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Delivery: <= 6 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 20840.10-2025: Instrument transformers - Part 10: Additional requirements for low-power passive current transformers Status: Valid
Basic dataStandard ID: GB/T 20840.10-2025 (GB/T20840.10-2025)Description (Translated English): Instrument transformers - Part 10: Additional requirements for low-power passive current transformers Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: K41 Classification of International Standard: 29.180 Word Count Estimation: 38,323 Date of Issue: 2025-01-24 Date of Implementation: 2025-08-01 Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration GB/T 20840.10-2025: Instrument transformers - Part 10: Additional requirements for low-power passive current transformers---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. ICS 29.180 CCSK41 National Standard of the People's Republic of China Instrument transformers Part 10.Low power passive current transformers Supplementary technical requirements for transformers (IEC 61869-10.2017,MOD) Released on 2025-01-24 2025-08-01 Implementation State Administration for Market Regulation The National Standardization Administration issued Table of ContentsPreface III Introduction V 1 Scope 1 2 Normative references 1 3 Terms and Definitions 1 5 Rating 5 6 Design and Structure 8 7 Test 10 601 Inquiry, Bidding and Ordering Notes 15 Appendix 10A (Informative) Comparison of this document with IEC 61869-10.2017 structure number 17 Appendix 10B (Informative) Technical differences between this document and IEC 61869-10.2017 and their causes 18 Appendix 10C (Informative) Working Principle of Rogowski Coil 19 Appendix 10D (Informative) Working Principle of Low Power Iron Core Current Transformer (Proportional LPCT) 23 Appendix 10E (Informative) Nominal accuracy class using corrected ratio and ratio correction factor 25 Appendix 10F (Normative) Accuracy test related to the position of the primary conductor 28 Reference 30 Figure 1001 General block diagram of single-phase low-power passive current transformer VI Figure 1002 Terminal marking 9 Figure 1003 Test arrangement for the influence of adjacent phase magnetic field 14 Figure 10C.1 Equivalent circuit of a Rogowski coil 21 Figure 10C.2 Integral and non-integral output signals of a Rogowski coil 21 Figure 10C.3 Frequency dependence test of Rogowski coil 22 Figure 10D.1 Principle of iron core current transformer 23 Figure 10D.2 Equivalent circuit of an iron core current transformer with voltage output 24 Figure 10E.1 Improvement of nominal accuracy based on its own ratio correction factor CFI 25 Figure 10E.2 Accuracy test of passive LPCT 26 Figure 10E.3 Accuracy class 1 based on rated transformation ratio 27 Figure 10E.4 Accuracy class 27 based on the ratio correction factor and the corrected ratio with a nominal value of 0.1 Figure 10F.1 Definition of the angle between the primary conductor and the passive LPCT 28 Figure 10F.2 Schematic diagram of primary conductor position corresponding to position factor 29 Figure 10F.3 Accuracy measurement test arrangement 29 Table 1001 Passive LPCT ratio difference and phase error limits for measurement 6 Table 1002 Ratio difference and phase error limits for passive LPCT protection 7 Table 1003 Pinout of RJ45 connector for passive LPCT 10 Table 11 Test Item 11 Table 1004 Items required to determine passive LPCT performance 15 Table 10A.1 Comparison of structure numbers between this document and IEC 61869-10.2017 17 Table 10B.1 Technical differences between this document and IEC 61869-10.2017 and their causes 18 Table 10E.1 Transformation ratios, ratio differences based on average values and corresponding primary currents 27 Table 10E.2 Ratio difference, ratio correction factor and ratio difference based on ratio correction factor 27 Table 10F.1 Passive LPCT primary conductor position factor limits 28ForewordThis document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1.Structure and drafting rules for standardization documents" Drafting. This document is part 10 of GB/T 20840 "Transformers". GB/T 20840 has published the following parts. --- Part 1.General technical requirements; --- Part 2.Supplementary technical requirements for current transformers; --- Part 3.Supplementary technical requirements for electromagnetic voltage transformers; --- Part 4.Supplementary technical requirements for combined transformers; --- Part 5.Supplementary technical requirements for capacitor voltage transformers; --- Part 6.Supplementary general technical requirements for low power transformers; --- Part 7.Electronic voltage transformer; --- Part 8.Electronic current transformer; --- Part 9.Digital interface for transformers; --- Part 10.Supplementary technical requirements for low power passive current transformers; --- Part 11.Supplementary technical requirements for low power passive voltage transformers; --- Part 14.Supplementary technical requirements for DC current