POWER SYSTEM MAXIMUM LOAD ABILITY WITH GENERATION CONSTRAINTS

The control of reactive power aims at both increasing the limit of power transfer between areas and monitoring the bus voltage magnitude. In order to increase the amount of energy transfer, suppliers must produce reactive power close to the place where it is needed. Additionally, extra reactive power capacity must be kept to protect the integrity of the system against unforeseeable contingencies and sudden changes of power load levels. The present work is addressed to the determination of operational solutions (that is, those satisfying all operational limits) of maximum loadability considering the reactive power reserve. A constraint related to the quadratic deviation of a pre-specified level of reactive power generation is included in the static optimization problem that models the computation of the maximum loadability solution. This modified problem is solved through the nonlinear version of the Interior Point method. It is shown how the critical loadability and the reactive power margins are modified as the priority of reactive power reserve changes. Numerical results obtained with a 57-buses system illustrate the application of the proposed approach.