摘要
Many conventional switching power supplies in input AC line voltage and filtering it with large electrolytic computers and low power motor drive systems operate by rectifying the capacitors. This results in undesirable side effects such as the generation of distorted input current waveform. The input power factor is also poor. Further, the input current has the shape of narrow pulses, which in turn increases its value. The reduction in input current harmonics and improved power factor operation of motor drive systems and switching power supplies are important from the energy saving point of view and also to satisfy the harmonic standards. This paper proposes a full bridge PWM rectifier with load current feedforward. The proposed approach has some advantages, including a quick response for the load fluctuation, the reduction of the number of sensors and simplified control, as compared with the conventional methods. From simulated results, it is clarified that the proposed control method is effective and useful.