Ormazabal Digital Transformation Center

The transformation center is an element that, despite our ignorance, is essential for the electrical grid to function like a Swiss watch

Everyone has passed, without knowing it – or maybe they have – in front of or over an electrical transformation center. Whether strolling through the city or the countryside, these key elements of our daily lives are strange, everyday objects that, unless you have an electrician friend or have read an article about how energy reaches our homes, we rarely understand or identify. The truth is that very few people know the true importance of these transformer stations and how, thanks to a crucial and innovative technological development, they allow us to use energy in our homes, workplaces, or various public facilities. In short, these unknowns, whose function we are going to reveal today, are one of those everyday mysteries that provoke such fascination in people accustomed to asking questions. Are you curious? Well, let’s get to it.

Let’s go step by step. Perhaps the most important thing is to explain, very quickly, how the electrical grid works. We, the consumers, are part of a long chain where the continuous availability of energy, the security of the infrastructure and its intercommunication are absolutely necessary. The electrical grid is a sort of spider web made up of various elements such as cables, electrical switchgear, poles, towers, substations…

In short, and so that we understand each other, energy comes from different sources of electrical generation that could be classified into two large groups: either traditional or renewable.

The former are far from us – think of a combined cycle plant located on the outskirts of our city -, so electricity must be transported efficiently to urban centers: that is when the energy is passed to high voltage. This energy is transported via cabling located on high-voltage towers to an electrical substation, which allows its voltage to be reduced from high to medium voltage. This reduces risks, and the energy is ready for distribution to consumption points.

In contrast, energy generated by renewables undergoes a substantially different journey; it is transported directly at medium voltage to substations located near our cities. Furthermore, this energy is often generated within the buildings themselves, equipped with systems such as photovoltaic panels, so it directly accesses the buildings’ electrical supply systems.

All of this is very well, but when do the famous transformer stations come into play? Well, these would act as large energy controllers and distributors in the vast tangle that is the electrical grid. In football terms, transformer substations would be the creative midfielders, crucial for intelligently distributing the play and constantly measuring where to pass the ball. Located at the substation exits to our electrical grids, transformer substations (TCs)—their abbreviation—distribute and distribute electrical energy to consumption areas thanks to sophisticated grid protection and automation systems, such as those implemented by Ormazabal, a leading company in the sector. Thus, the web is transformed, around the consumption points, into interconnected rings thanks to the work of the CTs.

All of this makes it possible to ensure the supply, rational exploitation of resources, and security of the electrical energy consumption environment, achieving an efficient, safe, and sustainable electrical distribution; capable of supplying and adapting to the different existing energy demand needs. Without our strange friends, we would have a big problem, since we would run out of electricity. That’s how important they are. And they are present in residential areas, shopping centers, factories, hospitals, railways, highways, electric charging stations… And so on, a very long and endless etcetera.

Well, now that we know what their job is, all that remains is to know what they are made of and how they work.

What is a transformer center made of, what types are there and how does it work?

A transformer center is made up of five main elements:

• Envelope: This is the covering of the center. There are precast concrete, sheet metal or even brick-based civil works coverings.

The concrete envelopes isolate and protect the critical elements of the transformation center

• Transformer: It is the main element of the CT and is an electrical element that allows the voltage of an electrical circuit to be increased or decreased for subsequent distribution.

Transformers are essential for the functioning of the electrical grid

• Cell: This element – ​​which is the protagonist of the complexity and technological development of the center – is used for different functions depending on its type, but it would be a large switch that cuts off or lets the electrical energy flow. To achieve this, the technological development that has taken place is essential, obtaining a solution that allows the network to operate at medium voltage values ​​with total safety for the operator and the network in the most adverse conditions.
  

  Ormazabal CGMCOSMOS 2LV cell

   

• Protection Relays: Intelligent protection, measurement and control elements are implemented associated with this switch or cell. Being able to provide electricity companies, private and industrial clients with continuous monitoring of current and voltage values, history of faults that occur, and remote network operation if necessary. A true revolution.
  

  The relays are integrated into the cell’s operation

   

• Low voltage panel: This element distributes and protects energy to our homes. By transforming (reducing) the voltage in the transformer, the current increases, and this element allows said current to be distributed and protected across a specific number of outlets that will then be sent to our homes.

As with other aspects, transformer substations are divided into different categories depending on their use. You’ve probably been walking through a park and seen oval-shaped vents emerging from the grass; or perhaps on the outskirts of an industrial estate, you’ve noticed concrete blocks with metal doors, various electrical signs, and the unmistakable seal of quality that is the Ormazabal brand. Well, these are transformer substations, and they represent two clear examples of some of the types that exist depending on their physical location. Let’s look at them one by one:

• Prefabricated envelope transformer substation: Perhaps the most common type and easiest to observe if we look closely. They are concrete blocks of different sizes, which can range from three to eight meters long with access through metal doors. They were a real revolution when Ormazabal launched them on the market, managing to reduce installation times from one month to just a couple of days. Sometimes, and with the intention of taking advantage of their structure as a large canvas, these are customized with representative drawings of the place where they are located. Even if you don’t realize it, there isn’t a day that goes by that you don’t walk past one of them.

A transformation center can also be an artistic mural (Photograph by Óscar Daniel López)

• Underground CT: These types of centers are hidden to coexist with urban spaces, either through pedestrian traffic,vehicles or for aesthetic reasons. Recognizable by their vents—some would misname them chimneys—they are accessible through a trapdoor located at the top. Some models, such as those developed by Ormazabal, are floodable to guarantee the security of the network and its service even in the worst rain conditions.

Infographic of the interior of an Ormazabal brand underground transformation center Ormazabal

• Semi-buried CT: This is a solution that buries a significant part of its structure to continue allowing accessibility through two smaller doors. It is relatively common to see this type of center in urban areas.

This is a semi-buried transformation center

• CT in a civil works building: Whether located on the ground floor of a building and separated from the public road by a ventilated metal “facade”, or within a brick civil work, this type of CT was the most traditional until the arrival of the envelopes prefabricated.

• Outdoor CT: Very recognizable in rural areas, they are located on top of a high voltage tower. With hardly any protection, since they are at the mercy of inclement weather, this type is not used for powers above 160 kVA.

In any case, the connection of these centers that we see within cities, the connections (the connection to the network) are underground; only seeing areas connected in the areas of high voltage towers located outside urban centers.

How does each CT work, in detail?

Now that we are experts in the components that form part of a transformation center and its typology, the pending subject remains: knowing how the centers work.

When the energy arrives, through the electrical network, to the transformation centers, it is distributed through the medium voltage cells – switches. Normally, the most common configuration of electric companies is that of an input and output ring together with a protection cell designed to protect each transformer in case of a problem such as an overload of the network.

Thus, the transformer is responsible for reducing the voltage value, allowing the current value at its output to increase and obtaining a large amount of current that, subsequently, is distributed through the low voltage panel in numerous outputs.

This is how, once the transformation center has managed to adapt the current to its ideal value for consumption in our homes, the energy is channeled to our plugs; making everything work correctly.

For this reason, each transformation center is crucial to protect and secure the electricity supply.