Grid-Integrated and Standalone Photovoltaic Distributed Generation Systems
Analysis, Design, and Control
Bo Zhao
State Grid Zhejiang Electric Power Research Institute
Hangzhou, China
Caisheng Wang
Electrical and Computer Engineering Department, Wayne State University
Detroit, USA
Xuesong Zhang
State Grid Zhejiang Electric Power Research Institute
Hangzhou, China
This edition first published 2018 by John Wiley & Sons Singapore Pte. Ltd under exclusive licence granted by China Electric Power Press for all media and languages (excluding simplified and traditional Chinese) throughout the world (excluding Mainland China), and with non-exclusive license for electronic versions in Mainland China.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions.
The right of Bo Zhao, Caisheng Wang and Xuesong Zhang to be identified as the authors of this work has been asserted in accordance with law.
Registered Office
John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA
John Wiley & Sons Singapore Pte. Ltd, 1 Fusionopolis Walk, \#07-01 Solaris South Tower, Singapore 138628
Editorial Office
1 Fusionopolis Walk, \#07-01 Solaris South Tower, Singapore 138628
For details of our global editorial offices, customer services, and more information about Wiley products visit us at www.wiley.com.
Wiley also publishes its books in a variety of electronic formats and by print-on-demand. Some content that appears in standard print versions of this book may not be available in other formats.
Limit of Liability/Disclaimer of Warranty
While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.
Library of Congress Cataloging-in-Publication Data
Names: Zhao, Bo, 1977- author.
Title: Grid-Integrated and standalone photovoltaic distributed generationsystems : analysis, design and control / Dr. Bo Zhao, State Grid ZhejiangElectric Power Research Institute, Hangzhou, China; Dr. Caisheng Wang, Electrical and Computer Engineering Department, Wayne State University, Detroit, USA; Dr. Xuesong Zhang, State Grid Zhejiang Electric Power Research Institute, Hangzhou, China.
Description: Hoboken, NJ, USA : Wiley, 2017. | Includes bibliographical references and index. |
Identifiers: LCCN 2017011367 (print) | LCCN 2017026557 (ebook) | ISBN 9781119187363 (pdf) | ISBN 9781119187356 (epub) | ISBN 9781119187332 (cloth)
Subjects: LCSH: Photovoltaic power generation. | Interconnected electric utility systems. | Distributed generation of electric power.
With the progress of technology, human beings have undergone the transition from industrial civilization to ecological civilization, from extensive and inefficient expending to economical and efficient consumption, and from high carbon production to low carbon production. The present fossil-energy-dominated world energy paradigm is gradually changing into a multiple energy structure and will eventually be dominated by nonfossil energy. Against this background, the development of distributed photovoltaic (PV) generation systems, characterized by adaptation to local conditions, clean and efficient, decentralized layout, and local consumption, have experienced phenomenal growth in the past two decades. The world total solar power capacity had reached over 227 GW by 2015 and over 50 GW of the solar capacity were added in that year. Over 28 GW of solar power had been installed in the USA by the end of 2016. The PV capacity in Germany is currently over 40 GW. China is expected to deploy 70 GW PVs by 2017. The International Energy Agency estimates that solar power will become one of the mainstream energy sources by 2050 and contribute about 11% of world electricity generation. The majority of these PV systems have been and will be installed in distribution networks. As a result, the PV penetration level will become unprecedentedly high (e.g., well over 50%) and continue to grow in many distribution networks around the world. The high penetration of PV systems has led to great technical challenges, including voltage problems, harmonics, grid protection, and so on, in the operation and development of modern distribution networks.
In recent years, the authors and their teams have undertaken a series of PV-related projects, such as the implementation of PV systems for Jiaxing PV Science Park, Jianshan New Industrial Zone in Haining, and Hangzhou Bay New Zone PV Science Park. The main characteristic of these projects was to analyze the impact of integration of distributed PVs into the distribution networks at high penetration and develop measures to better accommodate those sources.
This book is the result of over 10 years of research on distributed PVs and integration of PVs in distribution networks and microgrids. It combines the theory, modeling, analysis and control, and the actual implementation of distributed PVs in one place. The book is focused on the operation and control of distribution networks and microgrids with high penetration of distributed PVs, covering the topics of PV hosting capacity analysis, power flow of distribution networks, reactive voltage regulation, short-circuit current calculation, power quality evaluation, methods of integrating distributed PVs into distribution networks at high penetration levels, and actual system implementation experiences. The book is intended to be a resource for all engineers, and for all those interested in designing policies for facilitating renewable energy development. An overview of the chapters covered in the book is now presented.
