KR100690665B1 - 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 damping coefficient is obtained by using a motor voltage, a motor current, a phase difference between a stroke and a current, and a stroke, and a discharge valve of the reciprocating compressor is operated at an inflection point of the damping coefficient. By detecting the opening time and automatically executing the variable capacity operation according to the load condition on the basis of the stroke at the time when the discharge valve is opened, the driving efficiency is improved. A stroke estimator for estimating a stroke using the stroke estimator; A damping coefficient calculating unit for detecting a phase difference between the stroke estimate and the current and calculating a damping coefficient using the phase difference, the motor current, and the stroke estimate; and an inflection point of the damping coefficient using the damping coefficient output from the damping coefficient calculating unit. And a damping coefficient inflection point detecting unit for detecting a damping coefficient inflection point detection signal output from the damping coefficient inflection point detecting unit, and a stroke command value converting unit for varying a stroke command value based on the analysis result. If the inflection point of the damping coefficient is generated, the unit applies the currently detected stroke estimate to the stroke command value, and if the inflection point of the damping coefficient does not occur, determines whether the inflection point has occurred before the detection point of the current damping coefficient, The stroke command value is varied based on this.

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: damping coefficient calculation unit 200: damping coefficient 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 particularly, to obtain a damping coefficient using a motor voltage, a motor current, a phase difference between a stroke and a current, and a stroke, and to discharge the reciprocating compressor to an inflection point of the damping coefficient. The present invention relates to an operation control apparatus and method for a reciprocating compressor that detects a time point at which a valve is opened and automatically executes a variable capacity operation according to a load condition based on a stroke at the time point 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]

여기서, R:레지스턴스
L:인덕턴스
α:모터상수

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, 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, to obtain a damping coefficient using the motor voltage, the motor current, the phase difference between the stroke and the current, the stroke, the discharge valve of the reciprocating compressor is opened at the inflection point of the damping coefficient It is an object of the present invention to provide an operation control apparatus and method for a reciprocating compressor that improves operation efficiency by detecting a time point and automatically executing a variable capacity operation according to a load condition based on the stroke at the time when the discharge valve is opened. There is this.

The present invention for achieving the above object,
A stroke estimator for estimating a stroke using a motor voltage and a motor current;
A damping coefficient calculation unit for detecting a phase difference between the stroke estimate and the current and calculating a damping coefficient using the phase difference, the motor current, and the stroke estimate;
A damping coefficient inflection point detector for detecting an inflection point of the damping coefficient by using the damping coefficient output from the damping coefficient calculation unit;
A damping coefficient inflection point detection signal outputted from the damping coefficient inflection point detecting unit, and includes a stroke command value converting unit for varying the stroke command value based on the analysis result;
The stroke command value conversion unit,
When the inflection point of the damping coefficient occurs, the currently detected stroke estimate is applied as the stroke command value.
If the inflection point of the damping coefficient does not occur, it is determined whether the inflection point has occurred before the current damping coefficient detection time, and the stroke command value is varied based on the determination result.

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The present invention for achieving the above object,
Detecting a motor voltage and a motor current;
Calculating a stroke by using the motor voltage and the motor current, and calculating a damping coefficient by detecting a phase difference between the motor current and the stroke;
Determining whether an inflection point of the damping coefficient is generated and varying a stroke command value based on the determination result;
Comparing the detected stroke with a stroke command value, and performing a process of adding and subtracting an applied voltage based on the comparison result;
The process of varying the stroke command value,
Applying the currently detected stroke as a stroke command value when an inflection point of the damping coefficient occurs;
And if the inflection point of the damping coefficient does not occur, determining whether the inflection point has occurred before the current time of detection of the damping coefficient, and varying the stroke command value based on the determination result.

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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 damping coefficient calculator 100 for detecting a phase difference between the stroke estimate and the current and calculating a damping coefficient using the phase difference, the motor current, and the stroke estimate; A damping coefficient inflection point detector (200) for detecting an inflection point of the damping coefficient by using the damping coefficient output from the damping coefficient calculating unit (100); A damping coefficient inflection point detection signal output from the damping coefficient inflection point detecting unit 200 is analyzed, and a stroke command value converting unit 200 for varying the stroke command value based on the analysis result is provided, and the operation of the present invention will be described. do.

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 estimate value at the time of detecting the damping coefficient inflection point at the time of opening the discharge valve according to the present invention to prevent the decrease in efficiency due to the stroke deviation of the reciprocating compressor. Describe the operation.

First, the damping coefficient calculating unit 100 detects the phase difference between the stroke estimate and the current, and calculates the damping coefficient by the following equation using the phase difference, the motor current, and the stroke estimate.

이때, 댐핑계수 변곡점 검출부(200)는, 상기 댐핑계수 연산부(100)에서 출력되는 댐핑계수를 이용하여, 그 댐핑계수의 변곡점을 검출하여 그에 따른 댐핑계수 변곡점 검출신호를 스트로크 지령치 변환부(300)에 인가한다.[Equation]

At this time, the damping coefficient inflection point detection unit 200 detects the inflection point of the damping coefficient by using the damping coefficient output from the damping coefficient calculating unit 100 and converts the damping coefficient inflection point detection signal according to the stroke command value converting unit 300. To apply.

