Lsis Co., Ltd.

Ls Industrial Systems Co., Ltd.

Seung Hyun Bang

Won Joon Choe

Jung Wook Sim

Gyeong Ho Lee

Min Jee Kim

Hae Yong Park

Kwon Bae Park

Kil Young Ahn

This specification relates to fault current limiter (FCL). More particularly, to solve problems of protecting and designing current limiting impedance in a protective coordination system, as limitations of the related art, the fault current limiter may measure heat capacity of a current limiting impedance unit by detecting fault current flowing to the current limiting impedance unit and limiting the fault current flowing to the current limiting impedance unit according to the measured heat capacity, which may result in preventing the current limiting impedance unit from being damaged due to the fault current, preventing an extended accident due to the damaged current limiting impedance unit and enabling a stabilized system and line protection.

Fault current limiter

The fault current detecting circuit includes: a current detection unit that outputs a current detection signal; a first comparing circuit unit that compares the current detection signal with a predetermined reference current value and outputs a first output signal; a differentiator that differentiates the current detection signal to output a change slope of the current detection signal; a second comparing circuit unit that compares the change slope with a predetermined reference change slope value and outputs a second output signal; a third comparing circuit unit that compares the current detection signal with a predetermined current detection limit reference value and output a third output signal; and a trip determining unit that outputs a trip control signal only when the first output signal and the second output signal are maintained to be received and the third output signal is not received.

Fault current detecting circuit

Provided is a protection coordination system. The system includes a current limiter arranged on a line between a first relay and a second relay to limit a fault current generated to within a predetermined scope.

Protection coordination system

Provided is a fault current limiter, the limiter including a detector detecting an inflow of a fault current and transmitting a turn-off signal to a power semiconductor element; the power semiconductor element changed to an OFF state by the turn-off signal; and a resistance element connected in parallel to the power semiconductor element to block the fault current.

Provided is a fault current limiter, the limiter including a detector detecting an inflow of a fault current and transmitting a turn-on signal to a first switch and transmitting a turn-off signal to a power semiconductor element, the power semiconductor element changed to an OFF state by the turn-off signal, the first switch forming a current limiting circuit by being switched to an ON state by the turn-on signal, and a resistance element blocking the fault current, wherein the series connection between the resistance element and the first switch is connected in parallel to the power semiconductor element.

A method for driving an IGBT, wherein a transient voltage applied across the IGBT is reduced by altering a rate of change of a gate-emitter voltage of the IGBT.

Method for driving IGBT

The present invention is related to a hybrid fault current limiter comprising a switching unit detaching a moving contact located on a cable and transmitting a trip signal if a fault current is flowed at an electric power system, a semiconductor switching unit connected in series with the switching unit and configured to be turned off to limit the flow of the fault current when the trip signal is transmitted, and a circuit breaking unit connected in parallel to the switching unit and the semiconductor switching unit and configured to limit the fault current detoured from the switching unit and the semiconductor switching unit. The present invention provides rapid treatment for the fault current problem by applying the algorithm sensing the occurrence of the fault current and the algorithm limiting the fault current simultaneously.

Growing community of inventors

Busan, South Korea

Seung Hyun Bang