Numerical Initial Value Problems in Ordinary Differential Equations

Fault location is an important application among intelligent monitoring and outage management tasks used for realization of self healing networks, one of the most attractive features of smart grids. The data gathered from various intelligent electronic devices (IEDs) installed throughout the power system could be utilized for smart approaches to locating faults in both transmission and distribution systems. This paper discusses issues associated with improving accuracy of fault location methods in smart grids using an abundance of IED data. Two examples of how the gathered data from different IEDs is used to improve fault location accuracy in transmission and distribution systems are discussed in detail.

Smart Fault Location for Smart Grids

Comparison of impedance based fault location methods for power distribution systems

Phasor measurement units (PMUs) are rapidly being deployed in electric power networks across the globe. Wide-area measurement system (WAMS), which builds upon PMUs and fast communication links, is consequently emerging as an advanced monitoring and control infrastructure. Rapid adaptation of such devices and technologies has led the researchers to investigate multitude of challenges and pursue opportunities in synchrophasor measurement technology, PMU structural design, PMU placement, miscellaneous applications of PMU from local perspectives, and various WAMS functionalities from the system perspective. Relevant research articles appeared in the IEEE and IET publications from 1983 through 2014 are rigorously surveyed in this paper to represent a panorama of research progress lines. This bibliography will aid academic researchers and practicing engineers in adopting appropriate topics and will stimulate utilities toward development and implementation of software packages.

Synchrophasor Measurement Technology in Power Systems: Panorama and State-of-the-Art

A smart grid for improving the management of a power utility grid is provided. The smart grid as presently disclosed includes using sensors in various portions of the power utility grid, using communications and computing technology, such as additional bus structures, to upgrade an electric power grid so that it can operate more efficiently and reliably and support additional services to consumers. The smart grid may include distributed intelligence in the power utility grid (separate from the control center intelligence) including devices that generate data in different sections of the grid, analyze the generated data, and automatically modify the operation of a section of the power grid.

Method and system for managing a power grid

One-end algorithm for locating an open conductor failure combined with an earth fault on power lines has been presented. Two cases: an open conductor failure occurring in front of and behind a earth fault, respectively, have been considered. The sample case with the fault data obtained from ATP-EMTP simulation is included and discussed.

Location of open conductor failure combined with phase-to-earth fault on power line

Summary form only given as follows. This paper presents a new, accurate and robust fault locating algorithm for series compensated lines. The algorithm is developed as a one-end fundamental frequency based technique and offsets both the series compensation effect and the reactance effect resulting from the remote end in-feed. The method uses phase coordinates (abc) instead of symmetrical components [012]. The basic algorithm is presented for a line compensated by one three-phase bank of series capacitors. The presented fault locating method has been extensively tested using the EMTP model of a 400 kV 300 km transmission line. The enclosed results demonstrate very high accuracy and robustness of the algorithm.

A new accurate fault locating algorithm for series compensated lines

The presented fault location algorithm for distribution networks is based on voltage and current phasor estimation. The algorithm was investigated and proved on the basis of voltage and current data obtained from versatile EMTP/ATP simulations. The developed algorithm utilizes the current measurements delivered from the faulty feeder or from the substation. In the latter case the estimation error depends on accuracy of pre-fault condition determination in the MV substation. The distance to fault estimation error depends on the accuracy of measurements as well as cable parameters. The evaluation by using EMTP/ATP simulation has proved the validity of the algorithm and gives accurate fault location estimation.

A new fault location algorithm for distribution networks

The paper presents a digital protective relay as a complex real-time microprocessor system. From this point of view the basic hardware and software structures and functions of a digital relay have been described and classified.

A digital protective relay as a real-time microprocessor system

Design of ferroresonance suppression circuit for capacitive voltage transformer is presented. For this purpose an analytical approach to ferroresonance is firstly introduced. With use of the harmonic balance method the condition for avoiding stable subharmonic oscillations of the 3rd mode is stated. In the next step the ATP-EMTP simulation based investigations are carried out to find the suppression circuit parameter (or parameters) which assure damping of the nonlinear oscillations in accordance to the requirements of the standards. Two kinds of suppression circuits designed for the considered capacitive voltage transformer construction are investigated. The obtained results are presented and discussed.

Eugeniusz Rosolowski

Papers

Location of open conductor failure combined with phase-to-earth fault on power line

A new accurate fault locating algorithm for series compensated lines

A new fault location algorithm for distribution networks

A digital protective relay as a real-time microprocessor system

Design of ferroresonance suppression circuit for capacitive voltage transformer - analytical approach supported by simulation