Wind farm substation: an overview

Almost in every wind farm a step-up substation is built to collect all the energy generated by the turbines and received through the MV cables. The exceptions are new wind farms or existing wind farms extensions built near a substation that can be upgraded to absorb the additional energy produced: in these cases, only a control center with the SCADA and the medium voltage system is realized.

Although there are different possible technical solutions, normally a substation will be composed by the following elements:

  • Medium voltage system
  • High voltage system
  • Capacitors banks
  • Auxiliary services
  • Control, protection and metering system
  • Communication system
  • Fire protection and intruders protection systems

Medium voltage system is composed by the general busbar, disconnectors, circuit breakers and current transformer.

High voltage system is made of one or more transformers, together with earthing reactance, surge arresters, current transformer, voltage transformer, circuit breaker and disconnector with earthing switch.

Capacitors banks are installed to comply with the grid requirements regarding active and reactive power.

The auxiliary services supply energy both in AC/DC current, and count with a group of battery that can generate energy for several hours to operate the substation in case of emergency, a rectifier and often a backup diesel generator, with a tank big enough to provide energy for 3 days..

Control, protection and metering system allows the correct operation of the wind farm according to local regulations and grid requirements. Basically they are protection relays for the switchgear and power transformers

The communication system, must guarantee the correct communication with the adjacent substations and with the grid owner control center, in order to make possible the correct operation of the wind farm substation. Normally communications are through optical fiber/carried wire.

Fire protection system is normally composed by optical or infrared detectors, fire extinguisher, external bells or siren, while te intruders protection system are normally a fence plus a closed circuit TV.

Also the SCADA server is normally located inside the substation, together with a parabolic antenna to grant broad band connection.

There are several available solutions to connect with the existing high voltage distribution network: normally a dedicated line is used, while in other situations a tap off (or “T” connection) is used. A third solution is to open   the existing line between 2 substations.

The 3 solution are shown on the following diagrams:

9 responses to “Wind farm substation: an overview”

  1. Godwin Avatar

    I need to know more about this wind power I want to open my own wind power company to help people in Western Africa country I need you to tell me how to start my own company and what to do thank you for your understanding

  2. Gavin Avatar

    Hello Godwin.
    I am an engineer and technical translator.
    I have recently translated a Masters on Wind Power which is taught by the University of Barcelona and the engineering education company Structuralia Telephone: (+34) 91 490 42 00 ;

    The course is available in English. I suggest you contact Structuralia. The course covers technical, financial and legal issues.

  3. Samuel Chelliah Avatar
    Samuel Chelliah

    My quest is regarding a solar station and a wind farm. In our wind farm, we have nine units of 800 kW each. The generation at 400V is stepped up to 33 kV and then further stepped up to 220 kV at the receiving station. The maintenance is being maintained by the supplier. There are totally around 100 units in the wind farm. In the control room, there is only a data acquisition which indicates the on line generation. The is supervisory control. I was also told that the 33 kV breaker is auto reclosing in case the incoming supply fails.
    We are now proposing to install a solar station with power evacuation of 33 kV. I want to know whether similar breakers with auto reclosing facility can be provided.

  4. Kayondo T Avatar
    Kayondo T

    Good day please, Ssuuna Twaha of Kampala Uganda and needs to set up a substation aiming generating 10Mw using wind system.
    Kindly advise the requirements on 33 or 11kv output power

  5. Ben Pecora Avatar
    Ben Pecora

    what is the cost to build this storage system

  6. Ben Pecora Avatar
    Ben Pecora

    how much does it cost to build a storage station for excess wind energy

  7. Lou Ann Dickinson Avatar
    Lou Ann Dickinson

    I want to know if there are any danger living close to industrial wind turbines sub stations ( wind turbines will be 656 feet tall) so with all this high voltage what are the dangers?

  8. J.R. Louviere Avatar
    J.R. Louviere

    what parts of the substation require pipping and bolting ?

    1. Francesco Miceli Avatar

      Hello J.R. – not sure I undertand your question, sorry!

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