Electrical Substation

Electrical power system is composed of high-voltage trans­mission lines that feed power to a medium-voltage (MV) network by means of substations. In North America these MV networks generally operate at voltages between 2.4 kV and 69 kV. In turn, they supply millions of independent low-voltage sys­tems that function between 120 V and 600 V.

A substation is the part of the electrical generation, distribution and transmission system, where the voltage is transformed from low to high or high to low, or several other significant functions.

Electrical Substations are used throughout an electrical sys­tem. Starting with the generating station, an electrical substa­tion raises the medium-voltage produced by the synchronous power generators to the high voltage required in order to transmit the current or power efficiently. The high voltage transmission-line is then reduced in those substations located close to the power consuming centers. The electrical equipment in such distribution substations is similar to that found in sub­stations associated with generating plants.

Electrical Substations equipment is mentioned below:

A medium-voltage Electrical substation usually contains the following major components:

• Transformers
• Surge arresters
• Circuit breakers      
• Current-limiting reactors
• Horn-gap switches   
• Instrument transformers
• Disconnect switches
• Relays and protective devices
• Grounding switches

Substations are essential parts of the electrical distribution system. The link between high-voltage transmission lines and low-voltage power distribution systems is the substation. The function of a distribution sub­station is to receive electrical power from a high-voltage transmission system and convert it to voltage levels suitable for industrial, commercial, or residential use. The major functional component of a substation is the transformer. However, there are many other types of spe­cialized equipment required for the operation of a substation. The design of typical substations which are used for electrical dis­tribution  are Transformers, Surge arresters, Circuit breakers, Current-limiting reactors, Horn-gap switches, Instrument transformers, Disconnect switches, Relays and protective devices, Grounding switches and many more.

Questionnaire:

• What is Electrical substation? Explain
• What are the equipments used in electrical substation?