52,277 research outputs found
Data-Driven Diagnostics of Mechanism and Source of Sustained Oscillations
Sustained oscillations observed in power systems can damage equipment,
degrade the power quality and increase the risks of cascading blackouts. There
are several mechanisms that can give rise to oscillations, each requiring
different countermeasure to suppress or eliminate the oscillation. This work
develops mathematical framework for analysis of sustained oscillations and
identifies statistical signatures of each mechanism, based on which a novel
oscillation diagnosis method is developed via real-time processing of phasor
measurement units (PMUs) data. Case studies show that the proposed method can
accurately identify the exact mechanism for sustained oscillation, and
meanwhile provide insightful information to locate the oscillation sources.Comment: The paper has been accepted by IEEE Transactions on Power System
Real-Time Local Volt/VAR Control Under External Disturbances with High PV Penetration
Volt/var control (VVC) of smart PV inverter is becoming one of the most
popular solutions to address the voltage challenges associated with high PV
penetration. This work focuses on the local droop VVC recommended by the grid
integration standards IEEE1547, rule21 and addresses their major challenges
i.e. appropriate parameters selection under changing conditions, and the
control being vulnerable to instability (or voltage oscillations) and
significant steady state error (SSE). This is achieved by proposing a two-layer
local real-time adaptive VVC that has two major features i.e. a) it is able to
ensure both low SSE and control stability simultaneously without compromising
either, and b) it dynamically adapts its parameters to ensure good performance
in a wide range of external disturbances such as sudden cloud cover, cloud
intermittency, and substation voltage changes. A theoretical analysis and
convergence proof of the proposed control is also discussed. The proposed
control is implementation friendly as it fits well within the integration
standard framework and depends only on the local bus information. The
performance is compared with the existing droop VVC methods in several
scenarios on a large unbalanced 3-phase feeder with detailed secondary side
modeling.Comment: IEEE Transactions on Smart Grid, 201
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