transformers; --- Part 15.Supplementary technical requirements for DC voltage transformers; --- Part 99.Terminology; --- Part 100.Application Guidelines for Current Transformers for Power System Protection; --- Part 102.Ferroresistance in substations with electromagnetic voltage transformers; --- Part 103.Application of transformers in power quality measurements. This document is modified to adopt IEC 61869-10.2017 "Transformers - Part 10.Supplementary technical requirements for low power passive current transformers" beg". Compared with IEC 61869-10.2017, this document has many structural adjustments. Comparison table of structural changes between the two documents See Appendix 10A. This document has many technical differences compared with IEC 61869-10.2017. A list of these technical differences and their reasons is given in Appendix 10B. The following editorial changes were made to this document. --- The order of symbols has been adjusted (see 3.7); --- Change "φtdr is 0" to "the phase shift (φtdr) caused by the rated delay time is 0" (see 5.6.1001); --- The header format of Table 1001 and Table 1002 has been adjusted (see 5.6.1003.3 and 5.6.1004.4); --- Change the title of Table 1002 from "Error Limits" to "Protection Passive LPCT Ratio Difference and Phase Error Limits", Composite The error symbols "εc, εcorI" are corrected to "εc, εccorI" (see 5.6.1004.4); --- Added "Note. Derivative type LPCT preferably uses 150mV" (see 5.1004); ---Change "Example 2.5P31000A of passive LPCT for protection, Example 3.0.2/5P31000A of multi-purpose passive LPCT" to Change to "Example 2.5P31500A of passive LPCT for protection, Example 3.0.2(5P 31500A)" (see 6.13.1005); --- Added the introductory sentence of Table 1003."Table 1003 gives the pin assignment of passive LPCT using RJ45 type connector" (see 6.602.1); --- Correct (I2th × 1s) to (I2th × tth) and add "where tth is the specified duration of the rated short-time thermal current (Ith)" (see 7.2.1001); --- The format of Table 1004 was adjusted, and the definition item number corresponding to CFI was corrected from "3.4.1003" to "3.4.1001"; --- Adjust the text content in the upper part of Figure 10A.1 of IEC 61869-10.2017 to the title of the sub-figure, and correct "LPPC" to "LPCT"; ---Correct "1%" and "0.1%" in the titles of Figures 10A.3 and 10A.4 of IEC 61869-10.2017 to "1" and "0.1%" respectively "0.1", and the curve position was corrected; --- The format of Table 10A.2 of IEC 61869-10.2017 was adjusted and some data were corrected; --- Correct the symbol "RB" for high impedance load in Figure 10B.1 of IEC 61869-10.2017 to "Rb"; --- The winding symbol in Figure 10C.1 and the inductance symbol in Figure 10C.2 of IEC 61869-10.2017 have been adjusted; --- Replace the "low power passive current transformer" that appears repeatedly in the text with the abbreviation "passive LPCT"; ---The formulas in the whole text are numbered; --- Replaced IEC 61869-8 with the informative reference GB/T 20840.8 (see Chapter 1, Table 1003); --- Replaced IEC 61869-6.2016 with the informative reference GB/T 20840.6-2017 (see 5.6.1001, 5.6.1003.3, --- Replaced IEC 61869-2 with the informative reference GB/T 20840.2 (see Note to Table 1002); --- Replaced IEC 61869-7 with the informative reference GB/T 20840.7 (see Table 1003); --- Replaced IEC 60028 with the informative reference GB/T 5585.1 (see 7.2.1001); --- Replaced IEC 60121 with the informative reference GB/T 3954 (see 7.2.1001). Please note that some of the contents of this document may involve patents. The issuing organization of this document does not assume the responsibility for identifying patents. This document was proposed by the China Electrical Equipment Industry Association. This document is under the jurisdiction of the National Technical Committee for Standardization of Transformers (SAC/TC222). This document was drafted by. China Electric Power Research Institute Co., Ltd., Shenyang Transformer Research Institute Co., Ltd., Dalian First Instrument Transformer Co., Ltd. Limited Liability Company, Nanjing NARI Relay Protection Electric Co., Ltd., Zhejiang Tianji Instrument Transformer Co., Ltd., Jiangsu Kexing Electric Co., Ltd., Dalian Northern Instrument Transformer Group Co., Ltd., Jiangsu Jingjiang Instrument Transformer Co., Ltd., Chongqing Shancheng Electric Appliance Factory Co., Ltd., Xi'an High Voltage Electric Appliance Research Institute Institute of Electric Power Co., Ltd., Denggao Electric Co., Ltd., Zhejiang Chint Electric Co., Ltd., Yunnan Power Grid Co., Ltd. Research Institute, State Grid Shaanxi Electric Power Company Electric Power Research Institute. The main drafters of this document are. Liu Bin, Liu Yufeng, Liu Yong, Sha Yuzhou, Xu Lei, Tang Fuxin, Deng Xiaopin, Yang Feng, Zhao Guoqing, Wang Benjin, Zhou Nan, Xu Wen, Feng Jianhua, Huang Xiaofeng, Li Hui, Wu Shipu, Liu Hongwen, Wang Jing.IntroductionThe purpose of formulating the transformer standard is to establish a set of optimal evaluation criteria for the transformer, and