The power system has seen many strides in the past. The recent introduction of reform and restructuring of power industry has imposed further challenges to planners and operators, since new operational strategies are to be adopted over existing system, in order to maintain system security, reliability and supply quality. Introduction of power electronic devices and their application for interfacing distributed generation from renewable energy sources and existing grid is inevitable. However, they have given rise to newer problems which need to be addressed. Thus, enormous challenges are being faced by present day power industries which require efficient planners, technology, solution methods and software to address their problems effectively. The present book aims to put before readers the current problems faced by the power sector and the attempts being made by experts to solve them.