Sakuma, Shizuoka
Sakuma (佐久間町; -chō) is a town located in Iwata District, Shizuoka, Japan.
As of 2003, the town has an estimated population of 5,625 and a density of 33.38 persons per km². The total area is 168.53 km².
Sakuma is the location of the Sakuma Dam, an important electrical generating plant.
Near Sakuma in 1965 the first high-voltage direct-current transmission in Japan was built in form of a back-to-back-system for coupling the two parts of Japanese electricity mains, which are operated at 50 Hz and 60 Hz. As static inverters, mercury steam electric rectifiers were used. This plant, which permitted a maximum power exchange of 300 megawatts between both power systems with a symmetrical voltage of 125 kV, was replaced in 1993 by the first static inverter plant of the world equipped with photo-thyristors.