Shin Shinano

Shin Shinano is an electrical frequency converter station in Asahi that bridges Japan's western and eastern power grids using high-voltage direct current technology. The facility operates at 125 kV and enables power exchange between regions that historically operated at different electrical frequencies.

Opened in 1977, the station introduced thyristor-based HVDC conversion systems with oil-insulated valves manufactured by Hitachi and Toshiba. This technology made reliable power exchange possible between the two grids for the first time.

The station represents Japanese engineering excellence in power distribution, enabling the connection between regions operating at different electrical frequencies.

The station can transmit up to 600 MW of power and regulates flow between the 50 Hz western and 60 Hz eastern grids. Access to the facility is restricted for safety reasons, so plan accordingly if you wish to view it from nearby.

The facility includes a dedicated maintenance workshop where technicians service valve components in controlled conditions to prevent oil contamination. This careful approach keeps the insulating oil free from impurities that could damage the system.