Flicker characteristic estimation of an electric arc furnace feeder

This paper describes the estimation of the stochastic flicker characteristics for an electric are furnace over a complete heat. These characteristics include stationarity, normality and correlation. Besides, the basic statistic probability were assessed by varying sampling period, too. The estimation and the assessment were implemented by a microcomputer-based instrumentation system. The test results for a typical AC are furnace show that (1) most nicker characteristics are stationary or weakly stationary during different periods of a heat cycle, but most of their probability density functions are not normally distributed, (2) the voltage and current fluctuations in the same phase are highly correlated, (3) the nicker converges at a,value with a +/- 5% deviations from the value based on a basic sampling period, if the sampling period is decreased below 12 seconds.