Synchrophasor measurement‐based approach for online available transfer capability evaluation

Abstract

This study proposes a synchrophasor measurement-based approach for online available transfer capability (ATC) evaluation. It utilises an expression which correlates the nodal power injections to the line flows. A new set of measurement-dependent injection distribution factors (MDIDFs) has been computed using this expression. The measurements, obtained from optimally placed phasor measurement units, are used to carry out linear state estimation (LSE). The voltage phasors of all system buses, obtained by LSE, are required to compute the MDIDFs. ATCs for bilateral and multilateral transactions are directly evaluated using these MDIDFs for system intact and contingency cases. If required, the MDIDFs can also be used to directly compute AC power transfer distribution factors and line outage distribution factors without factorising the Jacobian of AC power flow (ACPF). The proposed approach has been validated in real-time digital simulator at different system operating points of WSCC 9-bus and IEEE 14-bus systems. Simulations are also performed on an Indian 246-bus Northern Regional Power Grid system to demonstrate the effectiveness of the proposed approach. The results thus obtained, when compared with those evaluated through repeated ACPF-based approach, prove the efficacy of the proposed approach.