June 2010
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 Open Access |
| Singular Perturbation Method for Robust Control of Nonlinear Systems |
| Hadi Bafandegan Mogaver, Asef Zare, Mohammad Rasoul Tanhatalab |
| Pages: 1-6 |
| FULL TEXT (PDF) |
| Abstract: |
| This paper, we consider robust control of nonlinear systems, via inclusion nonlinear systems solution and H□□ controller using singular perturbation method. First, using technique for solving inclusion nonlinear systems, we transform the nonlinear system to ordinary nonlinear system. Then using normal form equations, we eliminate the nonlinear part of the system matrix of equations of system and transform it to a linear diagonal form. Separating new equations to slow and fast subsystems, due to the singular perturbation method and with the assumption of norm boundedness of the fast dynamics, we can treat them as disturbance and design H∞ controller for a system with a lower order than the original one that stabilizes the overall system. The proposed method is applied to a nominal system. |
| Open Access |
| Adaptive Sliding Mode Control Desgin for a Class of Nonlinear Systems with Unknown Dead Zone of Unknown Bounds |
| Ibrahim Fahad Jasim, Najah Fahad Jasim |
| Pages: 7-11 |
| FULL TEXT (PDF) |
| Abstract: |
| The control problem for a class of a nonlinear systems that contain the coupling of unmeasured states and unknown parameters is addressed. The system actuation is assumed to suffer from unknown dead zone nonlinearity. The parameters bounds of the unknown dead zone to be considered are unknown. Adaptive sliding mode controller, unmeasured states observer, and unknown parameters estimators are suggested such that global stability is achieved. Simulation for a single link mechanical system with unknown dead zone and friction torque is implemented for proving the efficacy of the suggested scheme. |
| Open Access |
| Motion control of a population of Artemias |
| L. Fortuna, M. Frasca, M.G. Xibilia, A. A. Ali, M. T. Rashid |
| Pages: 12-15 |
| FULL TEXT (PDF) |
| Abstract: |
| In this work, the collective behavior of Artemia Salina is studied both experimentally and theoretically. Several experiments have been designed to investigate the Artemia motion under different environment conditions. From the results of such experiments, a strategy to control the direction of motion of an Artemia population, by exploiting their sensitivity to light, has been derived and then implemented. |
| Open Access |
| A New anticipatory speed-controller for IC engines based on torque sensing loop |
| Abdul baki Khalaf Ali, Imad abdul-kadhem kheioon, Mushtaq Kadhim Ali |
| Pages: 16-21 |
| FULL TEXT (PDF) |
| Abstract: |
| Some engineering applications requires constant engine speed such as power generators, production lines ..etc. The current paper focuses on adding a new closed loop based on engine torque. Load cells can be used to measure the torque of load applied , the electrical signal is properly handled to manipulate a special fuel actuator to compensate for the reduction in engine speed. The speed loop still acts as the most outer closed loop. This method leads to rapid speed compensation and lead control action. |
| Open Access |
| Soft Computing Control System of an Unmanned Airship |
| Wong Wei Kitt, Ali Chekima, Jamal A. Dhargam, Farrah Wong, Tamer A. Tabet |
| Pages: 22-27 |
| FULL TEXT (PDF) |
| Abstract: |
| Soft computing control system have been applied in various applications particularly in the fields of robotics controls. The advantage of having a soft computing controls methods is that it enable more flexibility to the control system compared with conventional model based controls system. Firstly, soft computing methods enable a transfer of human controls and thinking into the machine via training. Secondly it is more robust to error compared to conventional model based system. In this paper, a UAV airship is controlled using fuzzy logic for its propulsion and steering system. The airship is tested on a simulation level before test flight. The prototype airship has on board GPS and compass for telemetry and transmitted to the ground control system via a wireless link. |
| Open Access |
| Hard Constraints Explicit Model Predictive Control of an Inverted Pendulum |
| Haider A. F. Mohamed, Masood Askari, M. Moghavvemi |
| Pages: 28-32 |
| FULL TEXT (PDF) |
| Abstract: |
| In this paper, explicit model predictive controller is applied to an inverted pendulum apparatus. Explicit solutions to constrained linear model predictive controller can be computed by solving multi-parametric quadratic programs. The solution is a piecewise affine function, which can be evaluated at each sample to obtain the optimal control law. The on-line computation effort is restricted to a table-lookup. This admits implementation on low cost hardware at high sampling frequencies in real-time systems with high reliability and low software complexity. This is useful for systems with limited power and CPU resources. |
