How to prevent the insulation material of the current transformer from being damaged?

1. Reasonable selection
Choose the appropriate type of insulation material according to the installation location and working environment of the current transformer. For example, in a humid environment, it is preferred to choose insulation materials with good moisture resistance, such as epoxy casting insulation materials, which can effectively prevent moisture intrusion and avoid the degradation of insulation performance.
Consider the voltage level factor. For high-voltage application scenarios, it is necessary to choose insulation materials with high dielectric strength. For example, in current transformers with voltage levels of 110kV and above, high-quality oil-paper insulation or SF6 gas insulation materials can be used to withstand high electric field strength and prevent insulation breakdown.
Select according to the operating temperature range of the current transformer. If the working environment temperature is high, insulation materials with good thermal stability should be selected. For example, for some current transformers that are exposed to the sun for a long time outdoors or close to heat sources, choosing insulation materials above Class A (allowing a higher operating temperature) can effectively prevent insulation damage caused by high temperature.
2. Control of the installation process
During the installation process, ensure that the current transformer is installed in the correct position to avoid unnecessary mechanical stress. For example, when installing a pillar-type current transformer, ensure that it is installed vertically on the pillar to prevent the insulating material from being damaged by additional pressure or tension due to tilting.
For oil-immersed current transformers, pay attention to the injection amount and quality of the insulating oil. The insulating oil should fill the entire oil tank, and the oil performance indicators (such as dielectric strength, water content, etc.) should meet the requirements. When injecting insulating oil, prevent air from mixing, because bubbles will reduce the insulating properties of the insulating oil and may cause partial discharge under the action of the electric field, damaging the insulating material.
The environmental conditions at the installation site should also be paid attention to. If the ambient humidity is high, dehumidification measures should be taken, such as using a dehumidifier, to prevent the insulating material from getting wet during the installation process. For current transformers installed outdoors, avoid performing key installation steps such as winding connection and insulation material packaging on rainy days.
3. Operating environment maintenance
Control ambient temperature and humidity. For current transformers installed indoors, the temperature and humidity of the environment can be kept appropriate by installing air conditioners and dehumidification systems. During high temperatures in summer, ensure that the indoor temperature does not exceed the allowable operating temperature of the insulating material; in humid seasons, control the ambient humidity within a reasonable range (such as no more than 70%) to reduce the possibility of moisture in the insulating material.
Avoid polluting the environment. If the current transformer is installed in an area with chemical pollution (such as near a chemical plant), take protective measures, such as installing a protective cover, to prevent corrosive gases from contacting the insulating material. Clean the casing and surrounding environment of the current transformer regularly to reduce the impact of pollutants such as dust and oil on the insulating material.
Prevent overvoltage and overcurrent. In the power system, installing overvoltage protection devices such as lightning arresters can prevent lightning overvoltage and operating overvoltage from damaging the insulating material of the current transformer. At the same time, through reasonable power system scheduling and relay protection settings, avoid the occurrence of overcurrent conditions, because overcurrent will cause the current transformer to heat up and accelerate the aging of the insulating material.
4. Regular inspection and maintenance
Perform regular appearance inspections to check whether there are cracks, discharge marks, discoloration, etc. on the surface of the insulating material. If problems are found, measures should be taken in time. For example, for insulating materials with slight cracks on the surface, special insulating repair materials can be used for repair.
Conduct electrical performance tests, including insulation resistance test, dielectric loss factor test and partial discharge test. Based on the test results, timely discover potential problems of insulation materials. For example, if the insulation resistance decreases, analyze the cause. It may be moisture or aging of the insulation material. Drying treatment or replacement of insulation materials is required.
For oil-immersed current transformers, regularly check the performance of the insulating oil. If the water content of the insulating oil increases or the dielectric strength decreases, the oil should be treated (such as filtering, drying) or the insulating oil should be replaced in time to ensure a good operating environment for the insulating material.