This paper presents a transient-based algorithm for high-impedance fault identification on distribution networks. It uses the discrete wavelet transform to monitor high- and low-frequency voltage components at several points of the power system, being able to indicate the most likely area within which the disturbance has occurred, without requiring data synchronization nor the knowledge of feeder or load parameters. The proposed algorithm is evaluated through electromagnetic transients program simulations of high-impedance faults in a 13.8 kV system modeled from actual Brazilian distribution grid data. Solid faults, capacitor bank switching, and feeder energization are also simulated, considering the system with and without distributed generation. Obtained results show that the algorithm significantly reduces the search field of the high-impedance fault, reliably distinguishing it from other disturbances.

This paper presents an innovative two-terminal traveling wave (TW)-based fault location formulation. It depends only on the time difference between the first incident TW and the successive reflection from the fault point, at both line ends. Thereby, the proposed formulation requires neither data synchronization nor line parameters, which are sources of error that usually affect TW-based fault location schemes. Several faults on a typical 500 kV line were simulated to compare the proposed formulation performance with that of a classical twoend approach. The obtained results attest that the proposed formulation is able to accurately locate faults on transmission lines, even when data synchronism errors and uncertainties in the monitored line parameters exist.

In this paper, a new two-terminal traveling-wave-based fault-location algorithm is proposed. Its main advantage over similar two-terminal algorithms lies in the fact it does not require the data from both line terminals to be synchronized. In order to do so, the algorithm is applied in real time, and a communication system is used, whose data-transmission latency is taken into account in the proposed formulation. The fault locator routines were implemented using the real-time digital simulator (RTDS), such that a wide variety of fault scenarios in a 230-kV transmission line 200 km long was evaluated in real time, considering communication systems with different latency variability levels. The obtained results indicate the proposed algorithm is able to locate faults using either synchronized or unsynchronized two-terminal data, whereas classical methods work properly for synchronized measurements only.

A novel algorithm for transient detection based on Park's transformation is proposed. It is very simple, self-adapts to electrical noise and phase imbalances, and is appropriate to be used in connection with traveling-wave fault location (TWFL) methods. The proposed technique is evaluated through Electromagnetic Transients Program simulations. A 230-kV transmission system case study is carried out, in which power system voltage and current waveforms are picked up one sample at a time. It is shown that the method is very reliable and suitable for multiterminal TWFL algorithms.

This letter presents a two-terminal traveling-wave (TW)-based earth fault-location algorithm. It works using unsynchronized data and does not require information about the line parameters. Evaluated signals are decoupled into aerial and ground modes and, then, only the incident TWs of each mode are detected at the line ends. Earth fault case studies are carried out to attest the proposed algorithm feasibility, comparing its performance with those of one- and two-terminal approaches reported in the literature. Obtained results reveal that the proposed algorithm is straightforward and quite reliable.

This paper proposes a two-terminal traveling-wave-based transmission-line protection using only the first wavefront arrival time at each line terminal (polarity and magnitude of transients are not required), leading to a simple, accurate, and fast protection. In real time, the protection system detects internal and external faults and identifies the fault directionality. In addition, the protection zone and the protection operating time are also formulated. The effects of the sampling rate and the traveling-wave propagation velocity estimation are considered, and some paradigms, such as the need of a high-sampling frequency and an accurate traveling-wave propagation velocity estimation are properly addressed. Two traveling-wave-based protective relays were implemented and evaluated in realistic real-time hardware-in-the-loop simulations considering the communication equipment between the relays, in which reliability and protection operating time could be assessed accordingly.