KR100690662B1 - Driving control apparatus for refrigerator for reciprocating compressor - Google Patents

Abstract

The present invention relates to an operation control apparatus and method for a reciprocating compressor, wherein a phase difference between a stroke and a current is obtained by using a motor voltage and a motor current, and a discharge valve of the reciprocating compressor is opened at an inflection point for the phase difference between the stroke and the current. By detecting the timing and automatically performing variable capacity operation in accordance with the load condition on the basis of the stroke at the time when the discharge valve is opened, the operation efficiency is improved. To this end, the present invention provides a reciprocating compressor comprising: a stroke estimator for estimating a stroke using a motor voltage and a motor current; A phase difference detector for detecting a phase difference between the stroke estimate and the current; A phase difference inflection point detector for detecting an inflection point with respect to the phase difference between the stroke estimate and the current; And a stroke command value converting portion for analyzing the phase difference inflection point detection signal output from the phase difference inflection point detecting unit and varying the stroke command value based on the analysis result.

Description

Operation control apparatus and method of reciprocating compressor {DRIVING CONTROL APPARATUS FOR REFRIGERATOR FOR RECIPROCATING COMPRESSOR}

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

Fig. 2 is a flow chart showing stroke control in Fig. 1;

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.

4 is a graph showing a relationship between a damping coefficient and a stroke in FIG.

5 is an operation flow chart for the operation control method of the reciprocating compressor of the present invention.

FIG. 6 is a graph showing a state in which a stroke correction value is determined according to a relationship between a load condition and a stroke in FIG. 5; FIG.

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

100: phase difference detection unit 200: phase difference inflection point detection unit

300: Stroke command value conversion part

The present invention relates to an operation control apparatus and method for a reciprocating compressor, and in particular, to obtain a phase difference between a stroke and a current by using a motor voltage and a motor current, and a discharge valve of the reciprocating compressor as an inflection point for the phase difference between the stroke and the current. The present invention relates to an operation control apparatus and method for a reciprocating compressor that detects a point in time at which is opened and automatically executes a variable capacity operation according to a load condition based on the stroke at the point in time at which the discharge valve is opened.

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]

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, when the stroke of the conventional reciprocating compressor described above, accurate stroke estimation and control is difficult due to motor constants and component errors.

The present invention has been made to solve the above problems, the phase difference between the stroke and the current is obtained by using the motor voltage, the motor current, and the timing of opening the discharge valve of the reciprocating compressor to the inflection point for the phase difference between the stroke and the current. The purpose of the present invention is to provide an operation control apparatus and method for a reciprocating compressor which improves the driving efficiency by detecting the capacity and automatically executing the variable capacity operation according to the load conditions based on the stroke at the time when the discharge valve is opened. have.

The present invention for achieving the above object, in the reciprocating compressor,

A stroke estimator for estimating a stroke using a motor voltage and a motor current;

A phase difference detector for detecting a phase difference between the stroke estimate and the current;

A phase difference inflection point detector for detecting an inflection point with respect to the phase difference between the stroke estimate and the current;

And a stroke command value converting unit for analyzing the phase difference inflection point detection signal output from the phase difference inflection point detecting unit and varying the stroke command value based on the analysis result.

The present invention for achieving the above object,

In a reciprocating compressor,

Detecting a motor voltage and a motor current;

Calculating a stroke estimate using the motor voltage and the motor current, and detecting a phase difference between the motor current and the stroke estimate;

Determining whether an inflection point occurs with respect to a phase difference between the motor current and the stroke estimate value, and varying a stroke command value based on the determination result;

And comparing the detected stroke estimate value with the stroke command value and applying or subtracting the applied voltage based on the comparison result.

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

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 detector 4 for detecting a motor current applied to the 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; A controller (2) for controlling the stroke by varying the voltage applied to the motor in accordance with the difference signal; A phase difference detector (100) for detecting a phase difference between the stroke estimate and the current; A phase difference inflection point detector (200) for detecting an inflection point for the phase difference between the stroke estimate and the current; A stroke command value converting unit 300 which analyzes the phase difference inflection point detection signal output from the phase difference inflection point detecting unit 200 and varies the stroke command value based on the analysis result 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 calculates a stroke estimate using the motor current, the motor voltage, and the motor parameter, and then applies the stroke estimate to the comparator 1.

