Figure9: transmission network V. PRINCIPLE AND DESIGNING Basic principle and relay design:- A short circuit fault on a power transmission line generates voltages and current signals of several frequency range which propagate away from the fault point in both directions along the transmission system with velocity close to the speed of light. It has been long recognized that the actual faulted position can be determined on line if the transient signals are time tagged at key points on the power system network. The global positioning system, with its ability to provide synchronization with an accuracy of microsecond over the wide area, provides an ideal tool for performing time tagging of the fault generated transients. Basic Principle:-The basic principle of the technique can be demonstrated by referring to the 400KV, EHV (Electrical High Voltage) transmission network, shown in figure(9). Relays are installed at the bus bars P,Q,R and S and are responsible for the protection of the network . The protection of the network PQR and tripping of the breakers associated with that network is studied. High frequency signals are generated at the fault point and travel outward from that point along the network conductors. In time they reach the monitored bus bar are detected by the relays connected to them. Each relay record the arrival instant of the signal generated by the fault. The recorded arrival …show more content…
CONCLUSION The positional protection using GPS is a high speed protection system and offers a high accuracy in fault location. The protection system monitors the network to which it is connected and is not limited to individual unit plant as in traditional protection scheme. Thus the use of GPS in protection of transmission systems is beneficial with respect to Value regarding programmatic goals: more reliable monitoring using GPS related technologies. Technical merit: new fault location algorithm based on new input
Equipment such as switchgear can be worked on safely by ensuring a range of actions have taken place. The equipment used on the high voltage lines are the same.
On August 14th, 2003, a major blackout swept across portions of the northeastern United States and Canada. It was reported that a series of equipment outages in the Midwest led to uncontrolled cascading outages of power transmission lines and generators serving parts of the Northeast, Midwest and Canada. Automatic protective systems operated to open circuits and shut down power plants to prevent further spread of the outages. This is very similar to what happened in The Great Northeast Blackout of 1965. In both situations, the “grid system” shut down one generator in line at a time to protect a surge from the station before it.
...ial approaches which are Normal Accident and HROs, although it seems certain that both of them tends to limit the progression that can contribute toward achieving to highly protective systems. This is because the scope of the problems is too narrow and the potential of the solutions is too limited as well. Hence, Laporte and Consolini et.al., (1991) as cited in Marais, et.al., (2004) conclude that the most interesting feature of the high reliability organization is to prioritize both performance and security by the managerial oversight. In addition, the goal agreement must be an official announcement. In essence, it is recommended that there is a continuing need in the high risk organizations for more awareness of developing security system and high reliability environment in order to gain highly successful method to lower risk in an advance technology system.
Knob and tube wiring was state-of-the-art up until around 1950. The main concerns with this old wiring method is overheating, deteriorating insulation, improper connections, and that it is not a grounded system. K&T wiring was ideal for when it was originally designed to hold modest currents. But nowadays the electrical demands for the average house are considerably greater. Sixty years ago t...
Unknown. "Switching & Transmission: How reliable is the public network?" Electric Library, accessed on April 17, 1998, http://www.elibrary.com/getdoc.cgi…1563841@library_a&dtype=0-0.html
Gaussian elimination avoids the need of matrix inversion while solving the nodal equation of large power systems. Moreover it also leads to reduced order network equivalents. This is used to analyze power system with special focus on voltages at some selected buses. For this purpose selective numbering of s...
Circuit breakers and fuses provide equipment and installation protection and operate only in response to an electrical overload or short circuit. Hence these devices cannot detect earth fault currents below their operating current. If they are the only means of protection, it is possible for sufficient earth fault current to flow undetected to constitute an electrical hazard (fire and electrocution).
In today’s society, the need to have an adequate supply of electricity to run everyday tasks is in greater demand than ever. Everyday we turn our lights in our homes on and off without really thinking about if there is enough electricity to power each and every light. Throughout this paper, we examine Kirchhoff’s Voltage Law the sum of the electrical potential differences around any closed network is zero [1]. Represented by the equation ΣV=0, which means v1+ v2+ v3+…+ vn=0 [2]. A way at looking at this equation in words is by the sum of the voltage rises in the loop will equal the sum of voltage drops in the loop [2]. By applying this principle electrical engineers can use this to determine if there is enough energy to power an entire circuit ranging from small items like a flashlight, to skyscrapers in the world’s largest cities.
The electricity grid is the term for the network of power lines, transformers, and any other tool required for the transportation of electricity to the consumer’s house. The current grid relies upon the workers to collect the data needed and report back to the engineers and overseers who then instruct how to maintain the grid. Now, in the computer age, the smart grid has been made possible. The smart grid is similar in concept to a smartphone. Smartphones are run by powerful computers that provide the maximum efficiency possible to give the phone more features and run faster. This is what the smart grid can do; it maximizes grid efficiency and makes it compatible with newer technologies. The smart grid incorporates two-way comm...
For the prevantion of the electricity blackout we need to build smart power grid. A modernized electrical grid that uses analog or digital information and communications technology to gather and act on information, such as information about the behaviours of suppliers and consumers is known as a smart grid. This is used to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity in an automated fashion[12]. The important aspects of smart grid is to electronic power conditioning and control of the production and distribution of
generation at each generator, find the power flow in each line and transformer of the interconnecting network and the voltage magnitude and phase angle at each bus.
Sources of PQ problems in all the fields such as domestic, commercial are industrial are closely related with power electronics. For example residential equipments such as PC’s and TV, office equipments like printers and industrial equipment such as PLCs.
circumstances and failures that can occur in any element of power system. Moreover, the rapid
GPS is a system of satellites radio-transmitters that orbit the planet in great numbers; their purpose is to be able to pinpoint the exact location of an individual or any type of vessel that is equipped with a receiver transmitter within a very small radius. GPS navigation has had a great impact upon society in general as well and its commercial and military applications. Global Positioning is made available at no cost to anyone who has a GPS receiver unit anywhere on the planet. A GPS unit is able to give the user longitude/latitude information as well as, altitude, traveling speed, distance traveled, distance remaining and time in any type of weather conditions imaginable.
[8] Mann, B.J.; Morrison, I. F., "Digital Calculation of Impedance for Transmission Line Protection," Power Apparatus and Systems, IEEE Transactions on , vol.PAS-90, no.1, pp.270,279, Jan. 1971