Harmonik telah mejadi satu masalah yang serius dalam elektrik sistem. Transformer arus, pemutus litar, dan gegantiarus lampau telah diujikaji semasa dalam keadaan herotab arus harmonik untuk melihat perlaksaannya. Kandungan harmonic dengan frekuensi yang berbeza akan meningkatkan jumlah arus beban dan juga akan mengakibat bahan elektrik contohnya Transformer arus, pemutus litar, dan gegantiarus lampau gagal diguna. Penyelidikan ini akan menunjukkan pengaruh arus dalam mengganggu ketepatan transformer arus, pemutus litar, dan gegantiatus lampau. Punca rectifier ini merupakan bekalan voltan sebanyak 240V, 50Hz. Litar rectifier ini digunakan sebagai beban tak linear dalam penyelidikan ini. Jumlah herotan harmonic bagi voltan dan arus masukan akan berubah apabila nilai perintang dan kapasitor boleh laras diubah. Keputusan penyelidik ini akan diuji dengan meter FLUKE 43B dan lain-lain Keputusan akan dicatat. Keputusan dalam penyelidik ini akan dibanding dengan keputusan teory. Berdasarkan projek ini, transformer arus, pemutus litar, dan geganti arus lampau gagal diguna kerana masalah hamonik. Kebanyakan radas tidak boleh tahan terlalu tinggi jumlah herotan harmonik arus. Pembelaan system membentuk daripada transformer arus, pemutus litar, dan geganti arus lampau. Tetapi, harmonic sangat bahaya kepada system ini. Oleh itu, semasa memasang system ini di rumah perlu menguji dan menentukan berapa tinggi tentang harmonic di bangunan itu. Harmonik yang terlalu tinggi akan merosakkan alat-alat bahan electik di dalam bangunan.
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Harmonic is a very serious problem in power system. Some of the power system equipment such as current transformer, circuit breaker and over-current relay are experimented under harmonic current distortion condition to analyze its performance. The harmonic components with different frequencies will increase total load current and may be affect the power equipment such as relay and circuit breaker cannot operation. This research presents the effect of harmonic on disturbing the accuracy of current transformer, analyze the performance of circuit breaker under harmonic condition and analyze the accuracy of over current relay in either sensing the load current or making decision to send tripping signal. The source of the system was voltage supply of 240V, 50Hz. The rectifier circuit is used as non-linear load in whole project. The total harmonic distortion for input current would change by varied the variable resistor and variable capacitor. The result is measured by measurement tools such as FLUKE 43B, multi-meter, and so on. The result is collected and analyzed. The practically result are compared with theoretical value and the percentage of error is determined. Based on the research, over-current relay, circuit breaker and current transformer cannot function in good condition due to presence too high of harmonic current. Most of power equipment cannot support too high of harmonic. Protection system is build with relay, circuit breaker and current transformer. Therefore, harmonic is a very important fact that should consider when installs the protection system in a building. Harmonic will cause overheat to the electric equipment and damages the equipments as the load current is higher than normal rating.
Effect harmonic on power system equipments_Lee Choon Hooi_E3_2010_875003639_00003084333_NI