标准编号:	GB/T 1094.15-2020
中文名称:	电力变压器 第15部分：充气式电力变压器
英文名称:	Power transformers—Part 15：Gas-filled power transformers
中标分类:	K41    变压器
行业分类:	GB    国家标准
ICS分类:	29.180 29.180    变压器、电抗器 29.180
发布机构:	国家市场监督管理总局 国家标准化管理委员会
发布日期:	2020-03-31
实施日期:	2020-10-1
标准状态:	现行
翻译语言:	英文
文件格式:	PDF
中文字符数:	25000 字
翻译价格(元):	1750.00 元
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.



GB/T 1094 consists of the following parts under the general title of Power Transformers:



——Part 1: General;



——Part 2: Temperature rise for liquid-immersed transformers;



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



——Part 4: Guide to the lightning impulse and switching impulse testing—Power transformers and reactors;



——Part 5: Ability to withstand short circuit;



——Part 6: Reactors;



——Part 7: Loading guide for oil-immersed power transformers;



——Part 10: Determination of sound levels;



——Part 10.1: Determination of sound levels—Application guide;



——Part 11: Dry-type transformers;



——Part 12: Loading guide for dry-type power transformers;



——Part 14: Design and application of liquid-immersed transformers using high-temperature insulation material;



——Part 15: Gas-filled power transformers;



——Part 16: Transformers for wind turbine applications;



——Part 18: Measurement of frequency response;



——Part 23: DC magnetic bias suppression devices.



This part is Part 15 of GB/T 1094.



This part is developed in accordance with the rules given in GB/T 1.1-2009.



This part has been redrafted and modified in relation to IEC 60076-15:2015 Power transformers—Part 15: Gas-filled power transformers.



The main technical differences with respect to IEC 60076-15: 2015 are as follows:



——As for the normative references, adjustments of technical differences are made to this part to keep them in line with the technical conditions in China. The adjustments are embodied in a concentrated way in Clause 2 "Normative references", specifically as follows:



 IEC 60076-1:2011 is replaced by GB/T 1094.1-2013, which is modified in relation to the international standard;



 IEC 60076-2:2011 is replaced by GB/T 1094.2-2013, which is modified in relation to the international standard;



 IEC 60076-3 is replaced by GB/T 1094.3-2017, which is modified in relation to the international standard;



 IEC 60076-5 is replaced by GB/T 1094.5, which is modified in relation to the international standard;



 IEC 60076-10 is replaced by GB/T 1094.10, which is modified in relation to the international standard;



 IEC 60137 is replaced by GB/T 4109, which is modified in relation to the international standard;



 IEC 60480 is replaced by GB/T 8905, which is modified in relation to the international standard;



 IEC 62271-1 is replaced by GB/T 11022, which is modified in relation to the international standard;



 The reference of GB/T 12022 and GB/T 13499-2002 is added;



 The reference of IEC 60376 is deleted;



——In order to adapt to China's national conditions, the content "In case capacitive bushing is adopted, a dry bushing shall be used, and on-load tap changer shall be gas-filled switch” is added in 5.10;

 



——In order to adapt to China's national conditions, the "product model" is added in rating plates of 8.2; and the contents “Maximum system short-circuit power or current used to determine the transformer withstand capability if not infinite" in 8.2 of IEC 60076-15:2015 is adjusted to 8.3 of this standard;



——In order to adapt to China's national conditions, the ambient temperature during the test is changed from "10°C-+40°C" to "5°C -+40°C” in 11.1.1;



——In order to adapt to China's national conditions, "insulating gas test" is added in 11.1.2.2;



——In order to adapt to China's national conditions, the content “Measurement of DC insulation resistance of windings-to-earth and between windings" in 11.1.2.3 and 11.1.4 is adjusted to 11.1.2.2.