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.

Here, the stroke command value is converted based on the stroke estimation value at the time of opening the discharge valve and the stroke estimate at the time of detecting the phase difference inflection point of the current according to the present invention, thereby preventing the efficiency decrease due to the stroke deviation of the reciprocating compressor. The same stroke deviation removing operation will be described.

First, the phase difference detection unit 100 detects a phase difference between the stroke estimate and the current, and the phase difference inflection point detection unit 200 detects an inflection point for the phase difference between the stroke estimate and the current and converts the phase difference inflection point detection signal according to the stroke command value conversion. Applied to the unit 300.

Accordingly, the stroke command value converting unit 300 analyzes the phase difference inflection point detection signal output from the phase difference inflection point detecting unit 200 and varies the stroke command value based on the analysis result.

That is, the stroke command value converting unit 300 applies the currently detected stroke estimate as the stroke command value when an inflection point with respect to the phase difference between the current and the stroke estimate is generated, and if the inflection point with respect to the phase difference between the current and the stroke estimate is not generated. It is determined whether an inflection point has occurred before the phase difference detection time between the current current and the stroke estimate value, and the stroke command value is varied based on the determination result.

Here, the stroke command value converting unit 300 increases the stroke command value if the inflection point has not occurred before the phase difference detection time between the current current and the stroke estimate value, and if the inflection point occurs before the phase difference detection time between the current current and the stroke estimate value. The stroke correction value is added to the stroke command value.

At this time, the stroke command value converting unit 300 includes a storage means (not shown), and stores the stroke correction value according to the load condition by experiment.

The stroke command value converting unit 300 detects a current driving load and selects a stroke correction value according to the detected driving load from a storage means (not shown). Obtain the absolute value of the phase difference.

For example, when the stroke cannot be increased to the stroke where TCV (Top Clearance Volume) becomes '0' under specific load conditions, for example, due to the specification of the reciprocating compressor motor, the stroke '1' is detected. After that, it is operated by '3' stroke by adding or subtracting by a certain amount, where '1' is the moment when the discharge valve is opened and '2' is the stroke where TCV becomes '0'.

In more detail, the present invention will be described with reference to FIG. 5. First, the motor voltage and the motor current are detected (SP10), the stroke is calculated using the motor voltage and the motor current, and the phase difference between the motor current and the stroke estimate is calculated. It detects (SP11).

Then, it is determined whether an inflection point occurs with respect to the phase difference between the motor current and the stroke estimation value (SP12), and the stroke command value is varied based on the determination result (SP13 to SP17).

That is, when an inflection point for the phase difference between the motor current and the stroke estimate value is applied, the currently detected stroke is applied as the stroke command value (SP13), and a flag for indicating that the inflection point has occurred is set to '1'. If the inflection point for the phase difference between the motor current and the stroke estimate value does not occur, it is determined whether the inflection point has occurred before the phase difference detection time between the current motor current and the stroke estimate value (SP15), and the stroke command value is changed based on the determination result (SP15). SP16, SP17), if the inflection point did not occur before the phase difference detection time between the current motor current and the stroke estimate value, increase the stroke command value (SP16); and if the inflection point occurred before the phase difference detection time between the current motor current and the stroke estimate value, stroke command value The stroke correction value is added to (stroke estimation value at the inflection point) (SP17).

Here, the stroke correction value (a) is preset according to the load condition by experiment, that is, for example, the load is detected by using an absolute value for the phase difference between the stroke estimate value and the current, and the stroke correction value according to the detected load. Select.

At this time, the stroke correction value a is set to be a full stroke (Top Clearance = 0) under the maximum load condition.

Then, the current stroke, i.e., the stroke estimate value and the stroke command value is compared (SP18), and when the stroke estimate value is larger than the stroke command value, the motor applied voltage is decreased (SP19), and if the stroke estimate value is smaller than the stroke command value, the motor is applied. Increase the voltage (SP20).

That is, the present invention obtains the phase difference between the stroke and the current by using the motor voltage and the motor current, detects the point of time when the discharge valve of the reciprocating compressor opens at the inflection point of the phase difference between the stroke and the current, In the system to which the operation control of the reciprocating compressor of the present invention is applied, as shown in FIG. 6, the capacity of the variable drive operation is automatically executed according to the load condition based on the stroke. For example, the smaller the load, the smaller the required capacity and the capacity of the compressor, so that the necessary capacity always matches the capacity of the compressor.

