standardization of power transformers

TRANSFORM Partner

Dipl.-Ing. Karl-Heinz Häger

Alstom Grid GmbH Activity Schorch Transformers

Standardization of Power Transformers

Dipl.-Ing. Karl-Heinz Häger

1974 – 1982: Study Electrical Engineering at RWTH Aachen

1982: Diplom-Ingenieur

1982 – 1985: Design engineer for power transformers at Schorch GmbH

1985 – 1993: Test field engineer for power transformers

Since 1993: Head of high voltage test laboratory for large power

transformers

Since 1994: Member of National German Committee for standardization of

power transformers

Since 2005: Chairman of National German Committee for standardization of

power transformers, German speaker in CENELEC, German speaker in

IEC, member in different working groups

07.06.2013 Karl-Heinz Häger, Alstom Grid GmbH Activity Schorch Transformers

Standardization of power transformers

Why do we need standards?

Example: Commission Regulation (EC) No 2257/94 of 16 September 1994


Introduction

Does not fit without standard

Fits with standard


Introduction

Introduction

Standards for power transformers:

Edition of new standards

Maintenance on standards

Use / application of standards


Content

Standardization in generation, transmisson and distribution of electrical energy

Different voltage levels,

generation (27 kV)

transmission (400 kV)

generation (by wind power) (220 kV, 110 kV, 20 kV)

distribution (110 kV, 20 kV)

generation (by solar power) and consumption (end user) (0,4 kV)

Each voltage level is equipped with components and each component has an

input and an output:

cables

overhead lines

surge arresters

switch gears

power transformers

etc.


Generation and transmission of electrical energy

Power transformers are basic elements in a worldwide network.

The standardization concerns mainly the specification of technical data, the testing

of manufactured transformers and the operation and maintenance.

Standardization does not affect design and manufacturing:


Generation and transmission of electrical energy


Standardized power transformers

Organisations:

Institute of Electrical and Electronics Engineers

… is the world´s largest professional association dedicated to advancing

technological innovation and excellence for the benefit of humanity

International Electrotechnical Commission

… is the world´s leading organization that prepares and publishes International

Standards for all electrical, electronic and related technologies


Administration

Technical Committee: TC14

1st Publication: 1955


IEC-Standards for power transformers

US-comment on the first edition of IEC 76:



Situation of the IEC-Standard for power transformers:

IEC 76 was renamed into IEC 60076

Actually 21 parts (published, under revision or under work)

Cover a range of approx. 5 kVA to more than 1000 MVA

750 MVA, 2011

500 kVAc approx. 1955




Minimum one winding must have a nominal voltage over 1000 Volts

Highest system voltages are 420 kV and more




Not accessible to the general public:

Application mainly in networks of public utilities and industry (not for private use,

end consumer use)



Important

Part 1: General

Definitions

Ratings

Normal and unusual service conditions

Specifications, tolerances

Test procedures

etc.



Important

Part 2: Temperature rise for liquid-immersed transformers

Part 3: Insulation levels, dielectric tests and external clearances in air

Part 5: Ability to withstand short circuit



Special

Part 4: Guide for the lightning impulse and switching impulse testing

Part 6: Reactors

Part 7: Loading guide for oil immersed power transformers

Part 8: Application guide

Part 10: Determination of sound levels

Part 11: Dry-type transformers

Part 12 Loading guide for dry-type power transformers



Others („very special“, published or under work)

Examples:

Part 13: Self protected liquid-liquid filled transformers

Part 14: Design and application of liquid-immersed power transformers using high-

temperature insulation materials

Part 15: Gas-filled power transformers

Part 16: Transformers for wind turbine applications

Part 18: Measurement of frequency response for power transformers

Part 19: Rules for the determination of uncertainties in the measurement of the

losses on power transformers and reactors

Part 20: Energy efficiency for distribution transformers



Special

IEC 61378: Converter transformers (Part 1 to 3)

Part 1: Transformers for industrial applications

Part 2: Transformers for HVDC-applications

Part 3: Application guide



Example:

IEC 60076 Part 21: Requirements, terminology and test code for step voltage

regulators

IEC 62032: Application, Specification and Testing of Phase-shifting transformers


Dual-Logo-Standards for power transformers

Tap changers: IEC 60213 Part 1 and 2

Bushings: IEC 60137

Transformeroil:

for new transformers oil: IEC 60296

for used transformer oil: IEC 60422

for evaluation of DGA-results after testing: IEC 61181

for evaluation of DGA-results in operation: IEC 60599


IEC-Standards for components of power transformers

EN-Standards

European standards are worked out by CENELEC

(European Committee for Electrotechnical Standardization)

Dresden Agreement: To avoid duplication, efforts and to reduce time when

preparing standards, new standards are jointly planned between IEC and

Cenelec.

Result: IEC- and EN-Standards are identical (except some minor deviations

referring mainly environmental and safety aspects).


European standards for power transformers

DIN-VDE-Standards

Published by DKE (= DIN + VDE)

Contract between Federal Republic of Germany and DIN: The DIN is

recognized as the only responsible organization for standardization in

Germany.

Similar to the Dresden Agreement, DKE adapts all EN-Standards.


German standards for power tansformers

Germany: DKE K321 Transformatoren (= steering committee)

Members and manufacturers and utilities

K321 nominates representatives (German Speakers) for:

Europe in CLC TC14 and worldwide in IEC TC14


Edition and maintenance of standards

Edition of an new standard (main steps):

Proposal by IEC TC14, CLC TC14 (or K321)

Enquiry/Questlionaire to national members

Call for experts for a working group and a convener

The working group creates a committee draft (CD)

CD is forwarded to national members for comments

Comments are to be processed by the working group

Publication of a committee draft for voting (CDV)

Publication of a final draft international standard (FDIS)

Publication of a standard

(similar procedure for a revision of an existing standard)


Edition and mintenance of standards

Meaning of standards

The legal meanings in application of standards are different on the international

level, in the European Community and on the national level:


Application of Standards

Application of IEC-standards (international level):

IEC-Standards are more or less a collection of technical details, rules, requirements

and instructions.

These standards become meaningful, when they are implemented in contracts.


Application of standards

Application of EN-standards (European Community):

By application of EN-Standards it should be avoided, that single members protect

their own marked by unnecessary technical requirements and put other members of

the European Community into disadvantage.



Application of DIN-Standards (Germany):

In Germany, the application of standards in principle is voluntary!

Independent from the application of a standard or from the application of self

created rules, the engineer always is fully responsible for his activities.

But in case of doubts, the application of standards might prove proper technical

acting (and might be considered as „state of the art“).



In this context, the titles of the IEC 76 and IEC 60076 are meaningful:

IEC 76 (1955): Recommendations for power transformers

IEC 60076 (2012): Power Transformers


Summary

standardization of power transformers

Documents