44 Advantage of vacuum CB * Used up to 66 KV. * Vacuum is highly dielectric, so arc can’t persists. * Separation of contacts causes the release of metal vapour. Source:Electric Substation Types The main purposes for establishment of a substation are: * Need for connecting a generator to the transmission system: We . Replacement of the existing 7 MVA (2 MVA & 5 MVA 66kV: kV transformers) switchyard with a new 66 kV switchyard consisting of two new 10 MVA DSC
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66 KV Switchyard | HMEL
k.v.switchhyard Puffer cylinder Interrupter 9. The substation site must be reasonably central to the distribution area to be served. For medium-voltage distribution substations, metal-enclosed switch gear may be used and no live conductors exposed at all. The metering and protection relays shall be part of switchgear only. Substations located in coastal areas affected by flooding and tropical storms may often require an elevated structure to keep equipment sensitive to surges hardened against these elements.
A compact substation is generally an outdoor substation built in a metal enclosure, in which each item of the electrical equipment is located very near to each other to create a relatively smaller footprint size of the substation. The air space required increases with system voltage and with the lightning surge voltage rating. My presentations Profile Feedback Log out. Where land is costly, such as in urban areas, gas insulated switchgear may save money overall.
This gas has a higher insulating value than k.v.switchyqrd, allowing the dimensions of the apparatus to be reduced. Electrified railways also use substations, often distribution substations.
Retrieved 11 October The voltage across one of the capacitor is taken to aux PT. These are sets of busbarsusually in multiples of three, since three-phase electrical power distribution is largely universal around the world. United States Department of Agriculture. Converter substations may be associated with HVDC converter plants, traction currentor interconnected non-synchronous networks. Former high-voltage substation in Stuttgart, Germany, now kV switching station.
Substations transform voltage from high to low, or the reverse, or perform any k.v.swigchyard several other important functions. For important substations a ring bus, double bus, or so-called “breaker and a half” setup can be used, so that the failure of any one circuit breaker does not interrupt power to other circuits, and so that parts of the substation may be de-energized for maintenance and repairs.
Apparatus to be protected: Currents flowing in the Earth’s surface during a fault can cause metal objects to have a significantly different voltage than the ground under a person’s feet; this touch potential presents a hazard of electrocution. The arrangement of switches, circuit breakers, and buses used affects the cost and reliability of the substation. Each set shall be 7. Unplanned switching events are caused by a fault in a transmission line or any other component, for example:.
The downtown areas of large cities feature complicated distribution substations, with high-voltage switching, and switching and backup systems on the low-voltage side.
The Ni-Cd Battery bank shall be installed in separate room with proper ventilation system as per safety requirement. It resembles a distribution substation although power flow is in the opposite direction, from many wind turbines up into the transmission grid. The Control supply shall be V DC.
In this case the generators from the power station supply their power into the yard onto the Generator Bus on one side of the yard, and the transmission lines take their power from a Feeder Bus on the other side of the yard. Distributed automatic control at substations is one element of the so-called smart grid.
The site must be secure from intrusion by passers-by, both to protect people from injury by electric shock or arcs, and to protect the electrical system from misoperation due to vandalism. In addition to transforming voltage, distribution substations also isolate faults in either the transmission or distribution systems.
They can be used as coupling capacitors in power line carrier network. This ionised medium acts as conductor and an arc is struck between the contacts.
Each sub bank shall be provided with motorized 11KV Isolator. A small “switching station” may be little more than a bus plus some circuit breakers. A distribution substation transfers power from the transmission system to the distribution system of an area.
A grounding earthing system must be designed.