| Open Access |
| A ROBUST PRACTICAL GENERALIZED PREDICTIVE CONTROL FOR BOILER SUPER HEATER TEMPERATURE CONTROL |
| Zaki Maki Mohialdeen |
| Pages: 33-38 |
| FULL TEXT (PDF) |
| Abstract: |
| A practical method of robust generalized predictive controller (GPC) application is developed using a combination of Ziegler-Nichols type functions relating the GPC controller parameters to a first order with time delay process parameters and a model matching controller. The GPC controller and the model matching controller are used in a master/slave configuration, with the GPC as the master controller and the model matching controller as the slave controller. The model matching controller parameters are selected to obtain the desired overall performance. The effectiveness of the proposed control method is tested by simulation using a mathematical model of the boiler super heater temperature process. |
| Open Access |
| Parameter Identification of a PMSG Using a PSO Algorithm Based on Experimental Tests |
| A. J. Mahdi, W. H. Tang, Q. H. Wu |
| Pages: 39-44 |
| FULL TEXT (PDF) |
| Abstract: |
| An accurate model for a permanent magnet synchronous generator (PMSG) is important for the design of a high-performance PMSG control system. The performance of such control systems is influenced by PMSG parameter variations under real operation conditions. In this paper, the electrical parameters of a PMSG (the phase resistance, the phase inductance and the rotor permanent magnet (PM) flux linkage) are identified by a particle swarm optimisation (PSO) algorithm based on experimental tests. The advantages of adopting the PSO algorithm in this research include easy implementation, a high computational efficiency and stable convergence characteristics. For PMSG parameter identification, the normalised root mean square error (NRMSE) between the measured and simulated data is calculated and minimised using PSO. |
| Open Access |
| A combined 2-dimensional fuzzy regression model to study effect of climate change on the electrical peak load |
| Hamed Shakouri G., Hosain Zaman |
| Pages: 45-49 |
| FULL TEXT (PDF) |
| Abstract: |
| This paper studies the impact of climate change on the electricity consumption by means of a fuzzy regression approach. The climate factors which have been considered in this paper are humidity and temperature, whereas the simultaneous effect of these two climate factors is considered. The impacts of other climate variables, like the wind, with a minor effect on energy consumption are ignored. The innovation which applies in this paper is the division of the year into two parts by using the temperature-day graph in the year. To index the humidity, data of the minimum humidity per day are used. For temperature, the maximum temperature of the first part of the year (warm days) and the minimum of the second part (cold days) are used. The indicator for the consumption is the daily peak load. The model results show high sensitivity to the temperature but low sensitivity to the humidity. Moreover, it is concluded that the model structure cannot be the same and for the cold par additional variables such as gas consumption should be considered. |
| Open Access |
| Damping of Power Systems Oscillations by using Genetic Algorithm-Based Optimal Controller |
| Akram F. Bati |
| Pages: 50-55 |
| FULL TEXT (PDF) |
| Abstract: |
| In this paper, the power system stabilizer (PSS) and Thyristor controlled phase shifter(TCPS) interaction is investigated . The objective of this work is to study and design a controller capable of doing the task of damping in less economical control effort, and to globally link all controllers of national network in an optimal manner , toward smarter grids . This can be well done if a specific coordination between PSS and FACTS devices , is accomplished . Firstly, A genetic algorithm-based controller is used. Genetic Algorithm (GA) is utilized to search for optimum controller parameter settings that optimize a given eigenvalue based objective function. Secondly, an optimal pole shifting, based on modern control theory for multi-input multi-output systems, is used. It requires solving first order or second order linear matrix Lyapunov equation for shifting dominant poles to much better location that guaranteed less overshoot and less settling time of system transient response following a disturbance. |
| Open Access |
| A Study of the Optimal Allocation of Shunt Capacitor Based on Modified Loss Sensitivity Algorithm |
| Warid Sayel Warid, Emad Allawi Mohsin |
| Pages: 56-61 |
| FULL TEXT (PDF) |
| Abstract: |
