Beginner Guide to Prefabricated Substation

No doubt that the world is gradually moving towards more environmentally sustainable energy solutions. Therefore, integrated prefabricated substations have proven to be an efficient option for power distribution across energy-consuming sites. Despite being more expensive, these power distribution hubs use pretty compact materials and reduce the time required to set up the entire network. This article shall focus on what prefabricated substations are, what are their components, aspects, working, advantages, and more. Keep reading to see why these systems can be masterstrokes in the world of energy!

Figure no 1 Prefabricated substations

 

1) What is a prefabricated substation?

“A prefabricated substation (modular substations) works exactly like a typical substation with the only difference being that it is manufactured in a company rather than by construction.”

Such units comprise all the components necessary for power distribution such as transformers, switchgear, and control panels placed inside a robust structure. The structure or enclosure acts as the shield for the equipment and prevents weather, dust or any other forms of damage. Moreover, these substations are also sometimes portable, i.e., you can move or shift them as per requirements.

Figure no 2 Prefabricated 33kV Compact Substation (American Type)

Prefabricated substations can be easily transported and installed. Since these installations are factory-built, they are standard and do not require a lot of time for installation. They also have multiple applications in different areas.  

The fact that these components are factory-assembled minimizes the likelihood of errors and the barriers around the assembly. So, it protects both the workers and equipment.

2) What are the components of a prefabricated substation?

A prefabricated substation has many main parts, distributed and interconnected to form a distribution. This control system of electricity in one unit is called a super box. These systems are completely assembled in the factory and mounted in a robust enclosure. The following are the major components:

i) Transformer: Transformers encompass the bulk of power supply substations. It steps up or steps down (transfer) voltages depending on the requirement.

ii) Switchgear: Switchgear on the other hand helps control the electricity supply while safeguarding the system. It comprises switches and devices that are capable of disconnecting portions of a system during faults or maintenance.

Figure no 3 components of a substation

iii) Circuit breakers: You can consider them as safety switches. They prevent the flow of electricity if a short circuit, overload or any other fault exists.

iv) Busbars: Busbars are the strips of metal that carry electrical power within the substation. They connect different parts thereby helping to distribute power evenly.

v) Control panels: Control panels are cabinets with tools for the supervision and management of the substation. It consists of meters, alarms and systems fitted to control the equipment.

vi) Enclosure: The enclosure is the overhanging structure that serves to shield all parts. It is useful as it excludes rain, dust, and dirt and protects people in the neighbourhood.

vii) Cables and wires: Cables and wires connect the components of the switches or the substations to the grid or the buildings.

viii) Cooling system: Cooling systems such as fans or vents are best to prevent the overheating of the equipment.

All these components work to ensure the delivery of electric energy securely, efficiently and effectively to required places.

3) What is the working principle of a prefabricated substation?

The operational principle of a whole-built substation is that it transforms high-voltage electricity to transmit it to consumers for secure utilisation. It follows certain principles, which are here below;

• Electricity intake: An electric substation processes current ranging from a range of volts between 11 kV and 132 kV. Moreover, it depends on the provider's source. Higher voltage ensures less energy loss during transmission.

• Voltage Transformation: A transformer does both transformations in a single unit or component. For instance, a 33 kV may be reduced up to 11 kV or 400 volts for local distribution. This is to say that the transmission is of a range level suitable for household, office or industrial usage.

Figure no 4 Working of a prefabricated substation

• Operational Management and Protection: Such systems require switchgear and circuit breakers for their operation and protection. Short circuit breakers are capable of interrupting fault currents for instance 50 kA. That way, it shields all components and containment losses thereafter.

• Electricity Routing: Busbar distribution units ensure electricity is routed. These types of conductors transmit currents generally not exceeding 5000 Amperes. It mostly depends on the design of the substation. After this, wires and cables come into the field to apportion electricity to different consumers or systems.

• Monitoring: The control panel monitors the machine for any voltage, current, and temperature abnormalities that might occur.

• Cooling: You know every transformer produces heat and more so when the load is high. The cooling systems installed ensure that the operational temperatures are at safe levels. Keep in mind that typically a transformer can handle a load of about 1MVA to 50MVA.

 

4) What are the types of prefabricated substations?

