Finite element computation of electric field and charge density ofa pulsed energized electrostatic precipitator

This paper numerically analyzes the governing equations in pulsed energized wire-duct electrostatic precipitators (WDEP). The electric field along its spatial distribution and the voltage-current characteristics are evaluated in the presence of dust. The finite element method (FEM) and a modified method of characteristics are used to solve the time-dependent Poisson's equation and to satisfy the current continuity condition, respectively. The two methods are repeated iteratively to obtain a self-consistent solution of the describing equations. The effect of pulse rate variation on the computed results is also investigated. Comparing the computed results with previously obtained experimental and calculated values tests the effectiveness of this approach. The agreement with experimental results is found to be satisfactor

Finite element solution of monopolar corona as influenced by ionlife time

This paper presents an iterative finite element technique for the analysis of monopolar ionized field in transmission line conductor to plane configurations. One of the main underlying assumptions adopted in the literature, namely, the constant ion mobility, is waived in a simple way. The impact of waiving this assumption on the computed corona current and ground plane current density profile is investigated. A laboratory model was built to check the accuracy of the calculated corona current and the ground plane current density characteristics. It has been found that the present calculated corona current and the ground plane current density, which assumed variable ion mobility, agreed well with those measured experimentally for laboratory and full scale models and are less than those obtained when assuming constant ion mobilit

"A Systematic Approach to Nuclear Microscopy of Water Trees for a Large Number of Field-aged HV Cable Samples"

In order to perform micro-PIXE measurements on water trees in underground HV cables when a large number of cable samples are involved, a sequence of tests has been devised to minimize time and effort for sample preparation, water tree detection and analysis. These tests include electrical diagnostic tests to predict the possible presence of water trees, optical microscopy on cable insulation to detect water trees in the samples screened by the electrical tests, scanning electron microscopy for detailed surface topography of water trees, and nuclear microscopy for elemental composition and distribution maps of water trees. Correlations among the results of the four types of measurements are discussed to evaluate the usefulness of the methodolog

Finite element analysis of corona in wire-duct electrostaticprecipitators

This paper is aimed at the analysis of corona power loss associated with wire duct electrostatic precipitators (WDEP). The finite element method (FEM) is used to solve the Poisson's equation and a modified method of characteristics is used to satisfy the current continuity condition. The two methods are repeated iteratively to get a self consistent solution of the describing equations. The effectiveness of this approach is tested by comparing the computed results with previously experimental and calculated values. The agreement with experimental results is found to be satisfactor

"Particle Swarm Based Design of Variable Structure Stabilizer for a Nonlinear Model of SMIB System"

In this paper, a particle swarm-(PSO) based variable structure stabilizer (VSC) is proposed for enhancing the dynamic stability of a nonlinear model of synchronous machine infinite busbar system (SMIB). Unlike the methods reported in the literature which involve either linearizing the model of synchronous machine around a suitable operation point or applying nonlinear transformation techniques before linear control theory is used in designing a fixed parameter PSS, the present method formulates the design of VSC as an optimization problem and utilized the PSO algorithm to provide a simple and systematic way of arriving at the optimal feedback gains and switching vector values of the stabilizer. When compared to previous methods, simulation results showed the effectiveness of the proposed stabilizer design

Corona power loss, electric field, and current density profiles in bundled horizontal and vertical bipolar conductors

In this paper, computation of the corona current and, hence, the corona power loss associated with bipolar high-voltage direct current (HVDC) conductors is presented using the finite-element method (FEM) and the method of characteristics (MOC). The former method is used to solve Poisson's equation while the latter is used to satisfy the current continuity condition. The ground-plane current density and electric field profiles associated with the HVDC conductors are also calculated as a prerequisite for the computation of the corona current. The effectiveness of the present method is demonstrated using HVDC full-scale and laboratory-model transmission lines. Horizontal and vertical bipolar configurations are tested with 2 and 4 bundles. Comparison between previously measured and computed profiles and present calculations shows satisfactory agreement with previous measured and calculated values

Finite element computation of electric field and charge density ofa pulsed energized electrostatic precipitator

This paper numerically analyzes the governing equations in pulsed energized wire-duct electrostatic precipitators (WDEP). The electric field along its spatial distribution and the voltage-current characteristics are evaluated in the presence of dust. The finite element method (FEM) and a modified method of characteristics are used to solve the time-dependent Poisson's equation and to satisfy the current continuity condition, respectively. The two methods are repeated iteratively to obtain a self-consistent solution of the describing equations. The effect of pulse rate variation on the computed results is also investigated. Comparing the computed results with previously obtained experimental and calculated values tests the effectiveness of this approach. The agreement with experimental results is found to be satisfactor