Corona ring

About: Corona ring is a research topic. Over the lifetime, 1503 publications have been published within this topic receiving 14530 citations.

Optimal design of corona ring on HV composite insulator using PSO approach with dynamic population size

Abstract: This paper deals with the use of corona ring at the HV end fitting for improving the electric field and potential distributions and then for minimizing the corona discharges on 230 kV AC transmission line composite insulator. A single corona ring is installed at the energized end side. Three-dimensional finite element method (FEM) software is employed to compute the electric field. As the performance of high voltage insulator strings closely depends on designs and locations of corona ring, the effects of the corona ring radius, the ring tube radius and the ring vertical position are examined. The minimization of the electric field necessitates the optimization of corona ring. For this purpose, new nonlinear mathematical objective function linking the electric field strength to the corona ring structure parameters is established. The optimization problem is achieved by minimizing the objective function using a modified particles swarm optimization (PSO) algorithm with a dynamic population size. The algorithm adjusts the size of population for each iteration. Based on the average value and the best solution of the objective function, we propose a new mathematical model to update the population size. This algorithm enables the population size reduction leading to computing time decrease. According to the results, FEM-PSO hybridization technique could be very helpful in optimization of corona ring design.

Calculation of Spark Breakdown or Corona Starting Voltages in Nonuniform Fields.

Abstract: The processes leading to a spark breakdown or corona discharge are discussed very briefly. A quantitative breakdown criterion for use in high-voltage design is derived by which spark breakdown or corona starting voltages in nonuniform fields can be calculated. The criterion is applied to the sphere gap, and it is shown how it can give a very detailed and accurate description of known breakdown characteristics.

Partial discharge patterns in high voltage insulation

Abstract: Partial discharge (PD) is an electrical discharge, which does not bridge the electrodes between an insulation system completely under high electric field stress. PD events may affect the performance of insulation system because in long term, it may cause the breakdown of insulation system and failure of high voltage component due to repetition of PD events. In this work, two techniques of analysing PD data have been studied; the phase resolved partial discharge (PRPD) pattern and pulse sequential analysis (PSA) techniques. These two techniques were used to distinguish three main types of PD; they are corona, void and surface discharges. PD data were obtained from the measurement in high voltage laboratory in the University of Southampton, UK. In the end of the analysis, comparison between the PRPD and PSA methods was done to evaluate the advantages and disadvantages between the two techniques.

Electrical Characterization of a Corona Discharge for Surface Treatment

Abstract: Electrical characterization is based on a display of voltage and charge which appears as a simple parallelogram. The area is a measure of energy input per cycle and is independent of voltage waveform but very dependent on the maximum voltage. A useful model for such corona discharges employs a Zener diode to simulate the corona drop. The buffer dielectric plays a major roll in controlling the corona power, and the air gap importance depends on the electrode system employed. Proper interpretation of the voltage-charge traces provides insight as to the corona performance and serves as a diagnostic procedure for obtaining optimum performance.