KR100533011B1 - Driving control apparatus and method for reciprocating compressor - Google Patents

Abstract

The present invention relates to an operation control apparatus and method for a reciprocating compressor, wherein a stroke deviation generated due to a motor constant deviation, a motor voltage and motor current detection deviation, an initial position deviation of a piston, and the like is generated at an inflection point of a gas spring constant value. By correcting on the basis of the stroke, the stroke can be controlled more precisely. To this end, the present invention provides a reciprocating compressor comprising: a current detector for detecting a current applied to the compressor; A voltage detector detecting a voltage applied to the compressor; A stroke estimator for estimating a stroke of the compressor based on the current output from the current detector and the voltage output from the voltage detector; A gas spring constant calculating unit configured to calculate a gas spring constant by performing a predetermined calculation process on the stroke estimation value output from the stroke estimating unit and the current of the current detecting unit; A gas spring constant inflection point detector for comparing the gas spring constant output from the gas spring constant calculating unit with previous gas spring constants and detecting a gas spring constant inflection point based on a comparison result; And a stroke command value determining unit that determines the stroke command value at the time when the gas spring constant inflection point detection signal is generated to be the final stroke command value of 'TDC = O'.

Description

Operation Control System and Method of Reciprocating Compressor {DRIVING CONTROL APPARATUS AND METHOD FOR RECIPROCATING COMPRESSOR}

The present invention relates to an operation control apparatus and method of a reciprocating compressor, and in particular, a stroke deviation generated due to a motor constant deviation, a motor voltage and motor current detection deviation, an initial position deviation of a piston, and the like is generated at an inflection point of a gas spring constant value. An operation control apparatus and method for a reciprocating compressor to be corrected based on the stroke.

In general, a reciprocating compressor (Reciprocating Compressor) is a piston in a cylinder reciprocating linearly in the inside of the cylinder to suck and compress the refrigerant gas and discharge, more specifically, according to the method of driving the piston (Recipro) method It can be divided into and linear method.

Recipro method combines the crankshaft with the rotary motor and piston with the crankshaft to convert the rotational force of the rotary motor into linear reciprocating motion, whereas the linear method is applied to the actuator of the linear motor. Directly connecting the piston to reciprocate the piston by the linear motion of the motor.

The present invention relates to a reciprocating compressor applying a linear system.

As described above, the linear reciprocating compressor does not have a crankshaft for converting rotational motion into linear motion and thus has low frictional loss, and thus, the compression efficiency is higher than that of a general compressor.

When the reciprocating compressor is used in a refrigerator or an air conditioner, the compression ratio of the reciprocating compressor may be varied by varying a voltage input to the reciprocating compressor, thereby freezing capacity. Can be controlled.

1 is a block diagram showing a configuration of an operation control apparatus of a conventional reciprocating compressor, and as shown therein, a current detection unit 4 for detecting a motor current applied to a motor; A voltage detector (3) for detecting a motor voltage applied to the motor; A stroke estimator (5) for estimating a stroke based on the detected motor current, motor voltage and motor parameters; A comparator (1) for comparing the stroke estimate value with the stroke command value and outputting a difference signal accordingly; In accordance with the difference signal, the controller 2 is configured to control the stroke by varying the voltage applied to the motor, and the operation of such a conventional apparatus will be described.

First, the current detector 4 detects a motor current applied to the motor, and the voltage detector 3 detects a motor voltage applied to the motor.

At this time, the stroke estimator 5 applies the motor current, the motor voltage, and the motor parameter to the following equation to calculate a stroke estimate, and then applies the stroke estimate to the comparator 1.

[Equation]

Where R: resistance

        L: Inductance

        α: motor constant

Accordingly, the comparator 1 compares the stroke estimate and the stroke command value and applies a difference signal to the controller 2 according to which the controller 2 varies the voltage applied to the motor to make a stroke. To control.

That is, as shown in Fig. 2, the controller 2 decreases the motor applied voltage when the stroke estimate is larger than the stroke command value, and increases the motor applied voltage when the stroke estimate is smaller than the stroke command value.

At this time, the above-mentioned reciprocating compressor performs stroke control by estimating the stroke by using the motor constant α, resistance R and inductance L. There is a problem that the error is large.

