The electrical substation is a key component of the power grid. These substations are used to convert AC voltages between different voltage levels. It may be difficult to notice, but electrical power is transformed at different voltage levels as it travels from an electrical plant. Electrical substations can be used to “step-up” or “step-down” voltage levels to deliver it to the desired location. This article will cover the different types of substations, as well as equipment that is used in a typical electrical substation.

Use of Electrical Substations:

Substations, also called electrical grids, are a vital component of the system for delivering electricity to wherever it’s needed. This is done by adjusting voltages to a certain level, compensating for voltage fluctuations, switching transmission and distributed circuits into or out of the grid, measuring the quality of electric power flowing through the circuits and connecting communication signals, eliminating electrical surges and lightning from the system, and connecting electric generation plants to the system.

Types of Electrical Substations:

Depending on its location and use, the electrical substation may be classified into different types. Let’s go into detail.

Generating Substations:

Substations of this type are used to boost the voltage generated by electrical power plants. In the US, generation voltages typically range between 11 kV and 13.8 kV. In the US, it is more economical to produce power at a low voltage and then increase the voltage up to the transmission level (138 kV, 230 kV, 500 kV). Substations that generate power are used to transfer the electricity from the power station to the transmission lines. A typical generating substation will use three single-phase transformers rather than a three-phase transformer.

Sub-transmission Substations:

This substation type is located between a transmission system and a distribution network. It is used to reduce the voltage from transmission to distribution. Sub-transmission voltages typically range between 33 kV and 145 kV. Sometimes, the sub transmission substation taps into the power lines of large industrial customers.

Distribution Substations:

The electrical distribution substations connect two or three distribution lines of different voltages. They are usually located near the load center. Distribution substations contain step-down transformers that convert the voltage of the distribution level into the customer’s premises. Distribution substations are available in voltages ranging from 11 kV up to 33 kV, with a step-down of 400 V. Substations can be pole-mounted, underground, or mounted on poles to distribute electrical power to residential customers, small businesses, and large commercial buildings.

Mobile Substations:

Mobile substations consist of large trucks or semi-trucks with substations attached. They have a small distribution transformer and a few circuit breakers. These substations can be transported and installed at the fault site to restore power. Mobile substations must be built to withstand harsh road conditions and weather. Mobile substations can be easily moved to the location where power is required, rather than having to construct a permanent installation. Utility companies that must service rapidly growing or relocated populations find them extremely useful. Mobile substations can also be used to isolate certain sections of the grid, allowing maintenance work to be performed without impacting the rest of it.

For nearly half a century, Swartz Engineering has been at the forefront of industry safety. They are a family-owned company specializing in power distribution for the electrical industry. They are the leading manufacturer of mobile substation.