The transformer load remains unchanged; why is there such a large temperature variation?

During operation, the temperature of a transformer is affected by various factors; even when the load remains constant, the temperature can still change significantly. Here are some possible causes of temperature changes, along with the associated risks and solutions: 1. **Changes in ambient temperature**: If the temperature of the environment in which the transformer is located rises, such as due to seasonal changes or poor ventilation inside the substation, this can lead to an increase in the transformer’s temperature. 2. **Changes in cooling conditions**: The cooling conditions of a transformer directly affect its operating temperature. For example, damage, blockage, or decreased efficiency of heat sinks (such as cooling fans or heat sinks) can all impair the heat dissipation effect, leading to a rise in temperature. 3. **Insulation aging**: Prolonged operation of transformers can cause the insulation materials to age, increasing thermal resistance and thereby raising temperatures. 4. **Load fluctuations**: Although you mentioned that the load remains constant, short-term fluctuations in the load or issues such as harmonics in the system can cause a sudden increase in temperature. 5. **Changes in the cooling system**: In oil-immersed transformers, a decrease in the efficiency of the cooling oil, a drop in the oil level, or deterioration of the oil quality can all lead to a reduced cooling capacity and an increase in temperature. 6. **Other abnormalities**: Issues such as poor internal contacts, local short circuits, and overheating of the core can all cause the temperature of the transformer to rise abnormally. Regarding the increase in temperature from 60 degrees to 80 degrees that you mentioned, if this change occurs over a very short period of time, it is clearly an abnormal signal that requires immediate inspection. Here are some potential problems and suggestions for solutions: **Potential problems**: - **Transformer overheating**: Prolonged overheating can accelerate the aging of internal components and reduce their insulation properties, leading to malfunctions or even damage. - **Reduced lifespan**: For every 10°C increase in temperature, the lifespan of insulating materials is approximately halved; therefore, temperature has a significant impact on transformers. ****Solutions**: 1. **Regular maintenance and inspection**: Periodically clean the radiator and check the fan’s operating condition to ensure that the cooling system functions properly. 2. **Monitoring and Control**: Install temperature monitoring devices; if abnormal temperatures are detected, immediately investigate the cause and take appropriate action. 3. **Improve heat dissipation conditions**: If the issue is caused by high ambient temperatures or poor ventilation, the ambient temperature can be controlled by improving ventilation or installing air conditioning systems. 4. **Improve grid quality**: Regularly check the voltage and harmonic levels in the grid, and strive to minimize abnormal loads on transformers. 5. **Professional testing**: If the cause cannot be determined, it is necessary to contact professionals promptly for testing and fault analysis. Please remember to carry out regular professional inspections and maintenance to ensure that the transformer operates within a safe temperature range. .