KR20170000624A

KR20170000624A - Apparatus and method for controlling turbo air compressor using anti-surge auto control technology

Info

Publication number: KR20170000624A
Application number: KR1020150089787A
Authority: KR
Inventors: 김태옥
Original assignee: 금오기전 주식회사
Priority date: 2015-06-24
Filing date: 2015-06-24
Publication date: 2017-01-03
Also published as: KR101785063B1

Abstract

The purpose of the present invention is to provide a control device and a control method for a turbo air compressor wherein an automatic anti-surge control technology is applied to stably operate the turbo air compressor and prevent vibration and damage to the turbo air compressor system. The control device and the control method, by applying the automatic anti-surge control technology, monitors speeds of changes in a current and a pressure of a motor and controls BOV based on the speeds to prevent the BOV from approaching a surge danger line. The control device for the turbo air compressor includes: a surge current setting unit setting a surge current using the changes in the current and the pressure of the motor at a preset point based on a system pressure of the turbo air compressor; a measuring unit measuring the current and the pressure of the motor driving a compressing impeller; a current comparing unit determining a load to the current of the motor by comparing the surge current set by the surge current setting unit and the current of the motor measured by the measuring unit; a speed motor comparing a present current based on a difference between the preset surge current and the preset current of the motor if the load to the current of the motor is checked by the current comparing unit with a previous current saved in a speed information database and calculating unit calculating a surge access speed based on the difference obtained by the comparison; a surge change determining unit comparing the surge access speed calculated by the speed calculating unit with a margin width indicating a surge line movement current; and a BOV control unit controlling the BOV not to approach the surge danger line while changing a control speed based on the change in the pressure measured by the surge change determining unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-surge automatic control technology,

The present invention relates to a control apparatus and method for a turbo air compressor, and more particularly to a control apparatus and method for a turbo air compressor which monitors a motor current and a pressure change rate and controls a BOV (blow off valve) To an apparatus and method for controlling a turbo air compressor to which an anti-surge automatic control technology is applied.

The use of compressed air is indispensable in all industrial fields such as heavy industry, shipbuilding, steel, electronics, and hospitals. Large compressors and air compressors, peripherals needed for pressure and air flow control are used to provide constant pressure and air volume. Recently, the frequency of use of turbo air compressors has been rapidly increasing in order to increase the efficiency of air compressors. Until the early 2000s, turbo air compressors have mostly been imported and used in the US, Germany, and Japan. Recently, they have been developed by Samsung Techwin and Hyundai Heavy Industries.

Turbo air compressors are more energy efficient than other compressors, but compressed air control is relatively difficult. Since at least three stages of compression control are required to compress the air to high pressure, the rotational speed of the final stage impeller is several tens of thousands of RPM or more, and the surge may occur when the influence of the surrounding environment or compression control in the non- Therefore, it is necessary to precisely control the mechanical conditions such as vibration. Especially, since the impeller rotates at a high speed, it is important because it can damage the system and cause injury if it is not controlled accurately.

In recent years, as the efficiency of the turbo air compressor has increased and the capacity of the compressor has increased, not only the size of the system has increased but also the pressure of the compressor has been increased. In the case of a large-scale system such as a turbo air compressor, the problem of high temperature, high pressure, vibration, and noise occurring in the entire system limits the accessibility for the driver to the safety as much as possible.

Accordingly, there is an increasing demand for a turbo air compressor control device for developing a control device optimized for a turbo air compressor, in order to prevent surge and reduce energy consumption to enable more efficient operation of the turbo air compressor.

Patent Registration No. 10-0322233 (date of registration 2002.01.14) Korean Patent Registration No. 10-0298543 (registered date 2001.06.01)

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide an anti-surge automatic control technology that monitors a motor current and a pressure change rate, To prevent a surge danger line from being brought close to the turbine air compressor, thereby preventing vibrations and system damage, and stably operating the turbo air compressor.

