3상 정류기의 고조파 경감을 위한 스위칭 회로에 관한 연구 = A Study on the Switching Circuit of Three Phase Diode rectifier for Harmonic Reduction

다국어 초록 (Multilingual Abstract)

In this paper, a new control circuit for shaping the line current and reducing the total harmonics distortion in three phase diode rectifier is presented. In the past years, three phase diode rectifier have been used widely. Because a three-phase diode rectifier don't need controller, it's a cheap and reliable method to get DC voltage. However an harmonics problems which make an acoustic noise, overheat, a disorder of computer system and sometimes mess a communication system are caused.
In an uncontrolled diode rectifier, current is drawn from the ac mains only during the period in the ac cycle when the instantaneous voltage is greater than the voltage across the dc-link capacitor. As a result, current is of pulsed nature with the amplitude dependent on the size of the capacitor. a pulsed natured current is so discontinuous that it makes a harmonics problems. In this study, the three bidirectional switches rated at very small power are installed in a conventional three phase diode rectifier. Using those switches, an idle current charges to capacitors continuously. Simulation's and Experimental's results demonstrate a reduction of harmonics, a improvement of power factor and THD.