In modern society, the utility power grid is supposed to guarantee load management, demand side management, as well as to use the market price of electricity and forecasting of energy (e.g., based on wind and solar renewable sources) in order to optimize the whole electrical distribution system. An optimized power system is expected to have the following characteristics: high efficiency, high availability, good quality of service and high level of security, which leads to the concepts of distributed generation and smart-grid. This book discusses different emerging technologies, principles and applications of power electronics and hydroelectric power. Some of the topics discussed include parallel three-phase back-to-back converters; risk management of hydropower projects; and cascade converters for wide conversion ratios.