What happens if a transformer is overloaded?
Time：2025-03-17 Auther：ZTelec-www.ztelectransformer.com
As a vital equipment in the power system, the transformer undertakes the key tasks of voltage conversion, power transmission and distribution. However, in actual operation, the transformer may face overload. When the transformer is overloaded, it will cause a series of problems, which will have a serious impact on the performance and life of the transformer and the safe and stable operation of the entire power system. Understanding the consequences and countermeasures of transformer overload is of great significance to ensure the reliable operation of the power system.
Transformer overload means that the actual load current of the transformer during operation exceeds its rated current value. The rated current is the maximum current that the transformer can operate stably for a long time under normal working conditions. When the load current exceeds this value, the transformer is considered to be in an overloaded state.
What happens if a transformer is overloaded?
1. Temperature increase
When overloaded, the current increases, the copper loss in the winding increases, and more heat is generated. Due to the limited heat dissipation conditions of the winding, the heat cannot be dissipated in time, causing the winding temperature to rise rapidly. Overload will also increase the magnetic flux density in the core, which can cause increased iron loss and increased core temperature.
2. Accelerated insulation aging
High temperature will accelerate the aging of insulation materials and reduce insulation performance. Long-term overload operation will make the insulation material gradually brittle, prone to cracks and breakage, thereby reducing the reliability of insulation.
3. Shorten the service life
Overload operation will cause overload of various components inside the transformer, which will accelerate the aging of the components. Long-term overload operation may shorten the life of the transformer and lead to early replacement and repair of the transformer.
4. Increase loss
The operating efficiency of the transformer is related to the load. Overload will cause greater power loss. This will lead to waste of electricity and increase in energy costs.
5. Increased safety hazards
Overload operation may cause problems such as excessive current inside the transformer and abnormal voltage fluctuations. These problems may cause safety hazards such as fire and explosion, posing a threat to personal and property safety.
6. Oil deterioration: Increased oil temperature will accelerate the deterioration of transformer oil, affecting its insulation and cooling performance.
Causes of transformer overload
Sudden increase in load: For example, the sudden start-up of large industrial equipment, the simultaneous use of a large number of electrical equipment, etc., will cause the transformer load to rise sharply and exceed its rated capacity.
Power system failure: For example, short circuit failures and voltage fluctuations in the power grid may cause abnormal changes in the transformer load and cause overload.
Unreasonable design: When selecting a transformer, if the load growth is underestimated and a transformer with a smaller rated capacity is selected, overload is likely to occur.
In order to avoid problems caused by overload operation of the transformer, the transformer should be operated strictly in accordance with the rated capacity to avoid long-term overload operation. In addition, regular inspection and maintenance of the transformer to maintain its normal operating state is also an important means to prevent overload problems. When we find the signs of overload in the transformer, we should immediately take measures to reduce the load and repair possible faults in a timely manner to ensure the safe and stable operation of the transformer.
