  Ad hoc electrical networks are formed by connecting power sources and loads
without pre-determining the network topology. These systems are well-suited to
addressing the lack of electricity in rural areas because they can be assembled
and modified by non-expert users without central oversight. There are two core
aspects to ad hoc system design: 1) designing source and load units such that
the microgrid formed from the arbitrary interconnection of many units is always
stable and 2) developing control strategies to autonomously manage the
microgrid (i.e., perform power dispatch and voltage regulation) in a
decentralized manner and under large uncertainty. To address these challenges
we apply a number of nonlinear control techniques---including Brayton-Moser
potential theory and primal-dual dynamics---to obtain conditions under which an
ad hoc dc microgrid will have a suitable and asymptotically stable equilibrium
point. Further, we propose a new decentralized control scheme that coordinates
many sources to achieve a specified power dispatch from each. A simulated
comparison to previous research is included.
