Causes of Transformer Differential Current and Hazards of Transformer Bias Current
Transformer differential current is caused by factors such as incomplete symmetry of the magnetic circuit or insulation damage. Differential current occurs when the primary and secondary sides of the transformer are grounded or when the load is unbalanced.
Firstly, transformer differential current leads to energy waste. Differential current causes additional power loss in the transformer, increasing the load on the power grid. Moreover, it generates heat, further increasing energy losses and reducing transformer efficiency. Therefore, differential current increases grid losses and lowers energy utilization efficiency.
Secondly, transformer differential current produces leakage flux, leading to unstable operation. The differential current generates extra magnetic flux, part of which leaks into the air as stray flux. This leakage flux causes instability in the transformer’s operating voltage, affecting the normal operation of electrical equipment.
In addition, transformer differential current may cause equipment overload. Differential current induces current in the transformer windings; excessive differential current can exceed the rated current of the equipment, resulting in overload and potential damage. This not only damages the transformer itself but also impacts the entire power grid and may even cause fire hazards.
The hazards of transformer bias current also include resonance phenomena. Harmonic currents within the differential current can cause resonance between internal inductance and capacitance in the transformer, leading to equipment oscillation, increased noise, and other issues that disrupt normal operation.
Furthermore, differential current may accelerate insulation aging. Currents in the differential flow generate localized intense thermal effects in windings, core, and insulation components, causing insulation layers to degrade more quickly and reducing insulation performance. When insulation ages to a critical point, insulation breakdown may occur, leading to electrical accidents or even fires.
Additionally, differential current may cause environmental pollution. Harmful substances such as acids or alkalis may be present in the differential current, contaminating the surrounding environment.
In summary, although transformer differential current is unavoidable, it results in increased energy waste, equipment damage, resonance, insulation aging, and environmental pollution. Therefore, measures should be taken to minimize the generation and impact of transformer differential current to ensure the safe and stable operation of the power grid.