In the power system, the choice of insulation materials for transformers and switchgear directly affects the safety and life of equipment operation.With the popularization of new environmentally friendly materials in 2025, how to scientifically select types under complex working conditions has become the focus of industry attention.From the three dimensions of material characteristics, application scenarios, and cost-effectiveness, this paper combines the latest industry data to compare and analyze the adaptability of mainstream materials such as epoxy resin and silicone rubber, and provides practical selection suggestions to help engineers optimize the design of insulation schemes.

1. Comparison of core properties of insulation materials for power equipment

The 2025 industry report shows that the temperature resistance level and dielectric strength of insulation materials are still the primary indicators of selection.Taking transformers as an example, oil-immersed equipment mostly uses cellulose cardboard, and its breakdown voltage can reach 35kV/mm, but the temperature resistance of the new aramid composite material is increased to 220℃, which is more suitable for high temperature environments.

1.1 Performance table of commonly used materials for transformers

Compare epoxy cast parts with Nomex paper: the former has high mechanical strength (bending strength ≥120MPa) and is suitable for large-capacity transformers; the latter has excellent moisture resistance (water absorption <1%) and has more advantages in coastal areas with humidity>80%.The measured data of a southern substation show that the failure rate of transformers using improved Nomex has decreased by 42%.

1.2 Key points for material selection of switchgear

SMC composite materials (sheet molded plastics) are generally used in medium voltage switchgear, which has flame retardant properties of V0 and a weight reduction of 30%.However, it should be noted that areas above 2000 meters above sea level should choose electro-corrosion-resistant materials, such as epoxy resins with AlOo填料 fillers, which can increase the resistance to partial discharge by more than 3 times.

2. Material adaptation strategies in different scenarios

According to the 2025 technical specifications of the State Grid, environmental adaptability has become the new standard for selection.For example, chemical parks need to focus on corrosion resistance-the life of PTFE-coated switchgear in the HSS environment is 5-8 years longer than conventional materials.

2.1 Special climate response plan

In alpine areas (below -40℃), it is recommended to use silicone rubber composite insulators, the elastic modulus of which is only reduced by 15% at low temperatures, and the epoxy resin will become brittle and crack.A case of transformation of a Northeast substation proved that the failure rate of equipment in winter was reduced by 67% after the replacement of materials.

2.2 Intelligent equipment matching selection

The online monitoring system of intelligent substations requires materials to be temperature sensitive.The new type of epoxy resin doped with silicon carbide can trigger an early warning at 120℃, and an overheating alarm is issued 20 minutes earlier than traditional materials, which buys critical time for troubleshooting.

3. The practice of balancing cost and efficiency

Against the background of a 12% increase in material costs in 2025, the whole life cycle cost calculation has become the mainstream.Although the unit price of silicone rubber bus bushing is 40% higher than that of PVC, its maintenance-free characteristics can save about 150,000 yuan/km in operation and maintenance costs for 8 years.

3.1 Economical program configuration

For agricultural network renovation projects with limited budgets, glass fiber reinforced polyester (FRP) materials are recommended.The measured data show that its insulation properties meet the needs of 10kV power distribution, and the material cost is 35% lower than SMC, which is particularly suitable for township substations with a load rate of <60%.

3.2 Optimization of high-end equipment and materials

Nano-modified composite materials are recommended for UHV projects above 750kV.Adding 2% graphene epoxy resin can control the partial discharge below 5pC, and with the vacuum pouring process, the noise of the transformer can be reduced by 8 decibels to meet the environmental protection requirements of urban central substations.

The selection of insulation materials for power equipment needs to comprehensively consider technical parameters, environmental characteristics and economic benefits.With the rapid development of environmentally friendly and intelligent materials, it is recommended that engineering units establish a dynamic selection database and regularly update the material performance comparison table.The core principle is to find the best balance between technological innovation and practical value based on the safety of equipment operation and the cost of the whole life cycle.In the next three years, with the commercial application of biodegradable insulation materials, the industry selection standards may usher in a new round of innovation.