Abstract The quadruple-tank process has been widely used in control literature to illustrate many concepts in multivariable control, particularly, performance limitations due to multivariable right half-plane zeros. The main feature of the quadruple-tank process is the flexibility in positioning one of its multivariable zeros on either half of the‘s’ plane A nonlinear and linear dynamic model for the quadruple-tank process are derived. The nonlinear model is derived from Johansson nonlinear dynamic system and describes the complicated dynamics of the physical plant when the system is setting in the non-minimum phase. The simulation results show that PID controllers have acceptable performances especially when the system is minimum-phase system while in the non-minimum-phase the controller is poor. Also it is shown that the linear quadratic Gaussian with loop transfer recover (LQG/LTR) is better than PID controller when the system is minimum-phase while in the non-minimum-phase the controller is not acceptable because (LQG/LTR) compensators generally cannot be designed for non-minimum-phase plants. Simulation results show that the proposed Decentralized fuzzy logic controller has a remarkable performance for tracking the multi step reference trajectories while at the same time it is robust against voltage changes. The Simulation results confirm the effectiveness of the proposed control methodology.
أبوبكر عبدالكريم أبو شاقور (2010)

Abstract— Horizontal-Axis Wind Turbine (HAWT) small scaled is widely employed for generating electricity for domestic uses due to higher efficiencies among other turbines. Three-Blade HAWTs power performance can be further improved by optimizing lift (CL), drag (CD) coefficients and thus power (CP) coefficient. In this study, Taguchi design of experiments (DOE) of L9 orthogonal array (OA) with three parameters and one interaction, namely airfoil, angle of attack, interaction (between the airfoil and the attack angle), and Reynolds number with three value levels are used to determine the single quality (CL, CD, CP) optimization. For multi-qualities optimization, the Grey-based Taguchi is employed which combines the Taguchi DOE orthogonal array with grey relational analysis to determine the grey relational grade, which can convert the multi-response grey relational grade into single grey relational grade, thus the optimal design parameters can be achieved. The Q-Blade software is used to determine lift and drag coefficients and empirical equation used for power coefficient. The obtained results show that the most influence design parameter on airfoil coefficients is Reynolds number with 72.6% contribution followed by attack angle with 16.8%, interaction with 9.1% and airfoil with 1.5%. The F-value indicates that Reynolds number and angle of attack give at least 97.5% and 90% confidence respectively, for this specific set of experiments. arabic 14 English 86
Abdulhamed M. Hwas, Ali M. Hatab(12-2020)

This paper is concerned with calculating boiler efficiency as one of the most important types of performance measurements in any steam power plant. That has a key role in determining the overall effectiveness of the whole system within the power station. For this calculation, a Visual-Basic program was developed, and a steam power plant known as El-Khmus power plant, Libya was selected as a case study. The calculation of the boiler efficiency was applied by using heating balance method. The findings showed how the maximum heat energy which produced from the boiler increases the boiler efficiency through increasing the temperature of the feed water, and decreasing the exhaust temperature along with humidity levels of the of fuel used within the boiler. arabic 15 English 78
Rajab HOKOMA, Nabil M. Muhaisen(1-2012)