The following editorial changes have also been made in this part:



——The last paragraph of Clause 1 of IEC 60076-15:2015 is adjusted to the content of Note 1 of this part, and the “Note” of IEC 60076-15:2015 to “Note 2” of this part;



——The “Note” in 3.3 of IEC 60076-15:2015 is adjusted to 3.1 of this part;



——The title of 3.5 of IEC 60076-15:2015 is deleted, and 3.5.1, 3.5.2 and 3.5.3 are adjusted to 3.5, 3.6 and 3.7 of this part;



——The contents of “Note 2” in 5.11.1 of IEC 60076-15:2015 is adjusted to the contents of official text;



——The number 5.5 cited in item 1) of 8.2 in IEC 60076-15:2015 is adjusted to 6.5;



——The text of the penultimate paragraph in 11.1.4 of IEC 60076-15:2015 is deleted;



——The contents of “Note” in 11.2 of IEC 60076-15:2015 is adjusted to the contents of official text;



——The "compound gauge" in "Recommended components for gas-filled power transformers" in Table C.1 of IEC 60076-15:2015 is deleted;



——Annex A and Annex B in IEC 60076-15:2015 are adjusted to Annex B and Annex A of this part.



——The bibliography is adjusted.



This standard was proposed by the China Electrical Equipment Industry Association.



This part is under the jurisdiction of SAC/TC 44 National Technical Committee on Transformers of Standardization Administration of China.



Power transformers

Part 15: Gas-filled power transformers



1 Scope



This part of GB/T 1094 specifies the terms and definitions, service conditions, rating and general requirements, requirements for transformers having a tapped winding, connection phase displacement symbols, rating plates, safety, environmental and other requirements, tolerances, tests, electromagnetic compatibility (EMC), high frequency switching transients, earthing terminal, information required with enquiry and order of gas-filled power transformers.



This part applies to three-phase and single-phase gas-filled power transformers (including auto-transformers) with the exception of certain categories of small and special transformers such as:



——single-phase transformers with rated power less than 1kVA and three-phase transformers less than 5kVA;



——transformers, which have no windings with rated voltage higher than 1,000V;



——instrument transformers;



——traction transformers mounted on rolling stock;



——starting transformers;



——testing transformers;



——welding transformers.



When standards do not exist for such categories of transformers (in particular transformer having no winding exceeding 1,000V for industrial applications), this part may still be applicable either as a whole or in part. This part does not address the requirements that would make a transformer suitable for mounting in a position accessible to the general public. For those categories of power transformers and reactors which have their own standards, this part is applicable only to the extent in which it is specifically called up by cross-reference in the other standard. Such standards exist for:



——reactors in general (GB/T 1094.6);



——self-protected transformers (IEC 60076-13);



——transformers for wind turbine applications (GB/T 1094.16);



——traction transformers and traction reactors (GB/T 25120);



——converter transformers for industrial applications (GB/T 18494.1);



——converter transformers for HVDC applications (GB/T 18494.2).



Note 1: At several places in this part, it is specified or recommended that an 'agreement' shall be reached concerning alternative or additional technical solutions or procedures. Such agreement is made between the manufacturer and the purchaser. The matters should preferably be raised at an early stage and the agreements included in the contract specification.



Note 2: This part can be applicable to the gas parts of a transformer in which an insulating gas is used with an insulating liquid.



2 Normative references



The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.



GB/T 1094.1-2013 Power transformers—Part 1: General (IEC 60076-1:2011, MOD)

GB/T 1094.2-2013 Power transformers—Part 2: Temperature rise for liquid-immersed transformers (IEC 60076-2:2011, MOD)

GB/T 1094.3-2017 Power transformers—Part 3: Insulation levels, dielectric tests and external clearances in air (IEC 60076-3:2013, MOD)

GB/T 1094.5 Power transformers—Part 5: Ability to withstand short circuit (GB/T 1094.5-2008, IEC 60076-5:2006, MOD)

GB/T 1094.10 Power transformers—Part 10: Determination of sound levels (GB/T 1094.10-2003, IEC 60076-10:2001, MOD)

