IEEE Power & Energy Magazine - September/October 2020 - 72

aggregators. The aggregators could operate or not within the DR
program proposed during the event, according to the request
based on the feasibility to provide the service. The proposed
CBP has some constraints, including the following:
✔ Reduction offers can be sent by the aggregator for any
hour of the day and week.
✔ Reduction offers must be sent by the aggregator one
day ahead.
✔ A maximum of four events is allowed each week.
✔ There is a maximum of one event per day.
✔ There must be a minimum of 10 hours between events.
✔ Events must be announced by the VTN three hours before they begin, and confirmation must be sent by the
VEN one hour prior to the start of an event.
✔ The beginning and length of an event must accord
with the reduction offer and the offer duration.
✔ The value of the requested reduction must be less than
or equal to that of the load reduction offer.
In the tested cases, the aggregator is enrolled in the DR program and provides a consumption reduction of approximately
50% in each performed test. The event status and consumption
are presented in Figure 14 in green
and red, respectively. The event status shows the period during which
the VTN requested the reduction
OpenADR
DRMS
(sending an event message) accordTCP/IP
ing to the reduction offer as well as
VTN
BACnet
World
Wide
Web
the offer duration specified by the
Server
VEN. Thus, Figure 14 describes
a scenario in which the aggregaVEN
tor took part in the event, reducing
the customers' consumption. At the
same time, the aggregator managed
DERs on the Savona campus to
cover the customer consumption in
real time.
Aggregator Platform
Figures 15-17 include detailed
graphs of the test cor responding to 14 December 2018. The
BMS
forecast consumption is roughly
(SEB)
10 kW, decreasing between 12 p.m.
and 2 p.m. (Figure 16). The reducServer SEB
tion offer (Figure 15) was nearly
5 kW. The offer duration increases
during the period between 12 p.m.
and 1 p.m., and the mean period
BACnet Gateway
of the offer is 1 h. Therefore, the
DRMS (from the DSO through
the VTN) proposes a reduction
between 12 p.m. and 1:30 p.m. (Figure 17) to the aggregator (VEN),
Geothermal
Illumination Air-Conditioning Loads
Energy
Solar
taking advantage of the maximum
Probes
Devices
Meters
Panels
consumption reduction. Thus, the
aggregator provides a consumption
reduction either by dispatching
figure 8. The PoC scheme. TCP/IP: Transmission Control Protocol/Internet Protocol.
Customer Domain

Aggregator Domain

DSO Domain

CBP manages the capacity by creating events that have consumption constraints, according to the two pieces of information reported by the aggregators (which implement the VENs):
the reduction offer and the offer duration (Figure 10). The
VTN gathers additional information: temperature, humidity,
and cloud cover (Figure 11). Additionally, the aggregators
send consumption forecasts (Figure 12). The consumption
forecast at the aggregators' level is more accurate and provides higher confidence values than the one at the individual
grid participant level (Figure 13). The DSO should audit the
forecasting and consumption to verify the consumption and
check the grid stability. Figure 13 shows the mean power forecasting and the real mean power registered. The power forecasting does not account for the variations provided by the
FSs. Thus, there are several periods (specified in Table 1) during which the registered mean power is lower than the forecast
mean power.
The CBP takes advantage of the data provided by the
aggregators to design strategies for consumption reduction.
Thus, the DSO sends requests (events in OpenADR terminology) with specific restrictions or DR programs to different

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