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An accurate fault location estimation (FLE) helps in quick power system restoration in the event of transmission lines exposed to faults. However, the accuracy of FLE gets affected in shunt FACTS-compensated system. Therefore, it is indispensable to develop an efficient FLE algorithm which serves the purpose of accurate estimation of fault location in shunt-compensated system. Consequently, this paper proposes a traveling wave-based FLE algorithm utilizing short-time matrix pencil method (STMPM) to estimate the fault location in the aforementioned system. In the proposed algorithm, STMPM is used to decompose windowed signal into time-indexed complex frequencies. From the fact that damping factors extracted from complex frequencies are near or equal to zero when the arriving traveling waves after inception of fault are at the middle of sliding window, the arrival time of waves is estimated and fault location is obtained. The efficacy of the proposed algorithm is tested on 100 MVAR STATCOM-compensated 500 kV transmission system under several fault scenarios and diverse operating conditions. The performance of STMPM-based FLE algorithm is compared with that of the existing methods and found to be more robust and reliable. Further, real-time validation of the proposed algorithm is carried out in OPAL-RT environment. [ABSTRACT FROM AUTHOR]

Summary: The existence of midpoint series flexible alternating current transmission system (FACTS) devices leads to degrade the performance of mho relay, leading in erroneous estimation of fault location, ie, overreach or underreach for wide variation in network parameters. This research article proposes a novel mho relay algorithm to improve the performance of distance relay in presence of FACTS device using phasor measurement unit (PMU). First, the complete model of transmission system employing static synchronous series compensator (SSSC) and its control strategy is described analytically, where the error introduced in measurement of impedance due to SSSC on the performance of distance relay. Second, a novel mho relay procedure is developed based on PMU to protect the first zone of double‐circuit transmission line for single line‐to‐ground (SLG) fault. The proposed work is analysed and simulated with 48‐pulse SSSC carried out with Bergeron model of transmission line using power system computer‐aided design (PSCAD) computer simulation. Finally, the simulation results represent that the suggested adaptive scheme is truthful, reliable, and secure with change in compensation level of SSSC. [ABSTRACT FROM AUTHOR]

Summary: Saturation of the current transformer (CT) results in maloperation of current‐dependent protective relays. While enhancing in the core area may prevent the saturation, it simultaneously increases the size, the weight, and, subsequently, the price of the CT, which is desirable for neither the CT manufactures nor the operators. This paper conducts a probabilistic analysis to investigate the impact of influential factors on CT saturation for CT dimensioning. The main aim of the probabilistic analysis is to identify the busses of the power network in which they may be highly exposed to the CT saturation phenomena. The proposed probabilistic framework is performed based on the time‐domain fault analysis. In the probabilistic time‐domain fault analysis, the effects of fault location, fault type, and fault resistance are investigated. Also, the effects of load and generation are considered probabilistically. On the basis of the selected random variables (RVs), the probability density function (PDF) of the voltage of the knee point (VKP) is obtained. Also, a new criterion so‐called depth of saturation (DofS) is introduced that shows the level of exposure to saturation phenomena for each bus. The results show that the proposed probabilistic framework helps to find a general observation to VKP of each CT from the CT‐dimensioning aspect. Also, the proposed probabilistic framework provides some useful information about the probability of saturation area in the power system. [ABSTRACT FROM AUTHOR]