Real-Time Measurement Approach for Tracking the ΔV10 Estimate Value of DC EAF

This investigation develops a revisable method for estimating the estimate value of equivalent 10 Hz voltage flicker (DV10) of a DC Electric Arc Furnace (EAF). This study also discusses three 161kV DC EAFs by field measurement, with those results indicating that the estimated DV10 value is significantly smaller than the survey value. The key point is that the conventional means of estimating DV10 is inappropriate. There is a main cause as the assumed Qmax is too small.

Although DC EAF is regularly operated in a constant MVA mode, the reactive power variation in the Main Transformer (MT) is more significant than that in the Furnace Transformer (FT). A substantial difference exists between estimated maximum reactive power fluctuation (DQmax) and the survey value from actual DC EAF operations. However, this study proposes a revisable method that can obtain a more accurate DV10 estimate than the conventional method.





References:
[1] Gu, J.C., Wu, C.J., and Chiang, J.C.: ‘Effects of High Voltage Side Voltage Flicker Sources on Low Voltage Side Customers’. Research Report, Power Research Institute, Taiwan Power Company, 1994
[2] Wu, C.J., and Lee, L.H.: ‘Electric Power Quality Evaluation of 161kV Large Size Steel Plants’. Research Report, Power Research Institute, Taiwan Power Company, 1995
[3] Manchur, G., and Erven, C.C.: ‘Development of A Model for Estimating Flicker from Electric Arc Furnaces’, IEEE Trans. on Power Delivery, 1992, 7 (1), pp. 416-426
[4] ‘New trend in supply problems of arc furnace for steel plants’. Technology Report, Electrical Engineering Society, Japanese, 1978, 2 (72)
[5] Mendis, S.R., Do, A.V., and Boyd, D.M.: ‘Investigation of Transmission System Voltage Flicker due to Multiple AC and DC Furnace Operations’. IEEE Trans. on Power Delivery, 1995, 10 (1), pp.483-496
[6] Chiang, J.C.: ‘Electric Power Quality Actual Illustration’ (Chwa Book Co., Taiwan, 2000 1st edn.)
[7] ‘The Survey of DC Arc Furnace’. Technology Report, Nihon Kou-Kan Co., Japanese, 1989
[8] Wu, C.J.: ‘Measurement and Analysis of Voltage Flicker’. Research Report, Power Research Institute, Energy Commission, Ministry of Economic Affairs, Taiwan, 2000.
[9] J. L. Guan, J. C. Gu, and C. J. Wu, "A Novel Method for Estimating Voltage Flicker," IEEE Trans. on Power Delivery, vol. 20, no. 1, pp. 242-247, Jan. 2005.
[10] J. L. Guan, J. C. Gu, and C. J. Wu, " Real-time Measurement Approach for Tracking the Actual Coefficient of / of Electric Arc Furnaces," IEEE Trans. on Power Delivery, vol. 19, no. 1, pp. 309-315, Jan. 2004.