Peningkatan penggunaan beban tak lelurus dalam sistem kuasa elektrik meningkatkn
lagi tahap harmonic. Peningkatan harmonik menyebabkan jangka hayat transformer
menurun. Penggunaan system kadar yang dipanggil Faktor – K adalah untuk memastikan
transformer boleh beroperasi dengan selamat apabila disambung dengan beban tak lelurus.
Laporan ini menunjukkan kesan harmonik terhadap transformer pengagihan daripada
eksperimen yang dibuat terhadap transformer tiga fasa dengan kadaran 500 VA. Kesan
harmonik dikaji dengan menyambungkan beban tak lelurus pada keluaran transformer.
Beban yang digunakan dalam eksperimen ini adalah perintang dan penerus. Eksperimen
dijalankan untuk mengkaji kesan harmonik terhadap transformer seperti kehilangan,
kadaran kuasa, factor kuasa dan peningkatan suhu transformer. Dalam laporan ini
mengandungi langkah yang digunakan untuk mengurangkan kesan harmonik terhadap
transformer dengan menggunakan kaedah nyahkadaran. Nyahkadaran yang digunakan
adalah Standard BS7821. Keputusan daripada eksperimen menunjukkan suhu akan
meningkat apabila jumlah herotan harmonik bertambah. Jumlah kehilangan dan kadaran
transformer juga akan meningkat apabila jumlah herotan harmonik meningkat. Faktor
kuasa akan menurun apabila jumlah herotan harmonik meningkat. Untuk %THDi 24.3%,
38.8%, 64.3%, 70.8% dan 80.7%, peratus nyahkadaran transformer adalah 92.59%,
89.91%, 86.82%, 85.51% and 85.40%.
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The increases use of non – linear load has increased the level of harmonics in electrical
power system. The increases of harmonics cause the reducing of the transformers life
expectancy. The used of rating system called K – Factor is to ensure that the transformer
can operate safely when supplying non-sinusoidal load current. The effect of harmonic on
distribution transformer is reported in this thesis. The experiment was conducted at three
phase transformer with capacity of 500 VA. The effect of harmonics on distribution
transformer has been investigated by connecting non – linear load to the output of
transformer. The load used in the experiment are resistance and rectifier. In addition, the
effect of harmonic to the transformer such as losses, power rating, power factor and
temperature rise. The analyzing the derating method also introduced to reduce the harmonic
effect on transformer. The derating method is suggested accordance to BS7821 standard.
The results show that the temperature increased linearly when total harmonic distortion
increases. The power loss also increased linearly when total harmonic distortion increased.
The power factor of transformer decreased linearly when total harmonic distortion
increased. For %THDi 24.3%, 38.8%, 64.3%, 70.8% and 80.7%, the percentage of derating
transformer is 92.59%, 89.91%, 86.82% , 85.51% and 85.40%.
system called K – Factor is to ensure that the transformer can operate safely when supplying non-sinusoidal load current; resistance and rectifier; analyzing the derating method also introduced to reduce the harmonic
effect on transformer.