The present invention has been made in order to solve the above problems, the stroke deviation caused by the motor constant deviation, the motor voltage and motor current detection deviation, the initial position deviation of the piston, etc. stroke generated at the inflection point of the gas spring constant value It is an object of the present invention to provide an operation control apparatus and method for a reciprocating compressor capable of more precisely controlling a stroke by correcting the reference to.

In order to achieve the above object, the present invention provides a reciprocating compressor comprising: a current detector for detecting a current applied to the compressor; A voltage detector detecting a voltage applied to the compressor; A stroke estimator for estimating a stroke of the compressor based on the current output from the current detector and the voltage output from the voltage detector; A gas spring constant calculating unit configured to calculate a gas spring constant by performing a predetermined calculation process on the stroke estimation value output from the stroke estimating unit and the current of the current detecting unit; A gas spring constant inflection point detector for comparing the gas spring constant output from the gas spring constant calculating unit with previous gas spring constants and detecting a gas spring constant inflection point based on a comparison result; And a stroke command value determining unit that determines the stroke command value at the time when the gas spring constant inflection point detection signal is generated as a final stroke command value having 'TDC = O'.

According to an aspect of the present invention, there is provided a method of controlling a reciprocating compressor, the method including: detecting a voltage and a current of a motor currently driven, and estimating a stroke using the motor voltage and the motor current; Calculating a gas spring constant using the stroke estimate and the motor current, and then determining whether an inflection point of the gas spring constants has occurred; As a result of the determination, if the inflection point of the gas spring constant does not occur, the stroke command value is increased and the process is repeated. If the inflection point of the gas spring constant occurs, the stroke command value at the gas spring constant inflection point is determined as the final stroke command value. Characterized by performing as a process.

Hereinafter, with reference to the accompanying drawings, the operation and effects of the operation control apparatus and method of the reciprocating compressor according to the present invention will be described in detail.

First of all, the present invention focuses on the fact that the point where the inflection point of the gas spring constant occurs is a stroke with TDC = 0.

Figure 3 is a block diagram showing the configuration of an embodiment of the operation control device of the reciprocating compressor of the present invention.

As shown in Fig. 3, the present invention includes a current detecting unit 10 for detecting a current applied to the compressor L.comp; A voltage detector 20 detecting a voltage applied to the compressor L.comp; A stroke estimator (30) for estimating the stroke of the compressor (L.comp) based on the current output from the current detector (10) and the voltage output from the voltage detector (20); A gas spring constant calculator 40 for calculating a gas spring constant by a predetermined calculation process of the stroke estimate value output from the stroke estimator 30 and the current of the current detector 10; A gas spring constant inflection point detector (50) for comparing the gas spring constant output from the gas spring constant calculation unit (40) with previous gas spring constants and detecting a gas spring constant inflection point based on a comparison result; A stroke command value determining unit (60) for determining a stroke command value at the time when the gas spring constant inflection point detection signal is generated as a final stroke command value of 'TDC = O'; A comparator (70) for comparing the stroke estimated value output from the stroke estimating unit (30) with the stroke command value and outputting a difference value according thereto; The controller 80 controls the stroke by varying the voltage applied to the compressor (L.comp) according to the difference value output from the comparator 70.

7 is an operation flowchart of an embodiment of the operation control method of the reciprocating compressor of the present invention.

As shown in Fig. 7, the present invention provides a process (SP10) of setting, by a user, a stroke correction value which is a stroke distance of a piston desired by a user; Detecting the voltage and current of the motor currently driven, and estimating the stroke using the motor voltage and the motor current (SP11, SP12); Calculating a gas spring constant using the stroke estimate and the motor current, and then determining whether inflection points of the gas spring constants have occurred (SP13, SP14); If the inflection point of the gas spring constant does not occur, increasing the stroke command value, comparing the stroke command value with the stroke estimate value and increasing or decreasing the motor applied voltage based on the comparison result (SP15 to SP18); As a result of the determination, when an inflection point of the gas spring constant occurs, determining whether the stroke correction value is equal to '0' (SP19); As a result of the determination, if the stroke correction value is equal to '0', the stroke command value at the gas spring constant inflection point is determined as the final stroke command value. If the stroke command value is not equal to '0', the stroke correction value is subtracted from the current stroke command value. A process of determining the final stroke command value (SP20, SP21) is made, and this operation of the present invention will be described.

