G e n e r a t o rCircuit Breakers

Guide Book

G e n e r a t o rCircuit Breakers

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F O R E W O R D

Welcome to our Generator Circuit-Breaker (GCB) World!

After decades of presence in this industry, we are proud to provide you with the first edition of our User guide. The aim of it is to deliver specific knowledge on generator circuit-breaker to engineers, professionals and utilities interested to understand the best way to protect power plant generator and step-up transformers as long as to synchronize efficiently the grid to the plant.

Nowadays, power plant owners have to support heavy load of electricity supply with few liberty for unexpected maintenance causing the loss of hours of production. Aging power plants have to be maintained and upgraded, while new plants have to be quickly built and provide maximum kwhours. No space is allowed for failure and this is a constant pressure against each hour loss. The best example illustrated in this guide is the protection against flash over occurring in a step-up transformer due to a short-circuit. Statistically speaking, specialists will say that this kind of event may occur only with unexpected rare events leading to eventually a major damage into the transformer. But in that case, which has happened and still can do, the cost to stop generator and make the necessary repair will be out of scale compared to the investment in a generator circuit-breaker. Plus frequent switching for synchronization through the GCB will prevent for fast aging on other equipments. Well, at that point of stage, you will have understood that we are convinced that a generator circuit-breaker is an ideal solution for power plant protection...so we would like to share with you our experience and knowledge as one of the major manufacturer of such equipment.

With more than 1500 GCB installed all over the world, we have key references for different applications such as hydro power plant, pump storage, gas turbine, steam turbine, combined cycle, nuclear and geothermal, becoming on of the market leader in this field. SF6 technology used in our GCB makes our solution very reliable and cost effective for any kind of application over 50MW up to 1600MW. Every year, we invest significantly in R&D in order to continuously find the right balance between performances, cost and reliability. Our center of excellence in this respect, located in Villeurbanne-France on the same location than our production facility, is composed by senior experts internationally recognized in their field, but also with new engineers aimed to be the experts of tomorrow for our future developments. Lastly, we have succeeded to provide full spring mechanism, the most reliable solution against older technology, to the whole range of our GCB.

One other key point to mention is the availability of professional local team in each region of the world to support technical and sales meeting, as well as supervision of erection and commissioning. By this deployment, we wish to give full satisfaction to our customers, providing local support in a quick manner and good cultural understanding.

In a conclusion, having this guide in your hands, you have been recognized by our team as one those specialists interested to learn more about generator circuit-breaker. We hope that you can make good use of this book, giving you some literature on theorical phenomenon, general introduction to the main parts of the GCB, and finally a tool to specify it within your own application with drawings, technical data, etc. Of course, this can not replace fully the discussions we can have together in order to further explain our technology and, in this respect, we are always available for a meeting, a phone call, looking for your full understanding and satisfaction.

William BOISSYCommercial Manager

First editionCopyright © september 2009 by Areva T&D

All right reserved. No part of this book may be reproduced or transmitted in any form by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permis-sion in writing from the publisher.

Published by Areva T&DTour Areva1, place de la CoupoleF-92084 Paris La Défense

Areva T&D Worldwide Contact Centrehttp://www.areva-td.com/contactcentre/Tel: +44 (0) 1785 250 070

Dirk UHDEGeneral Manager

TABLE OF CONTENT

1|Introduction 2.1| 2.2| 4| 5| 6|

1.1. Areva Group 1.2. Areva T&D 1.3. Areva T&D’s Generator Circuit Breakers background 1.4. Generator Circuit Breakers in Power Plants1.5. General Features

2.1. SF6 Interrupting chamber principle 2.1.1. Arc interruption 2.1.2. Sulfur Hexafluoride (SF6 ) gas Characteristics

2.2. Operating Mechanisms 2.2.1. Full Spring Mechanism 2.2.2. Motor Drive type CMK 2.2.3. Low voltage Centralizing cubicle

4.1. High performances (up to 50000A for 1600 MW Power Plant)4.2. Design4.3. A proven technology4.4. Installation & Maintenance

