This book gives a comprehensive and in-depth introduction to the development of active power decoupling technology in single-phase current-source converters. It covers cutting-edge topics such as virtual-impedance control and harmonic state-space modeling and presents topology construction principles, specific decoupling topologies, advanced decoupling controls, and stability analysis. This book will be an invaluable tool for researchers, engineers, and designers in the field of power electronics involved in designing power converters with high power density and reliability.