Patent ID: 8493866

Claim:
A method for sending protection or control signals from an active computer in a high-voltage power transmission system comprising a hierarchical structure comprising at least two hierarchical levels including a pole level and a converter level and active protection computers and active and standby control computers in the hierarchical structure, at least two power converters operatively interconnected with a direct current power line and connected to the control computers, and at least two separate computer communication networks to which all of the active protection computers and active and standby control computers are operatively connected, the method comprising: sending, from said active computer in the high-voltage power transmission system, protection or control signals that are to be received by at least one other computer at a same or another hierarchical level simultaneously on said at least two separate computer communication networks to which said active computer is connected; and synchronizing said sending of said protection or control signals with processing being performed in relation to said protection or control signals in said active computer, wherein the sending comprises sending at least some of said protection or control signals using a broadcasting or multicasting scheme so that more than one other computer can receive said protection or control signals via said two separate networks.