signal generator for generating a high frequency signal, a DC voltage generator for generating a DC voltage having a predetermined magnitude, and an adder for superimposing the high frequency signal on the DC voltage. Control device. The method of claim 10, The compensator includes a low frequency filter for removing a high frequency signal from the output of the position sensor, the control device of the linear compressor, characterized in that for compensating using a signal from which the high frequency signal is removed by the low frequency filter. The method of claim 13, The compensating unit amplifies the temperature information after the temperature information from which the high frequency signal is removed by the low frequency filter and the position information obtained from the output of the position sensor is linear, and then compensates the position information; And a command value calculation unit for outputting a drive signal for driving the compressor according to the position information compensated by the unit. The method of claim 13, When the temperature information from which the high frequency signal is removed by the low frequency filter and the position information obtained from the output of the position sensor have nonlinearity, the compensator receives the temperature information and the position information, respectively, and uses the prepared lookup table. And a command value calculator for compensating the position information according to the position information and outputting a driving signal for driving the compressor according to the compensated position information. In the control device of the linear compressor, A position sensor for detecting a position of a piston reciprocating in the cylinder of the compressor; A power supply unit supplying driving power to the position sensor; And And a compensation unit for calculating a piston resonance point movement amount and a load from the position of the piston and compensating an output of the position sensor which is distorted according to the calculated load. The method of claim 16, The power supply control unit of the linear compressor, characterized in that for supplying AC power to the position sensor.