Authors:
Ognjen Gagrica
1
;
Tadeusz Uhl
1
;
Phuong H. Nguyen
2
and
J. F. G. Cobben
2
Affiliations:
1
AGH University of Science and Technology, Poland
;
2
Eindhoven University of Technology, Netherlands
Keyword(s):
Voltage Unbalance, Power Quality, Photovoltaic, Distributed Generation, Smart Grid.
Related
Ontology
Subjects/Areas/Topics:
Architectures for Smart Grids
;
Energy and Economy
;
Energy Monitoring
;
Energy-Aware Systems and Technologies
;
Load Balancing in Smart Grids
;
Microgeneration
;
Renewable Energy Resources
;
Smart Grids
Abstract:
In the hierarchy of power transmission and distribution systems, the three-phase LV distribution networks
are most susceptible to voltage unbalance (VU). The main causes are large presence of randomly distributed
single-phase loads and, following the latest trends, the increasing presence of single-phase distributed
generators. Most widely accepted VU calculation is based on percentile ratio of negative and positive
sequence voltage (voltage unbalance factor, VUF). Obtaining sequence voltages is a complex domain
calculation and requires simultaneous sampling of three-phase voltages and angles. This is why the existing
VU monitoring and mitigation solutions are dominantly three-phase. Without an additional three-phase
aggregation device, there is an inherent gap in VU monitoring for single-phase loads and generators. In this
paper, the data concentrators for a growing PV micro-inverter niche are identified as an infrastructure that
could be exploited to somewhat close this gap. Due to
potential technical limitations of PV data
concentrators, a non-complex VUF approximation formula is tested as a "light" calculation alternative, by
comparing it against conventional VUF. The comparison results are obtained from Monte Carlo load flow
simulation for an unbalanced LV network.
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