報告書番号

H12004

タイトル（和文）

高精度到達時間差算定手法に基づくパルス性電磁波の到来方向推定システムの開発

タイトル（英文）

Development of a DOA estimating system for pulsed electromagnetic wave based on a high accuracy TDOA estimation method

概要 （図表や脚注は「報告書全文」に掲載しております）

電力設備の絶縁不良がいしや金具の接触不良箇所において発生する火花放電は，絶縁劣化を加速し，設備故障を引き起こす恐れがある。設備故障を未然に防止するためには，火花放電を早期に検出し，火花放電の発生源を速やかに除去する必要がある。火花放電が発生する箇所の近傍には金属製の電力設備が存在することがあり，その金属面からの反射によってマルチパス波が発生する。従って，このような複雑な電磁波伝搬環境下でも高精度に発生源を探査できるシステムの開発が急務となっている。このため，本報告では，（1）様々な分野で提案された到達時間差の算定法を調査し，マルチパス波が存在する環境においても適用可能な算定法を選択し，これに基づく到来方向推定システムを開発し，実測によりその適用性と推定精度を検討した結果，（2）到来方向の推定精度を向上させるため，高精度到達時間差算定手法を提案し，これによる推定結果，について述べる。

概要 （英文）

Spark discharge which occurs at deteriorated insulators or an unintended narrow gap between metal supports on electric power equipment, accelerates the degradation of insulation materials and cause equipment failure. Therefore, to maintain the electric power equipment properly, it is necessary to detect and locate the position of the spark discharge source as soon as possible. In our previous study, a system for estimating the direction of arrival (DOA) of pulsed electromagnetic (EM) waves based on the coherent signal subspace method (CSSM) was developed. The system can be applied to multiple sources or in a multipath environment. However, to estimate the DOA with high accuracy, complicated calibration of the system is necessary, which may be a limiting factor for practical application. On the other hand, in the case of a single source, the DOA estimation based on time difference of arrival (TDOA) method, which has a simpler procedure than the CSSM, may be useful. However, the applicability of TDOA-based methods in a multipath environment has not yet been clarified. In this paper, firstly, the TDOA estimation methods proposed in other fields are investigated in detail, and to evaluate the applicability of the investigated methods, numerical simulation of the TDOA estimation in multipath environment is performed. Secondly, a DOA estimating system based on the TDOA method is developed, and the applicability and the estimation accuracy are confirmed by some experimental measurement. Thirdly, we propose a new technique for improving the TDOA estimation. The DOA estimation results obtained by the estimating system with the proposed high accuracy TDOA estimation method are shown.

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