Another object of the present invention is to provide an anti-surge controller that can obtain a response in controlling a BOV (Blow Off Valve) by setting a P gain to a limit value through a control technique combining an adaptive PID control with a general PID control. And an apparatus and method for controlling the turbo air compressor to which the automatic control technology is applied.

Other objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

According to another aspect of the present invention, there is provided a control apparatus for a turbo air compressor to which an anti-surge automatic control technology according to the present invention is applied, using a motor current and a pressure change at a predetermined point based on a system pressure of a turbo air compressor A surge current setting section for setting a surge current; a measurement section for measuring a motor current and a motor pressure from a motor for driving the compression impeller; and a control section for controlling the surge current set in the surge current setting section and the motor current measured in the measurement section, A current comparator for determining whether a motor current is loaded or not by comparing a current value of a motor current with an after current ) Is compared with a previous current stored in the speed information DB, and a surge access according to the difference A surge change judging unit for comparing the surge access speed calculated by the speed calculator with a margin width indicating surge line motion current; a surge change judging unit for comparing a surge change rate detected by the surge change judging unit And a BOV control unit for controlling the BOV (Blow Off Valve) while changing the control speed based on the state of the BOV control unit to prevent the BOV from approaching the surge risk line.

Preferably, the measuring unit includes a current measuring unit that measures a motor current from a motor that drives the compression impeller, and a pressure measuring unit that measures a motor pressure from a motor that drives the compression impeller.

Preferably, when the surge access speed is greater than or equal to the margin width as a result of the comparison in the surge change determining unit, the BOV control unit determines that the BOV control speed is higher than the preset control speed by the comparison result in the surge change determining unit And a second BOV control unit for controlling the BOV (Blow Off Valve) control speed at a preset control speed when the surge access speed is smaller than the margin width as a result of comparison in the surge change determination unit .

Preferably, the BOV control unit further includes a PID control unit for outputting a control value for PID control by increasing the proportional gain P gain of the PID control to a maximum value of the rated current when the motor current measured by the measuring unit is smaller than the rated current .

According to another aspect of the present invention, there is provided a method of controlling a turbo air compressor using an anti-surge automatic control technology, the method comprising: (A) determining, by a surge current setting unit, (B) measuring the motor current and the motor pressure from the motor driving the compression impeller through the measuring unit, (C) measuring the motor current and the motor pressure through the current comparing unit, Determining whether a motor is loaded by comparing a surge current with the measured motor current; and (D) determining whether a load is generated in the motor, Calculating an after current according to a difference between the motor current and the set surge current; and (E) comparing the calculated surge access speed with a previously calculated immediately preceding current to calculate a surge access speed according to the difference; and (F) comparing the calculated surge access speed with a surge line movement current (BOV) control speed through a first BOV control section to a preset control speed (BOV SEG TIME) if the surge access speed is greater than or equal to the margin width as a result of the comparison (B) controlling the Blow Off Valve (BOV) control speed to a predetermined control speed (e.g., a predetermined speed) through the second BOV controller if the surge access speed is smaller than the margin width, (I) storing the current in the speed information DB and repeating the steps (A) to (C) until the operation of the air compressor is stopped, And repeating the sieving step.

Preferably, in the step (C), if the motor current is smaller than or equal to the surge current, it is determined that no load is generated in the motor. Conversely, if the motor current is larger than the surge current, it is determined that a load is generated in the motor.

Preferably, comparing the measured motor current with the rated current during the PID control of the turbo air compressor after the step (G) or (H), and comparing the measured motor current with the rated current And increasing the proportional gain (P gain) of the PID control to the maximum value of the rated current in a short period of time through the PID controller and outputting the PID control value for the PID control.

The apparatus and method for controlling the turbo air compressor using the anti-surge automatic control technology according to the present invention as described above have the following effects.

First, anti-surge automatic control technology is applied to control BOV (Blow Off Valve) based on motor current and pressure change to prevent approaching surge risk line and prevent vibration and system damage. And the turbo air compressor can be stably operated.

