| Abstract |
Switch mode power supplies use a full bridge rectifier to derive raw de voltage from the ac mains, which results in current spikes with high harmonic content. This leads to a poor power factor condition. The usual approach for performing active line harmonic reduction of off-line switch mode power supplies is to add a high power factor, boost pre-regulator, to the existing converter design. This paper analyses the classical boost circuit with input current shaping and shows that the ripple on the output capacitor is excessive, thus in turn a second regulating stage is required. In the new topology, the output ripple is determined and compensating signals are injected. Total power is processed only once, leading to greater efficiency. |