Manufacturers of prefabricated substations have different model types and sizes according to their respective functions as well as the environment. You can categorize them by the construction features, type of installation or the field of application. Here are the main types:

Compact Substations

Compact substations are small and completely sealed units created to fit in confined places. They find applications in urban areas, shopping malls or industrial plants. Compact substations accept voltages within the range of 11 kV to 36 kV and are relatively simple to install.

Underground Substations

These substations are below ground level either for space saving or aesthetics. They are most suited for highly populated and urbanized areas or places with aesthetic appeal. The components, including transformers and switchgear, are built for operational underground environments. Additionally, there are cooling and ventilation systems for safe use.

Mobile Substations

You can transport these mobile substations easily by mounting them on trailers or skid platforms. They are best for temporary supply of electricity in cases of disturbance, maintenance, or construction works. These units can withstand voltages from 11 kV up to 132 kV and are special regarding rapid deployment and execution.

Renewable Energy Substations

These are particularly used to connect renewable energy sources such as wind farms or solar plants to the grid table. These substations often include better control systems to manage such variations in energy outputs. They can handle the load voltages of 66 kV and above.

Pad-mounted substation

A pad-mounted substation is another type of installed substation which is pre-fabricated, usually used in urban or suburban areas. Such types of substations are placed on concrete pads. They normally cater to residential or light commercial use. They are small in size and can withstand inclement weather. Hence, these properties make them well-suited for locations involving space constraints as well as aesthetic considerations.

Figure no 5 Pad-mounted substation

5) What are the benefits of fabricated substations?

All prefabricated substations are highly innovative as they would adequately take care of the power distribution requirements of any area. These advantages are a result of their design, efficiency, and versatility.

+ Reduced Lead Time: Prefabricated substations are factory-built and therefore do not take long to be installed on-site. This reduces work time and is of great benefit especially where urgent projects are undertaken.

+ Reduced Space Requirement: These substations are of modular structure and therefore they are most suitable for regions which have space constraints. For example, inner cities or industrial areas.

+ Economical: On-site construction, labour and material expenses are highly reduced with the use of prefabricated substations. Hence, total costs are significantly reduced. Such structures also cut down maintenance costs in the long run.

+ Great Quality and Consistency: Construction of these substations is done under factory conditions. Hence, they are thoroughly assembled and tested. Construction errors are also minimized ensuring reliability in operation.

+ Security: The purpose of the enclosures is to shield both personnel and equipment. They avoid risks by minimizing high voltages. Apart from this, they hide equipment from the ambient such as rain, dust, and extreme temperatures.

+ Environmentally Friendly: Their design is so simple that energy losses are minimized as they are designed using sustainable materials and cooling systems.

Figure no 6 Environmental-friendly substations

 

6) What are the applications of a prefabricated substation?

All over the world, prefabricated substations have become a necessity for urban and rural areas that require efficient as well as reliable power distribution. The benefits of ease of installation, compact structures, and adaptability of these units qualify them for numerous environments. The Principal application areas include the following:

• Urban Areas: To improve the reliability of the power supply to residential and commercial constructions, cities use prefabricated substations. Such dissected units are very convenient in congested areas due to their small sizes.

• Industrial Plants: Industries particularly manufacturing, mining, and oil & gas would require a steady and stable high-power capacity. These power needs are fulfilled using prefabricated substations that can withstand high voltage and harsh environments.

• Transportation Infrastructure: Prefabrication substation is also used in railways, airports and seaports for powering systems. These systems may include lighting, signal, and operational systems.

• Emergency Power Supply: In times of disaster and emergencies like blackouts, mobile prefabricated substations may be used.

• Remote Areas: When it comes to rural regions, prefabricated substations provide an uninterrupted power supply. They can be built where ordinary substations may not be efficient.

• Data Centers: Data centres are always in need of reliable and stable electricity. Prefabricated substations provide these significant facilities because of their reliability and maintenance.

• Construction Sites: Temporary electricity is fundamental when dealing with construction works. In this instance, prefabricated substations are to be installed so that electricity has been provided for that period.

7) Conclusion

Alright! So, pre-manufactured substations are the best part of today’s technology as they require a short time for installation. Moreover, there seems a reduction in costs, and a sparing of real estate. They are used in urban areas, in the industry and in renewable energy projects to cater for effective power supply. Delixi’s products which provide reliability and quality are used in smart grids and industrial plants amongst others. Such solutions allow importing and exporting electric energy safely and efficiently. These substations are carefully pre-fabricated by Delixi. For more information please look at their website.