Key Points for Safe Operation and Maintenance of 1500kVA/11kV Substation Transformers

The 1500kVA/11kV substation transformer is a core component of the power system, and its operating condition directly impacts grid stability, safety, and efficiency. Safe operation requires continuous monitoring of critical parameters such as temperature, load conditions, and insulating oil quality. Implementing comprehensive monitoring and preventive measures ensures the transformer operates reliably while minimizing potential safety risks.

1. Importance of Operation and Maintenance Management

Effective transformer operation and maintenance management involves daily monitoring, scheduled inspections, and timely servicing. Key aspects include overload control, oil testing, temperature regulation, and core insulation monitoring. These elements form the foundation for ensuring long-term, stable, and safe operation.

2. Essential Operation and Maintenance Practices

2.1 Prevent Overload Operation

Prolonged overloads can cause coil overheating, accelerate insulation aging, and increase risks of short circuits and arcing. Load levels must be continuously monitored, and power distribution should be managed to keep the transformer within its rated capacity, thereby reducing overload hazards.

2.2 Maintain High Insulating Oil Quality

The condition of insulating oil directly affects the dielectric strength and cooling efficiency of the transformer. Regularly test oil for breakdown voltage, dielectric loss, and moisture content. Replace or treat substandard oil promptly to maintain optimal insulation and heat dissipation.

2.3 Inspect Core Insulation Condition

Aging or damaged core insulation can lead to excessive eddy currents and localized heating. Routine inspections should check for damaged clamping bolt sleeves or insulation wear. Any issues must be addressed immediately to prevent further degradation.

2.4 Ensure Reliable Conductor Connections

Poor wire connections can cause localized overheating, voltage drops, or short circuits. During installation and maintenance, ensure all connections are secure, corrosion-free, and adequately tightened. Monitor connection temperatures to detect early signs of faults.

2.5 Strengthen Lightning Protection

Overhead line connections expose transformers to lightning strike risks. Install and maintain surge arresters, lightning rods, and grounding systems to effectively divert lightning currents and prevent insulation breakdown during thunderstorms.

2.6 Improve Short-Circuit Protection Systems

Short circuits generate severe current surges that can damage transformer windings. Equip the system with reliable short-circuit protection devices, and regularly calibrate protective relays to ensure rapid fault isolation and minimal damage.

2.7 Maintain Effective Grounding

In low-voltage systems with protective earthing (PE), proper grounding of the transformer’s neutral point is essential. Regularly measure ground resistance and verify grounding integrity to ensure safe fault current discharge. Maintain good ventilation and cooling to prevent overheating under unbalanced load conditions.

The safe operation of a 1500kVA/11kV substation transformer depends on rigorous adherence to maintenance best practices. From overload prevention and oil quality control to core insulation checks, reliable connections, lightning protection, short-circuit safeguards, and grounding measures—each step contributes to system stability and extended equipment life. By combining standardized daily management with scheduled inspections, operators can minimize risks, maximize service life, and secure the reliability of the power system.