They are used to transform power from one voltage level to another voltage level. Transformer is the main component in such substations. Transformer substations are further classified into Step-up substations, Primary grid substations, Secondary substations and Distribution substations.
Generating voltage of the order of 11kV needs to be stepped up to a primary transmission voltage level of the order of kV or kV. Large consumers are supplied power at 11kV. Different connections are made between the various transmission lines.
Some are used to change the frequency from higher to lower or vice versa for industry utilisations. According to constructional features substations are classified into Indoor substations, Outdoor substations, Underground substations and Pole mounted substations. Single Line Diagram Any complex power system even though they are three phase circuits, can be represented by a single line diagram, showing various electrical components of power system and their interconnection. In single line representation of substation the electrical components such as power transformers, incoming and outgoing lines, bus-bars, switching and protecting equipments, are represented by standard symbols and their interconnections between them are shown by lines.
Single line diagrams are useful in planning a substation layout. Some of the standard symbols used to represent substation components are given in Table below. Auxiliary transformers supply power to auxiliary equipments at the substations. Current transformers CT : The lines in substations carry currents in the order of thousands of amperes. The measuring instruments are designed for low value of currents. Current transformers are connected in lines to supply measuring instruments and protective relays.
Potential transformers PT : The lines in substations operate at high voltages. The measuring instruments are designed for low value of voltages. Potential transformers are connected in lines to supply measuring instruments and protective relays. These transformers make the low voltage instruments suitable for measurement of high voltages.
Circuit breaker CB : Circuit breakers are used for opening or closing a circuit under normal as well as abnormal faulty conditions. Different types of CBs which are generally used are oil circuit breaker, air-blast circuit breaker, vacuum circuit breaker and SF6 circuit breaker. Isolators or Isolating switches: Isolators are employed in substations to isolate a part of the system for general maintenance.
Isolator switches are operated only under no load condition. They are provided on each side of every circuit breaker. Lightning arresters LA : Lightning arresters are the protective devices used for protection of equipment from lightning strokes. They are located at the starting of the substation and also provided near the transformer terminals. Earth switch: It is a switch normally kept open and connected between earth and conductor.
If the switch is closed it discharges the electric charge to ground, available on the uncharged line. Wave trap: This equipment is installed in the substation for trapping the high frequency communication signals sent on the line from remote substation and diverting them to the telecom panel in the substation control room. Coupling capacitor: A coupling capacitor is used in substations where communication is done by AC power line.
It offers very low impedance to high frequency carrier signal and allows them to enter the line matching unit and blocks the low frequency signal. Bus-bar: When number of lines operating at the same voltage levels needs to be connected electrically, bus-bars are used. Bus-bars are conductors made of copper or aluminum, with very low impedance and high current carrying capacity. Single bus-bar arrangement: It consists of single bus-bar. Both incoming and outgoing lines are connected to the single bus-bar.
The advantages of this arrangement are low maintenance, low initial cost and simple operation. The drawback of this arrangement is if any repair work is to be done on bus-bar, complete system get interrupted. Center Center of gravity of gravity mm mm. The spring control mechanism is vacuum packed in a reinforced plastic envelope.
No supervision is necessary. Open navigation menu. Close suggestions Search Search. User Settings. Skip carousel. Carousel Previous. Carousel Next. What is Scribd? Explore Ebooks. Bestsellers Editors' Picks All Ebooks.
Explore Audiobooks. Bestsellers Editors' Picks All audiobooks. Explore Magazines. Editors' Picks All magazines. Explore Podcasts All podcasts. Difficulty Beginner Intermediate Advanced.
Explore Documents. Document Information click to expand document information Description: datos tecnicos de los breaker areva. Did you find this document useful? Is this content inappropriate? Report this Document. Description: datos tecnicos de los breaker areva. Flag for inappropriate content.
Download now. Related titles. Carousel Previous Carousel Next. Jump to Page. Search inside document.
0コメント