Page 441 - Decision Making Applications in Modern Power Systems

400 Decision Making Applications in Modern Power Systems

Read/Input
), measured “ON” time (t ), building demand (P ), PV generation
Desired “ON” time(t d r bl
(Ppv), battery desired SOC (ψ d ) and measured SOC (ψ m),upper SOClimit (ψ max ),
Refrigerator operates with
“control cycle”
P pv > 0 No Yes ψ < ψ d
m
Deferrable load “OFF”
Tube lights “OFF”
Yes
No
P < P Yes Battery charge
pv bl
No ΔP = P – (P + P )
bb
pv
cl
P ncl < ΔP ≥ P No
dfl
Noncritical load “ON”
Refrigerator operates
Yes
with “regular cycle”
t dn – t rn ≥ t tcn – t di
t ∈ t ts Yes
di
Noncritical load “ON”
No CB load operates with
CB load operates with
“regular cycle,” “control cycle,”
Deferrable load “ON”
Deferrable load “OFF”
Refrigerator operates with “regular cycle,”
and noncritical load “ON”

No t dn > t rn ;t ∈ t ts Yes
di
Battery “charge” Deferrable load “ON”
FIGURE 15.4 Flowchart of control algorithm for demand-side management.

amount of power as compared to the building demand. In this case the ES is
responsible to balance the building demand. Therefore the SOC level of ES
decreases at every time instant. As the battery SOC deficits from the desired
level, the critical loads (i.e., LED bulbs and fans) remain switched “ON,”
while the refrigerator operates with “control cycle” mode. Besides that, other
loads get switched “OFF.” In this way the battery discharging rate decreases,
which helps to achieve its SOC at desired level. Moreover, when the PV
starts generation and the battery SOC is still less than its desired level, then
the battery starts charging while the surplus PV power (i.e., difference of
actual PV power and battery charging rate) feeds to the DC bus to supply the
building load.