Second, by controlling the BOV (Blow Off Valve) control, it is possible to control the operation of the air compressor efficiently and smoothly by controlling it not to approach the surge danger line. Also, by driving the motor smoothly all the time, The life of the compressor can be extended.

Third, the P gain is set to be high through the control method combining the general PID control and the adaptive PID control, so that a quick control can be performed in controlling the BOV (Blow Off Valve).

1 is a block diagram showing a configuration of a control apparatus for a turbo air compressor to which an anti-surge automatic control technology according to a preferred embodiment of the present invention is applied
2 is a flowchart illustrating a method of controlling a turbo air compressor to which an anti-surge automatic control technology according to a preferred embodiment of the present invention is applied
3 is a diagram for explaining a method of calculating a surge current, a current current, and a surge access speed in Fig. 2
4 is a flowchart illustrating a process of generating a PID control value through the PID controller of FIG.
5 is a view for explaining the output of the PID control value of FIG. 4;

Other objects, features and advantages of the present invention will become apparent from the detailed description of the embodiments with reference to the accompanying drawings.

A preferred embodiment of a control apparatus and method for a turbo air compressor to which the anti-surge automatic control technology according to the present invention is applied will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is provided to let you know. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Therefore, various equivalents It should be understood that water and variations may be present.

1 is a block diagram showing a configuration of a control apparatus for a turbo air compressor to which an anti-surge automatic control technology according to a preferred embodiment of the present invention is applied.

A surge current setting unit 100 for setting a surge current using a motor current and a pressure change at a predetermined point based on the system pressure of the turbo air compressor, A measuring unit 200 for measuring the motor current and the motor pressure from the motor, and a control unit 200 for comparing the surge current set by the surge current setting unit 100 and the motor current measured by the measuring unit 200, A current comparison unit 300 for comparing a surge motor current and a preset current difference according to the set surge current difference when the occurrence of a load of the motor current is confirmed through the current comparator 300; ) To the previous current stored in the speed information DB 700 and calculates a surge access speed according to the difference, and a speed calculator A surge change determining unit (500) for comparing the issued surge access speed with a margin width representing a surge line movement current; and a control unit for changing the control speed based on the state of the pressure change detected through the comparison in the surge change determining unit And a BOV control unit 600 for controlling the BOV (Blow Off Valve) so as not to approach the surge risk line.

The measuring unit 200 includes a current measuring unit 210 for measuring a motor current from a motor for driving a compression impeller and a pressure measuring unit 220 for measuring a motor pressure from a motor for driving the compression impeller.

If the surge access speed is greater than or equal to the margin width as a result of the comparison by the surge change determining unit 500, the BOV control unit 600 determines that the detected pressure change is performed quickly and sets the BOV (Blow Off Valve) A first BOV control unit 610 for controlling the surge change determining unit 500 to perform a faster comparison with the comparison result in the surge change determining unit 500 and a second BOV control unit 610 for comparing the detected pressure And a second BOV control unit 620 for controlling the BOV (Blow Off Valve) control speed at a predetermined control speed.

If the motor current measured by the measuring unit 200 is less than the rated current, the BOV control unit 600 increases the proportional gain P gain of the PID control to the maximum value of the rated current to output the control value for the PID control A PID controller 630 is further provided.

The operation of the control apparatus of the turbo air compressor to which the anti-surge automatic control technology according to the present invention is applied will now be described in detail with reference to the accompanying drawings. The same reference numerals as those in Fig. 1 designate the same members performing the same function.

2 is a flowchart illustrating a method of controlling a turbo air compressor to which an anti-surge automatic control technology according to a preferred embodiment of the present invention is applied.

2, a surge current is calculated and set using a motor current and a pressure change at a predetermined point based on the system pressure of the turbo air compressor through the surge current setting unit 100 (S10) .

The calculation of the surge current will now be described with reference to the graph of FIG. 3, which shows the current motor current (X axis) and motor pressure (Y axis).

