Saha Tapan Kumar - Monitoring and Estimation Techniques

1. Chapter 01
2. Chapter 02
3. Chapter 03
4. Chapter 04
5. Chapter 05
6. Chapter 06
7. Chapter 07
8. Chapter 08
9. Chapter 09

1. Chapter 01
2. Chapter 02
3. Chapter 03
4. Chapter 04
5. Chapter 05
6. Chapter 06
7. Chapter 07
8. Chapter 08
9. Chapter 09

Edited by

Tapan Kumar Saha

The University of Queensland
St. Lucia, Brisbane, Australia

Prithwiraj Purkait

Haldia Institute of Technology
West Bengal, India

This edition first published 2017
2017 John Wiley & Sons Singapore Pte. Ltd

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The right of Tapan Kumar Saha and Prithwiraj Purkait to be identified as the authors of the editorial material in this work has been asserted in accordance with law.

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Library of Congress CataloginginPublication Data

Names: Saha, Tapan Kumar, 1959 editor. | Purkait, Prithwiraj, 1973 editor.
Title: Transformer ageing : monitoring and estimation techniques / edited by
Tapan Kumar Saha, Prithwiraj Purkait.
Other titles: Transformer aging
Description: Chichester, West Sussex : John Wiley & Sons, Inc., 2018. |
Includes bibliographical references and index.
Identifiers: LCCN 2017003580 (print) | LCCN 2017004685 (ebook) | ISBN 9781119239963 (cloth) | ISBN 9781119239994 (Adobe PDF) | ISBN 9781119239987 (ePub)
Subjects: LCSH: Electric transformers--Maintenance and repair--Handbooks,
manuals, etc. | Electric lines--Maintenance and repair--Handbooks,
manuals, etc. | Electric insulators and insulation--Testing. | Electric power distribution.
Classification: LCC TK2551 .T7635 2018 (print) | LCC TK2551 (ebook) | DDC 621.31/4--dc23
LC record available at https://lccn.loc.gov/2017003580

Cover image: gjp311/Gettyimages
Cover design: Wiley

The transformer is one of the most important pieces of equipment in a power grid. The condition of large power transformers has a significant impact on the reliability of the power grid. Large power transformers are expensive and complex in design and operation. Transformer condition monitoring and assessment of their remaining life is an important task for transformer owners/operators. Transformer condition monitoring covers many areas closely related to transformer structure and operation. The condition of the insulation system plays a major role in determining the life of a transformer. Similarly, winding/core integrity, bushing, and tap changer health are also important in maintaining the overall reliable operation of a transformer.

Throughout the life of transformer operation, the insulation system degrades and the degradation mechanism depends on the operating conditions inside the tank. Thermal, hydrolytic, and oxidation processes are the main causes of ageing of a transformer. Many diagnosis techniques have been in use for several decades, and their interpretation tools have always been the focus of improvements over the years. Many new diagnosis tools are being investigated continuously by researchers and engineers in the field. New insulation systems for solid and liquid insulations are being proposed and investigated for power transformers. This book will provide fundamental knowledge of transformer insulation materials, their ageing mechanisms, traditional as well as advanced condition monitoring techniques, and interpretation techniques. Basic knowledge of the transformer will be a prerequisite for readers.

The research work presented in this book was conducted with funding support from the Australian Research Council and the Australian electricity supply industry, with collaboration from several transmission and distribution utilities in Australia over a period of 25 years. Our expectation is that this book will provide stateoftheart knowledge about transformer ageing, condition monitoring, and fault diagnosis. No single book is currently available that provides such an important knowledge base for transformer condition monitoring and life assessment. The authors hope that this book will be a onestop information provider for engineering students, practicing engineers, and researchers. We believe anyone working in transformer condition monitoring particularly engineers working in electricity utilities, graduate or senior undergraduate students and researchers, postdoctoral fellows, and academics will benefit from this publication.

The authors of this book have published scores of journal and conference articles via the IEEE, IET, and CIGRE. Many of these will provide an additional knowledge base resource for the reader. Many diagnostic algorithms have been developed throughout this journey, and they are currently available from the University of Queensland research team.

This book is organized into ten chapters. explains comprehensively the dissolved gas analysis (DGA), furan analysis, and degree of polymerization (DP), and their relevant international standards. In addition, this chapter introduces electricalbased traditional diagnoses, which include insulation resistance (IR), polarization index (PI), dielectric dissipation factor (DDF), capacitance and power factor, dispersion factor, and partial discharge (PD).

provides theoretical explanations of polarizationdepolarization current (PDC), recovery voltage measurements (RVM), and frequency domain dielectric spectroscopy (FDS), along with their interpretation schemes. The effects of moisture, ageing, temperature, and insulation geometry on the interpretation of PDC, RVM, and FDS measurements are also described in this chapter.