This part of GB/T 26218 specifies general definitions, methods for the evaluation of site pollution severity (SPS) and outlines the principles to arrive at an informed judgement on the probable behaviour of a given insulator in certain pollution environments.
This part is applicable to the selection of insulators, and the determination of their relevant dimensions, to be used in high-voltage systems with respect to pollution.
This part is generally applicable to all types of external insulation, including insulation forming part of other apparatus. The term “insulator” is used hereafter to refer to any type of insulator.
CIGRE C4 documents [1], [2], [3], form a useful complement to GB/T 26218 for those wishing to study in greater depth the performance of insulators under pollution.
This part does not deal with the effects of snow, ice or altitude on polluted insulators. Although this subject is dealt with by CIGRE [1], [4], current knowledge is very limited and practice is too diverse.
Foreword I
1 Scope and Object
2 Normative References
3 Terms, Definitions and Abbreviations
4 Proposed Approaches for the Selection and Dimensioning of an Insulator
5 Input Parameters for the Selection and Dimensioning of Insulators
6 System Requirements
7 Environmental Conditions
8 Evaluation of Site Pollution Severity (SPS)
9 Insulation Selection and Dimensioning
Appendix A (Informative) Flowchart Representation of the Design Approaches
Appendix B (Informative) Pollution Flashover Mechanisms
Appendix C (Normative) Measurement of ESDD and NSDD
Appendix D (Normative) Evaluation of Type B Pollution Severity
Appendix E (Normative) Use of Laboratory Test Methods
Appendix F (Normative) Deterministic and Statistical Approaches for Artificial Pollution Test Severity and Acceptance Criteria
Appendix G (Informative) Example of a Questionnaire to Collect Information on the Behavior of Insulators in Polluted Areas
Appendix H (Informative) Form Factor
Appendix I (Informative) Correspondence between Specific Creepage Distance and USCD
Appendix J (Informative) Comparison of Chapter and Article Numbers of this Part and Those of IEC/TS 60815-1: 2008
Appendix K (Informative) Technical Differences between this Part and IEC/TS 60815-1: 2008 and Their Reasons
Bibliography