GB/T 4109 Insulated bushings for alternating voltages above 1,000V (GB/T 4109-2008, IEC 60137:2008)

GB/T 8905 The guide for management and measuring SF6 gas in electrical equipment (GB/T 8905-2012, IEC 60480:2004, MOD)

GB/T 11022 Common specifications for high-voltage alternating-current switchgear and control gear standards (GB/T 11022-2011, IEC 62271-1:2007, MOD)

GB/T 12022 Industrial sulfur hexafluoride

GB/T 13499-2002 Power transformers—Application guide (IEC 60076-8:1997, IDT)

IEC 62271-4:2002 High-voltage switchgear and controlgear—Part 4: Handling procedures for sulphur hexafluoride (SF6) and its mixtures



3 Terms and definitions



For the purposes of this document, the following terms and definitions apply.



Note: See GB/T 1094.1, GB/T 1094.2, GB/T 1094.3, GB/T 1094.5, GB/T 1094.10 or GB/T 2900.95 for other terms.



3.1

gas-filled power transformer

transformer of which the magnetic circuit and windings are placed in an enclosure filled with an insulating gas



Note 1: Generally, sulfur hexafluoride (SF6) gas is used, and sometimes this transformer is called a gas-insulated transformer.



Note 2: The transformer whose magnetic circuit and winding are placed in a closed box filled with insulating liquid (such as perfluorocarbon, natural ester, synthetic ester, silicone oil, etc.) shall be regarded as liquid-immersed transformer.



3.2

rated gas pressure

gas pressure (gauge pressure) at 20°C designed for use in a gas-filled power transformer



3.3

guaranteed minimum gas pressure

minimum gas pressure (gauge pressure) at 20 °C, which is able to guarantee the insulation of a gas-filled power transformer



3.4

design pressure of tanks

relative pressure used to determine the design of the tanks



Note: It is at least equal to the maximum pressure in the tank at the highest temperature that the gas can reach under specified maximum service condition.



3.5

absolute leakage rate

F

amount of gas escaped by time unit at rated filling pressure (or density)



Note: It is expressed in Pa·m3/s.

 



3.6

permissible leakage rate

Fp

maximum permissible absolute leakage rate of gas at rated filling pressure (or density) specified by the manufacturer



Note: It is expressed in Pa·m3/s.



3.7

relative leakage rate

Frel

absolute leakage rate related to the total amount of gas in the transformer at rated filling pressure (or density)



Note: It is expressed in %/y or %/d.



4 Service conditions



Service conditions in GB/T 1094.1 apply. As far as cooling conditions are concerned, see GB/T 1094.2.



5 Rating and general requirements



5.1 Rated power



5.1.1 General



The rated power for each winding shall either be specified by the purchaser or the purchaser shall provide sufficient information to the manufacturer to determine the rated power at the enquiry stage.



The transformer shall have an assigned rated power for each winding which shall be marked on the rating plate. The rated power refers to continuous loading. This is a reference value for guarantees and tests concerning load losses and temperature rises, and also a guarantee value of the manufacturer.



If different values of apparent power are assigned under different circumstances, for example, with different methods of cooling, the highest of these values is the rated power.



A two-winding transformer has only one value of rated power, identical for both windings.



For multi-winding transformers, the purchaser shall specify the required power-loading combinations, stating, when necessary, the active and reactive outputs separately.



When the transformer has rated voltage applied to a primary winding, and rated current flows through the terminals of a secondary winding, the transformer receives the relevant rated power for that pair of windings.



The transformer shall be capable of carrying, in continuous service, the rated power (for a multi-winding transformer: the specified combination(s) of winding rated power(s) under conditions listed in Clause 4 of GB/T 1094.1-2013 and without exceeding the temperature-rise limitations specified in 5.3.



