就模鑄型變壓器而言，使用音射法來檢測與定位局部放電是十分困難，必須克服音波快速衰減與易受外部音源干擾等問題，此外針對模鑄型變壓器的局部放電與電暈，缺少一套完整之檢測、辨識與定位的流程。本論文提出使用導波管與特殊設計的音射探頭組兩種技術來改善上述等問題，實驗結果證明，同時使用導波管與特殊設計的音射探頭組兩種技術不只大幅提升量測系統的靈敏度與可信度。當電暈現象在空中同時產生瞬間的電磁場變化與超音波信號，依兩者時間差即可得知電暈與探頭的距離。最後將量測系統安裝在實際的變壓器，利用電磁信號與音射探頭的時間差可將局部放電的位置範圍縮小對稱於導波管的左右兩點，完成局部放電精準的定位。利用音射探頭組完成辨識局部放電與電暈，針對模鑄型變壓器的局部放電與電暈，提出一套檢測、辨識與定位的標準流程，最後利用這兩種技術與標準流程來守衛模鑄型變壓器的運轉。

The detection and location of partial discharge (PD) in cast-resin dry-type transformers using the acoustic emission (AE) method is very difficult: the sound absorption in filled epoxy is very high and is easily interfered with external sound sources. In addition, there is no operating procedure for the detection, identification and location of PD in cast-resin dry-type transformers. In this dissertation, the waveguide and a specially designed AE-sensor pair designed to overcome the shortcomings of the AE method are described. Test results indicate that two techniques using the waveguide and the pair of AE sensors not only greatly improve the sensitivity but also increase the reliability of the AE measurement system. When corona occurs, it is often accompanied by electromagnetic and ultrasonic signals. The location of corona can be estimated from the difference in arrival time of signals from the AE sensor pair. In a practical application using the proposed techniques, the winding of PD was found in a high-voltage transformers, and further analysis was carried out to reduce the scope of PD to two points which are bilaterally symmetrical about the waveguide. A more precise PD source can be located and therefore, the pair of AE sensors can easily distinguish PD from corona. An operating procedure for detection, identification and location of PD has been established based upon the techniques described above. The techniques and operating procedure can guard the cast-resin dry-type transformers.

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