HVMDC: a new concept to feed small loads

Feeding small loads from HVDC transmission lines is a problem that has been investigated by many authors. The high voltage modulated direct current transmission (HVMDC) is a new concept to feed small loads which uses basically the same equipment involved on the conventional HVDC transmission. In this scheme, the DC current is used for transmitting large blocks of power to distant parts while a controlled superposed AC ripple is used to supply small loads close to the generating station. These small loads mat be located not very far from the rectifier´s station due to the usual AC transmission long distance problems which depend upon the AC voltage, frequency and tranmission line characteristics. The authors present a theoretical steady-state analysis of such a HVMDC system and a preliminary HVMDC simulator study showing the feasibility of the proposed method, decreasing its advantages and problems