New topology of unified power flow controller(UPFC)connected to different buses on shunt side and series side makes the traditional steady-state model of UPFC difficult to apply. Sensitivity-based security correction method ignores the effect of reactive power and may introduce new insecurity factors. Based on this
a steady-state UPFC model with high adaptability is proposed
along with an optimization model for power flow calculation with UPFC. Then
considering the influence of reactive power
a variable of 0-1 is introduced to transform the security correction problem into a multi-objective optimization problem with the objective of minimizing the number of adjusting devices and the amount of adjusting. Furthermore
the generator nodes and load nodes are distinguished by weights to reduce the occurrence of load shedding. Finally
the multi-objective optimization problem is transformed into a single-objective optimization problem by using the maximum method
which decreases the solving difficulty of the model. The test results of 116-bus equivalent system show that the proposed security correction model can eliminate the overload fault of the system by using the least adjusting equipment and adjusting amount
and the UPFC can improve the efficiency of the security correction.