This paper describes a new scheme to locate a fault on a multi-terminal transmission line. It describes a simple new algorithm to identify the faulted section first. Then, to exactly locate the fault on this section, a method is described that uses the synchronized voltage measurements at all terminals. The main advantage of this method is that the current-transformer errors in the current measurements can be avoided. Since these errors can be as high as 10%, the fault location is extremely accurate with this method. The scheme can work for transposed as well as untransposed lines and is free of prefault conditions. The paper, after describing the scheme, describes very promising results from an Electromagnetic Transients Program simulation of a multi-terminal transmission line.

Fault location scheme for a multi-terminal transmission line using synchronized Voltage measurements

This paper delineates a novel analytical and computational approach to fault location for power transmission grids. The proposed methodology involves an online and an offline stage. The online stage is based solely on the utilization of the time-of-arrival (ToA) measurements of traveling waves propagating from the fault-occurrence point to synchronized wide-area monitoring devices installed at strategically selected substations. The captured waveforms are processed together at the time of fault in order to identify the location of the fault under study. The overall performance of the developed technique is demonstrated using Alternative Transients Program (ATP) simulations of fault transients and postprocessing the faulted waveform data via discrete wavelet transform. The applicability of the algorithm is independent of the fault type and can readily be extended to transmission grids of any size.

Traveling-Wave-Based Fault-Location Technique for Transmission Grids Via Wide-Area Synchronized Voltage Measurements

This paper presents a critical review on different application of Phasor Measurement Units (PMUs) in electric power system
networks incorporated with FACTS controllers for advanced power system monitoring, protection, and control. Also this paper
presents the current status of the research and developments in the field of the applications of PMUs in electric power system
networks incorporated with FACTS controllers. Authors strongly believe that this survey article will be very much useful to the
researchers for finding out the relevant references in the field of the applications of PMUs in electric power system networks
incorporated with FACTS controllers.

/pdf/applications-of-phasor-measurement-units-pmus-in-electric-o612nuurst.pdf

Applications of phasor measurement units (PMUs) in electric power system networks incorporated with FACTS controllers

This paper presents a novel time-domain fault location algorithm for parallel transmission lines using two terminal currents. Parallel transmission lines with faults can be decoupled into the common component net and differential component net. Since the differential component net is only composed of the parallel lines and its terminal voltages equal zero, the proposed algorithm is based on the fact that the difference between voltage distributions, calculated from two terminal currents, is the smallest at fault point. To be practical, unsynchronized data and the transient transferring ability of the current transformer are taken into consideration. The algorithm needs a very short data window, and any segment of current data can be used to locate faults. The proposed algorithm is verified successfully using the simulation data generated by the frequency-dependent line model of the Alternative Transients Program and the field recording data provided by traveling-wave fault locators. Locating results show the satisfactory accuracy of the algorithm for various fault types, fault distances, and fault resistances.

Parallel transmission lines fault location algorithm based on differential component net

A survey on intelligent system application to fault diagnosis in electric power system transmission lines

Two new methods are proposed for fault point location in parallel double-circuit multi-terminal transmission lines by using voltages and currents information from CCVTs and CTs at all terminal. These algorithms take advantage of the fact that the sum of currents flowing into a fault section equals the sum of the currents at all terminals. Algorithm 1 employs an impedance calculation and algorithm 2 employs the current diversion ratio method. Computer simulations are carried out and applications of the proposed methods are discussed. Both algorithms can be applied to all types of fault such as phase-to-ground and phase-to-phase faults. As one equation can be used for all types of fault, classification of fault types and selection of faulted phase are not required. Phase components of the line impedance are used directly, so compensation of unbalanced line impedance is not required.

Digital fault location for parallel double-circuit multi-terminal transmission lines

This paper proposes a time domain model of a fault locator with special reference to fault are nonlinearities by applying the MODELS language of the EMTP. It has been found that an impedance relay type locator is significantly influenced by the fault arc nonlinearities, while the current diversion ratio method is not influenced. This validates the advantage of the current diversion approach over the impedance approach.

Influence of fault arc characteristics on the accuracy of digital fault locators

This paper has proposed a time domain model of a fault locator with spacial reference to fault arc nonlinearities by applying the MODELS language of the EMTP. It has been found that an impedance relay type locator is significantly influenced by the fault arc nonlinearities, while the current diversion ratio method is not influenced. This validates the advantage of the current diversion approach over the impedance approach.

This paper demonstrates that the presence of multiple load taps cannot be neglected for single-phase-to-ground fault location. A new method has been developed taking this into consideration, that can be applied to correct the location error due to intermediate power sources. Then fault location methods for parallel double-circuit two-terminal transmission lines are discussed. Finally, a new fault location method is proposed for high-resistance grounded double-circuit transmission lines with three terminals.

Digital fault location for high resistance grounded transmission lines

In this paper, a time domain model of a fault locator is represented using the MODELS language in the ATP version of EMTP. The fault locator model consists of five parts: input analog filter; sampling hold and digital filters; magnitude and phase calculation; fault locating algorithm; and statistical output procedure. Using different simulation cases, various fault types are modeled, considering the fault resistance to be constant or nonlinear and then considering the input device error. The calculated results are presented and discussed, and confirm the validity of representing the fault locator in a time domain simulation using MODELS.

https://ieeexplore.ieee.org/iel4/5663/15169/00702755.pdf

Y. Mizuma

Papers

Digital fault location for parallel double-circuit multi-terminal transmission lines

Influence of fault arc characteristics on the accuracy of digital fault locators

Influence of fault arc characteristics on the accuracy of digital fault locators

Digital fault location for high resistance grounded transmission lines

Fault locator simulation using MODELS language