First, in the present invention, TDC is defined as the distance to the point where the piston is located at the bottom dead center with respect to the point where the piston is located at the top dead center of the discharge valve side.

First, the current detector 10 detects a current applied to the compressor L.comp, and the voltage detector 20 detects a voltage applied to the compressor L.comp.

At this time, the stroke estimator 30 estimates the stroke of the compressor L.comp based on the current output from the current detector 10 and the voltage output from the voltage detector 20, and the comparator 70 calculates the stroke of the compressor L.comp. The stroke command value is compared with the stroke estimate output from the stroke estimating unit 30, and a difference value corresponding thereto is applied to the controller 80. Accordingly, the controller 80 supplies the compressor L.comp according to the difference value. The stroke is controlled by varying the applied voltage.

On the other hand, the gas spring constant calculation unit 40 calculates the gas spring constant by a predetermined calculation process of the stroke estimation value output from the stroke estimating unit 30 and the current of the current detection unit 10 to obtain a gas spring constant inflection point detection unit 50 To apply.

The gas spring constant calculating unit 40 obtains a gas spring constant by the following equation.

[Equation]

Where I (jw) is the magnitude of current, X (jw) is the stroke magnitude, θ is the phase difference between current and stroke, α is the motor constant, k is the spring constant

Accordingly, the gas spring constant inflection point detection unit 50 compares the gas spring constant output from the gas spring constant calculation unit 40 with previous gas spring constants, and detects the gas spring constant inflection point based on the comparison result. That is, when the gas spring constant values change from the rising section to the falling section as shown in FIG. 5 or from the falling section to the rising section as shown in FIG. 4, the gas spring constant of the change point is detected as an inflection point.

Thereafter, the stroke command value determining unit 60 determines the stroke command value at the time when the gas spring constant inflection point detection signal is generated, the stroke command value of 'TDC = O', and at the stroke command value, the stroke correction value preset by the user. The subtracted value is determined as the final stroke command value and applied to the comparator 70.

In more detail, the present invention will be described with reference to FIG. 7. First, the user sets a stroke correction value which is the stroke distance of the piston desired by the user (SP10).

Here, the stroke correction value is a value to be subtracted based on TDC = 0 as a moving distance of the piston desired by the user, that is, TDC. For example, if the user sets the stroke correction value to '0.5 mm', A stroke command value of 15.5 mm is generated by subtracting 0.5 mm from the stroke command value 20 mm at TDC = 0.

next. The voltage and current of the currently driven motor are detected (SP11), and the stroke is estimated using the motor voltage and the motor current (SP12).

Next, the gas spring constant is calculated using the stroke estimate and the motor current (SP13), and then it is determined whether the inflection point of the gas spring constant has occurred (SP14), that is, the gas spring constant values are falling in the rising section. When changing to or from the falling section to the rising section, the gas spring constant of the change point is detected as the inflection point.

As a result of the determination (SP14), if the inflection point of the gas spring constant does not occur, the stroke command value is increased (SP15), and the stroke command value is compared with the stroke estimate (SP16), and the motor applied voltage is increased or decreased according to the comparison result. (SP17, SP18).

On the other hand, if the inflection point of the gas spring constant occurs, the determination result (SP14), it is determined whether the predetermined stroke correction value is equal to '0' (SP19).

As a result of the determination (SP19), if the stroke correction value is '0', the stroke command value at the gas spring constant inflection point is determined as the final stroke command value (SP21). If the stroke command value does not match with '0', the current stroke command value The stroke correction value is subtracted from to determine the final stroke command value (SP21).

The specific embodiments or examples made in the detailed description of the present invention are intended to clarify the technical contents of the present invention to the extent that they should not be construed as limited to these specific embodiments and should not be construed in consultation. Various changes can be made within the scope of.

As described in detail above, the present invention is to compensate for the stroke deviation caused by the motor constant deviation, the motor voltage and motor current detection deviation, the initial position deviation of the piston, and the like based on the stroke generated at the inflection point of the gas spring constant value. In addition, the stroke is more precisely controlled, thereby improving the operation efficiency of the compressor.

