Requirements, Methods, and Hazards of Transformer Operation

As a critical component in power systems, transformers are widely used in transmission, distribution, and industrial applications. Correct operation of transformers is essential not only for the stability of the power grid but also for the safety of personnel. Therefore, understanding the basic requirements, operational methods, and potential hazards of transformer operations is vital to ensuring safe and reliable power system performance.

I. Basic Requirements for Transformer Operation

1. Safety First

Before any operation, ensure that all personnel have received professional training and hold valid qualifications. Equip the site with full personal protective equipment (PPE), such as insulated gloves, goggles, and boots. Strictly implement work permit systems and supervision procedures to prevent unauthorized or unsupervised operations.

2. Familiarity with Equipment Status

Before operating, conduct a comprehensive inspection of the transformer’s condition, including:

• Voltage and current levels;
• Oil level and temperature within acceptable limits;
• Normal functioning of the cooling system;
• Signs of discharge or overheating on the casing;
• Integrity of grounding devices.

3. Compliance with Operating Procedures

Follow national and industry standards, as well as substation operation guidelines. Avoid misoperations or violations. For complex switching operations, develop detailed switching plans in advance and perform simulation rehearsals.

II. Main Methods of Transformer Operation

1. Startup Procedure

Steps for starting up a transformer include:

• Check cooling system, protection devices, and control circuits;
• Close the high-voltage side circuit breaker to energize the transformer without load;
• Observe for unusual noise, vibration, or odor;
• Once normal operation is confirmed, gradually apply the low-voltage side load.

2. Shutdown Procedure

The shutdown process involves:

• Gradually unload the low-voltage side;
• Open the low-voltage side circuit breaker;
• Open the high-voltage side circuit breaker;
• Discharge the transformer;
• Lock the switch and display warning signs to prevent accidental re-closing.

3. Paralleling and Decoupling Operations

When connecting two or more transformers in parallel, ensure the following conditions are met:

• Same voltage level;
• Consistent winding group;
• Similar short-circuit impedance;
• Identical phase sequence. Before paralleling, perform a phase comparison test to confirm phase alignment.

III. Major Hazards in Transformer Operation

1. Electrical Hazards

Due to high voltages and large currents, there is a risk of electric shock. Especially during incomplete de-energization or poor grounding, serious electric shocks can occur. Live operations or entering live compartments by mistake may also cause injury.

2. Mechanical Hazards

Transformers may produce vibrations, noise, or even explosions, particularly under short-circuit or overload conditions. These can result in physical injuries to nearby personnel.

3. Thermal Hazards

Prolonged overloading can lead to overheating, which may ignite surrounding flammable materials and cause fires. High temperatures also accelerate insulation aging and reduce equipment lifespan.

4. Oil Leakage and Explosion Risk (for Oil-immersed Transformers)

In oil-immersed transformers, internal short circuits or severe overheating may cause decomposition of the oil, leading to gas buildup and pressure rise, potentially resulting in oil spraying or explosion.

5. Operational Errors

Misoperation is a major cause of transformer accidents, including:

• Incorrect opening/closing of circuit breakers;
• Grounding without testing for voltage;
• Deviating from prescribed operation sequences;
• Ignoring protection device signals.

IV. Safety Recommendations for Operation

To ensure safe transformer operation, the following measures are recommended:

1. Strengthen Training: Regularly train operators in theory and practice to improve safety awareness and emergency response capabilities.
2. Improve Systems: Establish robust inspection, operation record, and incident analysis systems to ensure traceability and compliance.
3. Use Smart Monitoring Systems: Monitor equipment status online to detect anomalies and issue early warnings.
4. Implement Supervision Strictly: Complex operations must be supervised by designated personnel to ensure accuracy at every step.
5. Enhance Emergency Management: Develop emergency plans and conduct regular drills to ensure rapid response in unexpected situations.