  The trend in the electric power system is to move towards increased amounts
of distributed resources which suggests a transition from the current highly
centralized to a more distributed control structure. In this paper, we propose
a method which enables a fully distributed solution of the DC Optimal Power
Flow problem (DC-OPF), i.e. the generation settings which minimize cost while
supplying the load and ensuring that all line flows are below their limits are
determined in a distributed fashion. The approach consists of a distributed
procedure that aims at solving the first order optimality conditions in which
individual bus optimization variables are iteratively updated through simple
local computations and information is exchanged with neighboring entities. In
particular, the update for a specific bus consists of a term which takes into
account the coupling between the neighboring Lagrange multiplier variables and
a local innovation term that enforces the demand/supply balance. The buses
exchange information on the current update of their multipliers and the bus
angle with their neighboring buses. An analytical proof is given that the
proposed method converges to the optimal solution of the DC-OPF. Also, the
performance is evaluated using the IEEE Reliability Test System as a test case.
