Authors: Fuping Zeng | Siying Wu | Xu Yang | Zhaofeng Wan | Ju Tang | Mingxuan Zhang | Qiang Yao
Source: IEEE Access (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Fault Diagnosis and Condition Division Criterion of DC Gas Insulating Equipment Based on SF<sub>6</sub> Partial Discharge Decomposition Characteristics SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposition characteristics directly reflect the generation, development, and evolution of internal faults in gas-insulated equipment (GIE). However, establishing the DC-GIE internal insulation condition comprehensive division criterion and fault diagnosis method based on SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposition characteristics remains unsolved. Therefore, partial discharge (PD) and SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposition characteristics of typical insulation defects from initial discharge to the breakdown process are discussed in this paper. The average discharge magnitude in a second Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sec</sub> is selected as an electrical feature to characterize the PD condition, and the PD state is divided into three levels, namely, mild PD, medium PD, and severe PD. SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposition experiments are conducted under different PD conditions of each defect, and the SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposition characteristics under different failure conditions are obtained. On this basis, we construct five feature sets of 36 characteristic quantities for GIE PD fault diagnosis and analyze the validity. A minimum-redundancy-maximum-relevance-based feature selection algorithm is used to optimize the characteristic quantities, and an optimal feature set is selected, i.e., {C(SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> )/C(T), C(SOF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> )/C(CT), C(SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> )/C(ST)}. The characteristic quantities of SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposition component, which characterizes PD condition, are reconstructed, and the component characteristic criterion of PD condition division is proposed. Thus, a decision tree evaluation model for the PD condition of the typical insulation defect inside DC-GIE is constructed. This paper lays a foundation for the insulation condition evaluation and fault diagnosis of DC-GIE. Partial discharge ; Decomposition ; Fault (geology) ; Division (mathematics) ; Algorithm ; Computer science ; Topology (electrical circuits) ; Electrical engineering ; Mathematics ; Combinatorics ; Engineering ; Chemistry ; Arithmetic ; Organic chemistry ; Biology High voltage insulation and dielectric phenomena ; Electrostatic Discharge in Electronics ; Power Transformer Diagnostics and Insulation