Comprehensive Evaluation and Application of GIS Insulation Condition Part 2: Construction and Application of Comprehensive Evaluation Model Considering Universality and Economic Value

Bowen Tang,Siying Wu,Keli Gao,Xianglian Yan,Yuanzhang Sun,Fuping Zeng

doi:10.1109/access.2019.2925802

Abstract

On the basis of obtaining many characteristic information and optimization evaluation indicators for characterizing the internal insulation condition of gas insulated switchgear (GIS), how to effectively classify weights and integrate information on the evaluation indexes, and establish a comprehensive evaluation model for insulation condition considering economic value and universality is another difficult problem to be solved. In this research, the above-mentioned 23 comprehensive evaluation index system, which are optimized to cover the PD hazard, SF6 insulation performance and time, environment and economy, are put forward, the idea of correcting the SF6 decomposition component monitoring data are proposed, and the general mathematical correction formula and method are given. The improved DS evidence fusion theory is used to make information decision fusion. The multi-class information fusion evaluation model of GIS equipment insulation condition is established. The fuzzy level analysis is used as the evaluation method framework to solve the problem of the index weight setting and membership determination of the evaluation indexes. The application of the example shows that the evaluation model and technology established in this research has achieved multiple types of information complementation, and the evaluation results are reasonable and credible.

Highlights

With the advancement of gas insulated switchgear (GIS) insulation fault monitoring methods and techniques [1]–[3], many effective information reflecting the insulation condition can be obtained
GIS equipment insulation condition comprehensive evaluation method and technology based on multi-class information fusion
CASE STUDY According to the engineering project related to the GIS equipment insulation test of the research group, data samples of 220kV GIS faulty gas chamber interval running for 3 years were obtained

Summary

INTRODUCTION

With the advancement of gas insulated switchgear (GIS) insulation fault monitoring methods and techniques [1]–[3], many effective information reflecting the insulation condition can be obtained. Taking the SF6 insulation fault decomposition component characteristic information as an example, since the micromoisture and micro-oxygen content in the SF6 gas will make a large difference in the decomposition component ratio and the variation law, thereby reducing the feasibility and accuracy of the insulation condition evaluation. The mathematical model expressions of four SF6 decomposition characteristic component ratios f (SO2F2)/f (SOF2), f (CF4)/f (CO2), f (CF4+CO2)/f (SO2F2+SOF2) and f (CO2)/ f (SO2F2) under different micro-moisture contents are shown in (2)-(5): f1(x) = 90.35/(x + 489.90) + 0.28. The mathematical model expressions of four SF6 decomposition characteristic component ratios f (SO2F2)/f (SOF2), f (CF4)/f (CO2), f (CF4+CO2)/f (SO2F2+SOF2) and f (CO2)/ f (SO2F2) under different micro-oxygen contents are shown in (6)-(9): f5(x) = 411.90/(x + 3546) + 0.32. The PD hazard is combined with the SF6 gas insulation performance evaluation results, and the final decision results are obtained by the inference rules of DS theory

EVALUATION INDEX WEIGHT DETERMINATION

EVALUATION INDEX MEMBERSHIP ANALYSIS

CASE STUDY