Trends and Overview Regarding the Involvement of Micro-Grids in Modern Power Systems 87
itself from the utility supply. Thus by doing this it avoids
the risks of disturbances due to lighting strokes either
direct or indirect and other faults affecting the ongoing
supply. For example, in hospitals when open-heart sur-
gery is taking place interruptions in any case is highly
unacceptable. In unintentional mode, power system is
heavily loaded which can result in large fluctuations of
voltage and frequency resulting in the malfunctioning of
consumer equipments. MG is thus subjected to uninten-
tional islanding to avoid all this and maintains quality
supply to its connected loads.
Micro-grid can increase efficient service quality by pro-
viding power generation redundancy whenever needed. In
cases of extreme demand and loading conditions it en-
hances security of upstream networks against faults and
risks by operating in emergency iswlanding mode. MGs
as LV networks provide quality and reliable power in
contrast to heavy loaded HV networks [19]. In power
systems, power quality disaster level can be expressed as
overall losses caused by power quality events. Power
quality disaster level can be expressed as,
k
kFk Lk
EncEcE
Lk
(1)
where subscript k power quality event type:
E: Overall losses of all the power quality disasters
during monitoring period;
n: Number of power quality events;
k
E: Average direct loss of power quality even ts;
k
c: Correction coefficient of average direct loss;
k
E: Average latent loss of power quality events;
k
c: Correction coefficient of average latent loss.
kj
j
Fk
k
En
,
kj
j
Lk
k
En
Power quality disaster level if increased may result in
a high loss to utility or facility manag ers. The chances of
power transmission collapse is less in decentralized sys-
tems especially in DG. As MG has fewer number of con-
nected loads and this system is interconnected with util-
ity so micro grid central controller avoids such dangerous
consequences by immediate action of islanding. So, power
quality is im proved as well as disast er level is minimized.
5. Conclusion
This paper has discussed Micro-grid technology playing
a more numerous and important role in the world’s en-
ergy demand. Micro-grid safe operation increase chances
for fulfill the supply and demand of the consumer. Au-
tomated load management technique implemented by in-
telligent controller (neural implementation of controller)
network provides opportunity to overcome energy im-
balance. It further discussed the idea of non-autonomous
micro grid presented here can benefit utility, society and
local people of a certain locality. By implementing this
system losses are reduced, quality of power is improved
much better, tariff rates are reduced that can benefit poor
people and avoids interruption in supply that can benefit
critical places such as hospitals.
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