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 selection of power devices is no longer a mere 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, and they deliver system-level value chiefly in duties characterized by low-to-medium 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 load-side continuous power conversion, generation-side power conversion and grid interconnection support, grid-side power regulation, HVDC conversion, direct current (DC) transformation and DC power supply, DC interruption, and pulsed-power equipment. Drawing on the literature, standards, and project documentation, it then compares the technical schemes and their respective technology maturity levels. Industrial medium-voltage drives have accumulated long-term operational experience across multiple projects; product-grade solutions are available for wind-power, railway-supply, and grid power-flow control equipment. Hybrid commutated converter valves and current-source DC de-icing devices have been validated in demonstration projects, whereas other emerging converter, interruption, and pulsed-power designs remain at the prototype-test stage, with novel topologies 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 operational data and mass-production evidence.