Further, the motor current and the motor pressure are measured from the motor driving the compression impeller through the measuring unit 200 (S20).

Next, the current comparison unit 300 compares the set surge current with the measured motor current to determine whether the motor is loaded (S30). That is, if the motor current is smaller than or equal to the surge current, it is determined that no load is generated in the motor. Conversely, if the motor current is larger than the surge current, it is determined that a load is generated in the motor.

If it is determined that the load has been generated in the motor, the current calculator 400 determines whether a current (after) is present according to the difference between the preset surge motor current and the set surge current through the speed calculator 400 (S40). Then, the calculated after current is compared with a previously calculated previous current (S50), and a surge access speed according to the difference is calculated (S50). At this time, the calculated surge access speed indicates the motor current and the speed of the pressure change.

At this time, the current (after current) is calculated by the following equation (2), and the surge access rate is calculated by the following equation (3).

The surge change determining unit 500 compares the calculated surge access speed with the margin width indicating the surge line motion current (S60). At this time, if the surge access speed is greater than or equal to the margin width, it is determined that the detected pressure change is performed quickly. If the surge access speed is smaller than the margin width, it can be determined that the detected pressure change is gradually made.

Accordingly, the controller controls the BOV (Blow Off Valve) through the BOV control unit 600 so as not to approach the surge risk line while changing the control speed based on the state of the pressure change detected through the comparison. That is, when the surge access speed is greater than or equal to the margin width, it is determined that the detected pressure change is performed quickly, and the Blow Off Valve (BOV) control speed is set to a preset control speed (BOV SEG TIME) through the first BOV control unit 610, (The first BOV control) (step S70). When the surge access speed is smaller than the margin width, it is determined that the detected pressure change is gradually performed, and the BOV control speed is slower than the preset control speed BOV SEG TIME through the second BOV control unit 620 (Second BOV control) (S80).

At this time, the second BOV control controlled at the preset control speed is calculated by the following equation (4), and the first BOV control is calculated by the following equation (5).

Then, after current current (after current) is stored in the speed information DB 700 and changed to before current (S90), it is repeatedly performed from the step of S10 until the operation of the air compressor is stopped By controlling the BOV (Blow Off Valve) based on the motor current and pressure change, it is prevented from approaching the surge danger line, preventing vibration and system damage, and controlling the operation of the turbo air compressor stably.

Meanwhile, as shown in FIG. 4, during the PID control (S100), the motor current measured by the measuring unit 200 is compared with the rated current (S200).

If the measured motor current is smaller than the rated current as a result of the comparison, it is determined that a faster BOV (Blow Off Valve) control is required, and the proportional gain P gain of the PID control is determined through the PID controller 630 As shown in the figure, the maximum value of the rated current is increased in a short time and the PID control value for PID control is outputted (S300).

At this time, the PID control value is calculated by the following equation (6).

As described above, the P gain is set to be higher through the control method combining the general PID control and the adaptive PID control, so that the control of the BOV (Blow Off Valve) is performed more quickly.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims

A surge current setting unit for setting a surge current using a motor current and a pressure change at a predetermined point based on a system pressure of the turbo air compressor,
A measuring section for measuring a motor current and a motor pressure from a motor for driving the compression impeller,
A current comparator comparing the surge current set by the surge current setting unit and the motor current measured by the measuring unit to determine whether the motor current is loaded,
When the occurrence of a load of the motor current is confirmed through the current comparator, a current (after current) according to a preset surge motor current and the set surge current difference is detected as a before current stored in the speed information DB, A speed calculating unit for calculating a surge access speed according to the difference,
A surge change judging unit for comparing the surge access speed calculated by the speed calculator with a margin width indicating a surge line movement current;
And a BOV control unit for controlling the BOV (Blow Off Valve) while changing the control speed based on the state of the pressure change detected through the comparison in the surge change determination unit, so as not to approach the surge risk line Wherein the turbo air compressor is controlled by an anti-surge automatic control technique.

