KR20000040144A - Device and method for controlling sensorless peak of stroke and speed of linear compressor - Google Patents

Abstract

PURPOSE: A device and a method of sensorless peak control of the stroke and speed of a linear compressor is provided to reduce basic deviation due to a resistance and a capacitor by processing strokes by software and to reduce the price of a device. CONSTITUTION: 220V of power supply voltage is supplied from a power supply voltage terminal. The voltage is supplied to a linear compressor(L.COMP) via a resistance(R) for sensing current, a switch(SW), and a capacitor of an electric circuit part(10). A piston of the linear compressor reciprocates. The distance of the reciprocating stroke of the piston is stroke variable for varying cooling power of an air conditioner or a refrigerator. A current detection part(20) detects current supplied to the linear compressor via the resistance and provides the detected current to a speed calculating part(50) and a current differentiator(30). The current differentiator gains current differentiated value by performing differentiation of the detected current and provides the differentiated value to the speed calculating part. The speed calculating part receives the input of the current and voltage gained in the current detection part, and a voltage detection par(50) and the current differentiated value and calculates speed(v).

Description

Stroke and speed sensorless peak control device and method of linear compressor

In the present invention, the stroke of the linear compressor is designed to process the speed and the stroke calculation by software in the stroke sensorless method, thereby eliminating the use of many resistors and capacitors, thereby reducing the initial driving deviation and the driving deviation caused by temperature, and reducing the price. And a speed sensorless peak control device and method, in particular, the current derivative is processed by hardware and the remainder is processed by software to eliminate the large error of the current derivative and to enable accurate stroke calculation. A sensorless peak control device and method are disclosed.

1 is a block diagram of a stroke control apparatus of a conventional linear compressor. As shown in FIG. 1, a linear compressor (L.COMP) for adjusting a cooling force by varying a stroke by vertical movement of a piston, and an AC according to a switching signal. An electric circuit unit 10 for controlling a power applied to the linear compressor L.COMP by intermitting a power supply, a current detection unit 20 for detecting a current applied to the linear compressor L.COMP, and the current Of the current differentiator 30 for differentiating the current detected by the detector 20, the voltage detector 40 for detecting the voltage between both ends of the linear compressor L.COMP, and the linear compressor L.COMP. A speed calculator 50 for calculating the speed by receiving the voltage between the two ends, the detected current and the current differential value, and a stroke for calculating the stroke value from the calculated speed and outputting the calculated stroke value Computation unit 60, the stroke peak detection unit 70 for detecting the peak value of the stroke calculated by the stroke calculation unit 60, the stroke peak value detected by the stroke peak detection unit 70 and the stroke command value is compared to the stroke The microcomputer 80 is configured to supply a switching signal for controlling top dead center to the switch element SW of the electric circuit unit 10.

Referring to the prior art configured as described above in detail.

When the 220V power supply voltage is supplied from the power supply voltage terminal, the power supply voltage is supplied to the linear compressor (L.COMP) through the current sensing resistor (R), the switch element (SW), and the capacitor (C) of the electric circuit unit 10. Supplied.

Accordingly, a current flows in the linear compressor L.COMP.

Then, the piston of the linear compressor L.COMP performs a reciprocating motion. The reciprocating stroke distance of the piston is a stroke, and the stroke is varied to vary the cooling force.

That is, to adjust the cold power of the refrigerator or air conditioner.

At this time, the current detector 20 detects the current supplied to the linear compressor L.COMP through the current sensing resistor R, and provides the current to the current differentiator 30 and the speed calculator 50.

Then, the current differentiator 30 performs a differential operation on the detected current to obtain a current differential value.

The voltage detector 40 detects a voltage between both ends when driving the linear compressor (L.COMP).

Accordingly, the speed calculator 50 receives the current and voltage obtained by the current and voltage detectors 20 and 40 and the current derivatives obtained by the current differentiator 30, respectively, and calculates the speed υ as follows.

Where α is a constant value that converts an electrical force into a mechanical force, V _M Is the voltage between both ends of the linear compressor, R _ac Is the body resistance in the compressor, i: inrush current.

When the speed calculation unit 50 obtains the speed υ as in Equation (1) and provides it to the stroke calculation unit 60, the stroke calculation unit 60 calculates the speed calculation unit 60. Takes the speed υ and integrates the stroke ( x Find)).

