What is the thermal aging and electrical aging of insulating materials?
Environmental aging, also known as atmospheric aging, is due to ultraviolet light, ozone, salt spray, acid and other factors caused by pollution of chemical aging, which is the main reason for ultraviolet light. Thermal aging more common in low-voltage electrical appliances, the mechanism is under the action of temperature, the insulating material in some volatile components escape, the internal components of oxidative cracking, thermal cracking, hydrolysis, molecular chain polymerization and other chemical changes, and gradually lose insulation properties.
Insulation materials in electrical equipment during the operation, due to the long-term effects of various factors, there will be a series of irreversible physical and chemical changes, resulting in its electrical performance and mechanical properties decline, commonly known as aging. There are many factors that affect the aging of insulating materials. The main aging forms are environmental aging, heat aging and electrical aging.
Electrical aging more common in high-voltage electrical appliances, the main mechanism is the occurrence of partial discharge of insulating material under high pressure, resulting in strong oxidant ozone. Ozone is easy to cause ozone cracking of the material. Partial discharge will produce nitrogen oxides, which combine with the moisture to produce nitric acid, corrosion of insulating materials; partial discharge of high-speed charged particles bombardment of insulating material molecules, will promote its ionization, fission and damage; in addition to local discharge will make dielectric loss Increased, local heat of the material, resulting in heat aging.
