11 research outputs found

    Effect of equivalent salt deposit density on flashover voltage of contaminated insulator energized by HVDC

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    In Malaysia, the demand for electric power is increasing day by day due to more consumption of power in the industrial sector. Recently, the high voltage DC transmission lines are under construction near the coastal environments for transmitting the power to the all states of Malaysia. Therefore, there is a concern about the reliability of these systems especially under adverse environmental conditions due to sea salt spray contamination. This reliability of this contaminated insulator can be improved through its performance studies. For this performance study, an analytical expression between flashover voltage and ESDD of the contaminated insulator has been proposed using Dimensional Analysis technique. The results obtained from the analytical expression are compared with the experimental results and in close agreement are foun

    Shape Preserving GOl Rational Interpolation.

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    A GCl rational quartic function has been constructed with three parameters to preserve the shape of positive and monotone curve data. Simple data dependent constraints are derived on one of the parameters to preserve the shape of data while other two are free to refine the shape of curve at user choice

    G Scattered Data Interpolation with Minimized Sum of Squares of Principal Curvatures

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    One of the main focus of scattered data interpolation is fitting a smooth surface to a set of non-uniformly distributed data points which extends to all positions in a prescribed domain

    Second Order Partial Derivatives Estimation Using a Modification of the Lagrange Quadratic Interpolant

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    Partial derivative values are required to construct a smooth interpolated surface which passes through given three dimensional scattered data points. These partial derivative values are not avaliable in practice for raw three dimensional scattered data and the estimation of these values is thus desirable. This research concentrates on estimating the partial derivative values up to the second order. Many current methods concentrate on first order partial derivatives estimation as most applications require only up to the first order derivatives

    Development of user panel for polarization and depolarization current (PDC) measurement analysis of high voltage (HV) machine insulation system

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    Insulation system is the backbone in any HV machine and as well as power system. However, degradation that always happens in the insulation system will reduce the lifespan of the machine. Thus, condition monitoring of the insulation system is highly recommended in order to maintain the reliability and efficiency of the machine during operation. Polarization and Depolarization Current (PDC) measurement is one of the time domain condition monitoring that been acknowledge by the researchers around the globe. This predictive maintenance with the aid of online monitoring provides an indication of the machine's condition. The development of measurement technologies and data analysis techniques using computational methods give an advantage in saving time and improve safety. This paper presents the user panel that had been developed for the application of PDC diagnostic methods. Through this panel the conductivity level based on PDC measurement on the machine insulation system can be analyze and monitored. The developed user-friendly panel enable user to run the recorded PDC data to evaluate the performance of the insulator in term of its conductivity. It was found that the conductivity level of the insulation material is related to its PDC curves. The system developed was found successfully helping user to do analysis on PDC data by giving the PDC pattern and conductivity of the tested insulator

    A choice of weights for convex combination methods in estimating partial derivatives

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    Weights in convex combination methods are important parameters in the estimation of partial derivative values in three dimensional scattered data points. We introduce the three angles of the base triangle as weights in order to have more options for weight variety
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