Substation: Overview, Structure and Classification – Procedures and Documentation

Explore every aspect of substations: from their structure and function, types of substations, to design requirements and appropriate selection. Delve deeper into the various types of substations such as ultra-high voltage, high voltage, medium voltage, low voltage, and related services and documentation, along with important considerations for installation and pricing

1. Definition and Function of a Transformer Station

A transformer station, an indispensable component of the electrical system, serves as a hub for transformers and electrical distribution equipment. Its primary function is to transmit and transform electrical energy from one voltage level to another through electromagnetic induction, ensuring efficient and safe distribution of electric power.

vietnam substation

2. Structure of a Transformer Station

Each transformer station has a unique structure depending on its type and purpose, generally including:
– Transformer: The heart of the station, playing a key role in voltage transformation.
– Busbar and isolator system: Ensuring safety and ease of maintenance.
– Lightning protection and grounding system: Protecting the station from lightning impacts and overvoltage risks.
– Station service power system: Providing power for the station’s internal operations.
– Control area: Where the station is managed and operated.
– Distribution area: Distributing electrical power to various lines.

vietnam substation

 3. Design Requirements of a Transformer Station

In designing a transformer station, attention should be given to:
– Ensuring power quality: Selecting a central load position to minimize energy loss.
– Reasonable investment cost.
– Safety for people and equipment: Careful consideration of aesthetics, station location, and electrical safety.
– Ease of operation and maintenance.

vietnam substation

 4. Classification of Transformer Stations

4.1 By Voltage
– Ultra High Voltage: Above 500kV.
– High Voltage: From 66kV to 500kV.
– Medium Voltage: From 6kV to 35kV.
– Low Voltage: Below 0.4kV.

4.2 By Function
– Substation: Converts high to medium voltage.
– Distribution Substation: Transforms from medium to low voltage, commonly used in residential and industrial areas.

In electrical systems, distribution transformer stations play a central role in transforming and providing electrical energy. They receive power from intermediate transformer stations and convert voltage levels from 22kV – 35kV to lower levels, typically 0.4kV – 0.22kV, serving residential and industrial applications, with the most common type being the 22/0.4kV station.

There are various types of distribution transformer stations, each suited to specific environments and requirements:

a. Pole Mounted Transformer Station: All high and low voltage equipment, along with the transformer, are mounted on poles. Commonly use single-phase or three single-phase transformers combined.

vietnam substation

b. Frame Mounted Transformer Station: Characterized by the transformer placed on a support between two large poles, serving 35kV, 22kV down to 0.4kV voltage levels.

vietnam substation

c. Ground Mounted Transformer Station: Common in rural areas, offices, and small to medium enterprises. High voltage equipment is placed on poles, the transformer is typically placed on a concrete base on the ground, and the low voltage distribution cabinet is placed inside a building, surrounded by protective walls.

vietnam substation

d. Indoor Substation: The transformer and electrical equipment are installed inside a building, comprising three main rooms: high voltage room, transformer room, and low voltage room. Suitable for high-density urban areas and residential complexes.

vietnam substation

e. Kiosk Substation: This type of station includes three main compartments (medium voltage, low voltage, and transformer compartments) within a closed metal frame and sheet metal enclosure. Widely used in medium voltage electrical systems in industry, residential areas, and high-rise buildings.

vietnam substation

Each type of transformer station is designed to meet specific technical, safety, aesthetic, and economic efficiency requirements, depending on the terrain and environmental conditions.

4.3 By Usage
– Outdoor Substation: Suitable for factories and industrial zones.
– Indoor Substation: Common in urban areas, including closed substations and GIS substations.

5. Documentation and Procedures for Constructing a Transformer Station

vietnam substation

To construct a transformer station in Vietnam, a series of official procedures and regulations must be followed. Below is a summary of the necessary steps and documentation:

5.1. Preparation of Legal Documents and Papers: Initially, you need to prepare legal documents including a business license, land use rights (or land lease contract), and tax code. Each document should have at least three notarized copies, no more than three months old.

5.2. Electricity Purchase Request/Letter of Intent: This is the first step in the procedure to request the installation of a transformer station. You need to submit a request for electricity purchase at the local Electric Power Company or the Business Department of the Vietnam Electricity Group.

5.3. Determining the Location for Electricity Purchase and Purpose of Use: You need to provide copies of documents determining the location for electricity purchase (such as permanent residence book, house ownership certificate, house purchase contract, etc.), ID or passport of the legal representative, and the purpose of using electricity at the construction site of the transformer station (such as business registration certificate or investment license).

The translation of the provided content into English is as follows:

5.4. Application for Connection According to the Regulations of the Ministry of Industry and Trade**: Includes the connection application, schematic diagrams of the main equipment after the connection point, and technical documents about the intended connection equipment.

5.5. Survey and Connection Agreement**: After the Power Utility receives the application, they will conduct a survey and negotiate with you regarding the location of the connection point and technical requirements.

5.6. Signing Investment Contracts and Implementing Legal Procedures**: This includes agreements on compliance with the electric power development planning, obtaining construction permits, and environmental protection planning.

5.7. Construction and Installation of the Station**: This covers land clearance, application for road excavation permits (if necessary), procurement of materials and equipment, and organization of construction.

5.8. Acceptance and Energization**: Upon completion, you need to establish a Construction Acceptance Council, carry out acceptance and energization with the participation of the Power Utility.

6. Quotation and Service Provision

vietnam substation

For specific information about quotes and installation services for different types of substations, specialized companies will provide based on the specific requirements of the project and customer needs. Factors influencing the quotation include:

– Substation Capacity and Type: Prices vary depending on the capacity and type of the substation (ultra-high voltage, high voltage, medium voltage, low voltage).
– Technical Specifications and Quality: Specific technical requirements, material quality, and durability of the substation are also important factors affecting the price.
– Support and Warranty Services: Warranty packages, technical support, and maintenance services also influence the overall price.
– Installation Location and Transportation: Transportation costs and installation feasibility in different locations, especially in hard-to-reach areas, also affect the quotation.
– Legal Compliance and Regulation Adherence: Compliance with safety, environmental, and specific legal requirements is also a crucial part in determining the price.

Therefore, to receive an accurate and appropriate quotation, customers should directly contact us through the hotline: 0919758191 to discuss the specific requirements of the project. We will advise, design, and quote based on specific needs, ensuring that the substation solution provided is not only technically suitable but also meets the financial requirements and long-term goals of the customer.

Quanganhcons – Your Trusted Partner for Every Low Voltage Substation Construction Project!

Quang Anh CE co.,LTD
Office: 41F/22 Dang Thuy Tram Street, Ward 13, Binh Thanh District, Ho Chi Minh City
Hotline: 0919758191