1,321 research outputs found
Distributed Apportioning in a Power Network for providing Demand Response Services
Greater penetration of Distributed Energy Resources (DERs) in power networks
requires coordination strategies that allow for self-adjustment of
contributions in a network of DERs, owing to variability in generation and
demand. In this article, a distributed scheme is proposed that enables a DER in
a network to arrive at viable power reference commands that satisfies the DERs
local constraints on its generation and loads it has to service, while, the
aggregated behavior of multiple DERs in the network and their respective loads
meet the ancillary services demanded by the grid. The Net-load Management
system for a single unit is referred to as the Local Inverter System (LIS) in
this article . A distinguishing feature of the proposed consensus based
solution is the distributed finite time termination of the algorithm that
allows each LIS unit in the network to determine power reference commands in
the presence of communication delays in a distributed manner. The proposed
scheme allows prioritization of Renewable Energy Sources (RES) in the network
and also enables auto-adjustment of contributions from LIS units with lower
priority resources (non-RES). The methods are validated using
hardware-in-the-loop simulations with Raspberry PI devices as distributed
control units, implementing the proposed distributed algorithm and responsible
for determining and dispatching realtime power reference commands to simulated
power electronics interface emulating LIS units for demand response.Comment: 7 pages, 11 Figures, IEEE International Conference on Smart Grid
Communication
Efficient Synthesis of Network Updates
Software-defined networking (SDN) is revolutionizing the networking industry,
but current SDN programming platforms do not provide automated mechanisms for
updating global configurations on the fly. Implementing updates by hand is
challenging for SDN programmers because networks are distributed systems with
hundreds or thousands of interacting nodes. Even if initial and final
configurations are correct, naively updating individual nodes can lead to
incorrect transient behaviors, including loops, black holes, and access control
violations. This paper presents an approach for automatically synthesizing
updates that are guaranteed to preserve specified properties. We formalize
network updates as a distributed programming problem and develop a synthesis
algorithm based on counterexample-guided search and incremental model checking.
We describe a prototype implementation, and present results from experiments on
real-world topologies and properties demonstrating that our tool scales to
updates involving over one-thousand nodes
Distributed Delay-Tolerant Strategies for Equality-Constraint Sum-Preserving Resource Allocation
This paper proposes two nonlinear dynamics to solve constrained distributed
optimization problem for resource allocation over a multi-agent network. In
this setup, coupling constraint refers to resource-demand balance which is
preserved at all-times. The proposed solutions can address various model
nonlinearities, for example, due to quantization and/or saturation. Further, it
allows to reach faster convergence or to robustify the solution against
impulsive noise or uncertainties. We prove convergence over weakly connected
networks using convex analysis and Lyapunov theory. Our findings show that
convergence can be reached for general sign-preserving odd nonlinearity. We
further propose delay-tolerant mechanisms to handle general bounded
heterogeneous time-varying delays over the communication network of agents
while preserving all-time feasibility. This work finds application in CPU
scheduling and coverage control among others. This paper advances the
state-of-the-art by addressing (i) possible nonlinearity on the agents/links,
meanwhile handling (ii) resource-demand feasibility at all times, (iii)
uniform-connectivity instead of all-time connectivity, and (iv) possible
heterogeneous and time-varying delays. To our best knowledge, no existing work
addresses contributions (i)-(iv) altogether. Simulations and comparative
analysis are provided to corroborate our contributions
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