Suspension insulator and post insulator test items

The test items of suspension insulators and post insulators shall include the following: Measure the insulation resistance of the insulator; AC withstand voltage test of insulators. The insulation resistance value of the insulator shall meet the following requirements: The insulation resistance value of suspension insulators used for voltage levels of 330KV and below should not be less than 300MΩ; for suspension insulators used for voltage levels of 500kV, it should not be less than 500MΩ; The insulation resistance value of post insulators with voltage levels of 35kV and below shall not be lower than 500MΩ; Use Dingsheng Power DC2403...

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Review of Insulator Failure Modes

Composite insulators were developed 45 years ago, largely due to these defects, and were introduced on an industrial scale in the 1980s. When suppliers adjust their products through successive generations of designs based on their initial service experience, there is a learning curve, but the technology is now mature. In fact, in most countries, it is considered equivalent and interchangeable with porcelain and glass. This is an impressive achievement, especially if one thinks that 25 years ago, power engineers knew little about the technology and did not trust composite insulators.

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Research on Live Cleaning Method of 500kV Post Insulator

With the increase of operating time of 500 kV substation equipment, the pollution degree of pillar insulators becomes more and more serious. The creepage of the insulators is more and more obvious, and the discharge sound increases on rainy and foggy days. Regular cleaning or emergency cleaning of insulators is an extremely effective anti-pollution flashover measure. In response to the requirements of high equipment reliability, there are fewer opportunities for power outage maintenance. At the same time, with the advancement of state maintenance work, there are fewer opportunities for equipment power outages. The hidden danger of flashover threatens the safe...

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Reasons for measuring voltage distribution of suspension insulators

Measuring the voltage distribution (or zero checks) of suspension insulators and multi-element pillar insulator strings is one of the methods to check for degraded insulators. It is carried out without power failure. (1) Characteristics of voltage distribution on the insulator string The voltage that each element in the suspension insulator string bears is different. This is mainly due to the capacitance between the metal part of the insulator and the ground, the cross arm or the tower, and the point wire, which makes the voltage distribution of the insulator string Very uneven. The voltage drop on the insulators closer to the wire...

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Hydrophobic charged detection device for composite insulators-principle and function

A new type of product that fills the gap in the field of online water-repellency testing of composite insulators in my country. The structure is simple, the operation is convenient, and the judgment is accurate. It is suitable for online detection of the hydrophobicity of 110kV and above transmission line composite insulators. It is also suitable for the hydrophobicity detection experiment and factory inspection of various composite insulators and silicone rubber. It is suitable for the water repellency detection of RTV spraying materials for magnetic insulators. Detection principle The water-repellent state of composite insulators is judged according to the water spray...

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How to choose the arrester

(1) First fix the base of the lightning arrester, and then install each unit (section) of the lightning arrester in groups from bottom to top. (2) The arrester has passed the assembly test and qualified before leaving the factory. The on-site installation should be strictly assembled according to the manufacturer's number, and can not be exchanged to avoid the change of characteristics. (3) the valve type arrester with series and combined current negative should be selected during installation so that the nonlinear coefficients between the same phase combination units are close to each other, and the difference value should not be greater...

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Composite insulator

The composite insulator is composed of three parts: an insulating core rod, a silicone rubber umbrella cover, and connecting fittings at both ends. The insulating mandrel is the abbreviation of epoxy resin glass avant-garde drawing rod. The main job of the mandrel is to bear the mechanical load and has high tensile strength, generally up to 800~1000Mpa. Its specific strength (in-position strength and weight) The ratio) is 5-6 times that of high-quality carbon structural steel, and the strength cannot be reduced too much under long-term load. At the same time, it is the main part of the internal insulation. Even...

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Composite Insulator Features

Silicones in their cross-linked elastomeric form are the rubber materials found in most high voltage insulators and are also used as housings for arresters and bushings, among other electrical components. It is therefore worthwhile reviewing the chemistry of this important family of polymers. The proper name for silicones is ‘siloxanes’, which consist of silicon (not to be confused with silicone) and oxygen backbone that can be cross-linked by different chemical reactions. They can also be modified such that their polymeric structure remains non-reactive at typical application temperatures. These modified products, also classified as polydimethylsiloxanes (PDMS), demonstrate how versatile this group...

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Classification of arrestors

There are many kinds of lightning arresters, metal oxide lightning arresters, line type metal oxide lightning arresters, no gap line type metal oxide lightning arresters, fully insulated composite coat metal oxide lightning arresters, unloadable lightning arresters. The main type of lightning arrester has tube type lightning arrester, valve type lightning arrester, and zinc oxide lightning arrester. The main working principle of each type of arrester is different, but the essence of their work is the same, to protect communication cables and communication equipment from damage.

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Adhesion test between fiberglass rod & housing in composite insulators

The central weakness revealed in the insulators investigated during this research was poor adhesion-likely the result of production deficiencies. A possible mechanism behind what occurred during service could be that, over time, air-filled voids between the fiberglass rod and the silicone rubber housing filled with moisture due to diffusion through the housing. This eventually led to a partially conductive layer in this interface into which HV potential was transferred from the live fitting along the insulator. The short-circuited path amplified electrical stress and initiated corona, whose impact generally starts by degrading local hydrophobicity. The final result was either erosion or...

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