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Panda S.,Indian National Institute of Engineering
Journal of the Franklin Institute | Year: 2011

Power-system stability improvement by a static synchronous series compensator (SSSC)-based damping controller is thoroughly investigated in this paper. Both local and remote signals with associated time delays are considered in the present study. The design problem of the proposed controller is formulated as an optimization problem, and differential evolution (DE) algorithm is employed to search for the optimal controller parameters. The performances of the proposed controllers are evaluated under different disturbances for both single-machine infinite-bus power system and multi-machine power system. The performance of the proposed controllers with variations in the signal transmission delays has also been investigated. Simulation results are presented and compared with a recently published modern heuristic optimization technique under various disturbances to show the effectiveness and robustness of the proposed approach. The performances of the proposed controllers are also evaluated under N-2 contingency situation. © 2010 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.


Sharma S.,Indian National Institute of Engineering
International Journal of Advanced Manufacturing Technology | Year: 2011

In the case of the manufacturer-supplier relationship, suppliers are often advised to speedup their activities or expedite their operations. This leads to enhancing the production rate. In many cases, quality defects increase with an increase in production rate. In the absence of a suitable analytical tool, a supplier may become hesitant to decide in favor of this decision. In previous research by the author, a modification has been suggested concerning the flexibility in production rate. That formulation has been used with an inclusion of quality level to analyze the discussed case in this paper. Every company also faces this problem from time to time whether it is in supply chain relationship or independent. The proposed discussion is expected to be useful in many business/industrial situations. © 2010 Springer-Verlag London Limited.


Panda S.,Indian National Institute of Engineering
International Journal of Electrical Power and Energy Systems | Year: 2011

Design of an optimal controller requires optimization of multiple performance measures that are often noncommensurable and competing with each other. Design of such a controller is indeed a multi-objective optimization problem. Non-Dominated Sorting in Genetic Algorithms-II (NSGA-II) is a popular non-domination based genetic algorithm for solving multi-objective optimization problems. This paper investigates the application of NSGA-II technique for the tuning of a Proportional Integral Derivate (PID) controller for a Flexible AC Transmission System (FACTS)-based stabilizer. The design objective is to improve the damping of power system when subjected to a disturbance with minimum control effort. The proposed technique is applied to generate Pareto set of global optimal solutions to the given multi-objective optimization problem. Further, a fuzzy-based membership value assignment method is employed to choose the best compromise solution from the obtained Pareto solution set. Simulation results are presented and compared with a conventionally designed PID controller under various loading conditions and disturbances to show the effectiveness and robustness of the proposed approach. Finally, the proposed design approach is extended to a multi-machine power system to damp the modal oscillations with minimum control efforts. © 2011 Elsevier Ltd. All rights reserved.


Panda S.,Indian National Institute of Engineering
International Journal of Electrical Power and Energy Systems | Year: 2011

A robust coordination scheme to improve the stability of a power system by optimal design of multiple and multi-type damping controllers is presented in this paper. The controllers considered are power system stabilizer (PSS) and static synchronous series compensator (SSSC)-based controller. Local measurements are provided as input signals to all the controllers. The coordinated design problem is formulated as an optimization problem and differential evolution (DE) algorithm is employed to search for the optimal controller parameters. The performance of the proposed controllers is evaluated for both single-machine infinite-bus power system and multi-machine power system. Nonlinear simulation results are presented over a wide range of loading conditions and system configurations to show the effectiveness and robustness of the proposed coordinated design approach. It is observed that the proposed controllers provide efficient damping to power system oscillations under a wide range of operating conditions and under various disturbances. Further, simulation results show that, in a multi-machine power system, the modal oscillations are effectively damped by the proposed approach. © 2011 Elsevier Ltd. All rights reserved.


Mahapatro A.,Indian National Institute of Engineering | Khilar P.M.,National Institute of Technology Rourkela
IEEE Communications Surveys and Tutorials | Year: 2013

The sensor nodes in wireless sensor networks may be deployed in unattended and possibly hostile environments. The ill-disposed environment affects the monitoring infrastructure that includes the sensor nodes and the network. In addition, node failures and environmental hazards cause frequent topology changes, communication failures, and network partitioning. This in turn adds a new dimension to the fragility of the network topology. Such perturbations are far more common than those found in conventional wireless networks thus, demand efficient techniques for discovering disruptive behavior in such networks. Traditional fault diagnosis techniques devised for multiprocessor systems are not directly applicable to wireless sensor networks due to their specific requirements and limitations. This survey integrates research efforts that have been produced in fault diagnosis specifically for wireless sensor networks. The survey aims at clarifying and uncovering the potential of this technology by providing the technique-based taxonomy. The fault diagnosis techniques are classified based on the nature of the tests, correlation between sensor readings and characteristics of sensor nodes and the network. © 1998-2012 IEEE.

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