107 research outputs found
Output Impedance Diffusion into Lossy Power Lines
Output impedances are inherent elements of power sources in the electrical
grids. In this paper, we give an answer to the following question: What is the
effect of output impedances on the inductivity of the power network? To address
this question, we propose a measure to evaluate the inductivity of a power
grid, and we compute this measure for various types of output impedances.
Following this computation, it turns out that network inductivity highly
depends on the algebraic connectivity of the network. By exploiting the derived
expressions of the proposed measure, one can tune the output impedances in
order to enforce a desired level of inductivity on the power system.
Furthermore, the results show that the more "connected" the network is, the
more the output impedances diffuse into the network. Finally, using Kron
reduction, we provide examples that demonstrate the utility and validity of the
method
Control and prediction for blackouts caused by frequency collapse in smart grids
C.-W.W. is supported by a studentship funded by the College of Physical Sciences, University of Aberdeen. M.S.B. acknowledges EPSRC grant NO. EP/I032606/1.Peer reviewedPublisher PD
A Robust Consensus Algorithm for Current Sharing and Voltage Regulation in DC Microgrids
In this paper a novel distributed control algorithm for current sharing and
voltage regulation in Direct Current (DC) microgrids is proposed. The DC
microgrid is composed of several Distributed Generation units (DGUs), including
Buck converters and current loads. The considered model permits an arbitrary
network topology and is affected by unknown load demand and modelling
uncertainties. The proposed control strategy exploits a communication network
to achieve proportional current sharing using a consensus-like algorithm.
Voltage regulation is achieved by constraining the system to a suitable
manifold. Two robust control strategies of Sliding Mode (SM) type are developed
to reach the desired manifold in a finite time. The proposed control scheme is
formally analyzed, proving the achievement of proportional current sharing,
while guaranteeing that the weighted average voltage of the microgrid is
identical to the weighted average of the voltage references.Comment: 12 page
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