Abnormal sounds from inside a transformer are a significant warning sign that shouldn’t be ignored. These sounds can stem from various causes, each indicating a different operating state or potential problem within the transformer.

　　Firstly, a common cause of a heavy “humming” sound from within a transformer is severe overloading. When a transformer carries a load far exceeding its design capacity, the internal electromagnetic forces increase dramatically, resulting in strong vibrations and noise. This sound is usually accompanied by transformer overheating and decreased efficiency, posing a serious threat to the long-term stable operation of the equipment.

　　Secondly, if there are poor contacts or breakdowns inside the transformer, it may produce a “sizzling” or “crackling” discharge sound. This discharge sound is usually caused by aging, dampness, or damage to the insulation material. If not addressed promptly, it may lead to more serious electrical faults.

　　In addition, loose individual parts of the transformer cover connecting shaft bolts can also cause abnormal sounds. When these parts are loose, the transformer core may not be clamped tightly, causing the silicon steel sheets to vibrate and produce loud noise. This noise not only affects the normal operation of the equipment but may also interfere with the surrounding environment.

　　Grounding or short-circuit faults in the power grid can also cause the transformer to emit loud noises. When a large current flows through the windings, the transformer will produce intense vibrations and sounds due to electromagnetic forces. Abnormal sounds in this situation are usually accompanied by abnormal readings on the ammeter and overheating of the equipment.

　　When the transformer is connected to large power equipment or equipment that can generate harmonic currents, the operation of this equipment may also cause the transformer to emit a “wailing” sound. Harmonic currents can interfere with the normal operation of the transformer, causing electromagnetic vibrations and noise.

　　Furthermore, core resonance is also a major cause of the transformer emitting intermittent noise. When the natural frequency of the core is close to the external excitation frequency, resonance occurs, resulting in loud noise.

　　In addition, excessive primary voltage or current in the transformer can also lead to unusual sounds. Excessive voltage and current will cause a sharp increase in the electromagnetic force inside the transformer, resulting in strong vibrations and sounds.

　　Finally, problems such as overvoltage, winding or lead discharge to the casing, and disconnection of the core grounding wire may also cause the transformer to emit discharge sounds. These problems are usually caused by aging, dampness, or damage to the equipment. If not addressed promptly, they may pose a serious threat to equipment and personnel safety.

　　In summary, abnormal sounds from inside a transformer can stem from various causes, each requiring careful attention and appropriate handling. Only by ensuring the normal operation and stability of the transformer can we guarantee the safe and reliable power supply of the power system.