Series-parallel conversion systems, in which multiple standardized converter modules are connected in series or parallel at the input and output sides, to meet the demands of various applications. This book focuses on the control strategies for the series-parallel conversion systems with DC-DC converters and DC-AC inverters as the basic modules, respectively, to achieve input voltage/current sharing and output voltage/current sharing among the constituent modules. The detailed theoretical analysis with design examples and experimental validations are presented. This book is essential and valuable reference for graduate students and academics majoring in power electronics and engineers engaged in developing DC-DC converters, DC-AC inverters and power electronics transformers.