Abstract: A method, device, and system for detecting a current leak in a traction power rail. Magnetic or electrical properties of the rail are measured. The measurements are performed using a rail instrument that senses the properties around the rail at various times while the instrument is being moved down the rail, such as using a cart or train. The rail instrument may be a flux concentrator or open Rogowski coil. The locations of the rail, about which the readings are taken by the rail instrument, may be determined and correlated with the measurements themselves. The method may comprise measuring the magnetic field of the rail along a length of the rail, and identifying a leak based on differences between the magnetic field measurements. The system may comprise a cart comprising the rail instrument and a location instrument.

Abstract: A system measures parameters of the electricity drawn by an arc furnace and, based on an analysis of the parameters, provides indicators of whether arc coverage has been optimized. Factors related to optimization of arc coverage include electrode position, charge level, slag level and slag behaviour. More specifically, such indicators of whether arc coverage has been optimized may be used when determining a position for the electrode such that, to an extent possible, a stable arc cavity is maintained and an open arc condition is avoided. Conveniently, by avoiding open arc conditions, the internal linings of the furnace walls and roof may be protected from excessive wear and tear.

Abstract: A configuration of switches added to a line control circuit allows for switching back and forth between a configuration featuring a series-connected thyristor switch and reactor and a configuration featuring a parallel-connected thyristor switch and reactor. Connecting the reactor in series with the thyristor switch allows a controlled high-impedance circuit configuration that is particularly well adapted for cold furnace start-ups and furnace idling. In this manner, there is reduced need for such equipment as extra startup transformers, alternate low-voltage power supply configurations and temporary specialty electrical apparatus for cold furnace start-ups.

Abstract: It is proposed herein to employ thyristor firing angles as a fast prediction of flicker in power supply for an electric arc furnace. It is further proposed to actively modify operating variables for the electric arc furnace to maintain the flicker below a predefined threshold. Aspects of the present application use the thyristor firing angles in combination with control ranges of variable reactance devices to predict the flicker severity level generated by the electric arc furnace with thyristor-controlled variable reactance devices. Based on the predicted flicker level, at least one operating variable of the electric arc furnace may be changed, if required, to maintain flicker to acceptable limit.

Abstract: A system measures parameters of the electricity drawn by an arc furnace and, based on an analysis of the parameters, provides indicators of whether arc coverage has been optimized. Factors related to optimization of arc coverage include electrode position, charge level, slag level and slag behaviour. More specifically, such indicators of whether arc coverage has been optimized may be used when determining a position for the electrode such that, to an extent possible, a stable arc cavity is maintained and an open arc condition is avoided. Conveniently, by avoiding open arc conditions, the internal linings of the furnace walls and roof may be protected from excessive wear and tear.

Abstract: A configuration of switches added to a line control circuit allows for switching back and forth between a configuration featuring a series-connected thyristor switch and reactor and a configuration featuring a parallel-connected thyristor switch and reactor. Connecting the reactor in series with the thyristor switch allows a controlled high-impedance circuit configuration that is particularly well adapted for cold furnace start-ups and furnace idling. In this manner, there is reduced need for such equipment as extra startup transformers, alternate low-voltage power supply configurations and temporary specialty electrical apparatus for cold furnace start-ups.

Abstract: It is proposed herein to employ thyristor firing angles as a fast prediction of flicker in power supply for an electric arc furnace. It is further proposed to actively modify operating variables for the electric arc furnace to maintain the flicker below a predefined threshold. Aspects of the present application use the thyristor firing angles in combination with control ranges of variable reactance devices to predict the flicker severity level generated by the electric arc furnace with thyristor-controlled variable reactance devices. Based on the predicted flicker level, at least one operating variable of the electric arc furnace may be changed, if required, to maintain flicker to acceptable limit.