High-Voltage D-C Transmission: General Background and Present Technical Status

The keys to practical application of high-voltage (HV) direct current for power transmission are the rectifier and inverter, which supply the high voltage required for terminals of the d-c line. The grid-controlled mercury-arc tube with grading electrodes has proved to be a suitable valve in such converters. Special features and characteristics of HV converters and of the terminal stations are mentioned, and projects in operation and under construction are specified. Future fields of application are discussed.