A switching arrangement for switching off an electric current with a high slew rate, especially a short-circuit current, includes a main line with a first SCR-arrangement including at least a first SCR and a first reverse conducting diode arranged in parallel to the first SCR, and a first bypass line connected to the main line and arranged in a parallel way to the first SCR-arrangement. The first bypass line includes a second SCR-arrangement comprising at least a second SCR arranged in the same polarity as the first reverse conducting diode. The first bypass line further includes at least one capacitor and a DC-voltage source connected to the capacitor for pre-charging the capacitor.

A system for monitoring polarization and conduction of a thyristor includes a transformer configured to generate a secondary current from a triggering current waveform applied to a gate of the thyristor; a converter configured to convert the secondary current into a monitored voltage; a first hysteresis comparator configured to generate a first voltage pulse based on the monitored voltage when the triggering current waveform includes a first current pulse; a second hysteresis comparator configured to generate one or more second voltage pulses based on the monitored voltage when the triggering current waveform includes one or more second current pulses; a monitoring unit configured to receive the first and the one or more second voltage pulses, and determine whether the triggering current waveform satisfies pre-defined characteristics, and to determine whether a current flowing between the anode and cathode of the thyristor satisfies additional pre-defined characteristics.

A system for monitoring polarization and conduction of a thyristor includes a transformer configured to generate a secondary current from a triggering current waveform applied to a gate of the thyristor; a converter configured to convert the secondary current into a monitored voltage; a first hysteresis comparator configured to generate a first voltage pulse based on the monitored voltage when the triggering current waveform includes a first current pulse; a second hysteresis comparator configured to generate one or more second voltage pulses based on the monitored voltage when the triggering current waveform includes one or more second current pulses; a monitoring unit configured to receive the first and the one or more second voltage pulses, and determine whether the triggering current waveform satisfies pre-defined characteristics, and to determine whether a current flowing between the anode and cathode of the thyristor satisfies additional pre-defined characteristics.

A device is provided that includes a power transistor and an overcurrent detection logic. The overcurrent detection logic has a first stable state providing a first signal level on a status output terminal and a second stable state providing a second signal level on the status output terminal. The overcurrent detection logic changes from the first stable state to the second stable state in response to detecting that a current through the power transistor exceeds a current limit. The overcurrent detection logic remains in the second state when the current through the transistor drops below the limit after exceeding the current limit.

A switching arrangement for switching off an electric current with a high slew rate, especially a short-circuit current, includes a main line with a first SCR-arrangement including at least a first SCR and a first reverse conducting diode arranged in parallel to the first SCR, and a first bypass line connected to the main line and arranged in a parallel way to the first SCR-arrangement. The first bypass line includes a second SCR-arrangement comprising at least a second SCR arranged in the same polarity as the first reverse conducting diode. The first bypass line further includes at least one capacitor and a DC-voltage source connected to the capacitor for pre-charging the capacitor.

A system for monitoring polarization and conduction of a thyristor includes a transformer configured to generate a secondary current from a triggering current waveform applied to a gate of the thyristor; a converter configured to convert the secondary current into a monitored voltage; a first hysteresis comparator configured to generate a first voltage pulse based on the monitored voltage when the triggering current waveform includes a first current pulse; a second hysteresis comparator configured to generate one or more second voltage pulses based on the monitored voltage when the triggering current waveform includes one or more second current pulses; a monitoring unit configured to receive the first and the one or more second voltage pulses, and determine whether the triggering current waveform satisfies pre-defined characteristics, and to determine whether a current flowing between the anode and cathode of the thyristor satisfies additional pre-defined characteristics.

A system for monitoring polarization and conduction of a thyristor includes a transformer configured to generate a secondary current from a triggering current waveform applied to a gate of the thyristor; a converter configured to convert the secondary current into a monitored voltage; a first hysteresis comparator configured to generate a first voltage pulse based on the monitored voltage when the triggering current waveform includes a first current pulse; a second hysteresis comparator configured to generate one or more second voltage pulses based on the monitored voltage when the triggering current waveform includes one or more second current pulses; a monitoring unit configured to receive the first and the one or more second voltage pulses, and determine whether the triggering current waveform satisfies pre-defined characteristics, and to determine whether a current flowing between the anode and cathode of the thyristor satisfies additional pre-defined characteristics.

A system and method using thyristors to protect a series-connected Flexible AC Transmission Systems (FACTS) device from surge currents are disclosed. According to some embodiments, the system includes a thyristor connected in shunt with the FACTS device to be protected. The system further includes control circuitry coupled to the thyristor to drive a gate of the thyristor with a direct current (DC) signal and turn on the thyristor in a time span on order of microseconds. The system and method can be used to protect any series-connected FACTS device that is in danger of being exposed to surge current such as a reclose after a deadline.

A system and method using thyristors to protect a series-connected Flexible AC Transmission Systems (FACTS) device from surge currents are disclosed. According to some embodiments, the system includes a thyristor connected in shunt with the FACTS device to be protected. The system further includes control circuitry coupled to the thyristor to drive a gate of the thyristor with a direct current (DC) signal and turn on the thyristor in a time span on order of microseconds. The system and method can be used to protect any series-connected FACTS device that is in danger of being exposed to surge current such as a reclose after a deadline.

A rectifying bridge has a thyristor coupled in series with a rectifying element between a first rectified output terminal of a rectifying bridge circuit and a second rectified output terminal of the rectifying bridge circuit. A diode is coupled in series with a DC voltage source between a gate of the thyristor and the second rectified output terminal.