Post insulators and composite insulators are two very important types of insulating devices in power systems, each with its own characteristics and uses. The following are the main differences between them:

1. Definition and Composition:

Post insulators are insulating devices used to fix and support conductors, usually made of ceramic or glass. Their main function is to secure the conductors to poles or other supporting structures, maintaining isolation between the conductors and the grounded parts.

Composite insulators, on the other hand, are insulating devices made of multiple materials, typically including metal end fittings, insulating core rods, and sheaths. They are made from high-performance composite materials, such as fiberglass reinforced resin.

2. Performance Characteristics:

Post insulators have good weather resistance and can be used outdoors for long periods. They have high mechanical strength and can withstand large conductor and wind loads. In addition, they also have low dielectric loss and good pollution resistance.

Composite insulators are known for their excellent electrical and mechanical properties. They have high insulation resistance, good voltage and current resistance. Furthermore, composite insulators are lighter, have higher tensile strength, and excellent aging resistance.

3. Applications and Applications:

Post insulators are widely used in power lines, substations, and distribution systems to support and fix conductors, ensuring the insulation safety of the conductors.

Composite insulators are more commonly used in high-voltage transmission lines, insulation support in power systems, and lightning protection. They are suitable for various harsh environments, such as high temperature, high humidity, and heavily polluted areas.

4. Advantages and Disadvantages:

The advantages of post insulators are mature manufacturing processes, low cost, and high reliability. However, their electrical performance is relatively weak, especially in high voltage and high current environments.

Composite insulators have higher electrical and mechanical performance, suitable for a wider range of applications. However, their manufacturing process is relatively complex, and the cost is higher.

In summary, post insulators and composite insulators have their own uses and advantages in power systems. Post insulators are mainly used to support and fix conductors, while composite insulators are more used for insulation support and lightning protection in high-voltage transmission lines. When choosing which insulating device to use, it is necessary to consider the specific application scenarios and needs.