A laboratory investigation of a digital protection technique for parallel transmission lines

Abstract

A k t r r t A digital algorithm for the protection of parallel "fuloo linea bar beea implemented on a 16-bit dngle board co(~pp1c1: It haa been tested on a physical model codsting of two rpchtoMwu " i connected through a double circuit lirre. Tbe algorithm is baaed on comparing magnitudes of amcats of two prnllel linea Details of the experimental set-up rab tbe d t s of oa-line tests for various oparriag conditions arc prerented A procedure to adjua tbe relay setting8 adapcively is d m iacorpontsd The resulk? illustrate the succwful opardoa of the algorithm in detecting faults on parallel lines.

A new digital directional transverse differential current protection technique

“…The relay will operate when the current division io the two circuits Varies by a given tolerance. Recently, this form of transverse Merential protection relaying was presented digitally in [6,7]. The protection algorithm is based on the comparison of the average current in corresponding phases.…”

“…The previous discussion concluded that a technique based on the current magnitude only as described in [6,7] is highly influenced by the short-circuit impedance behind the buses.…”

Adaptive Protection of Parallel Transmission Lines Using Combined Cross-Differential and Impedance-Based Techniques

“…It identifies an internal fault when the difference between the two circuits currents exceeds a certain threshold [10]- [12]. This technique is immune to the mutual coupling effect and provides faster operation speed compared to the distance algorithm.…”

Improved Transverse Current Differential Protection Resistant to Power Swing

“…Transverse differential protection scheme based on average current is proposed in Gilany et al (1995). This method has limitation for far end fault.…”