DSP-based current sharing of average current controlled two-cell interleaved boost power factor correction converter

Power factor correction (PFC) pre-regulators are used between the ac line and non-linear load to improve the line current in terms of power factor and total harmonic distortion (THD). In medium-and high-power applications, the interleaved boost PFC converter is the proper solution for this purpose to obtain a pre-regulator with lower size. The operation of the interleaved boost PFC converter provides a reduction of the inductor and electromagnetic interference filter volumes compared with those of the conventional single switch boost PFC converter. However, proper current sharing and current ripple minimisation must be ensured to achieve these benefits. The current sharing between cells of a two-cell interleaved boost PFC converter, which is an important problem in applications is analysed and discussed in this study and the problem is removed by using a digital signal processing (DSP)-based simple practical solution. The proposed technique provides the proper current sharing by sensing only the rectifier output current (total current of cells) without using any external control loop. The simulation and the experimental results are presented to show the validity.