Constant-current D-C transmission

High voltage d-c electric power transmission has been envisioned for many years, but numerous obstacles have prevented its use to any great extent. Most of these obstacles appear to be overcome in the system described in this paper; this system comprises conversion of constant-potential a-c power to constant-current d-c power, transmission of constant-current d-c power, and reconversion to constant-potential a-c power. The promising features of this system are its unusual stability and reliability; as an example, the high-voltage constant-current d-c line may be short-circuited without damage to line or equipment.