Patent attributes
Unique systems, methods, techniques and apparatuses of power transmission systems are disclosed herein. One exemplary embodiment is an AC power transmission system converted for transmission of high voltage direct current (HVDC) power, the converted system comprising an AC cable system, a first converter system, a second converter system, and a control system. The first converter system is structured to receive and convert AC power to DC power and output the DC power. The second power converter system is structured to receive the DC power, convert the DC power to a second AC power, and output the second AC power. The control system is structured to receive power demand information, determine a reduced DC voltage less than a rated HVDC voltage, control the first converter system such that the DC power is controlled to the reduced voltage, and control the second power converter system to operate in an active power control mode.