Stochastic multi‐objective tie‐line power flow and frequency control in market clearing of multi‐area electricity markets considering power system security

Abstract

This study formulates a security-constrained multi-objective framework with unit commitment in multi-area electricity markets for day-ahead joint market-clearing. The dynamic and inertial characteristics of the power system are derived and incorporated into the market-clearing procedure in order to preserve power system security from the frequency viewpoint. In addition, two novel objective functions (tie-flow deviation index and Rocof index) besides the frequency-dependent social welfare and frequency excursion index have been defined to control the static frequency, rate of change of frequency (Rocof) and also the tie-line power flows, following the occurrence of a contingency. Comprehensive analysis tools for multi-area power systems and also pre- and post-contingency intervals are presented to verify the characteristics of the proposed model. The developed multi-objective programming is analysed through two case studies, a three-area system scheduled over 1 h and the IEEE two-area reliability test system over 24 h. It has been shown that the scheduling of energy and reserve services can be performed more effectively if the system frequency is considered in the market-clearing process. The proposed model can reconcile the need for reasonable total generation cost with concern for the independent system operator's responsibilities about the pre- and post-contingency tie-line power flow control and system security.