GB/T 1094.12-2013Power transformers -- Part 12: Loading guide for dry-type power transformers (English PDF)

Foreword

GB 1094 "Power Transformers" currently contains the following sections.

--- Part 1. General;

--- Part 2. liquid-immersed transformer temperature rise;

--- Part 3. Insulation levels, dielectric tests and external insulation air gap;

--- Part 4. Power transformers and reactors lightning impulse and switching impulse testing guidelines;

--- Part 5. ability to withstand short circuit;

--- Part 6. Reactors;

--- Part 7. oil-immersed power transformer loading guidelines;

--- Part 10. Determination of sound levels;

--- Part 10.1. Determination of sound levels - Application guide;

--- Part 11. Dry-type transformers;

--- Part 12. Dry-type power transformer loading guidelines;

--- Part 14. High temperature insulation materials liquid-immersed transformer design and application;

--- Part 16. Wind power transformers.

This section GB Part 12 1094.

This section drafted in accordance with GB/T 1.1-2009 given rules.

This Part replaces GB/T 17211-1998 "dry type power transformer loading guidelines." GB/T 17211-1998 corresponding IEC standard Quasi codenamed IEC 60905. 1987. Since the IEC standard code relating to power transformers are now adjusted to the IEC 60076 series, and in order IEC standards harmonized code and easy to use, this revision will be the standard code according to the new IEC standard series has been adjusted.

This section compared with the GB/T 17211-1998, the main technical changes are as follows.

--- According to GB/T 1.1-2009 of the provisions of the standard structure has been adjusted. Among them, the increase in the "Normative references" and "Techniques Terms and definitions "section, and the original" symbol "Adjusting chapter Appendix C;

--- Standard Scope increase forced air dry-type transformers, and an increase in "forced air" cooling mode hot temperature dry-type transformers Calculation liter;

--- Increasing the transformer nameplate super dangerous operation instructions;

--- Clear insulation failure is assumed due to the aging of the transformer end of life reasons, assumed the aging rate increases as temperature changes consistent with Azerbaijan Lunniwusi law, and further assume that the insulation system temperature for each additional 6K, aging rate doubled;

--- Increasing the calculation methods and test methods for copper and aluminum conductor winding time constant. In the calculation method, using different from the past Experience winding material specific heat capacity data;

--- Increased empirically determined constant time constant method;

--- Select the text deleted instance load curve;

--- Add a description of outdoor environmental conditions and operational impacts of the transformer housing;

--- Increase in Appendix A "rate of aging." This appendix aging rate of solid insulation material and the relationship between "energy" were introduced and presented Based on the analysis of heat resistance Arrhenius law;

--- Increase in Appendix B. "exemplary life lost three load mode." this section uses redrafted Law Amendment uses IEC 60076-12:2008 "Power transformers Part 12. Dry-type power transformers negative Load Guidelines. " this part of IEC 60076-12:2008 technical differences and for the following reasons.

--- In order to meet our technical requirements, by modifying the normative references in adopting international standards GB 1094.11 instead of IEC 60076-11;

--- To comply with China's actual situation, in 5.10.2, an effective heat capacity specific heat capacity calculated winding Formula epoxy material Value 24.5W · min/(K · kg) and 0.408W · h/(K · kg) were used instead of the symbol C1 and C2, while increasing to C1 and C2 described, with "Note 2. IEC 60076-12:2008 in, C1 to 24.5W · min/(K · kg), C2 is 0.408W · h/(K · kg) "instead of the IEC standard" Note 2. You can also use other winding insulation material and epoxy material. Correct this type of transformer, the corresponding specific heat 24.5W · min/(K · kg) or 0.408W · h/(K · kg) by the square of available manufacturing Experimental data instead. " for ease of use, this part of IEC 60076-12:2008 also made the following editorial changes.

--- Introduction, added "For ease of use, this section gives life lost three load modes of calculation are shown in Appendix B Cases, and gives the symbol table "in Appendix C;

--- Table 3 for the format has been adjusted;

--- Table B.2 delete the rightmost four content;

--- Appendix C added symbols C1 and C2.

