Low‐Frequency Oscillation Suppression of Pulse Train Controlled Cuk Converter Operating in Continuous Conduction Mode

The inductor current and output voltage of pulse train (PT) controlled switching converters in continuous conduction mode (CCM) suffer undesirable low‐frequency oscillation; thus, the steady state performance and transient performance will be affected seriously. Up to now, most previous works on PT control mainly focus on low‐order switching converters, with few research works reported on high‐order switching converters. In this paper, taking conventional Cuk converter as an example, the energy model based on energy balance for analyzing the low‐frequency oscillation of PT controlled high‐order switching converters is established. In order to suppress low‐frequency oscillation and achieve fast transient response, an improved Cuk converter with PT control is further proposed. The operation principle of PT controlled improved Cuk converter operating in CCM and the mechanism of suppressing low‐frequency oscillation are investigated in detail. The parameter design considerations of improved Cuk converter are also given. Finally, the experimental results are presented to verify the effectiveness of the proposed method and theoretical analysis.