| Minimization of active power losses is one of the essential aims for any electric utility, due to its importance in improvement of system properties towards minimum production cost and to support increase load requirement. In this paper we have studied the possibility of reducing the value of real power losses for (IEEE-14- Bus bar) global system transmission lines by choosing the best location to install shunt capacitor depending on new algorithm for calculate the optimal allocation, which considering the value of real power losses derivative with injection reactive power as an indicator of the ability of reducing losses at load buses. The results show the validity of this method for application in electric power transmission lines. |
| Open Access |
| Network Reconfiguration Using PSAT for Loss Reduction in Distribution Systems |
| Essa-J-Abdul Zehra, Mahmoud Moghavvemi, Maher M. I. Hashim, Kashem Muttaqi |
| Pages: 62-66 |
| FULL TEXT (PDF) |
| Abstract: |
| Network reconfiguration in distribution system is realized by changing the status of sectionalizing switches, and is usually done for the purpose of loss reduction. Loss reduction can result in substantial benefits for a utility. Other benefits from loss reduction include increased system capacity, and possible deferment or elimination of capital expenditures for system improvements and expansion. There is also improved voltage regulation as a result of reducing feeder voltage drop. Research work included by this paper focuses on using branch exchange method to minimize losses and solve the problems over different radial configuration. Solution’s algorithm for loss minimization has been developed based on two stages of solution methodology. The first stage determines maximum loss-reduction loop by comparing the size of circles for every loop. In a distribution system, a loop is associated by a tie-line and hence there are several loops in the system. To obtain the maximum lossreduction loop, size of modified zero loss-change circles are compared, and the loop within the largest circle is identified for maximum loss-reduction. The second stage determines the switching operation to be executed in that loop to reach a minimum loss network configuration by comparing the size of the loop circle for each branch-exchange. The smallest circle is to be identified for the best solution; the size of the loop circle is reduced when the losses are minimized. The performance of the proposed branch exchange method is tested on 16-bus distribution systems. |
| Open Access |
| Transient stability Assessment using Artificial Neural Network Considering Fault Location |
| P. K. Olulope, K. A. Folly, S. Chowdhury, S. P. Chowdhury |
| Pages: 67-72 |
| FULL TEXT (PDF) |
| Abstract: |
| This paper describes the capability of artificial neural network for predicting the critical clearing time of power system. It combines the advantages of time domain integration schemes with artificial neural network for real time transient stability assessment. The training of ANN is done using selected features as input and critical fault clearing time (CCT) as desire target. A single contingency was applied and the target CCT was found using time domain simulation. Multi layer feed forward neural network trained with Levenberg Marquardt (LM) back propagation algorithm is used to provide the estimated CCT. The effectiveness of ANN, the method is demonstrated on single machine infinite bus system (SMIB). The simulation shows that ANN can provide fast and accurate mapping which makes it applicable to real time scenario. |
| Open Access |
| Applying Fuzzy set method for solving mechanical engineering problems (Determining residual service life) |
| Waail Mahmod Al-wael, Maad M. Khalil |
| Pages: 73-77 |
| FULL TEXT (PDF) |
| Abstract: |
| In this paper we use fuzzy set method to solve one of the important problems in mechanical engineering (the residual service life). The residual service life for rolling stock can change depending on it’s using conditions. The Paper offer’s a new method depending on fuzzy set method by using the material mechanical and chemical corrosion mathematical model. |
| Open Access |
| ANFIS Modelling of Flexible Plate Structure |
| A. A. M. Al-Khafaji, I. Z. Mat Darus, M. F. Jamid |
| Pages: 78-82 |
| FULL TEXT (PDF) |
| Abstract: |
| This paper presented an investigation into the performance of system identification using an Adaptive Neuro-Fuzzy Inference System (ANFIS) technique for the dynamic modelling of a two dimensional flexible plate structure. It is confirmed experimentally, using National Instrumentation (NI) Data Acquisition System (DAQ) and flexible plate test rig that ANFIS can be effectively used for modelling the system with highly accurate results. The accuracy of the modelling results is demonstrated through validation tests including training and test validation and correlation tests. |