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 was assessed by varying the sampling period too. The estimation and the assessment were implemented by a microcomputer-based instrumentation system. The test results for a typical AC arc furnace show that (1) most flicker 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 flicker 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