Hydro Plant Electrical Systems

212 Pages·1999·11.763 MB·English

by  Clemen, David M.

Hydro Plant
Electrical Systems
Copyright 1999 by HCI Publications, Inc.
All rights reserved
Printed in the United States of America
ISBN 0-9651765-3-3
NOTICE
Neither the author, HCI Publications, nor any person acting
on behalf of them (a) makes any warranty, express or implied,
with respect to the use of any information, apparatus,
method, or process disclosed in this book or that such use
may not infringe privately owned rights; or (b) assumes any
liabilities with respect to the use of, or for damages resulting
from the use of, any information, apparatus, method, or
process disclosed in this book.
HCI Publications is the publisher of Hydro Review and
HRW-Hydro Review Worldwide magazines, Hydrowire and
Hydro World Alert newsletters, books, and other materials
useful to individuals and organizations having interests in
hydroelectricity. HCI also organizes hydro-related meetings
and events, including the HydroVision conferences.
HCI Publications
410 Archibald Street
Kansas City, MO 641 11
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
Foreword
lectrical engineering at hydropower plants is a highly specialized topic yet,
at the same time, one to which every hydropower professional is exposed
’ to some degree. At the heart of any hydropower enterprise is the genera-
tion and delivery of electricity, the technical aspects of which are fundamental
influences on the day-to-day operation, maintenance, civil design, and economics
of facilities. In addition to the basic production of electricity, the field of electrical
engineering encompasses some of the most rapidly-evolving new hydropower
technologies, including computerized control systems.
This book, Hydro Plant Electrical Systems, has its origins in a series of articles
that I authored for publication in Hydro Review and HRWmagazines from 1989
to 1998. Individually, the articles cover specific topics in hydro plant electrical
engineering. Taken together, they cover a wide range of issues encountered in
constructing, operating, or rehabilitating hydroelectric projects. Because of this
diversity, HCI Publications suggested that I compile and enhance the articles in
book format. This effort entailed considerable technical updating, as well as the
preparation of new material covering generators, transformers, controls and pro-
tective relays, surge protection, battery systems, unit and station auxiliaries, and
start-up and commissioning.
Numerous individuals have made essential contributions to this book. I
would like to thank HCI Publications’ staff. Among HCI staff, Carl Vansant,
Editor-in-Chief, has championed the idea of publishing the book and has over-
seen its development. Managing Editor Marla Barnes and Technical Editor John
Gulliver were responsible for shaping much of the material which originally
appeared as magazine articles. Contributing Editor Ellen Faulkner has been the
principal editor of this book, and her efforts are sincerely appreciated.
I am most grateful to my professional colleagues who reviewed the
manuscript; their comments have led to many improvements.These individuals
Hydro Plant Electrical Eng-ineering iii
include Willy Lord of SwedPower (Sweden), Bert Milano of the Bureau of Recla-
mation (U.S.), Bivind Nicolaysen of Norconsult International AS (Norway),
Tapio Piinsinen of Fortum Engineering Ltd. (Finland), and Paul Micale of the
Tennessee Valley Authority (U.S.) Paul is the chairman of the Hydroelectric
Power Subcommittee of the Institute for Electrical and Electronic Engineers.
Also, I wish to thank the following individuals who reviewed the final manu-
script: Brad Berreth of Current Design, LLC (U.S.), Earl Goodeve of Iris Power
Engineering, Inc. (Canada), and Dan Purzycki of North American Hydro (U.S.).
Thanks are especially due to Harza Engineering Company. It is on Harza
assignments that I have gained the majority of the experience that I am able to
share in this volume. In enabling me to put forth the extra effort that has led to
publishing this book, I am particularly grateful to Ed Carter, Head of Business
Development Operations, Vincent Zipparro, Chief Engineer, and Refaat Abdel-
Malek, President and CEO.
David M. Clemen, P.E.
Associate and Senior Electrical Engineer
Harza Engineering Company
CHAPTER 1 : Inboduction
Hydr~eleCtFicG enerator Basics
CHAPTER 2:
Types of Generators. ...................................... 2.1
Generator Components .................................... 2.4
Generator Ratings ........................................ 2.9
Excitation Systems ........................................ 2.11
References .............................................. 2-12
CHAPTER 3: Testing Generators Before Commissioning
Identifylng the Required Tests ............................... 3.1
Electrical Tests ........................................... 3.3
Keys to Successll Testing .................................. 3.13
References .............................................. 3-13
Bibilography ............................................ 3.14
Scheduled Inspection Outages for Hydroelecbic Generators
CHAPTER 4:
Why Have Scheduled Inspection Outages? ..................... 4.1
Major and Minor Inspection Outages ......................... 4.2
Determining the Frequency of Major Inspection Outages .......... 4.7
Working with the Manufacturer .............................. 4.10
Planning Inspection Outages: A Common-SenseA pproach ......... 4.10
References .............................................. 4-11
CHAPTER s: Ransformers at Hydroelecbic Plants
Generator Step-up Transformers. ............................ 5-1
Auxiliary Transformers. .................................... 5.3
Purchasing Transformers for a Hydroelectric Plant ............... 5-5
References .............................................. 5-6
Hydro Plant Electrical Engineering vii
Factory and Field Testing of Liquid-Immersed Ransformers
CHAPTER 6:
Writing Test Specifications. ................................. 6.1
Factory Dielectric Tests .................................... 6-2
Other Transformer Tests ................................... 6.13
References .............................................. 6-15
Bibliography ............................................ 6. 15
CHAPTER 7: Inspection and Maintenance Testing of
Liquid-Immersed Transformers
Transformer Inspection and Maintenance Tests ..................7 . 1
Insulator Maintenance Testing ............................... 7.6
Tests and Inspections of Other Components .................... 7.8
References .............................................. 7-9
Bibliography ............................................ 7.9
International Test Standards for Transformers
CHAPTER 8:
Standards for Transformer Efficiency (Losses) ................... 8. 1
Lightning Impulse Test Standards ............................ 8.2
