Load characteristics analysis of AC and DC arc furnaces using various power definitions and statistic method

Various power definitions and statistics are used to investigate the load characteristics of ac and dc electric arc furnaces, which occupy a major percentage of the Taiwan power system. It is very important to note their effects on power quality. It is also desirable to have an alternative way to study their load behaviors. Since ac and dc arc furnaces have different control methods, there will be different problems of load fluctuation, three-phase unbalance, and harmonics. However, traditional monitoring methods cannot fully reveal the load conditions. So several new power quantities are needed to explore the effect of unbalance and harmonics. The content of load fluctuation could be presented in the statistics. The results in this paper are helpful for load measurement and power-quality limitation.