<![CDATA[Abstrak Kegagalan isolator tegangan tinggi di Indonesia disebabkan oleh banyak faktor, salah satunya adalah adanya arus bocor pada permukaan isolator yang terkontaminasi. Material polimer epoxy resin dikembangkan sebagai alternative karena memliki beberapa kelebihan, antara lain sifat menolak air (hydrophobicity), lebih ringan, murah, dan instalasi lebih mudah. Oleh karena itu, Studi mengenai arus bocor diperlukan untuk mengetahui permukaan isolator. Pada penelitian ini, pengujian arus bocor dilakukan pada isolator resin epoksi pengisi silika. Peneltian ini difokuskan pada besar arus bocor, tipe sirip isolator, dan karakteristik harmonik permukaan isolator pada kondisi kering dan basah. Parameter harmonik tersebut meliputi bentuk gelombang, spektrum frekuensi (FFT), dan Total Harmonic Distortion (THD). Pengolahan THD dilakukan dengan menggunakan fungsi Fast Fourier Transform (FFT)menggunakan software Matlab 2012. Hasil pengujian dan analisis menunjukkan bahwa magnituda, bentuk gelombang, spektrum frekuensi, dan THD sangat dipengaruhi oleh kondisi permukaan dan besar permukaan isolator. Pada kondisi basah, arus bocor yang dihasilkan cukup besar dan nilai presentase THD mendekati nol, ini disebabkan permukaan isolator bersifat konduktif dan dapat menyebabkan pemanasan serta degradasi pada permukaan isolator. Pada  kondisi kering memiliki nilai arus bocor dan THD rendah sehingga kondisi permukaan normal. Dari hasil penelitian didapat bahwa indikator arus bocor dan komponen harmonik cukup efektif untuk mengetahui kondisi permukaan sampel isolator. Kata Kunci : isolator, arus bocor, polimer, resin epoksi , distorsi harmonik total, FFT Abstract High voltage insulator failures in Indonesia caused by many factors, one of which is the presence of leakage current on the surface of contaminated insulators. Epoxy resin polymer material was developed as an alternative because it has several advantages, include water-repellent (hydrophobicity), lighter, cheaper, and easier installation. The study of the leakage current is needed to determine the insulator surface. The research about leakage current on epoxy resin focused on the magnitude, fin-type insulator, and harmonic characteristics of the insulator surface under dry (clean) and wet condition. The harmonic parameters include waveform, frequency spectrum (FFT), and Total Harmonic Distortion (THD). Leakage current data processing is done by using the Fast Fourier Transform (FFT) using Matlab software. Result test and analysis showed that the magnitude, waveform, frequency spectrum, and the THD were strongly influenced by surface conditions and surface area of the insulator. In wet conditions, the leakage current was quite large and the percentage of THD value closed to zero, due to conductive insulator surface which caused heating and degradation on the insulator surface. On the contrary, the dry condition gave low leakage current and THD, so the surface of insulator became normal. The result of the experiment mentioned that the leakage current and harmonics sample were considerd to be effective to detect the condition of insulator surface. Keywords : insulator, leakage current, polymer, epoxy resin, total harmonic distortion, FFT]]>
