Digital Control of Bridgeless Interleaved PFC Boost Converter Based on Predicted Input Current

Abstract

In this study, digital control of bridgeless interleaved power factor correction (PFC) boost converter is presented by using DSP (digital signal processor) for prediction of input current without any current sensing. The complex control methods which have current sensing are utilized to get minimum ripple for current and appropriate sharing of current for interleaved PFC converters that reduce input current ripple and improve power rating, so they are much more convenient than the classic PFC converters. The current signals do not need to be sampled for proposed predictive control approach due to sampling of the voltages of input and output. The sampled voltages of input and output are employed to calculate input current for the converter. The parameters of converter, calculated input current and reference current that acquired from the voltage loop compensator are employed for predicting following duty cycle. By this way, the complex signal processing and current measuring are taken out when compared with the conventional control methods. An experimental circuit of bridgeless interleaved PFC boost converter has been installed to apply the proposed predictive control method via DSP board. It is seen from the results that appropriate sharing of current, the low value of total harmonic distortion (THD) and high rate of power factor can be acquired thanks to using the proposed predictive control strategy.