Abb Schweiz Ag

Ralf Baechle

Raeto Stadler

Peter Daehler

Marco Schoeni

A thyristor circuit includes at least one branch including at least one thyristor, a thyristor control circuit and a current detector. The current detector is configured to detect a current value representative of an electrical current flowing through the thyristor and to input the detected current value into the thyristor control circuit. The thyristor control circuit is configured to determine a fault condition in which the detected current value exceeds a predetermined current threshold based on a deteriorated blocking ability of the thyristor. Dependent on the determination result, the thyristor control circuit triggers the thyristor into a conductive state.

Thyristor circuit and thyristor protection method

A control device for an arc furnace includes an arc furnace control module for controlling the arc furnace and a flicker module for determining a flicker value in a grid supplying the arc furnace, wherein the arc furnace control module is adapted for controlling the arc furnace based on the flicker value and wherein the arc furnace control module and the flicker module are integrated into one structural component.

Integrated flicker control for arc furnace

A method and apparatus for balancing a three point DC voltage intermediate circuit involves a converter circuit which influences an electrical power flow in a three point DC voltage intermediate circuit. An intermediate circuit voltage mean value is formed from a first intermediate circuit voltage across a first capacitor, and from a second intermediate circuit voltage across a second capacitor. Based on an intermediate circuit voltage mean value exceeding a threshold value, the first capacitor is connected by means of the converter circuit to an energy store, and the energy store is then connected by means of the converter circuit to the second capacitor. If the threshold value is significantly undershot, the second capacitor is connected to the energy store by means of the converter circuit, and the energy store is then connected to the first capacitor by means of the converter circuit.

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Weilheim, Germany

Ralf Baechle