Page 230 - Decision Making Applications in Modern Power Systems

194 Decision Making Applications in Modern Power Systems

breakers are closed at identical rms voltages on its either side but with a
large phase angle difference (rare case in a traditional distribution system
when feeders are fed from the same sources but very common case in
modern distribution system when feeders are fed from different sources),
a large circulating current can flow leading to extreme damages. Thus
complete information of data including phase as well as magnitude is
required for proper reconfiguration of distribution feeders.
The µPMU can support reconfiguration processes appropriately by
providing complete voltage information, especially the voltage angle.
This will enable an automated system to take quick decision about recon-
figuration. Such rapid decisions will also decrease the outage times, thus
increasing the power reliability.
4. Planning: In the passive distribution system, planning was simple.
However, in active distribution system, a more careful planning is
required. In the modern system, power flows bidirectionally. In addition
to this, modern distribution system also possesses huge automation sys-
tem and complex loads. With increase in the span of distribution system,
these issues are likely to get escalated. Thus the errors introduced in the
planning stage may pose a great problem to the orderly operation of
the distribution system. The accuracy of the planning models depends on
the measurement accuracy and several other features such as load value,
impedance, and topology. Out of these, load value estimation and feeder
impedance are the two major areas of introduction of error. Moreover,
these parameters continually change with time. Therefore they should be
updated on a regular basis. Thus the inaccurate distribution modeling is
due to the absence of proper observability of the system and insufficient
measured data for calibrating or validating the performance of a model.
This insufficient data, in turn, imposes a limit on DG connection to a par-
ticular feeder [27]. Without knowing the DG characteristics, that is, how
the DG will behave during various grid connections, planners are unable
to produce a safe and reliable planning.
The µPMU with its high-speed and accurate data measurement can
make strategic decisions in modern distribution system planning and
operational models. It provides real impedance value unlike calculated
values of the traditional approaches. This provides a new level of detail
and significantly improves the accuracy of DG interconnection planning.
The µPMU measurements improve model validation contributing to cor-
rect voltage profile estimation and reverse power flows. Moreover, with
time as network conditions evolve, the µPMU information can empower
the planners to adapt to the changes by fine-tuning their models.
5. Cyberattack: Cyberattacks have become prevalent nowadays in distribu-
tion power system where attackers hack the information and modify it in
order to disrupt the operation of the system [28].The µPMU can decide
whether the information are hacked or not. It can be easily identified by