Which type of substation is the most commonly used today?

The most commonly used type of substation today is the air-insulated substation. These substations are designed to use air as the primary insulating medium for their components, making them generally simple and cost-effective to build and maintain. Air-insulated substations are also very versatile and can effectively operate in a variety of environmental conditions.

They are favored for their robustness and ease of accessibility, which allows for straightforward installation and maintenance. Additionally, air-insulated designs can be scaled easily, making them suitable for a wide range of applications from small distribution facilities to large transmission substations. Their design benefits include less material usage, lower capital costs, and relatively straightforward operational practices when compared to more complex types of substations.

In contrast, other types like underground enclosed substations might be utilized in urban areas to save space or reduce visual impact, but they come with higher costs and more complex construction requirements. Post and pillar designs are less common as they are generally considered outdated for most modern applications. High-profile substations, depending on the context, often pertain to specific requirements or applications rather than general use. Hence, the air-insulated substation stands out as the most practical and widely adopted solution in contemporary electrical infrastructure.