An unblocking assistance to distance relays protecting TCSC compensated transmission lines during power swing

Abstract

Summary Modern digital distance relays are incorporated with power swing blocking functions to avoid false operation during power swing. At the same time, it is also crucial to detect a fault correctly and quickly if occurs during power swing for unblocking and allowing the relay to trip the line. Detection of faults in thyristor controlled series capacitor (TCSC) compensated transmission lines during power swing is very challenging due to the nonlinear functioning of the thyristor controlled reactor and the metal‐oxide varistor protecting the series capacitor. This paper proposes a fault detection technique for TCSC compensated transmission lines during power swing using the generalized Teager‐Kaiser energy operator on the instantaneous current signal. The performance evaluation on a wide variety of test data generated on the modified WSCC three‐machine nine‐bus system and the modified IEEE 39‐bus New England system through EMTDC/PSCAD justify the efficacy of the proposed method.

Fault detection and faulty phase(s) identification in TCSC compensated transmission lines

“…Techniques available to detect a fault during the power swing in uncompensated lines find limitations in the presence of the nonlinear functioning of the compensation circuits [15]. The challenges are compounded as FACTS give rapid response to the fault events causing variation of the voltage and current signals measured by the relay that may mislead the relay operation [26].…”

“…To apply the CSH algorithm, g 2h is calculated based on (15) and (16) for each test signals similar to what is shown in Figs. 6-10.…”

“…FACTS devices control power flow, voltage regulation, ambulatory power control, transient stability, and damping oscillations of power systems [14]. However, the non-linear behaviour of TCSC and the metal-oxide varistor (MOV) protecting the series capacitor makes (a symmetrical type of) fault detection during power swing more enigmatic [15].…”

“…The generalised Teager-Kaiser energy of the instantaneous current signal has been suggested for a compensated line in [15]. In [16], a superimposed apparent-power-based technique is proposed to detect faults in a series-compensated line during power swing.…”

Comprehensive Analysis of the Impact of the TCSC on Distance Relays in Interconnected Transmission Networks

“…Thus, distance relays may face serious challenges in interconnected transmission networks under power swing phenomenon and especially in the presence of the TCSC. Few efforts have been exerted to evaluate distance relays for faults under power swing phenomenon in the presence of the TCSC such as the study in [13] that only covered capacitive mode of operation within a 30% to 40% compensation level.…”