This paper analyzes the control method of a multiphase interleaved DC–DC converter for supercapacitor energy storage system integration in a DC bus with reduced input and output filter size. A reduction in filter size is achieved by operating only in modes with duty cycles that correspond to smaller output current ripples. This leads to limited control of the charging and discharging process of the supercapacitor energy storage system. Therefore, a detailed analysis of the optimal charging strategy is provided in this paper for interleaved converters with different numbers of phases. The results show that such control can be used, albeit with some percentage loss in efficiency. Experimental results are presented in this paper to verify the theoretical results.