The Application of Glass Fiber Wounded Pipe in Transformer Tap Changers

In the complex internal structure of a power transformer, the tap changer is a crucial component that regulates the transformer's ratio during operation to maintain a stable output voltage. The performance and reliability of the tap changer directly affect the lifespan of the entire transformer and the stability of the power grid. In this precise and demanding application, glass fiber wounded pipes, as a key insulating and structural material, are playing an increasingly important role. This article will delve into why and how glass fiber wounded pipes have become an indispensable part of the transformer tap changer and analyze the core advantages they bring.

What is a glass fiber wounded pipe?

A glass fiber wounded pipe is typically made by impregnating high-performance insulating materials such as epoxy resin or polyester resin with non-alkaline glass fibers and then winding and curing it on specialized equipment. The components produced by this process have a series of outstanding characteristics:

Extremely high mechanical strength: It is capable of withstanding huge radial pressure and axial stress.

Excellent electrical insulation performance: It has high dielectric strength and can effectively isolates high voltages.

Outstanding heat resistance: It can work stably in high temperatures (such as F, H grades, above 155°C).

Low moisture absorption: It has good moisture-proof performance and stable performance.

Size stability: It has small deformation and high precision under temperature and humidity changes.

Resistant to chemical corrosion: It is capable of resisting the erosion of transformer oil and other chemical substances.

Why do tap changers require glass fiber wounded tubes?

The tap changer is one of the most frequently operating mechanical components in a transformer. When switching gears in an energized state, the tap changer will encounter:

High electric field intensity: There are very high potential differences between the switch contacts and to the ground.

Frequent mechanical operations: Strong materials are needed to support and guide the moving parts.

Thermal stress: The load current and switching arc generate heat.

Compatibility with transformer oil: All materials must be compatible with transformer oil for a long time, without decomposition or contamination of the oil quality.

Traditional insulating materials such as ordinary engineering plastics or laminated wood boards may have deficiencies in mechanical strength, heat resistance, or long-term stability. However, glass fiber wounded tubes perfectly solve these challenges.

The specific application of glass fiber wounded pipes in tap changers

In tap changers (especially vacuum on-load tap changers), glass fiber wrapped tubes are mainly used in the following core areas: 

1. Insulation supports and structural framework

The internal of the tap changer requires various supports, struts and frameworks to fix the contacts, vacuum interrupters and other components.

Glass fiber wounded tubes can provide mechanical support while ensuring the electrical insulation distance between components and between components and the ground.

Advantages: Compared to metal parts, it reduces weight, eliminates eddy current losses, and simplifies the insulation design. Its dimensional stability ensures the long-term stability of the entire assembly structure.

2. Outer insulation of the arc extinguishing chamber

In on-load tap-changing switches, the switching process generates arcs. Although the vacuum arc extinguishing chamber seals the arcs inside, reliable insulation protection is still required for its exterior.

The glass fiber wounded tube serves as the insulation sleeve or supporting structure for the vacuum bubble and withstands the overvoltage during switch operation.

Advantages: Good corona resistance, capable of withstanding the impact of high-frequency overvoltage, and prolonging the equipment lifespan.

3. Connecting rods and pull rods

Used to connect the moving contacts and the operating mechanism for linear motion.

The glass fiber wounded pipe can maintain electrical insulation while transmitting tension and pressure.

Advantages: High axial strength and rigidity, ensuring the accuracy of contact pressure and travel.

In modern power transformer designs that pursue higher efficiency, smaller size, and longer lifespan, the optimization of each component is crucial. The glass fiber wounded tube, with its comprehensive outstanding performance, has transitioned from an alternative material to an indispensable core insulation and structural component in transformer tap-changing switches. It is one of the key technologies for ensuring the safe and stable operation of transformers and reducing the total life cycle cost. For transformer manufacturers, grid operators, and maintenance engineers, a deep understanding and correct application of high-performance glass fiber wounded pipes is a wise move to enhance the competitiveness of equipment.