A 10,000-Kva Series Capacitor Improves Voltage on 66-Kv Line Supplying Large Electric Furnace Load

Duquesne Light Company placed in service on October 26, 1947, the largest kilovolt-ampere and highest voltage-series capacitor in the world, to improve voltage regulation and alleviate voltage flicker at a large steel mill and on the line serving it. The capacitor has a nominal rating of 10,000-kva and was installed on a 66-kv line. It was built by the Westinghouse Electric Corporation. This paper presents the calculated results of system studies made prior to the authorization of the series capacitor and the reasons for selecting the series capacitor. In addition, the results of staged tests showing the starting of a large induction motor and the energizing of the power transformers at the load with the capacitor in service are included. The improvement in utilization voltage is also shown.