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Accordingly, the stroke command value converting unit 300 analyzes the damping coefficient inflection point detection signal and varies the stroke command value based on the analysis result.

That is, when the inflection point of the damping coefficient occurs, the stroke command value converting unit 300 applies the currently detected stroke estimate as the stroke command value, and if the inflection point of the damping coefficient does not occur, the inflection point before the current damping coefficient is detected. Is determined, 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 does not occur before the current damping coefficient is detected, and if the inflection point occurs before the current damping coefficient is detected, the stroke correction value is applied to the stroke command value. We add.

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, a motor voltage and a motor current are detected (SP10), a stroke is calculated using the motor voltage and the motor current, and a phase difference between the motor current and the stroke is detected. The damping coefficient is calculated (SP11).

Then, it is determined whether the inflection point of the damping coefficient is generated (SP12), and the stroke command value is varied based on the determination result (SP13 to SP17).

That is, when the inflection point of the damping coefficient occurs, the currently detected stroke is applied as the stroke command value (SP13), and then a flag for indicating that the inflection point has occurred is set to '1'. If the inflection point of the damping coefficient does not occur, it is determined whether the inflection point has occurred before the detection time of the current damping coefficient (SP15), and the stroke command value is changed based on the determination result (SP16, SP17), and the detection of the current damping coefficient is detected. If the inflection point has not occurred before the point of time, the stroke command value is increased (SP16). If the inflection point occurs before the detection point of the current damping coefficient, the stroke correction value is added to the stroke command value (SP17).

Here, the stroke correction value (a) is preset according to the load condition by experiment, that is, for example, the load is detected using the absolute value of 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 damping coefficient by the motor voltage, the motor current, the phase difference between the stroke and the current, and the stroke, and detects the timing of opening the discharge valve of the reciprocating compressor at the inflection point of the damping coefficient, and the timing of opening the discharge valve. 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 reciprocating compressor according to the present invention is automatically executed according to the load condition based on the stroke of the stroke. The larger 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.

The specific embodiments or examples made in the detailed description of the present invention are for the purpose of clarifying the technical contents of the present invention only, and should not be construed as limited to these specific embodiments by consultation. Various changes can be made within the scope of.

As described in detail above, the present invention obtains a damping coefficient by a motor voltage, a motor current, a phase difference between a stroke and a current, and a stroke, and detects a time point at which the discharge valve of the reciprocating compressor opens at an inflection point of the damping coefficient, and discharges the same. 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 valve, there is an effect of improving the operating efficiency.

Claims (16)

A stroke estimator for estimating a stroke using a motor voltage and a motor current; A damping coefficient calculation unit for detecting a phase difference between the stroke estimate and the current and calculating a damping coefficient using the phase difference, the motor current, and the stroke estimate; A damping coefficient inflection point detector for detecting an inflection point of the damping coefficient by using the damping coefficient output from the damping coefficient calculation unit; A damping coefficient inflection point detection signal outputted from the damping coefficient inflection point detecting unit, and includes a stroke command value converting unit for varying the stroke command value based on the analysis result; The stroke command value conversion unit, When the inflection point of the damping coefficient occurs, the currently detected stroke estimate is applied as the stroke command value. And if the inflection point of the damping coefficient does not occur, it is determined whether an inflection point has occurred before the current damping coefficient is detected, and the stroke command value is varied based on the determination result. The method of claim 1, wherein the damping coefficient calculator, An operation control apparatus for a reciprocating compressor, characterized in that the damping coefficient is calculated by the following equation. [Equation]

delete According to claim 1, The stroke command value conversion unit, If no inflection point occurs before the current damping coefficient is detected, increase the stroke command value. And a stroke correction value is added to the stroke command value if an inflection point occurs before the current damping coefficient is detected. The method of claim 4, 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 4, 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. According to claim 4, 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 7, 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. Detecting a motor voltage and a motor current; Calculating a stroke by using the motor voltage and the motor current, and calculating a damping coefficient by detecting a phase difference between the motor current and the stroke; Determining whether an inflection point of the damping coefficient is generated and varying a stroke command value based on the determination result; Comparing the detected stroke with a stroke command value, and performing a process of adding and subtracting an applied voltage based on the comparison result; The process of varying the stroke command value, Applying the currently detected stroke as a stroke command value when an inflection point of the damping coefficient occurs; And if the inflection point of the damping coefficient does not occur, determining whether the inflection point has occurred before the current damping coefficient is detected, and varying the stroke command value based on the determination result. Way. The method of claim 9, wherein the damping coefficient is, An operation control method of a reciprocating compressor, characterized by the following equation. [Equation]

delete 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 current damping coefficient is detected; And adding a stroke correction value to a stroke command value if an inflection point occurs before the current damping coefficient is detected. The stroke correction value according to claim 12, Experimentally, the operation control method of the reciprocating compressor characterized in that the preset in accordance with the load conditions. The method of claim 12, 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 12, 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 15, 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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