The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Protection of power systems requires a high degree of reliability. Whenever a protection is called upon to operate, it must do so. Failure to do so may result in costly damage to plant, loss of supply to many consumers, and potentially, danger to life. Protection relays are designed in such a way as to ensure reliability of operation. Very often, the main threat to reliable operation is the circuit...
The paper will present implemented protection scheme on two, symmetrical, double core design Phase Shifting Transformers (PST) [6], each rated at 600MVA, 400kV, 866A, 50Hz, ±40° with in total 64 tap positions (32 advance and 32 retard). Thus, every individual tap introduce phase angle shift of 1,25°. The used PST protection scheme follows the protection recommendations published by IEEE [1]. It shall...
Distributed generation is increasingly likely to play a major role in electricity supply systems as recognition is made of its low carbon credentials. However, the integration of these units at distribution voltages is a major challenge for utilities. One particular issue is that generators may, unintentionally, continue to supply local demand when areas of the network are isolated from the main system...
Integrating Distributed Generation (DG) in distribution systems will have an impact on the fault current magnitudes. This could have an impact on the coordination of the protective devices. In this paper, the optimal DG locations are determined in order to minimize the overall relay operating times for a meshed distribution system. The problem is formulated as a Non-Linear Programming (NLP) problem...
Currently, there are many challenges in the development of numerical, multifunctional Intelligent Electronic Devices (IEDs) paraphrased as relays in this paper. These are to continuously improve the design quality, to reduce the development period for shorter time to market, and to optimise the development cost and the product cost. One effective solution for these challenges is to develop automated...
For decades, various versions of the Takagi algorithm have been used by microprocessor-based relays for fault location. This system provides accurate fault location, limited by nonhomogeneous infeed, load flow, fault resistance, and series-compensated or parallel lines. With the emphasis placed on reliability in today's power system, the need for improved accuracy in fault location has increased....
The digital substation and the implementation of IEC61850 are fundamental to the future of protection relays. The IEC61850 standard, "Communication Networks and Systems in Substation", provides the basis for the communication system for the digital sub-station's protection and control schemes. Section 9–2 defines the Ethernet based communication network providing data transfer between primary...
The new generation of current sensors has performance characteristics that can improve design and operation of modern power systems. This paper presents novel solutions for protection of capacitor banks using Rogowski coils as currents sensors.
Transmission level protection functions are increasingly being looked at for Distribution systems. This can be attributed mainly to the enhancements being planned for by the Operating Companies, to increase the system efficiency, and also to ensure reliable power supply to the end Consumers. Slowly, the catch word "Smart Grid" is being consciously and progressively transformed to practical...
The advent of IEC61850 Standard has ushered a new age for substation automation. This standard has gained a very strong footing in Europe and its application is spreading across the world. In USA the progress towards IEC61850 implementation is relatively slower. IEC61850 holds great promises for substation automation and protection. There are many advantages that this standard brings to the area of...
With the increased use of renewable wind energy, wind farms are being built in remote areas, often far from load centers. The required long transmission lines are often constructed with series capacitive compensation to electrically shorten the lines. Events in the transmission system can cause interactions between the series capacitors and the system's inherent impedance which can result in sub-synchronous...
Every pump storage hydro power plant has at least three different operating modes of the synchronous machine which can cause possible challenges during the design of the plant protection scheme. These three operating modes are generating mode, pumping mode and machine starting into pumping mode. The main differences between the generating and pumping operating modes are changes in direction of the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.