History and trends of converter technology for DC and AC transmission in Japan

The paper introduces development history and trends of converter technology for DC and AC transmission in Japan. The high voltage converter development started in 1960s in Japan. The paper describes technology trends in various aspects including semiconductor device, converter insulation, cooling, circuit topology and control. The paper covers the converter applications for HVDC, SVC and STATCOM associated with typical circuit topologies. For the control trends, the sophisticated performance requirements are introduced in addition to the hardware development. Finally, the paper tries to discuss future trends of converter technology in this field.