In other words,

The stroke obtained by integrating the velocity values x ) Is provided to the stroke peak detection unit 60, the stroke peak detection unit 60 receives the stroke calculated by the stroke calculation unit 60, obtains the peak value of the stroke, and provides it to the microcomputer 80.

Then, the microcomputer 80 adjusts the voltage applied to the linear compressor L.COMP by adjusting the turn on time and the turn off time of the switch SW of the electric circuit unit 10 using a stroke top dead center control algorithm. .

That is, when the stroke peak value detected by the said stroke peak detection part 70 is input, the microcomputer 80 compares with a stroke command value.

As a result of comparison, when the stroke peak value is larger than the stroke command value, a switching signal for reducing the turn-on time of the switch SW of the electric circuit unit 10 is supplied to the switch element SW of the electric circuit unit 10.

Accordingly, the switch SW is turned off to cut off the voltage applied to the linear compressor L.COMP.

In this way, the speed of the linear compressor L.COMP is reduced.

On the contrary, when the stroke peak value is smaller than the stroke command value, a switching signal for increasing the turn-on time of the switch element SW of the electric circuit unit 10 is output to the switch element SW of the electric circuit unit 10.

Then, the switch element SW is turned on to increase the voltage applied to the linear compressor L.COMP to increase the speed of the compressor.

In this way, the stroke top dead center is adjusted by controlling the voltage supplied to the linear compressor (L.COMP).

However, in the prior art as described above, implementing a circuit for speed calculation and stroke calculation in hardware requires a large number of resistors and capacitors, which have not only a basic deviation but also a function of temperature as a temperature function. As a result, accurate calculations cannot be made due to many influences, and thus, a price increases due to the need for many resistors and capacitors.

Therefore, an object of the present invention for solving the conventional problems as described above is to process the stroke calculation by software to reduce the basic deviation due to resistance and capacitor, and also to reduce the price of the linear compressor stroke and speed sensorless The present invention provides a peak control apparatus and method.

It is another object of the present invention to provide a stroke and speed sensorless peak control device and method for a linear compressor that reduces the basic deviation and lowers the price by software-processing not only the stroke calculation but also the speed calculation.

It is still another object of the present invention to provide a linear compressor stroke and speed sensorless peak control apparatus and method for eliminating a large error in current differential, which is a disadvantage of pulley digital, by processing only current differential in hardware.

1 is a block diagram of a stroke control device of a conventional linear compressor.

Figure 2 is a block diagram of a stroke sensorless peak control device of the linear compressor of the present invention.

3 is an operation flowchart for a stroke sensorless peak control method of the linear compressor of the present invention.

Figure 4 is a block diagram of a speed sensorless peak control device of the linear compressor of the present invention.

5 is an operation flowchart of a speed sensorless peak control method of the linear compressor according to the present invention;

*** Explanation of symbols for main parts of drawing ***

10: electric circuit unit 20: current detection unit

30: current differential 40: voltage detector

50: speed calculation unit 60: stroke calculation unit

70 stroke stroke detection unit 80 microcomputer

The present invention for achieving the above object is a linear compressor for controlling the cooling force by varying the stroke by the vertical movement of the piston, an electric circuit unit for controlling the power applied to the linear compressor by intermittent AC power in accordance with the switching signal, and A current detector for detecting a current applied to the linear compressor, a current differential to differentiate the current detected through the current detector, a voltage detector for detecting a voltage between both ends of the linear compressor, a voltage between both ends of the linear compressor, Speed calculation unit that calculates speed by inputting detection current and current differential value, and calculates and detects stroke and stroke peak value by inputting speed calculated above and controls stroke top dead center by comparing with stroke command value Consisting of microcomputers for Gong.

In addition, the present invention is a linear compressor for controlling the cooling force by varying the stroke by the vertical movement of the piston, an electric circuit unit for controlling the power applied to the linear compressor by intermittent AC power according to the switching signal, and applied to the linear compressor A current detector for detecting a current to be made; a current differential for differentiating a current detected through the current detector; a voltage detector for detecting a voltage between both ends of the linear compressor; a voltage between both ends of the linear compressor; It is characterized by comprising a microcomputer for controlling the stroke top dead center by receiving the current differential values and calculating the speed and stroke by software, detecting the peak values of the calculated strokes, and comparing them with the stroke command values.

