High Voltage Substations Overview (part 2)

High Voltage Substations Overview (part 2)


Continued from first part: High Voltage Substations Overview (part 1)


Distribution Substations

Transformers are used for the transformation of high and medium voltage to low voltage, flanked by specific protective devices and control systems, which constitute the low voltage distribution substations.

A distribution substation, is characterized by the apparent power of the transformer and whether it is aerial, terrestrial or underground.

The indoor substations (terrestrial or underground), are manufactured in specific areas to ensure waterproofing and adequate ventilation. Among the equipment of high and low voltage, special protective grids (cells) shall be inserted and the transformer is protected by a special cover.

The arrival and departure of electric lines may be:

  1. Aerial (with bare conductors) or
  2. Underground (with reinforced cables)
A distribution substation, usually includes: disconnect switches, circuit breakers, lightning arresters, provisions limiting the short circuit current, monitoring, measuring and recording instruments (power, current and potential transformers), SCADA etc.

The following example refers to a terrestrial distribution station:


1. Floor plan and incision of a terrestrial distribution substation

Floor plan of a terrestrial distribution substation

Floor plan of a terrestrial distribution substation

Incision of a terrestrial distribution substation

Incision of a terrestrial distribution substation

2. Single line schematic arrangement

Single line schematic arrangement of power substation

Single line schematic arrangement of power substation

3. Analytical (three-pole) schematic diagram

Analytical (three-pole) schematic diagram of distributive power substation

Analytical (three-pole) schematic diagram of distributive power substation

High Voltage Substation At Rockville Indiana (VIDEO)

Cant see this video? Click here to watch it on Youtube.

References:

- SIEMENS Substations Guide
- Andreas Goutis, ‘Electrical drawing, Part 1’


About Author //

author-pic

Emmanouil Angeladas

Emmanouil Angeladas - Bachelor in Electrical Engineering from Technological Educational Institute of Piraeus, Hellas. Electrical engineer working at Center of Renewable Energy Sources. I work in the field of maintenance, functional test and installation of measuring systems, including wind potential measurements in areas where wind turbines will be installed. I'm highly interested in HVDC systems, Fuel Cells technology and Microgrids.



5 Comments


  1. tonny s dungdung
    Apr 21, 2013

    TANKS


  2. jankhossa
    Apr 10, 2013

    please gives me some idea 1) on_load taping
    2) off_load taping
    which is used in grid station……..????


    • Praveen Prathap
      May 15, 2013

      Same as the name shows ;-)
      ON LOAD means raise/lower transformer output voltage at a substation without switching off(ON-LOAD) the feeder.
      OFF-LOAD means raise/lower transformer output voltage at a substation after switching off(OFF-LOAD) the feeder.

      The second one is safe. So it is recommended my the transformer manufacturers.


  3. deepakdj18
    Jan 31, 2013

    i have one question………please answer this…..

    Why potential transformers are installed before current transformer in a structure of switching yard?


    • Emmanouil Angeladas
      Feb 04, 2013

      There is no regulation for the connection of the transformers. You connect them in any order you wish…

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