PI controller gains tuning of the pressure control system by open-loop frequency response (thermal power plants)

The purpose of this experiment was to study whether the carotid sinus baroreflex system (CS system) increases its gain with time after vagotomy in compensation for the loss of the vagally mediated arterial pressure control system (V system). In 7 dogs anesthetized with pentobarbital sodium we determined the responsiveness of the V system by repeatedly measuring the overall open-loop gain (G) of the negative feedback control system. G was assessed as (delta API/delta APS) -- 1, where delta API and delta APS are, respectively, the immediate and steady-state falls in arterial pressure at the aortic arch following a stepwise reduction in blood volume. delta API, delta APS, and G in intact condition were -12.0 +/- 1.8 mmHg, -1.1 +/- 0.2 mmHg, and 10.1 +/- 0.7 (SD), respectively. delta API, delta APS, and G after vagotomy, i.e., G of the CS system (GCS), were -15.6 +/- 3.6 mmHg, -6.4 +/- 1.9 mmHg, and 1.6 +/- 0.4 GCS did not change with time over 4 h after vagotomy. We conclude that the CS system cannot augment its ability to restore arterial pressure in compensation for the lost function of the V system within 4 h after vagotomy in the anesthetized dog.

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T 20 Process Control System for Thermal Power Plants A Case Study: The 2 × 300 MW Plant of Port Klang—Malaya

IETE Technical Review ◽

10.1080/02564602.1987.11438114 ◽

1987 ◽

Vol 4 (5) ◽

pp. 203-205

Author(s):

G Meuriot

Keyword(s):

Control System ◽

Process Control ◽

Power Plants ◽

Thermal Power ◽

Process Control System ◽

Thermal Power Plants ◽

Port Klang

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Application of RELAP4/MOD6 to analysis of solar-thermal power plants: control system modelling

10.2172/5554016 ◽

1986 ◽

Author(s):

R. Byers

Keyword(s):

Control System ◽

Power Plants ◽

Thermal Power ◽

Solar Thermal ◽

System Modelling ◽

Thermal Power Plants ◽

Solar Thermal Power

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Estimation of open-loop gain of canine arterial pressure control system by a new method

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1981.240.6.h832 ◽

1981 ◽

Vol 240 (6) ◽

pp. H832-H836 ◽

Cited By ~ 2

Author(s):

H. Hosomi ◽

K. Yokoyama

Keyword(s):

Control System ◽

Arterial Pressure ◽

Pressure Change ◽

Pressure Control ◽

Systemic Arterial Pressure ◽

Open Loop ◽

Loop Gain ◽

Reflex Gain ◽

Pressure Control System ◽

Arterial Pressure Control System

We developed a method to estimate an overall open-loop gain of the arterial pressure control system without surgically opening the reflex loop. Dogs anesthetized by intravenous injection of Nembutal (35 mg/kg body wt) were bled by 2 ml/kg body wt within 2-3 s through a catheter inserted into the abdominal aorta. Arterial pressure change after the quick hemorrhage was monitored via a catheter placed in the aortic arch for more than 2 min. The overall open-loop gain of the lumped arterial pressure control system was assessed as (delta API/delta APs)-1, where delta API is the immediate fall and delta APs the steady-state fall in mean arterial pressure obtained by a filter with a 2-s time constant. The advantage of this method is that the overall open-loop gain can be estimated under the closed-loop condition in which the baroreceptor reflexes operate naturally around the existing range of systemic arterial pressure. This enables one to study time-varying characteristics of the reflex gain. The disadvantage is that the substantial constituents of the lumped reflex system remain to be confirmed.

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Unstable state of the arterial pressure control system after a mild hemorrhage

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1978.235.5.r279 ◽

1978 ◽

Vol 235 (5) ◽

pp. R279-R285

Author(s):

H. Hosomi

Keyword(s):

Heart Rate ◽

Control System ◽

Arterial Pressure ◽

Rapid Test ◽

Pressure Oscillation ◽

Pressure Control ◽

Open Loop ◽

Unstable State ◽

Pressure Control System ◽

Arterial Pressure Control System

The stability of the arterial pressure control system after a mild hemorrhage (5 ml/kg body wt) was studied in 10 anesthetized cats by analyzing the responses of arterial pressure and of heart rate and the dead time (L) of heart rate response to a minute, rapid test hemorrhage (1 ml/kg body wt). The overall open-loop gain (H) of the arterial pressure control system was estimated from the ratio of arterial pressure fall immediately after the quick hemorrhage over the steady-state fall. Increases in H and L were correlated with the tendency of the arterial pressure control system to be unstable and oscillate. Oscillation in arterial pressure was always accompanied by a marked increase in heart rate (deltaHR), which represents an enhanced activity of the sympathetic nervous system and serves to restore arterial pressure toward the prehemorrhage level. The present study indicates that the magnitude of deltaHR also serves as a good predictor of arterial pressure oscillation.

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