During scrap melting, electric-arc-furnace parameters such as voltage and current, real and reactive power, resistance and reactance etc. exhibit significant variations about longer term mean values. The parameters can be considered to be random variables. The statistical properties of the parameter variations have been evaluated in this paper using data recorded on two 65 MVA furnaces. It is shown that the random variations of a broad range of parameters can be considered to be weakly stationary, but that the variations generally do not follow a Gaussian probability distribution. A significant correlation was found between the resistance and reactance variations per phase. The measured data was used to develop a strategy whereby the mean and standard deviation of the random variations could be measured online, with good accuracy, using conventionally available data-acquisition equipment. It is shown that an improperly chosen sampling strategy can yield quite misleading results.
[1]
G. W. Brundrett,et al.
Human sensitivity to flicker
,
1974
.
[2]
Jacobus D. Van Wyk,et al.
On-Line Harmonic Analysis as a Diagnostic Design and Control Tool for Power Systems Feeding Arc Furnaces, Thyristor-Controlled Mill Drives, and Power Factor Correction Equipment
,
1983,
IEEE transactions on industry applications.
[3]
J. D. Lavers,et al.
A Method of Examining in Detail Electric Arc Furnace Performance
,
1985,
IEEE Transactions on Industry Applications.
[4]
G.F.L. Dixon,et al.
Supply to arc furnaces: measurement and prediction of supply-voltage fluctuation
,
1972
.
[5]
H. Saunders.
Literature Review : RANDOM DATA: ANALYSIS AND MEASUREMENT PROCEDURES J. S. Bendat and A.G. Piersol Wiley-Interscience, New York, N. Y. (1971)
,
1974
.