1 is a block diagram showing a configuration for a driving control apparatus of a conventional reciprocating compressor.

2 is a flowchart illustrating an operation control method of a conventional reciprocating compressor.

Figure 3 is a block diagram showing the configuration of the operation control device of the reciprocating compressor of the present invention.

FIG. 4 is a graph showing an inflection point detection mode when the gas spring constants are switched from a lowered state to a raised state in the gas spring constant inflection point detector in FIG. 3; FIG.

FIG. 5 is a graph showing an inflection point detection mode when the gas spring constants are switched from a rising state to a falling state in the gas spring constant inflection point detecting unit of FIG.

6 is a graph showing a state in which a stroke with TDC = 0 is detected at an inflection point of a gas spring constant.

7 is a flowchart illustrating an operation control method of the reciprocating compressor of the present invention.

***** Description of the symbols for the main parts of the drawings *****

10: current detector 20: voltage detector

30: stroke estimation unit 40: gas spring constant calculation unit

50: gas spring constant inflection point detection unit 60: stroke command value determination unit

70: comparator 80: controller

Claims (9)

In a reciprocating compressor, A current detector for detecting a current applied to the compressor; A voltage detector detecting a voltage applied to the compressor; A stroke estimator for estimating a stroke of the compressor based on the current output from the current detector and the voltage output from the voltage detector; A gas spring constant calculating unit configured to calculate a gas spring constant by performing a predetermined calculation process on the stroke estimation value output from the stroke estimating unit and the current of the current detecting unit; A gas spring constant inflection point detector for comparing the gas spring constant output from the gas spring constant calculating unit with previous gas spring constants and detecting a gas spring constant inflection point based on a comparison result; And a stroke command value determining unit which determines a stroke command value at the time when the gas spring constant inflection point detection signal is generated as a final stroke command value of 'TDC = O'. The operation control apparatus for a reciprocating compressor according to claim 1, wherein the gas spring constant calculating unit calculates a gas spring constant by the following equation. [Equation] Where I (jw) is the magnitude of current, X (jw) is the stroke magnitude, θ is the phase difference between current and stroke, α is the motor constant, k is the spring constant The gas spring constant inflection point detection unit, An operation control apparatus for a reciprocating compressor characterized by detecting the gas spring constant of the change point as an inflection point when the gas spring constant values change from the rising section to the falling section. The stroke command value determining unit according to claim 1, wherein A stroke command value of 'TDC = O' is determined when the gas spring constant inflection point detection signal is generated, and a value obtained by subtracting the stroke correction value preset by the user from the stroke command value is determined as the final stroke command value. Operation control apparatus of the reciprocating compressor, characterized in that. In the operation control method of a reciprocating compressor, Detecting a voltage and a current of a motor currently driven and estimating a stroke using the motor voltage and the motor current; Calculating a gas spring constant using the stroke estimate and the motor current, and then determining whether an inflection point of the gas spring constants has occurred; As a result of the determination, if the inflection point of the gas spring constant does not occur, the stroke command value is increased and the process is repeated. If the inflection point of the gas spring constant occurs, the stroke command value at the gas spring constant inflection point is determined as the final stroke command value. Operation control method of the reciprocating compressor, characterized in that performed in the process. The method of claim 5, further comprising the step of presetting, by the user, a stroke correction value which is the stroke distance of the piston desired by the user. The operation control method for a reciprocating compressor according to claim 5, wherein the gas spring constant is calculated by the following equation. [Equation] Where I (jw) is the magnitude of current, X (jw) is the stroke magnitude, θ is the phase difference between current and stroke, α is the motor constant, k is the spring constant The process of claim 5, wherein when the inflection point of the gas spring constant occurs, the process of determining the stroke command value at the gas spring constant inflection point as the final stroke command value is performed. And if the stroke correction value preset by the user is present, subtracting the stroke correction value from the current stroke command value to determine the final stroke command value. The method of claim 5, wherein after calculating a gas spring constant using the stroke estimate and the motor current, determining whether an inflection point of the gas spring constants is generated. When the gas spring constant values change from the rising section to the falling section or from the falling section to the rising section, the operation control of the reciprocating compressor comprising detecting the gas spring constant of the change point as an inflection point. Way.