Standards for Switching Surge Impulse Tests .................... 8.4
References .............................................. 8-5
Bibliography ............................................ 8-5
Dry Transformers at Hydroelectric Plants
CHAPTER 9:
Alternative Liquid-Immersed Transformers ..................... 9. 1
Dry Transformers ........................................ 9.2
Measuring the Performance of Dry Transformers ................9 .5
References .............................................. 9-7
CHAPTER 10: Controls and Protective Relaying
Choosing a Control System ................................. 10-1
Control Systems at Small Hydro Plants ........................ 10-2
Control Systems at Medium and Large Hydro Plants ............. 10-5
Equipment Architecture and Protocols ........................ 10-8
Protective Relaying ...................................... .10 .9
References .............................................. 10-14
Bibliography ........................................... .10 .14
viii Hydro Plant Electrical Engineering
CHAPTER 1 1 : Testing Unit Control Switchboards in the Factory and Field
Specifylng the Tests ....................................... 11. 1
Importance of Factory Testing ............................... 11-4
Field Testing ............................................ 11-5
Typical Problem Areas ..................................... 11-6
Considerations at Large Hydro Plants ......................... 11-9
References .............................................. 11-10
CHAPTER 12: Su~gaP rotection
Direct Lightning Protection ................................ 12-1
Schemes for Lightning Protection ............................ 12-5
Determining Ground Resistance ............................. 12-10
Protecting Hydro Plant Control Equipment from Surges .......... 12-1 1
References .............................................. 12-21
Bibliography ............................................ 12- 22
Standards ............................................... 12-22
Batteries at Hydropower Plants
CHAPTER 13:
Battery Types ........................................... .13 .1
Selecting and Installing Battery Systems ....................... 13-4
Battery Chargers ......................................... 13-7
Avoiding Common Problems ............................... 13-10
Battery Testing Procedures .................................. 13-11
References .............................................. 13-12
Bibliography. ............................................ 13-13
Uninterruptible h e rS upply Systems
CHAPTER 1A :
Types of UPS Systems ..................................... 14-1
Choosing a System Configuration ............................ 14-4
Sizing Hydro Plant UPS Systems ............................. 14-6
Writing Specifications for a UPS ............................. 14-7
References .............................................. 14-10
Hydyo Plant Electrical Engineering ix
BUS SpteM
CHAPTER 15:
Standards for Bus Systems .................................. 15-1
Choosing Bus Systems for a Hydro Plant ....................... 15-2
Testing Bus Equipment .................................... 15-4
References .............................................. 15-5
Lm-Voltage Switchgear for Hydropower Plants
CHAPTER 16:
Using LV Switchgear at Hydro Plants ......................... 16-1
LV Switchgear Operation .................................. 16-3
Breaker Ratings .......................................... 16-5
Protective Functions ...................................... 16-6
Upgrading LV Switchgear .................................. 16-8
Selecting a Supplier. ....................................... 16-8
References .............................................. 16-10
Bibliography ............................................. 6-10
CHAPTER 17: Start-up and Commissioning of a Hydroelectric Project
Stages in Start-up and Commissioning ........................ 17-1
Ensuring Successful Commissioning .......................... 17-4
Engineering Review During the Commissioning
of a Small Hydropower Plant ................................ 17-6
References .............................................. 17-11
SOURCES
INDEX
x Hydro Plant Electrical Engineering
Chapter 1
his book, Hydro Plant Electrical Systems, provides an overview of existing
practice in electrical engineering at hydroelectric projects. Rather than
focussing on design of specific electrical components, the emphasis is on
practical aspects of selecting, installing, testing, and maintaining the equipment.
The material covered represents both the practical experience of the author and
procedures documented in various industry standards, journal articles, and other
sources.
The book focuses on standard practices, as well as some newer practices
which appear to be growing in popularity in hydropower applications. However,
there are very few “textbook” hydroelectric plants. Every one has its own
constraints and challenges. These may arise from the physical setting of the pro-
ject, the historical design and previous installation of equipment, local regulations
and engineering traditions, environmental issues, or economic limitations. No
engineering project, electrical or otherwise, should be undertaken without an
understanding of these factors. Often, when site conditions force departures from
standard practice, the result is a valuable innovation.
Several sections of the book are devoted to testing of electrical equipment in
hydro plants, both before commissioning and to assess performance after several
years of operation. Numerous standards exist for the testing and evaluation of
electrical equipment. This book is in no way an attempt to replace or condense
those standards, but is intended to provide guidance on their practical
application. The reader will gain knowledge of the testing method and
equipment, sources of error and reasonable error tolerances, the parameters being
measured, and how to interpret the results. Other chapters address control sys-
tems, protective functions, emergency power supplies, and surge protection. The
final chapter covers start-up and commissioning of hydroelectric projects-the
moment that brings together all of the issues addressed separately in preceding
chapters.
Chapter 1 Inwodwction 1-1
The book will be most useful for readers with some familiarity with the gen-
eral principles and terminology of electrical engineering. However, other readers
will find much of the material quite accessible and helpful in understanding the
considerations that must go into designing and maintaining hydro plant equip-
ment. In addition to the Reference section, which lists cited works (including
applicable standards), many of the chapters contain a Bibliography section that
presents additional sources of information for interested readers.
1-2 Hydro Plant Electrical Engineering