Substations and generator sets

An electrical substation is an integral part of a generation, transmission and distribution system. A substation can interrupt or establish electrical circuit, change the voltage, frequency or other characteristics of electrical energy flowing in the circuit.

Substations can be generally divided into three major types (according to voltage levels): Transmission substations integrate transmission lines into a network with multiple parallel interconnections, so that power can flow freely over long distances from any generator to any consumer. This transmission grid is often called the bulk power system.

Substations do not (usually) have generators, although a power plant may have a substation nearby. A typical substation will contain line termination structures, high-voltage switchgear, one or more power transformers, low voltage switchgear, surge protection, controls, grounding (earthing) system, and metering.

To fulfill the function of a substation, they include a wide variety of equipment. Each of them will be explained in the next subsections. Power transformers are the most important equipment in an electrical substation. They are different from distribution transformers. They perform different functions. They are used to

Substation are used to transform the voltage with power transformer. From low voltage to high voltage at the power plant with breaker and control system to be able to transport the energy, and other substation at the arrival to decrease the voltage.

A typical substation will contain line termination structures, high-voltage switchgear, one or more power transformers, low voltage switchgear, surge protection, controls, grounding (earthing) system, and metering. Other devices such as power factor correction capacitors and voltage regulators may also be located at a substation.