IEEE Electrification - September 2021 - 117

Historical Load
Data
PS and FR Optimization
Load Forest
PL(t)
Interval Identification
PS, FR
* k PS h, WPS, PPS, PPS
P
* I PIPS h, Wch, Pch, Pch
P
- m FR h
- n PIFR h
Threshold Power
PTH
BESS Schedule
Figure 6. A PM system flow.
uncertainties, quantified as safety factors, are considered
when running the ROM and the system aims at minimizing
these uncertainties as much as is possible.
PM: BESS Schedule
For the PM (Figure 6), the EMS starts by creating a load
forecast using the historical load data. This load forecast
is used in conjunction with the historical load data and
the system constraints like BESS and inverter size to estimate
a threshold power PTH. The threshold power and
load forecast are then used to perform interval identification,
where the hours of the day are divided into either
PS intervals or FR intervals depending on whether or not
the load forecast for a particular hour exceeds the
threshold power. Having identified the correct service
to be dispatched for the forecasted time horizon, further
PS and FR optimization is performed where it is
ensured that the BESS has the required capacity to dispatch
the assigned service. The hours where the BESS
is prepared for PS are called PS preparation intervals
(PIPS), and for FR they are called FR preparation
intervals (PIFR). In case the BESS does not have the
required capacity or other system
limits are exceeded, the threshold
power is readjusted accordingly,
and the interval identification is
reiterated. This loop is repeated
until the correct threshold power
is found where all of the assigned
services of the hour are dispatched
within the system limits, thus
creating the BESS schedule.
PS
Safe PS
FR
ROM: BESS Operation
For the real-time operation (Figure
7), the assigned service of the
Frequency
Measurement
Figure 7. A ROM system flow.
IEEE Electrification Magazine / SEPTEMBER 2021 117
BESS Dispatch
PS
Charging
hour is initiated. In case of PS, the operation starts
with safe PS, where a safety factor quantified during
the load forecast is used to over shave during safe PS.
The operation is switched between safe PS, PS, and
charging depending on the switching parameters including
real-time power, real-time accumulated average
power, forecasted hourly average power, and
threshold power. this switching happens every minute
depending on how the switching parameters are developing.
during a FR-assigned interval, the frequency is
directly measured from the grid connection and the
BESS is dispatched in accordance with the specification
defined by the TSO.
Case Study
Introduction
In the following case study, the EMS developed within
the framework of behind the meter strategies has been
implemented. All inputs, processes, and outputs of the
PM are considered for the complete year of 2020. The
results are representative of the additional value that
IEEE Electrification - September 2021

Table of Contents for the Digital Edition of IEEE Electrification - September 2021
