OPF Equality Constraints

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Area MW Interchange

The area MW interchange constraints are enforced during the LP for those areas that have an AGC Status equal to OPF provided the area is not part of a super area that is also set on AGC. The AGC Status field for an area can be set using the OPF Area Records display, while the AGC Status field for the super area (if any) is set using the OPF Super Area Records display. Areas whose interchange is enforced during the LP do not have their interchange enforced during the power flow solution that is done as part of the LP process; during the power flow these areas are treated as though they were off of AGC (and hence the output of generators in that area is not varied during the power flow).

It is perfectly acceptable to have some areas on OPF AGC control and to have other areas on the more traditional power flow area AGC such as ED or Part. AGC. The interchange for such areas is controlled during the power flow solution.

Following a successful solution, marginal costs are calculated for the area interchange constraints; these values are displayed on the OPF Area Records display and can be contoured. See OPF Marginal Costs for details.

Bus MW and Mvar power balance

Enforced during the power flow solution. Following a successful solution, marginal costs are calculated for the bus MW (real power) balance constraint; these values are displayed on the OPF Bus Records display and can be contoured.

Generator Voltage Setpoint

Enforced during the power flow solution. Following a successful solution, marginal costs are calculated for the voltage setpoint constraint; these values are displayed on the OPF Bus Records display .

Super Area MW Interchange

Super area interchange constraints are enforced similar to the area constraints. That is, super area interchange constraints are enforced during the LP only for those super areas that have an AGC Status equal to OPF. The AGC Status field can be set using the OPF Super Area Records display. During the power flow solution that is part of the LP process, such super areas are treated as though they were off of AGC.

Interface MW limits when treated as Equality

Interface MW limits are enforced during the LP solution. Interface MW limits are normally treated as inequality constraints (see Inequality Constraints ), however they can optionally be treated as equality constraints. See the Interface Dialog for information on how to treat the limit as an equality constraint.

Transmission Line and Transformer (Branch) MVA limits

Branch MVA limits are enforced during the LP solution. Branch MVA limits are normally treated as inequality constraints (see Inequality Constraints ), however they can optionally be treated as equality constraints. See the Branch Information Dialog for information on how to treat the limit as an equality constraint.