This book aims to provide a broad view of the POWER QUALITY is well known in various engineering fields. It logically explains complicated concepts and stepwise methods to explain important topics. Each chapter is well supported with the necessary illustrations. All the chapters in the book are arranged in a proper sequence that permits each topic to build upon earlier studies. POWER QUALITY is an important research area. The techniques developed in this area so far require to be summarized appropriately. In this book, the fundamental theories of these techniques are introduced. This book is original in style and method. No pains have been spared to make it as compact, perfect, and reliable as possible. Every attempt has been made to make the book a unique one. In particular, this book can be very useful for practitioners and engineers interested in this area. Hopefully, the chapters presented in this book have just done that.