Selection Criteria: Regulatory Basis
The selection criteria and regulatory basis for insulators include the GB/T 1001 series (porcelain/glass insulators), GB/T 19519 (composite insulators), mechanical strength (electromechanical load), specific creepage distance (pollution considerations), and type selection (porcelain/glass/composite). Industry experts note that selection should follow established standards: GB/T 1001 for porcelain and glass insulators, and GB/T 19519 for composite insulators.
Key factors include mechanical strength (electromechanical load) and specific creepage distance (pollution level), with choices determined by voltage class and environmental conditions.
Key Standard Points
- GB/T 1001 series: Standards for porcelain/glass insulators (type testing);
standard selection; - GB/T 19519: Standard for composite insulators (silicone rubber); pollution resistance/lightweight design;
- Mechanical strength: Electromechanical load (mechanical strength grade); selected based on suspension/loading requirements;
- Specific creepage distance: Creepage distance/voltage (pollution level); prevention of pollution flashover;
- Type selection: Porcelain (standard), glass (self-shattering detection for zero-value units), or composite (pollution resistance);
selected based on the application scenario.
Key Selection Factors
First is strength matching.
Mechanical strength (electromechanical load) must match the application (suspension/tension) to prevent breakage.
Second is specific creepage distance.
Pollution level (specific creepage distance) matching (to prevent pollution flashover) is determined by the operating environment.
Type selection depends on the application scenario;
options include porcelain, glass, or composite materials (offering pollution resistance and lightweight properties), chosen based on environmental conditions.
Finally, verification is conducted through testing—specifically type tests (per GB/T 1001/19519) to verify electromechanical performance and flashover characteristics—ensuring compliance.
Pitfalls to Avoid
First, “insufficient strength”: inadequate mechanical strength can lead to breakage, so proper strength matching is essential.
Second, “insufficient creepage distance”: inadequate creepage distance in polluted areas can cause pollution flashover, necessitating verification of the specific creepage distance.
Third, “composite aging”: composite insulators are prone to aging (such as chalking), so service life must be taken into account.
Trends and Recommendations
Insulator technology is moving toward “high performance,” characterized by the widespread adoption of composite insulators (offering pollution resistance and lightweight design) and the trend toward online monitoring (of insulation status).
For those responsible for selection, the recommendation is to “adhere to standards, match strength requirements, and verify creepage distances.”
Strict adherence to insulator standards ensures the safety and stability of the power line.
