GE DMC490 Software Configuration Manual page 26

DMC490 Microgrid Controller Software Configuration Guide
State Of Charge This setting is the maximum capacity of the storage device. It
Maximum (kWh) specifies the maximum level of storage state of charge (SOC),
in kWh.
State Of Charge Specify the minimum level of storage state of charge, in kWh.
Minimum (kWh) Due to lifetime considerations, SOC cannot usually go below a
certain limit. This is referred to as maximum depth of
discharge (DOD). For example, for a 100kWh storage device
with 80% DOD, State Of Charge Minimum is set to 20 kWh.
Storage state of charge needs to be always above State Of
Upper
Boundary Store Charge Minimum and below State Of Charge Maximum.
Device1 (kW) However, a variety of practical complexities, such as storage
standby loss, delay in issuing the charging/discharging
commands, measurements errors, and startup or
environmental conditions, lead to the violation of these limits
and can render the real-time microgrid optimization problem
infeasible. Apart from the infeasibility of the optimization
problem, there is also a chance of an undesired phenomenon
occurring, which is frequent charging and discharging (cycling)
of storage devices. These undesired outcomes (that is,
infeasibility and cycling) are avoided in the DMC490 MGC by
having some pre and post processing units outside of the
optimization core to modify the commands issued by the
controller, such as storage stop/start, or to change some input
readings, such as SOC. This also requires defining some small
regions around State Of Charge Maximum and State Of
Charge Minimum.
Thus, two regions below State Of Charge Maximum, and two
regions on either side of State Of Charge Minimum are
defined as shown in the following figure. If SOC is located in
region E, no action is required; however, if SOC is within any of
four regions A to D, its measured value is appropriately
changed together with issuing some necessary
charging/discharging commands.
Upper Boundary Store Dev1 is the upper boundary of the
maximum acceptable charging level. Configure it to be within
a few percent of storage maximum capacity State Of Charge
Minimum, for example one to five percent (that is, 0.01 to
0.05).
Refer to Figure 14 for more details
Lower This setting is the lower boundary of the maximum acceptable
Boundary Store charging level. Configure it to be within a few percent of
Device2 (kW) storage maximum capacity (State Of Charge Minimum), for
example one to five percent (that is, 0.01 to 0.05).
Lower This setting is the upper boundary of the minimum acceptable
Boundary Store charging level. Configure it to be within a few percent of
storage minimum capacity (State Of Charge Minimum), for
Device1 (kW)
example one to five percent (that is, 0.01 to 0.05).
Lower This setting is the lower boundary of the minimum acceptable
Boundary Store charging level. Configure it to be within a few percent of
storage minimum capacity (State Of Charge Minimum), for
Device2 (kW)
example one to five percent (that is, 0.01 to 0.05).
26
0 to 1,000,000 300 kWh
kWh
0 to 1,000,000
50 kWh
kWh
0 to 1 kW 0 kW
0 to 1 kW 0 kW
0 to 1 kW 0 kW
0 to 1 kW 0 kW