Lsis Co., Ltd.

Korea Electrotechnology Research Institute

Hae Yong Park

Gyeong Ho Lee

Jung Wook Sim

Min Jee Kim

Won Joon Choe

Seung Hyun Bang

Kwon Bae Park

Sang Hun Park

Woo Young Lee

Hyun Jae Jang

Chae Yoon Bae

The DC interrupting device includes a main current conduction unit including a main interrupting switch, which is a mechanical switch, a reverse current power supply unit connected to an input terminal of the main current conduction unit and configured to generate a predetermined reverse current, and a reverse current conduction unit configured to supply the reverse current to an output terminal of the main current conduction unit. The reverse current power supply unit includes a first reverse current dedicated capacitor charged by a voltage applied to an input terminal of the main current conduction unit, a polarity reversing inductor configured to reverse a polarity of the first reverse current dedicated capacitor, and a reverse current power supply unit switch configured to perform circuit connection such that the polarity reversing inductor reverses the polarity of the first reverse current dedicated capacitor.

Inverse current injection-type direct current blocking device and method using vacuum gap switch

A fault current detection circuit comprises a primary current transformer that detects a current; a pair of secondary current transformers that convert a current detection signal into secondary conversion signals with a small current; a fault detection circuit section that determines whether or not a fault current occurs by comparing a current value according to a secondary conversion signal with a predetermined reference current value; a surge detection circuit section that determines whether or not a surge current occurs on the electric power circuit; and a trip determination unit that receives a fault detection signal and a surge detection signal, and generates a trip control signal when at least either one of the fault detection signal and the surge detection signal is received.

Fault current detecting circuit

A fault current limiter is provided. According to an embodiment of the present disclosure, the fault current limiter includes a switch whose contact point is opened when a fault current occurs; a current limiting element configured to limit the fault current when the fault current occurs; and a diode being serial-connected to the current limiting element, wherein a breakdown voltage of the diode is higher than a voltage drop by an impedance of the switch when a normal current flows.

Fault current limiter

The fast switch includes: a housing; a vacuum interrupter installed in the housing, connected to a main circuit, and configured to open and close the main circuit; a contact spring coupled to a mover of the vacuum interrupter, and configured to provide a contact force; an insulating rod connected to the contact spring; a permanent magnet actuator connected to a lower end of the insulating rod, and configured to provide a switching driving force; a first capacitor configured to provide a discharge current to a coil of the permanent magnet actuator; a driving coil connected to a lower end of the permanent magnet actuator; and a second capacitor configured to provide a discharge current to the driving coil.

Fast switch

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.

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.

Growing community of inventors

Changwon-si, South Korea

Hae Yong Park