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

2 is a block diagram of a speed sensorless peak control device of the linear compressor according to the present invention. As shown in FIG. 2, a linear compressor (L.COMP) for controlling a cooling force by varying a stroke by vertical movement of a piston, and switching is shown. According to the signal, the AC power is interrupted as the switch SW to control the electric power applied to the linear compressor L.COMP, and the current and voltage applied to the linear compressor L.COMP. The current and voltage detector 20 and 40 to detect, the current differential 30 to differentiate the current detected by the current detector 20, and the detection current / voltage and the current derivative to calculate the speed The speed calculation unit 50 receives the speed calculated above, calculates the stroke in software, detects the peak value of the calculated stroke, and compares the stroke with the stroke command value. And outputting a switching signal for controlling the voltage supplied to the switch element (SW) of the section 10 constitute a microcomputer 80 for controlling the stroke top dead center of the linear compressor.

4 is a block diagram of a stroke sensorless peak control device of the linear compressor according to the present invention. As shown in FIG. 4, a linear compressor (L.COMP) for controlling a cooling force by varying a stroke by vertical movement of a piston, and switching is shown. The electric circuit unit 10 which controls the power applied to the linear compressor L.COMP by intercepting the AC power with the switch SW according to the signal, and the current and current applied to the linear compressor L.COMP. Current / voltage detectors 20 and 40 to detect, current derivative 30 to obtain current differential values by differentiating the current detected by the current detector 20, and current / voltage and current supplied to the linear compressor. The electric circuit unit 10 receives the differential value by calculating the speed and the stroke by software, detects the peak value of the calculated stroke, and compares it with the stroke command value. Controlling on / off of the switch (SW) to constitute a microcomputer 80 for controlling the stroke top dead center.

Referring to the operation and effect of the present invention configured as described in detail as follows.

When the 220V power supply voltage is supplied from the power supply voltage terminal, the power supply voltage is supplied to the linear compressor (L.COMP) through the current sensing resistor (R), the switch (SW), and the capacitor (C) of the electric circuit unit 10. do.

Accordingly, a current flows in the linear compressor L.COMP.

Then, the piston of the linear compressor L.COMP performs a reciprocating motion. The reciprocating stroke distance of the piston is a stroke, and the stroke is varied to vary the cooling force.

That is, to adjust the cold power of the refrigerator or air conditioner.

At this time, the current detector 20 detects the current supplied to the linear compressor L.COMP through the current sensing resistor R and provides the current to the speed calculator 50 and the current differentiator 30.

Then, the current differentiator 30 performs a differential operation on the detected current to obtain a current differential value and provides it to the speed calculator 50.

The reason why the current derivative is processed by hardware rather than by software is that a large error may occur when the software is processed.

At this time, the voltage detector 40 detects the voltage between both ends when the linear compressor (L.COMP) is driven and provides the detected voltage to the speed calculator 50.

Accordingly, the speed calculator 50 receives the current and voltage obtained by the current and voltage detectors 20 and 40 and the current derivative obtained by differentiating from the current differentiator 30 and calculates the speed υ as follows. do.

Where α is a constant value that converts an electrical force into a mechanical force, V _M Is the voltage between both ends of the linear compressor, R _ac Is the body resistance in the compressor, i: inrush current.

The speed calculator 50 obtains the speed v as in Equation (1) and provides it to the microcomputer 80.

Then, the microcomputer 80 obtains a stroke in hardware and performs stroke top dead center control, which will be described below with reference to FIG. 3.

First, the microcomputer 80 receives the speed value υ input from the speed calculation unit 50 and integrates the speed value as described above to generate a stroke ( x Get)

However, if there is an offset error in the speed value before integrating the speed value, if the speed value including the offset error is integrated, the offset error continues to accumulate and the linear compressor may malfunction.

Therefore, in order to prevent a malfunction, the offset error is eliminated by resetting the stroke when the speed is maximum (or every cycle) (S31).

If the speed is not maximum, the speed value υ is integrated in software ( χ (k) ← χ (k-1) + υ (k) To obtain the stroke value χ (k) (S32).

In this way, if the stroke value χ (k) is obtained, the value for the predetermined value or more is removed (S33).

Stroke value obtained in the step S33 ( x (k)) is the maximum previously stored value ( χ _max (S34)

The stroke value (χ (k)) currently obtained is the maximum value previously stored ( χ _max Less than), the maximum previously stored value ( χ _max ), And the current stroke value χ (k) is the maximum value previously stored ( χ _max Is greater than), the current stroke value (χ (k)) is converted to the maximum value ( χ _max ← χ (k) (S35)

Then the maximum stroke value obtained so far ( χ _max ) And the stroke command value to be controlled (S36).

