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This paper proposes a new Teaching–Learning Algorithm ( TLA ) that uses the chaotic map to prevent the conventional TLA from getting stuck on local optima and enhancing the convergence characteristics, due to non-repetitions nature and ergodicity of chaotic functions. Some shortcomings are encountered in the original TLA , for instance, it can be trapped in local optima. This work tries to improve it by substituting the random in the initial algorithm with chaotic sequences. At this level, the initial population is chaotically generated and chaotic values are used in both phases. The global solutions are further enhanced by adding a new third chaotic phase. To demonstrate the effectiveness of the improved Teaching–Learning algorithm ( ITLA ), a fifteen of well-known benchmark functions are used. Experimental results demonstrate that ITLA outperforms significantly the conventional TLA , in terms of the accuracy of the final solution and the speed of convergence. The enhanced optimization algorithm is employed to solve the coordinated design problem of power system stabilizers ( PSS ) and thyristor-controlled series capacitor ( TCSC ), in order to investigate the feasibility and effectiveness of the proposed method in power systems. The performance of the proposed controllers is evaluated on a multi-machine power system under large disturbance and for different operating conditions through a nonlinear time-domain simulation. At the end, the results confirm the robustness of the proposed controllers in comparison to PSS designed by ITLA ( ITLAPSS ) and TCSC designed by ITLA ( ITLATCSC ). [ABSTRACT FROM AUTHOR]

The purpose of this paper is to present the extended version of the conventional DEED to overcome the ramp rate violations when its optimal solutions for one period (normally one day) are implemented repeatedly and periodically over consequent dispatch periods to meet the periodic load demands. This dynamic dispatch problem, which is referred to as EDEED, is a multi-objective optimization problem which simultaneously minimizes both fuel cost and pollutants emission while satisfying a set of constraints. A multi-objective particle swarm optimization (MOPSO) method has been applied in this article for solving EDEED problem. The performance of the proposed method has been evaluated on the 10-unit test system with non-smooth fuel cost and emission level functions in comparison with those methods reported in the literature. [ABSTRACT FROM AUTHOR]

Abstract: This paper proposes a tool of assistance to prelocate insulation faults affecting electrical single-phase cables by using measurements of voltage and current available in source substation. An equivalent network modeling faults to the ground is analyzed by employing the distributed parameters approach. The per-unit length values of these parameters are calculated according to the geometrical data of the cable. The specificity of this tool is the introduction of a resistance to model sheath-ground insulation what allows studying various types of short-circuits to the ground (frank and resistive). Scenarios of fault are applied to the underground cable 150kV, connecting high voltage (HTB) sub-stations of Tyna–Taparoura–Sidimansour in Sfax city of Tunisia. A study of validation is approved by the software Simulink–SimPowerSystems of Matlab. [Copyright &y& Elsevier]

Abstract—The PV systems have increasingly displayed remarkable usefulness and interest, particularly in a wide range of industrial applications, such as industrial control systems, medical applications and hybrid vehicles. Due to the necessity of systems continuity requirement imposed by these applications, a special careful consideration should be granted to the boost converter reliability performance. Indeed, the boost converter reliability could be affected by a faulty operation essentially related to semiconductor switch used. In this respect, this paper proposes an advanced fast FDM with a FT strategy applied in boost converter PV systems in order to guarantee their continuity. By implementing the FDM and FT strategies on a dSpace real-time system, both types of OCF and SCF in boost converter switch are detected, identified and compensated. The proposed FDM is founded on the signals variations (increase or decrease) of the PV current, voltage and power as well as the duty cycle of the PV system. Accordingly, the PV system cost and complexity dimensions should tend to decrease due to the particular use of current and voltage sensors, dedicated to maintain the systems effective control. Additionally, for the purpose of the FT strategy which is applied under a fault appearance or occurrence, a redundant switch has been incorporated into the original boost converter in order to compensate the fault. Finally, the experimental results prove to confirm the high performance and capability of the proposed FDM and FT strategy in maintaining the PV system continuity. [ABSTRACT FROM AUTHOR]

In this paper, a new method was proposed with the objective of maximizing the rate of wind power integration into the electric grid. This method was based on the optimization of the parameters of the turbine governors (TGs) by means of a genetic algorithm. The tuning of TGs' parameters was formulated relying on an objective function aiming at reaching the maximum wind power penetration rate. The dynamic grid modeling consisted of synchronous machines, regulators, and wind turbines. The IEEE 14-bus modified test system was adopted to test the grid using the Power System Analysis Toolbox. The simulation results revealed that, with the optimized TGs' parameters, the rate of wind power integration improved considerably. [ABSTRACT FROM AUTHOR]

This paper investigates detailed flexible approach for incorporating various flexible alternating current transmission systems (FACTS) controllers in multimachine power system environment such as static var compensator (SVC) and thyristor controlled series capacitor (TCSC) in order to improve power system stability. The incorporation of FACTS devices into multimachine power system requires the development of the mathematical model of the power system with FACTS controllers. The differential algebraic equation (DAE) model of multimachine power system with FACTS controllers such as SVC and TCSC devices has been developed in this paper. Despite the fact that SVC and TCSC devices have been incorporated individually in DAE model of multimachine system, the DAE model with coordination of FACTS controllers has not been developed. So, the methodology of incorporation of series and shunt FACTS controllers in coordinated control manner in the DAE model of power system has been developed in this paper. Thus, the objective of this paper is to develop a general methodology of DAE model of power system with incorporation of series and shunt FACTS controllers in individual and coordinated control manner in order to improve power system stability. The western system coordinating council (WSCC) 3-machine, 9-bus system is used to illustrate the application of all proposed models and techniques. [ABSTRACT FROM AUTHOR]

This paper proposes a novel hybrid algorithm combining chaotic Jaya (CJaya) and sequential quadratic programming (SQP), namely CJaya-SQP, for solving the coordinated design problem of static var compensator (SVC) and power system stabilizers (PSSs). The CJaya serves as a global optimizer and the SQP as a local optimizer for fine-tuning the solution. In the proposed algorithm, chaotic maps are used to generate the initial solutions and control the search process. In order to prove the performance of the CJaya-SQP, a set of benchmark optimization problems is used where the results are compared with those of the basic Jaya and other recognized algorithms. The proposed optimization method is then applied for the optimal tuning of PSSs and SVC controllers in such a way that damping ratios and damping factors of the electromechanical modes are optimally improved. To illustrate the robustness of the CJaya-SQP-based coordinated PSSs and SVC controllers, the four-machine, two-area system is used. Eigenvalue analysis and nonlinear time-domain simulation vividly show that the CJaya-SQP-based coordinated controllers improve greatly the system's dynamic stability with a robust damping of local and inter-area power oscillations. [ABSTRACT FROM AUTHOR]

Abstract: This article presents a prelocalization approach of insulation faults affecting single-phase cables by using electrical measurements of voltage and current available in one substation. This approach is based on the theory of distributed parameters for modeling the faults to the ground. The specificity of this approach is the introduction of a resistance modeling the sheath-ground insulation allowing us to study the various types of faults to the ground (frankly and resistive). The fault distance and resistances are determined by two methods numerical and analytical. Many fault scenarios applied to the 150kV underground cable connecting HTB sub-stations of Tyna–Taparoura–Sidimansour in Sfax, show a good agreement between the two methods. A simulation of the global system using the software Simulink-SimPowerSystems of Matlab is carried out giving us the voltages and currents on the source side necessary to the execution of the developed methods and the validation of the obtained results. [Copyright &y& Elsevier]