Transient operational constraints in power system optimization problems

Standards and codes on power system quality, define allowable deviations from nominal values for power system quantities such as frequency and voltage during steady state and transient conditions. However, integration of these time-restricted constraints in power system problems, especially optimization problems, is rather a challenging task. This paper classified time-restricted constraints into 6 categories and proposed an approximation method to effectively include a constraint from each category into an optimization problem, using only differentiable functions (which are the suitable functions for optimization problems). As an example, this article used the proposed formulation to integrate some transient constraints in an optimization problem that maximized the power of a pulse load in a notional model for the Next Generation of Integrated Shipboard Power Systems (NG-IPS). This example showed that this method can accurately integrate transient constraints into power system optimization problems.