Cahora Bassa (HVDC)

The Cahora Bassa HVDC is a cross-border high-voltage direct current transmission line ( HVDC), which is used for electrical power transmission between the Cahora Bassa dam in the north of Mozambique and the region around Johannesburg in South Africa. The line begins at Songo in Mozambique and ends after 1420 kilometers in the South African city of Apollo near Johannesburg. It was built in the years 1977-1979 from ZAMCO consortium ( AEG, BBC and Siemens) and went into operation on 15 March 1979. The line, which is located with a length of 900 kilometers in Mozambique, was renovated after the civil war from 1995 to 1998 Siemens and put into operation

For built by AEG electronics, the company Wacker Chemie has developed its first large silicon wafer to handle the current of 2 kA with only a thyristor can. For remote control of standing on porcelain insulators converter elements on glass fibers in the isolators Telefunken has created the basis for a high-speed optical communications. Was before the cut-off frequency of the optical transmission systems in the order of 10 kHz.

The transmission capacity is 1920 MW at bipolar DC voltage of ± 533 kV. The bipolar technology with potential return over the earth has been chosen to keep the operation of the system even after blowing up one half of the flow through the civil war zone path functional. In contrast to other HVDC systems, the two converter stations are not placed at both ends in a hall, but outdoors. The thyristors of the converter are housed in oil-filled and under high voltage in operation, containers which are mounted on electrical insulators. The HVDC in its present form has been renovated by the company Asea Brown Boveri (ABB) and operated by the utility company Eskom.