Electrical insulation paper is an important material in the production process of transformers. Insulated cable paper is used between the winding layers of the oil-immersed transformer, crepe paper is used for the leads, and spliced insulation paper is used for the winding layer. The role of insulating paper is to prevent short circuits, so how to measure its insulation performance, the most important indicator is the resistance value.
The three factors that affect the resistance value of the insulating paper are humidity, temperature, and discharge time.
The effect of discharge time.
After each measurement of insulation, the test shall be fully discharged, and the discharge time shall be greater than the charging time to facilitate the exhaustion of the remaining charge. Otherwise, when the measurement is re-measured, the charging current and the sinking current will be smaller than those in the first measurement due to the influence of the electric charge, thus causing a false phenomenon that the absorption value is increased more than the insulation resistance value.
The effect of humidity. When the relative humidity in the air is relatively large, it will absorb more water, the surface of the insulating paper absorbs moisture, and the surface forms a water film, which increases the conductance and reduces the insulation resistance value.
The effect of temperature. Temperature has a great influence on the resistance of DDP insulation paper. Generally, the insulation resistance decreases with increasing temperature. The reason is that when the temperature rises, the polarization in the insulating medium increases, and the conductance increases, causing the insulation resistance value to decrease.
ZTELEC provides customers with electrical insulation paper for transformers of different shapes, different sizes and different requirements for the convenience of customers. The company purchased related discs, dicers, forming and flanging machines, and creasing machines, which reduced the troubles of customers’ re-processing.