Note 1: The interpretation of rated power according to this subclause implies that it is a value of apparent power input to the transformer – including its own absorption of active and reactive power. The apparent power that the transformer delivers to the circuit connected to the terminals of the secondary winding under rated loading differs from the rated power. The voltage across the secondary terminals differs from rated voltage by the voltage drop (or rise) in the transformer. Allowance for voltage drop, with regard to load power factor, is made in the specification of the rated voltage and the tapping range (see Clause 7 of GB/T 13499-2002).



Note 2: For a multi-winding transformer, half the arithmetic sum of the rated power values of all windings (separate windings, not auto-connected) gives a rough estimate of its physical size as compared with a two winding transformer.



5.1.2 Preferred values of rated power



Preferred values of rated power in GB/T 1094.1 apply.



5.1.3 Minimum power under alternative cooling modes



Where the purchaser has a particular requirement for a minimum power under a particular cooling mode other than the cooling mode for rated power, this shall be stated and subjected to agreement between the supplier and the purchaser in the tender stage.



The transformer shall be capable of carrying, in continuous service, the specified minimum power (for a multi-winding transformer: the specified combination(s) of winding rated power(s) under conditions listed in Clause 4 of GB/T 1094.1-2013, and under the specified cooling mode, without exceeding the temperature-rise limitations specified in 5.3.



Note: An example of this is where the transformer is required to operate at a particular minimum percentage of rated power with the forced cooling out of service (GNAN) to allow for the loss of auxiliary supply and large GNAN rating will be pushed up the transformer cost. A minimum percentage of rated power is determined with consideration of the cost-effectiveness.



 

5.1.4 Loading beyond rated power



Temporary loading beyond rating capability is subjected to agreement between the supplier and the purchaser in the tender stage.



Note 1: The concept of GB/T 1094.7 may be applicable to the consideration of the loading beyond rated power of gas-filled power transformers, but constants and/or factors may not be applicable.



Any specific requirements for loading beyond rated power, operation at higher external cooling medium temperatures or reduced temperature rise limits shall be specified by the purchaser in the enquiry and the contract. Any additional tests or calculations required to verify compliance with these specific requirements shall also be specified.



Note 2: This option is intended to be used in particular to give a basis for design and guarantees concerning temporary emergency loading of power transformers.



The bushings, tap-changers, current transformers and other auxiliary equipment shall be selected so as not to restrict the loading capability of the transformer.



Note 3: The relevant component standards GB/T 4109 for bushings and GB/T 10230.1 for tap-changers are consulted for the loading capability of those components.



Note 4: These requirements do not apply to transformers for special applications, which do not need a loading capability beyond rated power. For these transformers, if such a capability is required, it is specified.



5.2 Cooling mode



5.2.1 General



The purchaser shall specify the cooling medium (air or water). If the purchaser has particular requirements for the cooling method(s) or cooling equipment, this shall be stated in the enquiry and the contract.



5.2.2 Identification symbols



Transformers shall be identified according to the cooling method employed. For gas-filled power transformers, this identification is expressed by a four-letter code as described below.



First letter (Internal cooling medium):



——G: insulating gas.



Second letter (Circulation mechanism for internal cooling medium):



——N: natural/thermosiphon flow through cooling equipment and in windings;



——F: forced circulation through cooling equipment (e.g., gas blower), thermosiphon flow in windings;



——D: forced circulation through cooling equipment, directed from the cooling equipment into at least the main windings.



Third letter (External cooling medium):



——A: air;



——W: water.



Fourth letter (Circulation mechanism for external cooling medium):



——N: natural convection;



——F: forced circulation (fans, air blowers, water pumps).



5.2.3 Transformers with alternative cooling methods



A transformer may be specified with alternative cooling methods. In this case, the specification and the rating plate shall then carry information about the power values at which the transformer fulfills the temperature rise limitations when these alternatives apply.



The power value for the alternative with the highest cooling capacity is the rated power of the transformer (or of an individual winding of a multi-winding transformer, as shown in GB/T 1094.1). The alternatives are conventionally listed in rising order of cooling capacity.