The apparatus according to claim 1, wherein the measuring unit
A current measuring unit for measuring a motor current from a motor for driving the compression impeller,
And a pressure measuring unit for measuring a motor pressure from a motor for driving the compression impeller.

2. The apparatus of claim 1, wherein the BOV control unit
If the surge access speed is greater than or equal to the margin width as a result of the comparison by the surge change determination unit, the first BOV control unit controls the BOV (Blow Off Valve) control speed faster than the preset control speed by the comparison result in the surge change determination unit Wow,
And a second BOV control unit for controlling the BOV (Blow Off Valve) control speed to a preset control speed if the surge access speed is smaller than the margin width as a result of the comparison by the surge change determination unit The controller of the turbo air compressor.

4. The apparatus of claim 3, wherein the BOV control unit
And a PID controller for outputting a control value for PID control by increasing the proportional gain P gain of the PID control to a maximum value of the rated current when the motor current measured by the measuring unit is smaller than the rated current Control device of turbo air compressor using anti - surge automatic control technology.

(A) calculating a surge current using a motor current and a pressure change at a predetermined point based on a system pressure of the turbo air compressor through a surge current setting unit,
(B) measuring a motor current and a motor pressure from a motor driving the compression impeller through a measurement unit,
(C) comparing the calculated surge current with the measured motor current through a current comparator to determine whether the motor is loaded;
(D) calculating an after current according to a difference between a surge motor current preset by the speed calculator and the set surge current when it is determined that a load is generated in the motor as a result of the load determination, Wow,
(E) comparing the calculated after current with a previously calculated previous current to calculate a surge access speed according to the difference,
(F) comparing the calculated surge access speed with a margin width representing a surge line movement current through a surge change determination unit,
(G) If the surge access speed is greater than or equal to the margin width as a result of the comparison, a BOV (Blow Off Valve) control rate is set to a BOV SEG TIME through a first BOV control section, As fast as possible,
(H) controlling the BOV (Blow Off Valve) control speed to be slower than or equal to a preset control speed through the second BOV control unit if the surge access speed is smaller than the margin width as a result of the comparison;
(I) storing the current after in the speed information DB, and repeatedly performing the entire steps from the step (A) until the operation of the air compressor is stopped. Control Method of Turbo Air Compressor Using Surge Automatic Control Technology.

6. The method of claim 5, wherein the surge current
Formula

Lt; / RTI >
Wherein the system press is a system pressure of the turbo air compressor, the press # 1 is a pressure of the motor, the current # 1 is a current of the motor, and the margin width is a surge line movement current. Control Method of Turbo Air Compressor Applied Technology.

6. The method of claim 5, wherein step (C)
When the motor current is smaller than or equal to the surge current, it is determined that no load is generated in the motor. On the contrary, if the motor current is larger than the surge current, it is determined that a load is generated in the motor. A method of controlling a compressor.

6. The method of claim 5, wherein the current
Formula

Lt; / RTI >
Here, the Surge Motor Current is a preset surge motor current, the Surge Press is a surge pressure, the Press # 1 is a motor pressure, the Current # 1 is a motor current, and the margin width is a surge line motion current Wherein the turbo air compressor is controlled by an anti-surge automatic control technique.

6. The method of claim 5, wherein the control in step (G)
Formula

Wherein the controller is controlled at a control speed calculated by the anti-surge automatic control technique.

6. The method of claim 5, wherein the control in step (H)
Formula

6. The method of claim 5, wherein after the step (G) or (H)
Comparing the measured motor current with the rated current during PID control of the turbo air compressor,
If the measured motor current is smaller than the rated current as a result of the comparison, the step of increasing the proportional gain (P gain) of the PID control to the maximum value of the rated current in a short period of time through the PID controller and outputting the PID control value for PID control Wherein the controller is further configured to control the turbo air compressor based on the anti-surge automatic control technique.

12. The method of claim 11, wherein the PID control value
Formula

Wherein the control is performed by using the anti-surge automatic control technique.