6.1. Isolated Phase Bus composition and its equipments6.2. Auxiliary Equipment6.3. Applicable Standards

I General Arrangements

II Connections

III Elementary Diagrams

IV Interlock Diagram

2.3. Cooling System 2.3.1. Conceptions 2.3.2. Redundancy

2.4. GCB Cell Equipment Proposal 2.4.1. SKG Disconnector 2.4.2. MKG Earthing switch 2.4.3. IKG Starting Switch 2.4.4. Capacitors 2.4.5. Surge Arrester 2.4.6. Current Transformers 2.4.7. Voltage Transformer

3.1. GCB sizing3.2. GCB type FKG (up to 9500A

for 150 MW Power Plant)3.3. GCB type FKG1 (up to 28000A from 150MW to 1200MW Power Plant)3.4. GCB Monitoring System: CB Watch-23.5. Tools for erection on site

7.1. Research & Development7.2. Commitment for Customers’ satisfaction7.3. Production7.4. Applicable Standard to the Quality, Environment, Health & Security7.5. AREVA T&D GCB: a large experience

Design & FunctionsSF6 Interrupting Chamber

Design & FunctionsOperating Mechanism

9|Annexures8|Inquiry Data for GCB7|Quality3|2.4|2.3|Design & FunctionsCooling System

Design & FunctionsEquipments in the GCB Cell

FKG SF6 Generator Circuit Breaker Range

PKG Air Blast GeneratorCircuit Breaker

Isolated Phase Busduct& GCB Package

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910

13

1417

3436

39

414147

49

979799

100

62

63

72

9194

52

53545556565759

505051

Power Plant Rehabilitationand Refurbishment

108

110111

113

113114

117

119

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INTRODUCTION122

23

24

9101113

14

15

16

1718

1920

1.5.1.12. Required generator-source asymmetrical interrupting capability for three-phase faults 1.5.1.13. Rated short-circuit closing current 1.5.2. System and Switching Conditions 1.5.2.1. First-pole-to-clear factor 1.5.2.2. Amplitude Factor 1.5.2.3. Rated Transient Recovery Voltage 1.5.2.4. Rated out-of-phase switching current 1.5.2.5. Out-of-phase 1.5.2.6. Time constant 1.5.3. Ambient Conditions 1.5.3.1. Minimum ambient temperature 1.5.3.2. Maximum ambient temperature 1.5.3.3. Altitude 1.5.4. Seismic withstand 1.5.5. Protection Degree (International Protection Rating, IP) 1.5.6. Design 1.5.6.1. Three-pole operation 1.5.6.2. Rated operating sequence 1.5.6.3. Mechanical endurance class 1.5.6.4. Pressure 1.5.6.5. Rated filling pressure 1.5.6.6. Alarm pressure 1.5.6.7. Minimum pressure (Lock out, interlocking or blocking pressure) 1.5.6.8. Operating times 1.5.6.8.1. Opening time 1.5.6.8.2. Closing time 1.5.6.8.3. Rated interrupting time 1.5.6.8.4. Arcing time 1.5.6.8.5. Make time 1.5.7. Operating and Control 1.5.7.1. Standard Devices 1.5.7.2 Options & Equipments1.5.8. Low voltage diagram explanation

1.1. Areva Group1.2. Areva T&D 1.2.1. Our History 1.2.2. A Global Network for a Global Answer 1.2.3. Villeurbanne Factory1.3. Areva T&D’s Generator Circuit Breaker background1.4. Generator Circuit Breaker (GCB) in Power Plants 1.4.1. GCB Location in the Power Plant diagram 1.4.2. The GCB is an efficient protection for the transformer and the generator 1.4.2.1. Protection of the Generator Step-Up transformer transformer against generator-fed short-circuit currents 1.4.2.2. Protection of the generator in case of unbalanced-load 1.4.2.3. Protection against the “rejection phenomena” 1.4.2.4. Protection against the “Transient Recovery Voltage” phenomena 1.4.3. Higher safety for synchronization of the generator train to the grid 1.4.3.1. Synchronization 1.4.3.2. Out-of-phase synchronization 1.4.3.3. Flash-over 1.4.4. During commissioning & start-up: increased ease of operation 1.4.5. During normal operation: increased independence 1.4.6. During maintenance times: increased ease of operation1.5. General Features 1.5.1. Definitions 1.5.1.1. Rated maximum voltage 1.5.1.2. Rated power frequency 1.5.1.3. Rated continuous current 1.5.1.4. Rated insulation level 1.5.1.5. Rated Lightning Withstand Level 1.5.1.6. Rated Power Frequency Withstand Voltage 1.5.1.7. Short-time current - carrying capability 1.5.1.8. Rated peak withstand current 1.5.1.9. Rated short-circuit symmetrical interrupting current 1.5.1.10. Rated short-circuit asymmetrical current 1.5.1.11. Required generator-source symmetrical interrupting capability for three-phase faults

