Abstract: As equipment for high-voltage direct current (HVDC) transmission, bulk renewable power delivery, and grid power-flow control moves toward higher voltage and larger capacity, the choice of power device is no longer a comparison of rated parameters but a system-level problem shaped jointly by device characteristics, converter topology, duty profile, and valve-level implementation. The integrated gate-commutated thyristor (IGCT) combines thyristor-like conductivity modulation, active turn-off capability, and a press-pack short-circuit failure mode. These attributes are not advantageous in every application: they deliver system-level value chiefly in duties characterized by low switching frequency, sustained high-current conduction, forced commutation, or fault interruption. Beginning with device-level mechanisms, this review traces the role of the IGCT in the main power circuit of alternating current (AC) side power conversion, HVDC conversion, direct current (DC) transformation and DC power supply, DC interruption, and fusion pulsed-power equipment. Drawing on the literature, standards, and project documentation, it then compares the valve-level requirements each design imposes and the level of validation so far achieved. Industrial medium-voltage drives have a long service record across multiple projects, and wind-power, railway-supply, and grid power-flow control equipment is commercially available.Hybrid commutated converter valves, and current-source DC de-icing equipment have been proven in demonstration projects, whereas other emerging conversion, interruption, and pulsed-power designs remain at the prototype-test stage, with new configurations still under investigation. In China, an end-to-end capability spanning device fabrication and valve-level integration has taken shape, and a supporting standards framework is emerging. The IGCT is not a universal substitute for other fully controllable devices; its wider deployment rests on gate-drive power supply, parameter consistency in series and parallel operation, transient energy management, thermo-mechanical design, and the availability of long-term field data and volume-production evidence.