Example:



GNAN/GDAF: The transformer has cooling equipment with blowers and fans but is also specified with a reduced power-carrying under natural cooling.



Note: The percentage of natural cooling capacity to forced cooling capacity of gas-filled transformers is smaller than that of oil-immersed transformers. It is not difficult generally in oil-immersed transformers to achieve ONAN capacity as 50 % of the OFAF or ODAF capacity. But in gas-filled transformers, it is sometimes difficult and not economical to achieve GNAN capacity as 50 % of the GDAF capacity. The purchaser consults with the manufacturer about natural cooling capacity to forced cooling capacity.



 

5.3 Temperature-rise limits



5.3.1 Classification and insulation system temperature



Transformers are classified by the insulation systems shown in Table 1.



An approximate value for practical purposes of hot-spot temperature can be calculated by using the concept of Annex B.



The application of insulating materials with different thermal classes leads to unconventional insulation systems (see the examples of unconventional insulation systems as described in GB/Z 1094.14).



Table 1 Classification and insulation system temperature

Letter designation a Thermal class

(insulation system temperature °C)

A 105

E 120

B 130

F 155

H 180

N 200

R 220

a Temperature classifications are given in GB/T 11021.



5.3.2 Normal temperature-rise limits



The temperature rise of each winding of the transformer, designed for operation at normal service conditions, shall not exceed the corresponding limit specified in Table 2 when tested in accordance with 11.5.



The temperature of the core, metallic parts and adjacent materials shall not reach a value that will cause damage to any part of the transformer.



In most of the gases, the temperature-rise limit of gas is higher than the temperature-rise limit of winding, so that the temperature-rise limit of gas is not necessary to be specified. If necessary, it is subjected to agreement between the supplier and the purchaser.

 

Table 2 Winding temperature-rise limits

Thermal class

(insulation system temperature °C) Average winding temperature-rise limits a

K

105 60

120 75

130 80

155 100

180 125

200 135

220 150

a Temperature-rise measured in accordance with 11.5.



5.3.3 Reduced temperature-rises for transformers designed for high cooling air temperatures or special air cooling conditions



Reduced temperature-rises for transformers designed for high cooling air temperatures or special air cooling conditions in GB/T 1094.2 apply.



5.3.4 High altitude temperature-rise correction



Unless otherwise agreed between the supplier and the purchaser, for transformers designed for operation at an altitude greater than 1,000 m but tested at normal altitudes, the limits of temperature-rise given in Table 2 shall be reduced by the following amounts for each 500 m by which the intended working altitude exceeds 1,000 m:



——natural-air-cooled transformers: 2 %;



——forced-air-cooled transformers: 3 %.



A corresponding reverse correction may be applied in cases where the altitude of the factory is above 1,000 m and the altitude of the installation site is below 1,000 m.



Any temperature-rise correction in dependence on altitude shall be rounded to the nearest whole number of Kelvin.



The influence of differing ambient temperature or altitude on the air cooling of the tank is disregarded for the water-cooled transformers.



5.3.5 Reduced temperature-rise for transformers designed for high cooling water

temperatures



Reduced temperature-rise for transformers designed for high cooling water temperatures in GB/T 1094.2 apply.



5.3.6 Temperature rise during specified load cycle



By agreement between manufacturer and purchaser, temperature rise limits can be guaranteed and/or a special test regarding load cycle operation specified (see GB/T 1094.7).

Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Service conditions
5 Rating and general requirements
6 Requirements for transformers having a tapped winding
7 Connection and connection symbols
8 Rating plates
9 Safety, environmental and other requirements
10 Tolerances
11 Tests
12 Electromagnetic compatibility (EMC)
13 High frequency switching transients
14 Earthing terminal
15 Information required with enquiry and order
Annex A (Informative) Transient loading – Mathematical model
Annex B (Informative) Technical requirements to be provided with enquiry and order
Annex C (Informative) Gauges, indicators and relays for gas-filled power transformers
Bibliography
Figure A.1 Temperature distribution model
Table 1 Classification and insulation system temperature
Table 2 Winding temperature-rise limits
Table 3 Exponents for the corrections of temperature-rise test results
Table C.1 Comparison of gauges, indicators and relays between gas-filled power transformers and oil-immersed power transformers

电力变压器
第15部分：充气式电力变压器
1 范围
GB/T 1094的本部分规定了充气式电力变压器的术语和定义，使用条件，额定值和一般要求，有一个带分接绕组的变压器的要求，联结和联结组标号，铭牌，安全、环境和其他要求，偏差，试验，电磁兼容(EMC)，高频操作暂态，接地端，以及询价和订货时需要的信息。
本部分适用于三相及单相充气式电力变压器(包括自耦变压器)，但不包括某些小型和特殊变压器，如：
——额定容量小于1 kVA的单相变压器和5 kVA的三相变压器；
——所有绕组额定电压均不高于1000V的变压器；
——互感器；
——电机车牵引变压器；
——启动变压器；
——试验变压器；
——电焊变压器。
当某些类型的变压器(尤其是所有绕组电压均不高于1000V的工业用特种变压器)没有相应的标准时，本部分可以整体或部分适用。本部分不涉及变压器安装在公共场所的要求。对于具有相关标准的变压器和电抗器，本部分只适用于被其产品标准明确提及可相互参考的内容范围。这些产品(标准)包括：
——电抗器(GB/T 1094.6)；
——自保护变压器(IEC 60076-13)；
——风力发电用变压器(GB/T 1094.16)；
——牵引变压器和牵引电抗器(GB/T 25120)；
——工业用变流变压器(GB/T 18494.1)；
——HVDC用换流变压器(GB/T 18494.2)。
注1：本部分中有几处规定或建议涉及的是某些替换方案、附加技术方案或程序需要达成的协议。这类协议宜由制造方与用户达成。问题宜在早期提出，协议宜包含在技术规范中。
注2：本部分也适用于同时使用绝缘气体和绝缘液体的变压器的气体部分。
2 规范性引用文件
下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。
GB/T 1094.1—2013 电力变压器 第1部分：总则(IEC 60076-1：2011， MOD)
GB/T 1094.2—2013 电力变压器 第2部分：液浸式变压器的温升(IEC 60076-2：2011， MOD)
