GE DMC490 Software Configuration Manual page 41

1. Dispatchable isochronous load share (default)
Isochronous
Margin Minus4 2. Renewable in isochronous
(%)
3. Single dispatch in isochronous (CHP)
4. Grid in isochronous
For example, due to the highly variable nature of solar and
wind power, a larger margin can be entered than for a hydro or
CHP installation.
Heat When connected to a grid, the grid compensates for any
Isochronous imbalance between load and generation in the microgrid,
Margin Plus (%) behaving like an isochronous machine for the microgrid.
However, for islanded microgrids, there is a need for an
Isochronous
isochronous machine to maintain load-generation balance and
Margin Minus
stabilize the microgrid for instantaneous load and renewable
(%)
generation variations above or below the forecasted values.
Such an isochronous machine provides reserve margins in both
positive and negative directions to address the deficit or
surplus of power, respectively. These margins are defined as a
percent of the total load in the microgrid and need to be
defined for both grid-connected and islanded microgrids.
Configure the margins for a microgrid, for both power deficit
(the plus margin) and power surplus (the minus margin). The
numbers 1 to 4 correspond to the following microgrid operation
modes. Configure all values. The higher the variation in power
generation, the greater the margin.
1. Dispatchable isochronous load share (default)
2. Renewable in isochronous
3. Single dispatch in isochronous (CHP)
4. Grid in isochronous
For example, due to the highly variable nature of solar and
wind power, a larger margin can be entered than for a hydro or
CHP installation.
Configure these settings for a microgrid, for heat deficit (plus
margin) and heat surplus (minus margin).
Constraint Mode Soft constraint means that there are slack variables (in different
time steps) in the power-balance constraints of the
optimization problem that are penalized in the objective
function.
Hard constraint means such slack variables do not exist. These
slack variables are defined to insure the feasibility of the
optimization problem without significantly
compromising/influencing the reserve-margin requirements of
the microgrid specified in the same panel.
Power Balance Power balance refers to a match between power generation
Penalty ($/kWh) and demand/load. The power being generated at any one time
ideally equals the power being consumed at that time.
Specify a penalty on power balance violation, for both excess
power and shortages.
Use this setting in conjunction with Constraint Mode.
DMC490 Configuration
0% to 100% 0.2%
Hard Hard
Soft
0 to 1000 0 $/kWh
$/kWh
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