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Number of results: 8
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Abstract

The early philosophical standpoint of Professor Bogusław Wolniewicz alluded mainly to the so-called first philosophy of Ludwig Wittgenstein, as expressed in his Tractatus Logico-Philosophicus. Professor Wolniewicz’s views have found their expressions, first, in the book (in Polish) Things and Facts. An introduction to the first philosophy of Ludwig Wittgenstein (1968), and finally in his monograph (in Polish) Ontology of Situations. Foundations and Applications (1985). In both cases, Wolniewicz’ standpoint has been expressed by giving a substantive interpretation to semiotical and logical concepts (i.e. by producing hypostases). This practice looks rather dubious to me, in both cases, although I hope that ontology of situations can be usefully treated as a general formal theory of semantical correlates characteristic for sentential statements.
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Abstract

The deployment of a distributed power-flow controller (DPFC) in a single-machine infinite-bus power system with two parallel transmission lines are considered for the analysis in this paper. This paper presents the network analysis of the DPFC for power flow control. The performance is evaluated on a given test system with a single line-to-ground fault. The improvement in the stability as well as power quality is evident from the results. Thus the DPFC has the ability to enhance the stability and power quality of the system.
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Abstract

This paper presents a new strategy for optimal placement of multi-type FACTS devices with a view to minimize losses besides enhancing the voltage profile using biogeography based optimization. The strategy places three types of FACTS devices that include static VAR compensator, thyristor controlled series compensator and unified power flow controller; and offers optimal locations for placement, type and parameters of the FACTS devices. Test results on IEEE 14, 30 and 57 bus systems reveal the superiority of the algorithm.
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Abstract

Bogusław Wolniewicz created an original formal system based on his considerations on the ontology and semantics embedded in Wittgenstein’s Tractatus. His system – called by Wolniewicz ‘ontology of situations’ – can be complemented by a philosophical interpretation. In this article I identify the implicit and intuitive underpinnings of the system, its formal content and its philosophical implications. I also indicate a few applications of the system to axiology and logical hermeneutics.
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Abstract

The static synchronous compensator (STATCOM) is the multipurpose FACTS device with the multiple input and multiple output system for the enhancement of its dynamic performance in power system. Based on artificial intelligence (AI) optimization technique, a novel controller is proposed for CSC based STATCOM. In this paper, the CSC based STATCOM is controlled by the LQR. But the best constant values for LQR controller's parameters are obtained laboriously through trial and error method, although time consuming. So the goal of this paper is to investigate the ability of AI techniques such as genetic algorithm (GA) and particle swarm optimization (PSO) methods to search the best values of LQR controller's parameters in a very short time with the desired criterion for the test system. Performances of the GA, PSO & ABC based LQR controllers are also compared. Applicability of the proposed scheme is demonstrated through simulation in MATLAB and the simulation results are shown an improvement in the input-output response of CSC-STATCOM.
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Abstract

This paper addresses the state-variable stabilising control of the power system using such series FACTS devices as TCPAR installed in the tie-line connecting control areas in an interconnected power system. This stabilising control is activated in the transient state and is supplementary with respect to the main steady-state control designed for power flow regulation. Stabilising control laws, proposed in this paper, have been derived for a linear multi-machine system model using direct Lyapunov method with the aim to maximise the rate of energy dissipation during power swings and therefore maximisation their damping. The proposed control strategy is executed by a multi-loop controller with frequency deviations in all control areas used as the input signals. Validity of the proposed state-variable control has been confirmed by modal analysis and by computer simulation for a multi-machine test system.
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Abstract

The problem of improving the voltage profile and reducing power loss in electrical networks must be solved in an optimal manner. This paper deals with comparative study of Genetic Algorithm (GA) and Differential Evolution (DE) based algorithm for the optimal allocation of multiple FACTS (Flexible AC Transmission System) devices in an interconnected power system for the economic operation as well as to enhance loadability of lines. Proper placement of FACTS devices like Static VAr Compensator (SVC), Thyristor Controlled Switched Capacitor (TCSC) and controlling reactive generations of the generators and transformer tap settings simultaneously improves the system performance greatly using the proposed approach. These GA & DE based methods are applied on standard IEEE 30 bus system. The system is reactively loaded starting from base to 200% of base load. FACTS devices are installed in the different locations of the power system and system performance is observed with and without FACTS devices. First, the locations, where the FACTS devices to be placed is determined by calculating active and reactive power flows in the lines. GA and DE based algorithm is then applied to find the amount of magnitudes of the FACTS devices. Finally the comparison between these two techniques for the placement of FACTS devices are presented.
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Abstract

Transmission line loss minimization in a power system is an important research issue and it can be achieved by means of reactive power compensation. The unscheduled increment of load in a power system has driven the system to experience stressed conditions. This phenomenon has also led to voltage profile depreciation below the acceptable secure limit. The significance and use of Flexible AC Transmission System (FACTS) devices and capacitor placement is in order to alleviate the voltage profile decay problem. The optimal value of compensating devices equires proper optimization technique, able to search the optimal solution with less computational burden. This paper presents a technique to provide simultaneous or individual controls of basic system parameter like transmission voltage, impedance and phase angle, thereby controlling the transmitted power using Unified Power Flow Controller (UPFC) based on Bacterial Foraging (BF) algorithm. Voltage stability level of the system is defined on the Fast Voltage Stability Index (FVSI) of the lines. The IEEE 14-bus system is used as the test system to demonstrate the applicability and efficiency of the proposed system. The test result showed that the ocation of UPFC improves the voltage profile and also minimize the real power loss.
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