What are the factors that affect the SMC insulation board
(1) Sample thickness: When the insulating material is very thin, the breakdown voltage is proportional to the thickness, that is, the electric strength has nothing to do with the thickness. When the thickness of the insulating material increases, it will be difficult to dissipate heat, impurities, bubbles and other elements will make the electric strength decline.
(2) Temperature: Above room temperature, the electrical strength decreases with the increase in temperature.
(3) Humidity: Moisture has entered the insulation material. The electrical strength decreases.
(4) Voltage effect time: The electrical strength of organic materials for most insulating boards decreases as the voltage effect time increases. In the experiment, the boost speed is fast and the electric strength is high, and the voltage effect of stepwise boost or slow boost is longer, which can better reflect the existence of defects such as thermal effects and internal air gaps in the material. Therefore, in general experimental methods, it is stipulated not to adopt the impulsive boost method, but to adopt the method of successive boosting or step-by-step boosting.
(5) Mechanical stress or mechanical damage: The electrical strength of the insulation material will decrease after mechanical stress or mechanical damage. Laminate sample processing should avoid strong damage as much as possible, use milling instead of wounds, and control the amount of processing to be small.
(6) Sample: The sample must not be contaminated, and the thin insulating plate sample must not be wrinkled. Will cause the breakdown voltage to drop.
(7) Water or carbon dust in transformer oil: If the sample is to be tested for breakdown in transformer oil, the transformer oil should meet the standard requirements. Over time, the transformer oil absorbs moisture and repeatedly breaks down the residual carbon powder, which will cause the breakdown voltage of the sample to drop. Transformer oil should be treated or replaced in due course.