Effect of thiobencarb formulations on freshwater shrimp, macrobrachium lanchesteri (De Man)

The effect of com-cob controlled-release formulations (CRF) of thiobencarb ( TAl and T A2) and alginate CRF (TAL 70192) to the freshwater shrimp, Macrobrachium lanchesteri (De Man), in comparison to a conventional granular formulation was studied in the laboratory. Mortality ofthe shrimps 24 h after exposure to the conventional formulation was significantly higher (P <= 0.05), and increased to 93.3% after 120 h. The CRF of TAl, TA2 and TAL 70192 caused mortality of 19.2,5.8 and 8.5%, respectively, 120 h after exposure. This difference is due to the slower release of thiobencarb using CRF

Dynamic Voltage Restorer Application for Power Quality Improvement in Electrical Distribution System: An Overview

Dynamic Voltage Restorer (DVR) is a custom power device that is used to improve voltage disturbances in electrical distribution system. The components of the DVR consist of voltage source inverter (VSI), injection transformers, passive filters and energy storage. The main function of the DVR is used to inject three phase voltage in series and in synchronism with the grid voltages in order to compensate voltage disturbances. The Development of (DVR) has been proposed by many researchers. This paper presents a review of the researches on the DVR application for power quality Improvement in electrical distribution network. The types of DVR control strategies and its configuration has been discussed and may assist the researchers in this area to develop and proposed their new idea in order to build the prototype and controller

Three phase inverter control using DSP controller for dynamic voltage restorer (DVR) application

This paper discusses the control technique improvement of a three-phase inverter using directquadrature- zero (d-q-0) controller based on DSP TMS320F2812 for dynamic voltage restorer (DVR) applications. The output of the inverter is then connected to a voltage grid via a second order filter and injection transformer. The control algorithms are developed using TMS320F 2812 DSP. The proposed technique achieves voltage regulation with low total harmonics distortion (THD) for both voltage and current. This paper also highlights a series of discussion, analysis and studies performed on the proposed control technique, including L-C filter design issue and the concept of DVR in the distribution system. An analysis and experimental results validate the effectiveness of the DSP controller in mitigating voltage sags and harmonics issues in the distribution syste

Mining Web usage using FRS

Web Usage Mining (WUM) is the application of data mining methods in extracting potentially useful information from web usage data. Its application includes improving website design, personalised service, target marketing etc. Among the outstanding research issues in WUM include inefficiency in mining large weblogs, extracted patterns that are not representative of actual user behavior, and mining results which are too general, uninteresting and lack insights. This paper attempts to address the above problems using a method of mining that captures user traversing activities more effectively based on the notion of regularity. A mining algorithm is introduced using the approach of vertical database. The experiments suggest that the method is efficient, scalable, and able to address confusion caused by large number of extracted patterns

Voltage stability analysis of load buses in electric power system using adaptive neuro-fuzzy inference system (anfis) and probabilistic neural network (pnn)

This paper presents the application of neural networks for analysing voltage stability of load buses in electric power system. Voltage stability margin (VSM) and load power margin (LPM) are used as the indicators for analysing voltage stability. The neural networks used in this research are divided into two types. The first type is using the neural network to predict the values of VSM and LPM. Multilayer perceptron back propagation (MLPBP) neural network and adaptive neuro-fuzzy inference system (ANFIS) will be used. The second type is to classify the values of VSM and LPM using the probabilistic neural network (PNN). The IEEE 30-bus system has been chosen as the reference electrical power system. All of the neural network-based models used in this research is developed using MATLAB

Voltage Swells Improvement in Low Voltage Network Using Dynamic Voltage Restorer

Abstract: Problem statement: Voltage disturbances are the most common power quality problem due to the increased use of a large numbers of sophisticated electronic equipment in industrial distribution system. The voltage disturbances such as voltage sags, swells, harmonics, unbalance and flickers. High quality in the power supply is needed, since failures due to such disturbances usually have a high impact on production cost. There are many different solutions to compensate voltage disturbances but the use of a DVR is considered to be the most cost effective method. The objective of this study is to propose a new topology of a DVR in order to mitigate voltage swells using a powerful power custom device namely the Dynamic Voltage Restorer (DVR). Approach: New configuration of a DVR with an improvement of a controller based on direct-quadrature-zero method has been introduced to compensate voltage swells in the network. Results: The effectiveness of the DVR with its controller were verify using Matlab/Simulink’s SimPower Toolbox and then implemented using 5KVA DVR experimental setup. Simulations and experimental results demonstrate the effective dynamic performance of the proposed configuration. Conclusion: The implimentation of the proposed DVR validate the capabilities in mitigating of voltage swells effectiveness.During voltage swells, the DVR injects an appropriate voltage to maintain the load voltage at its nominal value

SPACE VECTOR ANALYSIS IN ELECTRICAL DRIVES FOR SINGLE-PHASE INDUCTION MOTOR USING MATLAB/SIMULINK

Space Vector Pulse Width Modulation (SVPWM) has become the successful techniques to construct threephase sine wave Voltage Source Inverter (VSI) parallel to control three-phase motor using vector control. In this paper we present the analysis of SVPWM to construct two-phase sine wave VSI for single-phase induction motor. We also describes the modulation technique refer to dq components of main and auxiliary windings of single-phase induction motor. The VSI have four legs for this single-phase induction motor, and the four switching sequences had simulated in MATLAB and SIMULINK. The simulation result shows the feasibility of the proposed modulation techniques to drive single-phase induction motor

Triplen Harmonics Mitigation 3 Phase Four-Wire Electrical Distribution System Using Wye- Zig-Zag Transformers

This paper studies an application of wye- zigzag transformes for reducing harmonics in the neutral conductors of a three phase 415/240V distribution system. Triplen harmonic currents add up in the neutral conductor of the distribution system feeding the non linear loads such as personal computers and electronic office machines with switch mode power supplies. The zigzag transformer is installed between the distribution panel and the high harmonics producing loads. This research makes use of a star-zigzag grounded transformer