GB/T 1094.3—2017 电力变压器 第3部分：绝缘水平、绝缘试验和外绝缘空气间隙(IEC 60076-3：2013， MOD)
GB/T 1094.5 电力变压器 第5部分：承受短路的能力(GB/T 1094.5—2008， IEC 60076-5：2006， MOD)
GB/T 1094.10 电力变压器 第10部分：声级测定(GB/T 1094.10—2003， IEC 60076—10：2001， MOD)
GB/T 4109 交流电压高于1000V的绝缘套管(GB/T 4109—2008，IEC 60137：2008， MOD)
GB/T 8905 六氟化硫电气设备中气体管理和检测导则(GB/T 8905—2012， IEC 60480：2004， MOD)
GB/T 11022 高压开关设备和控制设备标准的共用技术要求(GB/T 11022—2011，IEC 62271-1：2007， MOD)
GB/T 12022 工业六氟化硫
GB/T 13499—2002 电力变压器应用导则(IEC 60076-8：1997，IDT)
IEC 62271-4：2002 高压开关设备和控制设备 第4部分：六氟化硫(SF6)及其混合物的处理规程[High-voltage switchgear and controlgear—Part 4：Handling procedures for sulphur hexafluoride (SF6) and its mixtures]
3 术语和定义
下列术语和定义适用于本文件。
注：其他术语见GB/T 1094.1、GB/T 1094.2、GB/T 1094.3、GB/T 1094.5、GB/T 1094.10或GB/T 2900.95。
3.1
充气式变压器 gas-filled power transformer
磁路和绕组放置在充满绝缘气体的封闭箱体(简称：气箱)内的变压器。
注1：充气式变压器也称为气体绝缘变压器，一般使用六氟化硫(SF6)。
注2：磁路和绕组放置在充满绝缘液体(如：全氟化碳、天然酯、合成酯、硅油等)的封闭箱体(简称：油箱)内的变压器应被视作液浸式变压器。
3.2
额定气压 rated gas pressure
20℃时，充气式电力变压器设计使用的气压(表压)。
3.3
最低保证气压 guaranteed minimum gas pressure
20℃，能保证充气式电力变压器绝缘的最低气压(表压)。
3.4
气箱的设计压力 design pressure of tanks
用于确定气箱设计的相对压力。
注：至少等于规定极限使用条件下气体达到最高温度时气箱的最大压力。
3.5
绝对泄漏率 absolute leakage rate
F
额定充气压力(或密度)下单位时间内泄漏的气体量。
注：单位为帕立方米每秒(Pa·m3/s)。
3.6
允许泄漏率 permissible leakage rate
Fp
制造商规定的额定充气压力(或密度)下最大允许的气体绝对泄漏率。
注：单位为帕立方米每秒(Pa·m3/s)。
3.7
相对泄漏率 relative leakage rate
Frel
额定充气压力(或密度)下绝对泄漏量与变压器内初始气体总量之比。
注：单位为百分之每年或百分之每日(％/年或％/d)。
4 使用条件
使用条件按照GB/T 1094.1的规定。冷却条件按照GB/T 1094.2的规定。
5 额定值和一般要求
5.1 额定容量
5.1.1 概述
每个绕组的额定容量应由用户规定，或在询价阶段由用户提供充足的信息给制造方，以便确定额定容量。
变压器每一绕组应规定其额定容量，并标志在铭牌上。额定容量指的是连续负载下的值。既是负载损耗和温升保证值和试验的依据，也是制造方的保证值。
如果对不同的条件(如：对不同的冷却方式)规定了不同的视在功率，则取其最高值为额定容量。
双绕组变压器只有一个额定容量，两个绕组的额定容量值相同。
对于多绕组变压器，用户应规定需要的容量-负载组合，如有必要，则应单独说明有功功率和无功功率。
将额定电压施加到变压器的一次绕组上，且只在一个二次绕组的端子上流过额定电流时，此变压器承受了与该对绕组相应的额定容量。
变压器在正常条件(见GB/T 1094.1—2013中第4章)下，应能连续地输送额定容量(对于多绕组变压器，则是指定绕组额定容量的组合)，且其温升不超过5.3规定的温升限值。