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1.1. AREVA GROUP

As we approach the end of the first decade of the 21st century, we take pride in the fact that AREVA has an important industrial presence in over 40 countries and a worldwide sales network in over 100 countries. The Group offers its customers reliable technological solutions for CO2-free power generation and electrical transmission and distribution. AREVA is the world leader in nuclear power and the only company to cover all industrial activities in this field (mining, chemistry, enrichment, fuel, services, engineering, nuclear propulsion, reactors, reprocessing, recycling, nuclear clean up and decommissioning).

AREVA’s businesses help meet the 21st century’s greatest challenges: making energy available to all, protecting the planet, and acting responsibly towards future generations.

In 2004, AREVA acquired the ALSTOM T&D division, which became AREVA T&D, and so became able to propose an integrate offer for energy professionals

1.2. AREVA T&D

1.2.1. OUR HISTORY

Today, AREVA T&D’s expertise is the collective experience of all the companies that have joined forces since the beginning. Among its oldest parents is the French Thomson Houston Company which was created in 1893 and subsequently merged in 1928 with the Société Alsacienne de Construction Mécanique (France) to create ALS.THOM.

The Company that would ultimately become AREVA T&D merged with its equivalent English counterpart, the General Electric Company, to become GEC ALSTHOM. The German company AEG (including part of SCHORCH GmbH) and SPRECHER & SCHUH from Switzerland are also among the legacy companies of what became ALSTOM and then finally AREVA T&D in 2004.

With recent partnerships throughout the numerous transformations of the company structure together with the past 20 years of strategic acquisitions, AREVA T&D has continually capitalized on the ancestral savoir-faire of its original founders, while consolidating and nurturing its strengths and knowledge to better serve the world market in its capacity as a truly global leader.

1.2.2. A GLOBAL NETWORK FOR A GLOBAL ANSWER

T & D

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AREVA T&D’s technologies and know-hows increase the safety, the reliability and the capacity of electric networks around the world, thanks to a lot of solution for electricity transmission and distribution.

AREVA T&D, with 67 industrial sites and a presence in more than a hundred countries, supplies a global answer to the needs of more than 30,000 clients in 160 countries with local resources:> Network consultants and expert knowledges on equipments, diagnostic> Installation, starting and supervision> Maintenance, and spare part management> Support for fixing and emergency intervention> Updating, rehabilitation> Utilization and management> Training

1.2.3. VILLEURBANNE FACTORY

The Factory located in Villeurbanne, France, develops and manufactures all our Generator Circuit Breakers. Its history began with the name of DELLE, the name of the village where it was created in 1913, near Belfort city. The transfer of workshops at Villeurbanne happened in 1916. 50 years later, in 1965, it became DELLE ALSTHOM then ALSTHOM and thus met the history of what would become AREVA T&D.

1.3. AREVA T&D’S GENERATOR CIRCUIT BREAKER (GCB) BACKGROUND

Based on decades of experience in the field of high voltage Circuit Breakers (with ratings up to 1,100 kV), AREVA T&D has been developing and manufacturing Generator Circuit Breakers for over 35 years.

At the beginning of the Nuclear Power Plant creation and since 1973, AREVA has the experience in developing, testing and manufacturing Generator Circuit Breakers.

Through the years, our GCBs have acquired a reputation for high reliability and long life in all climates and in all parts of the world: today, the key power generation players in the world acknowledge and select AREVA T&D Generator Circuit Breakers as the best choice for their power plants.

Our GCB’s design is in constant improvement in order to be ever at the state-of-the-art technology.Our range is entirely in compliance with the International Standard IEEE (Institute of Electrical and Electronics Engineers) C37.013 (ANSI) as well as the IEC (International Electrotechnical Commission) 62 271-100 standards and other relevant standards (mentioned later).

1.4. GENERATOR CIRCUIT BREAKER (GCB) IN POWER PLANTS