Please note that some of the content of this document may involve patents. Release mechanism of the present document does not assume responsibility for the identification of these patents.

This part is proposed by the China Electrical Equipment Industrial Association.

This part of the National Standardization Technical Committee transformers (SAC/TC44) centralized.

This section is drafted. Shenyang Transformer Research Institute Co., Ltd., Shun Special Electric Equipment Co., Ltd., Jilin Electric Power Science Research Hospital, Pearl Electric Co., Ltd., Xinhua special Electric Co., Ltd., Wolong Electric Group Beijing Huatai Transformer Co., Ltd., CLP Power Gas Group Co., Ltd., Guangzhou Prosperous Electric Co., Ltd., Baoding Tianwei Sundaravej Transformer Co., Ltd., Guangdong Haihong Transformer Co., Ltd., Railway Electrification Bureau Group Baoding Railway Transformer Co., Ltd., Tianjin special variable electrical transformer Limited.

Introduction

This part of the operating temperature and heat aging perspective provides dry-type power transformer loading guidelines and norms. It gives a super amount nameplate Consequences of setting load, and select the appropriate ratings and load new devices offer designers guidance.

GB 1094.11 is the basis of the contract, including dry-type power transformer temperature rise under continuous load requirements and temperature rise test. should

Note that, GB 1094.11 refers to the average winding temperature rise, and this part refers to the hot temperatures, and the value is only guidance only.

This section gives some mathematical model used to determine the different loads at different temperatures of the cooling medium and the load varying with time period or the result of momentary change. The model provides a method to calculate the transformer operating temperature, in particular winding hot spot temperature. Hot spot temperature Used to assess the loss of life in a specific time period.

This section based on the calculation results of temperature measurements or recommended permissible load limit. These recommendations relate to different load situation Status --- continuous load, short-term and long-term emergency load. Appendix A on aging law explained.

For ease of use, this section gives life lost three load mode calculation examples in Appendix B, and are given in Appendix C the symbol table.

Power Transformer

Part 12. Dry-type power transformer loading guidelines

1 Scope

GB 1094 this section applies to dry-type transformers GB 1094.11 within a predetermined range. This section provides a dry-type transformer insulation Estimation of life loss and aging rate, the method of the transformer insulation aging rate and lifespan of transformer losses expressed as operating temperature, time Between the functions and load.

Note. For wind power special purpose transformers, furnace transformers, welding transformers and other transformers, the manufacturer shall refer to the relevant specific load curve.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document.

Part 11 GB 1094.11 Power transformers. dry-type transformers (GB 1094.11-2007, IEC 60076-11:2004, MOD) GB/T 11026.1 heat resistance and electrical insulating materials - Part 1. Evaluation of aging procedures and test results (GB/T 11026.1-2003, IEC 60216-1:2001, IDT) GB/T 18494.1-2001 Converter transformers - Part 1. Transformers for industrial use (IEC 61378-1:1997, IDT)

3 Terms and Definitions

The following terms and definitions apply to this document.

Long-term emergency load long-timeemergencyloading A supported way because the system in some devices out of operation for a long time and caused the transformer to a new, higher steady-state Prior to temperature, these devices will not be running again.

Short-term emergency load short-timeemergencyloading Transient because one or more systems accident occurred, seriously disturbed the normal load distribution system, resulting in the (less than winding A time constant) serious overload.

Hot hot-spot

If not otherwise specified, "hot spots" refers to the windings of the hottest.

Relative thermal aging rate relativethermalageingrate at a given hot spot temperature, aging rate compared with the reference insulation hot temperatures, insulation aging transformer showed a decrease or an accelerated rate.

Transformer insulation life transformerinsulationlifetime Starting from an insulating state (i.e., generally considered a new insulation) to the normal operation due to thermal aging, field insulation, or mechanical stress shorted bit all time shift caused by the final state of the electrical fault risk is high between.