面向IPOS SAB DC–DC变换器系统的改进型电流纹波抑制算法研究

The input-parallel output-series (IPOS) single active bridge (SAB) dc–dc converter system often suffers from current ripple issues caused by enormous branch power differences due to the location of windward surface and wind turbines in the cascaded dc wind farm. Therefore, this article focuses on a dc current ripple suppression algorithm for the IPOS SAB system, and three improvements are as follows. First, the effect of branch power difference on dc current ripple is analyzed, current ripple model is derived by the Fourier decomposition of inductor current within a switching period, and its 2nd ripple component at switching frequency is the main current ripple analytically. Second, system operational regions are divided into Zone I and Zone II according to branch power ratios, and a current ripple suppression algorithm that consists of triangular synthesis phasor method and inverted phasor method is proposed by regulating branch carrier phase-shift angles in the two zones. Third, the proposed current ripple suppression algorithm is verified by simulations and experiments.