As a result of the comparison, the stroke maximum value ( χ _max Is larger than the stroke command value, a switching signal for turning off the switch element SW of the electric circuit unit 10 is generated and provided to the switch element SW.

Then, the switch device SW is turned off to cut off the voltage applied to the linear compressor L.COMP.

In this way, the switch element SW is cut off to reduce the voltage applied to the linear compressor L.COMP so that the stroke maximum value ( χ _max ) Follow the stroke command value.

In contrast, the stroke peak value ( χ _max Is smaller than the stroke command value, a switching signal for turning on the switch element SW of the electric circuit unit 10 is generated and provided to the switch element SW of the electric circuit unit 10.

Then, the switch device SW is turned on to continuously increase the voltage applied to the linear compressor L.COMP.

In this way, the voltage supplied to the linear compressor (L.COMP) is increased, χ _max ) Follow the stroke command value.

As a result, the present invention controls the stroke top dead center of the linear compressor by calculating the stroke in software when the speed value v calculated in hardware is input.

Therefore, when the stroke calculation unit is processed in hardware, the software can be processed without using many resistors and capacitors to reduce the driving deviation and reduce the number of elements to reduce the price.

Another embodiment will be described with reference to FIGS. 4 and 5 as follows.

When the 220V power supply voltage is supplied from the power supply voltage terminal, the power supply voltage is supplied to the linear compressor (L.COMP) through the current sensing resistor (R), the switch (SW), and the capacitor (C) of the electric circuit unit 10. do.

Accordingly, a current flows in the linear compressor L.COMP.

Then, the piston of the linear compressor L.COMP performs a reciprocating motion. The reciprocating stroke distance of the piston is a stroke, and the stroke is varied to vary the cooling force.

That is, to adjust the cold power of the refrigerator or air conditioner.

At this time, the current detection unit 20 detects the current supplied to the linear compressor (L.COMP) through the current sensing resistor (R) and provides it to the current differentiator 30 and the microcomputer 80, the voltage detection unit 40 Detects a voltage between both ends of the linear compressor (L.COMP) and provides the same to the microcomputer 80.

Then, the current differentiator 30 performs a differential operation on the detected current to obtain a current differential value and provide it to the microcomputer 80.

The reason why the current derivative is processed by hardware rather than by software is that a large error may occur when the software is processed.

Therefore, the microcomputer 80 receives the input current, voltage, and current derivative value through analog / digital conversion input terminals A / D, respectively, and converts them into digital data.

For example, analog / digital conversion input terminal (A / D) speed With current , Current derivative Read each of them (S51).

The speed (υ) is calculated by software by performing + and-operations on the read values. In other words, when υ = A-B-C, the speed is obtained.

finally Becomes

When the speed is obtained in software as described above, not only the error is small but also the calculation processing is easy.

In this way, the velocity υ is obtained and then the integral is applied to the velocity thus obtained. x (k)), the stroke ( x Before obtaining (k)), the offset error included in the speed value must be eliminated.

If the offset error is not eliminated, when the speed is integrated to obtain a stroke, the offset error continues to accumulate, and thus, the linear compressor is malfunctioned.

Therefore, in order to prevent a malfunction, the offset error is eliminated by resetting the stroke when the speed is maximum (or every cycle) (S53).

If the speed is not maximum, the speed value υ is integrated in software ( χ (k) ← χ (k-1) + υ (k) To obtain the stroke (χ (k)) (S54).

In this way, when the stroke χ (k) is obtained, the value for the predetermined value or more is removed (S55).

The stroke obtained in the step S33 ( x (k)) is the maximum previously stored value ( χ _max It is determined whether b) is large (S56).

Judgment shows that the current stroke (χ (k)) is the maximum value previously stored ( χ _max Less than), the maximum previously stored value ( χ _max ), And the current stroke (χ (k)) is the maximum value previously stored ( χ _max Greater than), converts the current stroke (χ (k)) to its maximum value ( χ _max ← χ (k) (S57)

Then the maximum stroke value obtained so far ( χ _max ) And stroke command value (S58).

As a result of the comparison, the stroke maximum value ( χ _max Is larger than the stroke command value, a switching signal for turning off the switch element SW of the electric circuit unit 10 is generated and provided to the switch element SW.

