Substation Connection: Procedures and Safety Technical Requirements

Substation connection is a complex process requiring thorough preparation to ensure safety and performance. This process must adhere to technical standards to provide stable and safe power supply.

Overview of Substation Connection

Connecting a substation to the power grid involves connecting electrical energy from the substation to the consuming equipment. This process must strictly comply with technical standards to ensure a stable and safe power supply to users.

Substation connection ensures efficient power transmission and distribution across the entire electrical system. Below is a electrical installation process and important components related to substation connection.

Substation Connection Procedure

1. Discussion and Agreement: The first step is coordination between the power utility and customers to agree on the connection location. This process also includes constructing medium-voltage lines and related items to supply electricity to customers efficiently.
2. Survey and Construction: Conduct a detailed site survey, build the foundation for the substation, and install the grounding system to ensure operational safety.
3. Equipment Installation: Substation connection requires the installation of devices such as transformers, electrical protection systems, measuring, and control equipment. Especially, 220kV transformers like 250MVA transformers are commonly used in this system.
4. Testing and Energizing: This is the final step to ensure all equipment is thoroughly tested before putting the entire system into official operation.

Main Components of a Substation

• Transformer: The core of the electrical system, models such as those from ABB or Mitsubishi are commonly used to efficiently convert voltage levels between different stages.
• Protection and Control Equipment: Comprising remote control and protection systems from Schneider and LS, allowing for safety monitoring and optimization of electrical operation.
• Grounding System: Ensures safety for humans and equipment by providing a safe path for electric currents to the ground.

Benefits and Roles

• Stable Power Supply: Substations ensure continuous and stable power supply for both residential and industrial areas, helping production systems run smoothly.
• Safety and Efficiency: The electrical protection system enhances reliability, minimizes incidents, and prevents unreasonable power loss.
• Infrastructure Development: Implementing substation connection not only serves current electricity consumption needs but also promotes long-term development of electric infrastructure, increasing network connectivity in the regional power grid.

Substation Connection Procedure

The connection process includes steps from technical survey, connection agreement, installation, to testing and acceptance. Each step needs to be executed accurately to ensure the safety and effective operation of the electrical system.

Substation connection is a thorough and meticulous process not only to ensure optimal operating efficiency but also to maintain the stability of the entire electrical system. Below are detailed steps in this process:

1. Survey and Agreement

• Technical Survey: The initial step in the process is to determine a suitable location for the substation, where site assessment and construction planning are crucial. This ensures the substation will operate effectively and safely.
• Connection Agreement: Next, agreements with relevant parties must be undertaken. This includes unifying necessary technical requirements and safety regulations to comply with during connection.

1. Equipment Installation

• Substation Installation: The installation begins with placing the transformer at the designated location and setting up the required equipment. This requires high precision to optimize operating capability.
• Installation of Grounding and Lightning Protection Systems: To ensure electrical safety, grounding and lightning protection systems are installed to prevent incidents caused by lightning strikes or electrical leakage.

1. Cable Connection and Inspection

• Internal and External Cable Connection: Connecting internal and external cables is crucial to ensure a complete and continuous electrical system. This is followed by continuity and insulation testing.
• Testing and Adjustment: After connection, the entire system must be inspected and parameters adjusted to ensure all devices operate according to standards.

1. Testing and Acceptance

• Quality Testing: Tests to evaluate the quality and safety of the system are necessary before usage.
• Acceptance and Energizing: Once all inspections are done, the system is accepted and energized to start operation.

1. Operation and Maintenance

• Substation Trial Run: After completing the connection, running the entire system helps identify potential issues that may require adjustment.
• Periodic Maintenance: To ensure the stability and efficiency of the substation, periodic maintenance is a compulsory step in management procedures.

With careful implementation of each step, the substation connection process not only helps optimize performance but also minimizes the risk of sudden power outages, contributing significantly to the sustainable operation of the energy system.

Technical and Safety Requirements for Substation Connection

Substation connection must comply with strict technical and safety standards. This not only protects the equipment but also ensures human safety during operation and use of electrical energy.

1. Technical Standards

• TCVN 3715:82: Applicable to complete substations (up to 1000kVA, voltage up to 20kV). The design must ensure insulation meets standards for bearing voltage and safe distances. The grounding system should have a resistance ≤ 4Ω, coordinated with lightning protection systems. Materials used, such as insulators and cables, must be fire-resistant and withstand outdoor conditions.
• Connection Procedure:
  • Pre-connection inspection: Insulation testing and grounding resistance measurement are initial necessary steps. Also, reviewing connection diagrams according to design principles is mandatory.
  • Connection Operation: Requires using insulated operation chairs for high work, connecting medium voltage cables with checks on polarization and seal cable ends.

2. Safety Requirements

• Site preparation: Isolate the power source by grid switch and hang a warning sign “DO NOT ENERGIZE – WORK IN PROGRESS”. Fully equip PPE like insulating gloves, insulating boots, and helmets.
• Installation operation: Use hoists or specialized carts to transfer equipment to avoid misalignment; tighten bolts according to specified torque to ensure stable electrical contact.

3. Post-connection Inspection

• Operation Testing: Measure the no-load current of the transformer to detect hidden short circuits and check vibration and noise levels.
• Acceptance: Draft an internal acceptance report before proposing energizing and trial loading for ≥24 continuous hours to confirm stability.

4. Incident Prevention Measures

• Overheating Protection: Arrange automatic cooling fans for medium-voltage cabinets and ensure a minimum ventilation gap of 1m around the station.
• Fire Protection: Install dry sand boxes and CO₂ fire extinguishers near transformers, use fire-retardant cables according to IEC 60332 standards.

Substation connection requires stringent adherence to technical standards to ensure safety and effectiveness. Investing in this process will optimize power supply, minimize risks, and provide long-term asset protection.

Contact QuangAnhcons via Hotline: +84 9 1975 8191 for detailed consultation on substation connection services and ensuring safety standards.

QuangAnhcons provides professional substation connection services, ensuring compliance with safety and technical standards, optimizing power supply for customers.