The effects of a fast switching fault current limiter on distance protection

Abstract

A b s t r o bThis work investigates the impact of a fast switching fault current limiter PCL) on a distance protection scheme. The FCL is modeled ntilizing GTOs to insert a resistive impedance in and on1 of the protected line. The examination is performed by analyzing the transient response of distance relay elements with and without the presence of the FCL in a protective scheme. Relay sdediviiy is explored while placing the FCL in front and behind the relay element. Furthermore, problems such as multiple tripping and nuisance tripping are investigated and solutions to these problems are addressedIndex T e n n e fault current limiter, distance protection, distribution system, mho relay . SYSTEM CONCEPTS A. Operaling Principle off! Fost Switching FCLFast switching is a form or current limiting that involves a rapid switch h i t commutes the current to an impedance connected in parallel during the occurrence of a fault [Y]. The switch mechanism nee& to occur on the order of microseconds and is usually performed h o u g h the use of a semi-conductor or extremely fast acting mechanical switch. Figure 1 shows a diagram of a fast switching FCL that utilize GTOs to perform the fast switching function and a resistor as its current limiting impedance.

Retraction notice to “Analysis of resistive SFCL in a test-bed microgrid” [Ain Shams Eng. J. 6 (2015) 883–892]

“…The distance relay can then compensate for the instantaneous impedance increase due to the SFCL; however, communications is needed. This is alluded to in [HBS03], but for a solid state FCL which inserts a fixed resistance during a fault. The authors of [HBS03] note that this arrangement improves the response of the distance relay.…”

Study on application of a high-speed trigger-type SFCL (TSFCL) for interconnection of power systems with different reliabilities

“…In the fault state, the increased fault current generates a resistance R SC in the HTSC module, due to quench occurrence; as a result, the SW, sensing the quench of the HTSC module, opens. The opening time of the SW was assumed to be one cycle, with a high speed [16,17] compared with conventional SWs using mechanical contacts [18], to reduce energy dissipated in the superconductor and the duration of the voltage sag which affects reliability and power quality of system [6]. The opening of the SW allows the fault current to bypass into the CLR.…”

A Generic Real-Time Computer Simulation Model for Superconducting Fault Current Limiters and Its Application in System Protection Studies

“…For a given current density, , and temperature, , the electric field developed by the superconductor, , is calculated from the equations given in [6] which account for the self induced magnetic field through the values of the parameters chosen. For this model, the critical current density and normal conducting state resistivity are approximated as linear functions of the temperature The effective resistance of the superconductor for the next time step in the real-time simulation can then be calculated as (3) where is the current through the superconducting branch of the fault current limiter and is the time step size for the simulation. E-J curves simulated for both constant and variable temperatures are shown in Fig.…”

“…• Investigate methods to modify relay settings and fault detection algorithms to prevent false trips such as the ones observed during this work. While methods for modifying the mho characteristic are suggested in [3] and design constraints for the SCFCL are suggested in [1], other approaches may also be possible. For example, in the case of a resistive type SCFCL it is conceivable to take advantage of the fact that transmission line impedances are dominantly inductive and therefore should be easily distinguishable from the additional SCFCL impedance by more sophisticated relay algorithms.…”