Insulated-gate bipolar transistor
An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily forming an electronic switch. It was developed to combine high efficiency with fast switching. It consists of four alternating layers (P–N–P–N) that are controlled by a metal–oxide–semiconductor (MOS) gate structure.
IGBT module (IGBTs and freewheeling diodes) with a rated current of 1200 A and a maximum voltage of 3300 V
Cross-section of a typical IGBT showing internal connection of MOSFET and bipolar device
IGBT module (IGBTs and freewheeling diodes) with a rated current of 1200 A and a maximum voltage of 3300 V
Opened IGBT module with four IGBTs (half of H-bridge) rated for 400 A 600 V
A thyristor is a solid-state semiconductor device which can be thought of as being a highly robust and switchable diode, allowing the passage of current in one direction but not the other, often under control of a gate electrode, that is used in high power applications like inverters and radar generators. It usually consists of four layers of alternating P- and N-type materials. It acts as a bistable switch. There are two designs, differing in what triggers the conducting state. In a three-lead thyristor, a small current on its gate lead controls the larger current of the anode-to-cathode path. In a two-lead thyristor, conduction begins when the potential difference between the anode and cathode themselves is sufficiently large. The thyristor continues conducting until the voltage across the device is reverse-biased or the voltage is removed, or through the control gate signal on newer types.
Thyristor
A bank of six 2000 A thyristors (white disks arranged in a row at top, and seen edge-on)
Valve hall containing thyristor valve stacks used for long-distance transmission of power from Manitoba Hydro dams