  High-voltage direct current (HVDC) is a commonly used technology for
long-distance power transmission, due to its low resistive losses and low
costs. In this paper, a novel distributed controller for multi-terminal HVDC
(MTDC) systems is proposed. Under certain conditions on the controller gains,
it is shown to stabilize the MTDC system. The controller is shown to always
keep the voltages close to the nominal voltage, while assuring that the
injected power is shared fairly among the converters. The theoretical results
are validated by simulations, where the affect of communication time-delays is
also studied.
