Curve Fitting in Parameter Estimation of High Voltage Impulses

摘要

With the adoption of digital recorders in high voltage measurements, there hasemerged a great need to finding a generally applicable and accepted method to calculate parameters from digital lightning impulse records. While several methods have been proposed, it remains debatable which one is the 'best' choice. There are still differing opinions even in some fundamental definitions of impulse characteristics. The notion of a 'mean curve' is especially under discussion. The whole issue is very much open and approaches from different points of view are welcome. Parameters of lightning impulses characteristic to high-voltage measurements were formerly calculated by hand from analogue oscillogrammes. Nowadays a digital recorders are used in impulse measurements and the calculation is done mainly by computers. The records, however, are often non-ideal including noise, distortions and other imperfections, especially in lightning impulses. So, computerized calculation from raw data is difficult and cause errors in results. Calculating the parameters from a smooth mean curve would lead to a better result.