Benefits of using linear state estimation for synchrophasor applications

Synchrophasor measurement‐based approach for online available transfer capability evaluation

“…As can be seen in Fig. 1, the overall process in the proposed approach to finally declare ATC after getting the PMU measurements from PMUs, involves two major steps: (i) computation of bus voltage phasors at all system buses through LSE [30][31][32][33][34][35] execution, which utilises the voltage and current phasor information obtained from optimally placed PMUs, and (ii) evaluation of ATC after computing the MDIDFs, which requires the information of all bus voltage phasors as an input.…”

“…This step is only relevant from the real-time LSE execution perspective. Hence, it can be assumed that this step is fast enough and thus, does not affect the computational complexity of our proposed approach [32,33].…”

“…The first constituent of the total time, in the proposed approach, i.e. the LSE execution time, is very small [30][31][32][33][34]. In fact for online applications, dynamic LSE [30,32] is generally used instead of the non-linear SE.…”

“…The change in system operating point may be due to an outage of system equipment such as line, transformer, generator and so on or due to the system load variation. The outage detection information is readily available from the topology processor unit of SE [33]. If no change is detected in the system topology, then the change in operating point is detected through change in system states obtained from LSE.…”

“…Thus, a synchrophasor measurement-based online ATC evaluation approach has been proposed in this paper. The measurements are obtained through optimally placed phasor measurement units (PMUs) [29], which are first used to run a linear state estimator (LSE) [30][31][32][33][34][35] to calculate the voltage phasors at all buses in the system. These voltage phasors are utilised to compute a new set of measurement-dependent injection distribution factors (MDIDFs) at the current operating point.…”