注1：按本条所阐述的额定容量，是指输入到变压器的视在功率值(包括变压器本身所吸取的有功功率和无功功率)。在额定负载下，变压器输出给与二次绕组端子相连的电路的视在功率与额定容量不等。因为变压器内部的电压降(或升)，二次端子之间的电压与额定电压不等。电压降的许可值(与负载功率因数有关)在额定电压和分接范围的技术规范中给出(见GB/T 13499—2002中第7章)。
注2：对于多绕组变压器，根据所有绕组(独立绕组，非自耦联结)额定容量值算术和的一半值，可以估算出多绕组变压器的物理尺寸(与双绕组变压器相比)。
5.1.2 额定容量优先数
额定容量优先数按照GB/T 1094.1的规定。
5.1.3 可变冷却方式下的最小容量
如果用户对特定冷却方式而非额定容量的冷却方式的最小容量有特殊要求，则应在投标阶段由制造方与用户协商确定。
变压器应能够在GB/T 1094.1—2013中第4章规定的条件及在指定的冷却方式下，连续输出规定的最小容量(对于多绕组变压器，为规定的绕组额定容量组合)而不超过5.3规定的温升限值。
注：如果变压器被要求能在比额定容量小的某规定容量下自冷运行，此时强迫冷却装置不工作，没有辅助设备损耗，则此要求的容量越大则变压器成本越高。此要求的容量需通过考虑成本来决定。
5.1.4 超额定容量负载
临时超额定容量负载由制造方与用户在询价或订货时协商。
注1：考虑充气式电力变压器超额定容量负载时，可采用GB/T 1094.7中的概念，但常数和(或)系数不适用。
对任何超额定容量负载，在较高的外部冷却介质温度或降低的温升限值下运行的特殊要求均应由用户在询价及订货时规定。并规定出任何附加的试验和计算方法，以验证产品符合这些特殊要求。
注2：此情况适用于给电力变压器临时紧急负载时的设计值和保证值提供基础。
套管、分接开关、电流互感器及其他辅助设备的选用不应限制变压器的负载能力。
注3：此类组部件的负载能力宜参考相关标准，如：对于套管为GB/T 4109，对于分接开关为GB/T 10230.1。
注4：此要求不适用于特殊用途的变压器，某些特殊用途的变压器不需要超过额定容量的负载能力。对于这类变压器，宜规定特殊要求。
5.2 冷却方式
5.2.1 概述
用户应规定冷却介质(空气或水)。如果用户对冷却方法或冷却设备有特殊要求，则应在询价和合同中注明。
5.2.2 标志符号
变压器应按照其冷却方式进行标志。对于充气式电力变压器，其冷却方式采用下面四个字母进行标志。
第一个字母(代表内部冷却介质)：
——G：绝缘气体。
第二个字母(代表内部冷却介质的循环方式)：
——N：在冷却设备和绕组中自然循环；
——F：在冷却设备(如气泵)中强迫循环，在绕组中自然循环；
——D：在冷却设备中强迫循环，且至少在主要绕组内部强迫导向循环。
第三个字母(代表外部冷却介质)：
——A：空气；
——W：水。
第四个字母(代表外部冷却介质的循环方式)：
——N：自然对流；
——F：强迫循环(风扇、鼓风机、水泵)。
5.2.3 具有多种冷却方式的变压器
一台变压器可规定有几种不同的冷却方式。此时，在说明书和铭牌上应给出不同冷却方式下的容量值，以便在采用某一冷却方式及所规定的容量下运行时，变压器温升不超过限值。
在最大冷却能力下的容量值就是变压器(或多绕组变压器某个绕组，见GB/T 1094.1)的额定容量，不同的冷却方式按照冷却能力增大的次序排列。
例如：
GNAN/GDAF ：变压器的冷却设备有气泵和风扇，但在自然冷却方式下，所带容量较低。
注：与油浸式变压器相比，充气式变压器自然冷却能力与强迫冷却能力的比值较小。一般来说，油浸式变压器的ONAN能力达到OFAF或ODAF能力的50％不难。但对充气式变压器而言，有时要使GNAN能力达到GDAF能力的50％很难，并且成本较高。用户可向制造方咨询自然冷却能力与强迫冷却能力的百分比比值。
5.3 温升限值
5.3.1 分类和绝缘系统温度
变压器可按照绝缘系统进行分类，具体见表1。
实际运用中热点温度的近似值可使用附录A中的方法计算。
具有不同耐热等级的绝缘材料构成非常规的绝缘系统(非常规绝缘系统的举例见GB/Z 1094.14)。
表1 分类和绝缘系统温度
分类a 耐热等级(绝缘系统温度)℃
A 105
E 120
B 130
F 155
H 180
N 200
R 220
a 温度分类见GB/T 11021。
5.3.2 正常温升限值
在按照11.5的规定进行试验时，在正常使用条件下运行的变压器各绕组的温升设计值不应超过表2中规定的相应限值。
铁心、金属部件和邻近材料的温度不应造成变压器任何部件的损伤。
大多数情况下，气体的温升限值高于绕组的温升限值，因此，气体的温升限值没有必要规定。如有必要规定，则应由制造方与用户协商确定。