Digital state feedback control and feed-forward compensation for a parallel module DC-DC converter using the pole placement technique

In this paper, a simple digital control scheme for the parallel module converter is proposed using a digital state feedback control method. In this approach, the large signal average converter model is used to derive the robust tracking control algorithm of the state feedback controller instead of using the small signal modeling approach. The proposed control system can precisely achieve the interleaved current sharing and the output voltage regulation, and can achieve the systematical controller design for digital implementation using the pole placement technique. Also, a dynamic gain feed-forward control method using the operation point of the converter is proposed to improve the audio susceptibility. For a design example, a parallel module bus regulator system in the low-earth-orbit (LEO) satellite power system application, which has an input voltage step change, is implemented using a TMS320F2812 DSP.