Gatecommutated

Gatecommutated thyristors, often abbreviated as GTOs, are a type of semiconductor switching device. They belong to the family of thyristors and are distinguished by their ability to be turned off by a control signal applied to their gate terminal. This is a significant advancement over conventional thyristors, which can only be turned off by reducing the anode current below a holding level.

GTOs are constructed with multiple PN junctions, similar to other thyristors. The key difference lies in the gate structure, which is designed to allow for both turn-on and turn-off control. When a positive gate current is applied, the GTO turns on and conducts current from anode to cathode. To turn off the GTO, a negative gate current is applied, which initiates the turn-off process by extracting charge carriers from the device.

The ability to actively turn off a GTO provides greater control over power electronic circuits. This enables simpler circuit designs and more efficient operation compared to circuits relying on natural commutation or other complex switching arrangements. GTOs are used in a variety of high-power applications, including motor drives, inverters, and static var compensators. Their capability to handle high voltages and currents makes them suitable for demanding industrial and utility-scale power systems. However, GTOs can exhibit relatively high switching losses and require careful gate drive circuitry.