Then, the switch device SW is turned off to cut off the voltage applied to the linear compressor L.COMP.

In this way, the switch element SW is cut off to reduce the voltage applied to the linear compressor L.COMP so that the stroke maximum value ( χ _max ) Follow the stroke command value.

In contrast, the stroke peak value ( χ _max Is smaller than the stroke command value, a switching signal for turning on the switch element SW of the electric circuit unit 10 is generated and provided to the switch element SW of the electric circuit unit 10.

Then, the switch device SW is turned on to continuously increase the voltage applied to the linear compressor L.COMP.

In this way, the voltage supplied to the linear compressor (L.COMP) is increased, χ _max ) Follows the stroke command value (S59).

As a result, the present invention controls the stroke top dead center of the linear compressor by calculating the stroke in software when the speed value v calculated in hardware is input.

Therefore, when the stroke calculation unit is processed in hardware, the software can be processed without using many resistors and capacitors to reduce the driving deviation and reduce the number of elements to reduce the price.

In addition, by processing the current derivative in hardware, the disadvantage of the Fully Digital method can eliminate the large error of the current derivative and enable accurate stroke calculation.

Therefore, in the stroke sensorless method, the present invention calculates the speed in hardware, processes the stroke in software, processes the current derivative in hardware, and calculates the linear part by software in calculating the remaining part including the speed and the stroke. By controlling so as not to use many resistors and capacitors, it is possible to reduce the drive deviation caused by temperature including the initial driving deviation, to lower the price, and to calculate the correct stroke.

Claims (6)

An electric circuit section for controlling the power applied to the linear compressor by intermitting an AC power input to the switch element, a current / voltage detection section for detecting current and voltage applied to the linear compressor, and a current detected through the current detection section. In the stroke control device comprising a current differential to be differentiated, and a speed calculation unit for calculating the speed by receiving the detection current / voltage and the current differential value, receives the speed calculated by the speed calculation unit to calculate the stroke in software, And a microcomputer that detects the peak value of the calculated stroke and compares the stroke command value to be controlled and outputs a switching signal for controlling stroke top dead center to the electric circuit unit to adjust the voltage supplied to the linear compressor. Switch of linear compressor to make Lock sensor-less control apparatus peak. A first step of checking whether the speed is maximum when inputting the calculated speed value; a second step of resetting the stroke to remove the offset error if the speed is maximum; and if the speed is not maximum in the first step, A third step of calculating the stroke by integrating the speed, a fourth step of obtaining the peak value of the stroke calculated above, and an input supplied to the linear compressor according to the stroke peak value obtained above and the stroke command value to be controlled accordingly. A stroke sensorless peak control method for a linear compressor, comprising a fifth step of adjusting a stroke by controlling voltage. The method of claim 2, wherein the fifth step comprises: a first step of comparing the stroke peak value with the stroke command value; a second step of reducing the voltage supplied to the linear compressor when the stroke peak value is larger than the stroke command value; And a third step of controlling the stroke top dead center of the linear compressor by increasing the voltage supplied to the linear compressor when the stroke peak value is smaller than the stroke command value. 3. The method of claim 2, wherein the offset error elimination in the second step further comprises the step of resetting every cycle. An electric circuit section for controlling the power applied to the linear compressor by intermitting an AC power input to the switch element, a current / voltage detection section for detecting current and voltage applied to the linear compressor, and a current detected through the current detection section. In the stroke control device consisting of a current differentiator for differentiation, the voltage / current and the current differential value detected above are respectively input, and the speed and the stroke are calculated by software, and the peak value of the calculated stroke is detected and compared with the stroke command value. Speed sensorless peak control device of the linear compressor, characterized in that composed of a microcomputer for controlling the stroke top dead center. A first step of reading voltage, current, and current differential value calculated by hardware through the analog / digital input terminal to the linear compressor; and a second step of calculating speed by performing +,-operation on the read value And a third step of eliminating the offset error by resetting the stroke when the speed calculated above is maximum, and calculating the stroke by integrating the speed if the speed is not maximum, and obtaining a peak value of the calculated stroke. And a fifth step of adjusting the increase and decrease of the voltage supplied to the linear compressor by comparing the stroke peak value and the stroke command value obtained above, and outputting a switching signal according to the speed sensorless peak control method of the linear compressor. .