A PLANT FOR TRANSMITTING HIGH VOLTAGE DC ELECTRIC POWER INCLUDING OVERVOLTAGE PROTECTION

摘要

A plant for transmitting electric power comprises a high voltage DC line (4-7), a DC breaker (8-13) connected in series with the DC line and configured to break a fault current upon occurrence of a fault on said DC line, means (21) configured to detect occurrence of a fault current, a control unit (22) configured to control a said DC breaker for protecting equipment connected to the DC line upon occurrence of a said fault current and means configured to dissipate energy stored in a faulty current path of the DC line between said location (23) and these means upon occurrence of a said fault to the moment of said control of said DC breaker. The energy dissipating means comprises a series connection of an energy consuming braking resistor (28) and a free-wheeling rectifying member (29) connected between ground and said DC line to conduct current while forming a free-wheeling path therethrough upon said control of said DC breaker upon occurrence of a said fault.