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 obtains the phase difference between the stroke and the current by using the motor voltage and the motor current, and detects the timing of opening the discharge valve of the reciprocating compressor at the inflection point of the phase difference between the stroke and the current. By executing the variable capacity operation automatically in accordance with the load condition on the basis of the stroke at the time of opening the discharge valve, there is an effect of improving the operating efficiency.

Claims (14)

In a reciprocating compressor, A stroke estimator for estimating a stroke using a motor voltage and a motor current, and outputting a stroke estimate according to the estimation result; A phase difference detector for detecting a phase difference between the stroke estimate and the current; A phase difference inflection point detector for detecting an inflection point with respect to the phase difference between the stroke estimate and the current; And a stroke command value converting unit for analyzing the phase difference inflection detection signal output from the phase difference inflection point detecting unit and varying the stroke command value based on the analysis result. The method of claim 1, wherein the stroke command value conversion unit, If an inflection point for the phase difference between the stroke estimate and the current occurs, the currently detected stroke estimate is applied as the stroke command value, If the inflection point for the phase difference between the stroke estimate value and the current does not occur, it is determined whether the inflection point has occurred before the current phase difference detection time, and the stroke command value is varied based on the determination result. . The method of claim 2, wherein the stroke command value conversion unit, If the inflection point does not occur before the phase difference detection time between the current stroke estimate and the current, increase the stroke command value. And a stroke correction value is added to a stroke command value if an inflection point occurs before the phase difference detection time between the current stroke estimate value and the current. The method of claim 3, wherein the stroke command value conversion unit, Experimentally, the operation control device of the reciprocating compressor comprising a storage means for pre-stored the stroke correction value according to the load conditions. The method of claim 3, wherein the stroke correction value, Operation control apparatus for a reciprocating compressor, characterized in that the set to be a full stroke (Top Clearance = 0) at the maximum load conditions. The method of claim 3, wherein the stroke command value conversion unit, An operation control apparatus for a reciprocating compressor, characterized in that it detects a current operating load and selects a stroke correction value according to the detected operating load from a storage means.  The method of claim 3, wherein the stroke command value conversion unit, An operation control apparatus for a reciprocating compressor, characterized by obtaining an operating load as an absolute value of a phase difference between a stroke estimate and a current. In a reciprocating compressor, Detecting a motor voltage and a motor current; Calculating a stroke estimate using the motor voltage and the motor current, and detecting a phase difference between the motor current and the stroke estimate; Determining whether an inflection point occurs with respect to a phase difference between the motor current and the stroke estimate value, and varying a stroke command value based on the determination result; And comparing the detected stroke estimate value with the stroke command value and applying or subtracting the applied voltage based on the comparison result. The method of claim 8, wherein the changing of the stroke command value comprises: Applying a currently estimated stroke estimate as a stroke command value when an inflection point for the phase difference between the motor current and the stroke estimate occurs; If the inflection point of the phase difference between the motor current and the stroke estimate value does not occur, determining whether the inflection point has occurred before the phase difference detection time between the current motor current and the stroke estimate value, and varying the stroke command value based on the determination result; Operation control method of the reciprocating compressor, characterized in that. The method of claim 9, wherein the varying of the stroke command value comprises: Increasing the stroke command value if an inflection point has not occurred before the phase difference detection time between the current motor current and the stroke estimate value; And adding a stroke correction value to a stroke command value if an inflection point occurs before a phase difference detection time between the current motor current and the stroke estimate value. The method of claim 10, wherein the stroke correction value, Experimentally, the operation control method of the reciprocating compressor characterized in that the preset in accordance with the load conditions. The method of claim 11, wherein the stroke correction value,  Operation control method of a reciprocating compressor, characterized in that the full stroke (Top Clearance = 0) is set at the maximum load conditions. The method of claim 10, wherein adding the stroke correction value comprises: Detecting a current driving load; And selecting a stroke correction value according to the detected driving load. The method of claim 13, wherein the driving load, An operation control method for a reciprocating compressor, characterized by detecting using an absolute value for a phase difference between a stroke and a current.

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