The book focuses on the topologies of non-isolated DC-DC converters with a wide voltage gain range for renewable energy systems. It addresses both theoretical principles and engineering practices. Each chapter introduces a family of non-isolated DC-DC converters, including advanced control methods. The inclusion of modeling and experimental verification provides in-depth applications in fuel cell vehicles, electric vehicles with multiple sources including batteries and super-capacitors, and photovoltaic systems. The book is beneficial for researchers, engineers, and graduate students in the fields of renewable energies, as well as electrical and electronic engineering.