Chapter 1 introduces the current status and future development trends of PVs around the world. The PV industry development history of different countries, including the USA, Japan, Germany, and China, and the relevant policies, laws, and demonstration projects in these countries are also briefly introduced. Chapter 2 gives a brief coverage of the basic techniques of distributed grid-connected PV systems, with focus on their configurations, components and maximum power point tracking techniques. Chapter 3 presents the load characteristics of a distribution network with and without distributed PVs and provides theoretical foundations for further analysis on PV penetration and power flow in distribution networks.
Chapter 4 covers the concepts of PV power penetration, capacity penetration and energy penetration, analyzes the key challenges in different development stages of distributed grid-connected PV, studies the impact of grid-connected PVs on distribution networks, explores the maximum allowable capacity of grid-connected PVs under the requirement of safe and stable operation of the distribution networks, and presents the methods to increase PV penetration in distribution networks.
Chapter 5 introduces various power flow calculation methods for distribution networks. It then shows the impact of PVs on the power flow in distributed networks, including voltage variation and distribution loss caused by the PVs added. Models of voltage and distribution loss considering PVs are established, which are then used to analyze the impact of different PV capacities and locations.
Chapter 6 addresses one of the important issues caused by high PV penetration: the voltage control of distribution networks with distributed PVs. In this chapter, the impacts on voltage due to distributed PVs are analyzed first and three control strategies (the constant power factor control strategy, variable power factor control strategy, and the reactive voltage control strategy) and relevant modeling methods are then introduced.
Chapter 7 analyzes the short-circuit characteristics of distributed PVs under symmetrical and asymmetrical grid voltage sags, discusses different low voltage ride-through (LVRT) standards for PVs and the LVRT control strategies, and characterizes the fault currents of PVs. An iterative algorithm is given in the chapter for the calculation of fault currents for distribution networks with distributed PVs.
Chapter 8 discusses the impact of grid-connected PVs on power quality. Chinese and international standards on PV integration harmonic requirements are compared and discussed. The differences in power quality terms and the methods for analyzing the impacts due to distributed PVs on distribution network power quality are given.
Chapter 9 discusses various technologies, including energy storage, demand response, and a network partition-based zonal control technology to better accommodate PVs for distribution networks.
Chapter 10 is a good addition to the other chapters in the book by addressing microgrids with PVs. The chapter reviews the configurations of AC, DC, and AC/DC hybrid microgrids, system unit sizing of microgrid components, and the control framework and the implementation of microgrids. The optimal design, planning, and control of microgrids are given in the chapter through a discussion of the implementation examples of two real standalone microgrids. The implementation and operation experiences and lessons learned from the two microgrids are also summarized in the chapter.
The authors are honored to have the privilege to work with their collaborators for this book, which is a result of an exemplar group effort. Mr. Yibin Feng and Dr. Junhui Zhao are the main authors of Chapter 1. Dr. Xuesong Zhang and Dr. Junhui Zhao are the leading authors of Chapter 2, along with Dr. Jinhui Zhou for Chapter 3, Miss Chen Xu and Dr. Jian Chen for Chapter 5, Prof. Li Guo for Chapter 7, Mr. Peng Li and Prof. Zaijun Wu for Chapter 8. Professor Ming Ding and Professor Hongbin Wu of Hefei University of Technology offered a great deal of help to the authors. Professor Saleh A. Al-Jufout from Tafila Technical University kindly helped proofread Chapter 5. The authors also would like to thank team members and students for their help and contributions to this book, including Da Lin, Ke Xu, Xiaohui Ge, Ziling Wang, Ke Wang, Meidong Xue, Xiangjin Wang, Chuanliang Xiao, Zhichen Xu, Haifeng Qiu, Tingli Hu, Chang Fu, Zhongyang Zhao, Michael Fornoff, and Nicholas Lin.
An important feature of this book is that there are case studies accompanied with simulation studies for many chapters. We hope this book and the examples given in the book will be useful to industry professionals, educators, students, and researchers worldwide in developing distributed PVs at high penetration level.
Bo Zhao
State Grid Zhejiang Electric Power
Research Institute, China Caisheng Wang
Wayne State University, USA Xuesong Zhang
State Grid Zhejiang Electric Power
Research Institute, China