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GB/T 22718-2008Thermal evaluation methods of insulation systems for high-voltage electrical machines (English PDF)

高压电机绝缘结构耐热性评定方法

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Issued by

SAMR; SAC

Level / Type

National · Recommended

Issue date

December 30, 2008

Implementation date

October 1, 2009

Scope

GB/T 22718-2008 is the English-translated version of 高压电机绝缘结构耐热性评定方法.

GB/T 22718-2008 fixes the methods for evaluating the thermal endurance of the insulation systems of high-voltage electrical machines rated 3 kV and above.

Clause 1 states that the evaluation works by comparison, the candidate test system being judged against a reference system of known practical service experience tested under the same conditions, and that the standard applies to the thermal evaluation of the insulation systems of rotating three-phase AC machines of 3 kV and above.

Clause 3 sets out the loop coil method for high-voltage machines of 10.5 kVp and below, beginning with the samples: a loop coil may be taken from an actual machine or may be a model coil or bar, and a model coil must reproduce the basic characteristics of the actual coil assembly.

The same subclause requires the insulating materials and components to be properly screened first and warns that the thermal class of a single insulation component is not the thermal class of the insulation system, while Appendix A supplies a typical model coil assembly drawing of the size commonly used to evaluate the insulation of high-voltage machines of 50 MVA, 15 kV and below.

It then fixes the sample numbers at not fewer than five at each ageing temperature in order to obtain statistically valid data, requires a quality assurance test of visual inspection and a pressure test before the first thermal ageing period so that only sound samples enter the ageing test, and requires the full set of diagnostic tests prescribed by the test procedure to be run before that first period as the initial diagnostic test.

The thermal ageing clause requires at least three ageing temperatures and tabulates the thermal classes of electrical insulation taken from GB/T 11021-2007.

Appendix A is an informative annex, and the standard cites GB/T 11021-2007 on thermal classification, GB/T 11026.4-1999 on single-chamber ageing ovens, GB/T 17948-2003 and GB/T 17948.3-2006 on the functional evaluation of rotating machine insulation, JB/T 1544-1999 on rapid thermal ageing of insulating varnishes and JB/T 9238-1999 on industrial thermocouples.

It was proposed by the China Electrical Equipment Industry Association, is administered by SAC/TC26 and was drafted by the Shanghai Electrical Apparatus Research Institute (Group) Co., Ltd. with motor and insulation manufacturers, under ICS 29.160.30 and Chinese standard class K20.

Its foreword records it as a first edition; it was issued on 2008-12-30 and has applied since 2009-10-01.

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Document preview — GB/T 22718-2008

National Standard of the People's Republic of China

ICS: 29.160.30
Classification: K 20

Issued by: State Administration for Market Regulation; Standardization Administration of the PRC

Foreword
1 Scope
2 Normative references

Foreword

Appendix A of this standard is an informative annex. The standard proposed by China Electrical Equipment Industrial Association.

The standard rotary motor by the National Standardization Technical Committee (SAC/TC26) centralized.

1 Scope

This standard specifies the above 3kV high voltage electrical insulation and heat resistance evaluation methods. Thermal evaluation method specified in this standard is In the test configuration and the reference configuration is practical operating experience under the same test conditions based on relatively.

This standard applies to the evaluation of the heat insulation voltage 3kV and above the three-phase AC electric rotating machines.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

GB/T 11021-2007 heat resistance, electrical insulation rating (IEC 60085:2004, IDT)

GB/T 11026.4-1999 determine the electrical insulation material heat resistance guide - Part 4: Ageing ovens - Single - chamber ovens (Idt IEC 60216-4-1:1990)

GB/T 17948-2003 rotating electrical machines - Functional evaluation of insulation General (IEC 60034-18-1:1992, IDT)

GB/T 17948.3-2006 rotating electrical machines - Functional evaluation of insulation windings Test procedures 50MVA, 15kV and The following motor insulation thermal evaluation and classification (IEC 60034-18-31:1992, IDT)

JB/T 1544-1999 and electrical insulating varnish varnished rapid thermal aging methods --- Hot Key slope method

JB/T 9238-1999 industrial thermocouple technical conditions

3 10.5 kVp and below high-voltage motor coil insulation ring Thermal evaluation method

3.1 Sample

3.1.1 Sample structure

Sample loop coil can be used on the actual motor may be a model coil or bar. If the model coil, it must be able to reflect The basic characteristics of the actual coil combination.

According to the present standard coil sample assessment, insulation materials and components of its use, it should first be properly screened. It should be noted A single element of insulation and heat level is not equal to the heat-resistant grade insulation structure.

Appendix A is a typical model coil assembly diagram, this coil size model commonly used in the assessment of 50MVA, 15kV and below High-voltage electrical insulation.

3.1.2 Number of samples

In order to obtain statistically valid data on each of the insulating structure at each aging temperature should adopt a sufficient number of samples aging test Inspection, the amount can not be less than five.

3.1.3 Quality Assurance Test

Before the start of the first heat aging-minute period, to deal with the appearance of the sample was visually observed on inspection and pressure test, only a test by checking Thus, in order to put the heat aging test.

3.1.4 The initial diagnostic test

Before the start of the first heat aging-minute period, each complete test should be carried out all the testing procedures specified diagnostic tests.

3.2 Thermal aging test

3.2.1 Aging temperature and test cycle

Heat aging sample temperature should be at least three points. Electrical insulating heat resistant grade are shown in Table 1 (GB/T 11021-2007).

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This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 15 pages — is available in the English PDF.

Referenced standards

Normative references

Cited by

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