Akademik Veri Yönetim Sistemi
JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.26, sa.1, ss.193-203, 2011 (SCI-Expanded)
In this study, a new improved control technique is developed to eliminate the input current harmonics in the Bridgeless Power Factor Correction (PFC) circuit. According to this approach, input voltage is not directly used as the reference like conventional methods. This is due the fact that the input ac mains voltage is not always a sinusoidal wave. In this method, a sampling circuit is designed according to positive and negative half cycle of input voltage. Thus, a reference signal is generated in the same phase and frequency of the input ac mains voltage. The desired power factor correction is achieved using the reference sine wave. In this manner, the injection of the input current harmonics as the result of the distorted input voltage to the ac mains is prevented. Sinusoidal PWM signals are generated by the control unit based on the measured sampling data. The system is operated and controlled by applying these signals to the gates of the switches. The system satisfies the conditions of IEC 61000-3-2 current harmonics standards successfully. The design, control and switching techniques of the circuit have been carried out using Simulink blocks in MATLAB/Simulink program. The proposed method and the theoretical analysis are verified by the results of experiments carried out in the laboratory.