Month: May 2014

Electric Substations : The Specifications

An electrical substation is a supplementary station of an electricity generation, transmission and distribution system where voltage is transformed from the high to low or the overturn utilizing transformers. Electric power might flow through several substations between generating plant and customer, and may be changed in voltage in several steps.

Electric Substations

A substation which has a step-up transformer enhances the voltage whilst decreasing the current, as a step-down transformer decreases the voltage whilst increasing the current for commercial and domestic distribution. The term, substation comes from the days prior the distribution system became a grid.

The first substations were linked to only one power station where the generator was placed, and were subsidiaries of that power station.

Machinery in substation

Substations usually have switching, control and protection equipment and one or more transformers. In a huge substation, circuit breakers are used for interrupting any overload currents or short-circuit which might occur on the network. Smaller distribution stations might use fuses or re-closer circuit breakers for protecting distribution circuits. Electric Substations do not, by and large, have generators, though a power plant might have a substation close at hand.

Other equipment, like; voltage regulators and power factor correction capacitors might also be situated at a substation

High-rise buildings might have quite a lot of indoor substations. Indoor substations are generally found in urban areas for reducing the noise from the transformers, for reasons of manifestation, or for protecting switchgear from the extreme climate or pollution situations.

Where a substation has a metallic barrier, it must be suitably grounded or earthed for protecting the people from high voltages which might occur throughout a fault in the network. Earth faults at a substation could cause a ground probable rise. Currents flowing in the Earth’s surface all through a fault could cause metal objects for having a considerably different voltage than the ground under the person’s feet; this touch probability presents a danger of electrocution.

 

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Distribution Substation: Specifications And Technicalities

Distribution Substation

The Distribution substation guidebook comprises of the approved standard arrangements for the installation, design and construction of distribution substations, connection of clients to these substations and interconnection of the substations to the surrounding LV and HV networks.  The distribution substation converts the voltage closer to the needed and required usable levels.

The distribution substation obtains power from one or more transmission or sub transmission lines at the resultant transmission or sub transmission voltage level and offers that power to one or more distribution feeders which invent in the substation and encompass the primary network. Most feeders originate radically from the substation for supplying the load.

There are five major functions of the Distribution Substation:

1.   Voltage transformation: One or more transformers would always be situated within the substation to step down the voltage to the prime distribution voltage level. These transformers would always be three phase banks, or they would be three single phase banks associated in a three phase configuration. The standard primary distribution voltage levels take account of 7.2kV, 4.16kV, 13.2kV, 12.47kV, 14.4kV, 34.5kV and 23.9kV.

2.   Switching and protection: Varied types of switchgear will be situated at the substation, comprising the following:

a. Switches

b. Circuit breakers

c. Reclosers

d. Fuses

3.   Voltage regulation: For the reason that current flows from source to load alongside the length of the feeder, and since the feeder has some quantity of impedance per unit length Z, the feeder would generate a voltage drop IZ volts per unit length.

4.   Metering: Most substations do have some kind of metering device which records, at a smallest amount, existing current and current maximum and minimum which have occurred in the last time period, for example 1 hour. Digital recording is also extensively used and competent of recording a large quantity of substation operational information.

 

 

 

What Is Known As Electric Substations?

Substations are a familiar sight at the side of cities and highways. Substations take the electrical energy from the transmission lines and from power plants and transform it from high to a lower voltage. They distribute electricity to customers and supervise and defend the distribution network to keep it working efficiently and safely, for instance by using circuit breakers, that is, the industrial strength equivalent of the humble fuse for cutting power in case of a problem.

electric substations

Substations are often classed as per the switchgear made use for protecting their circuits.

  • Air-insulated switchgear or also known as by the abbreviation AIS, is used to be the most ordinary design, although this needs a lot of space and for higher voltages is only reasonable outdoors. Even then, AIS or Air insulated switchgear might be unsuitable or undesirable in certain locations, such as residential areas.
  • Gas-insulated switchgear or also called as by the abbreviation as GIS might be more expensive if only the unit cost is measured up to, but is safer and requires less maintenance. The information that GIS units are five times smaller than AIS means cost savings and less or smaller intrusive buildings.

Electrical lines could be underground or overhead. The construction of overhead lines charges less, but outages are more common than on the underground lines, that is owing to the accidents, lightning strikes or bad weather.

What is found in an Electric Substations ? The equipment or tools found in switching devices and power transformers. Switching devices which are found in a substation are circuit breakers and dis connectors. Both these are used for cutting power in case of a problem, and measurement, defense and control equipment required for ensuring its safe and well organized operation. Since they are highly useful both commercially and residentially, therefore, they must be manufactured properly.