to provide a reference for the selection of raw materials, design, production and GB/T 20840 aims to specify the precautions applicable to transformers. The principles and relevant rules to be followed in design, manufacturing, testing, operation and maintenance are planned to consist of 17 parts. --- Part 1.General technical requirements. The purpose is to establish the requirements for the design, manufacture and production testing of various types of transformers. General technical requirements to be followed. --- Part 2.Supplementary technical requirements for current transformers. The purpose is to establish supplementary technical requirements applicable to various types of current transformers. Require. --- Part 3.Supplementary technical requirements for electromagnetic voltage transformers. The purpose is to establish the requirements applicable to various types of electromagnetic voltage transformers. Supplementary technical requirements. --- Part 4.Supplementary technical requirements for combined transformers. The purpose is to establish supplementary technical requirements applicable to various types of combined transformers. Require. --- Part 5.Supplementary technical requirements for capacitor voltage transformers. The purpose is to establish the requirements applicable to various types of capacitor voltage transformers. Supplementary technical requirements. --- Part 6.Supplementary general technical requirements for low power transformers. The purpose is to establish supplementary general technical requirements applicable to various types of low power transformers. Fill in the general technical requirements. --- Part 7.Electronic voltage transformers. The purpose is to establish supplementary technical requirements applicable to various types of electronic voltage transformers. --- Part 8.Electronic current transformers. The purpose is to establish supplementary technical requirements applicable to various types of electronic current transformers. --- Part 9.Digital interfaces for transformers. The purpose is to establish technical requirements for digital interfaces applicable to various types of electronic transformers. --- Part 10.Supplementary technical requirements for low power passive current transformers. The purpose is to establish Supplementary technical requirements for current transformers. --- Part 11.Supplementary technical requirements for low power passive voltage transformers. The purpose is to establish Supplementary technical requirements for voltage transformers. --- Part 14.Supplementary technical requirements for DC current transformers. The purpose is to establish supplementary technical requirements applicable to various types of DC current transformers. Fill in the technical requirements. --- Part 15.Supplementary technical requirements for DC voltage transformers. The purpose is to establish the requirements applicable to various types of DC voltage transformers. Supplementary technical requirements. --- Part 99.Terminology. The purpose is to establish terms and definitions applicable to various types of transformers. --- Part 100.Guidelines for the application of current transformers for power system protection. The purpose is to Provide guidance on the application of protection. --- Part 102.Ferroresistance in substations with electromagnetic voltage transformers. Provide guidance on the generation and suppression of ferromagnetic resonance in substations with voltage transformers. --- Part 103.Application of transformers in power quality measurement. The purpose is to describe the application of various types of transformers in power quality measurement. Provide guidance on use. GB/T 20840 defines the technical specifications of various types of transformer products through 17 parts, and gives specific technical requirements, test items, By establishing clear scope, terminology, technical requirements and test requirements for various products So that people engaged in product design, production, testing and use can operate more clearly and accurately, thus providing It lays the foundation for manufacturing high-quality products, better promotes trade, exchanges and technical cooperation, and provides guarantee for the normal operation of my country's power grid. This document is consistent with GB/T 20840.1-2010 "Mutual Inductors Part 1.General Technical Requirements" and GB/T 20840.6-2017 "Mutual Inductors This document complies with GB/T 20840.1-2010 and The writing structure of GB/T 20840.6-2017 is to supplement and modify the corresponding clauses. When the provisions of GB/T 20840.6-2017 are not mentioned in this document, they shall also apply to this document as long as it is reasonable. When the document indicates "supplement", "modification" or "replacement", it means the relevant part of GB/T 20840.1-2010 or GB/T 20840.6-2017. The terms are adapted accordingly in this document. For the chapters, clauses, figures, tables, notes and appendices added on the basis of GB/T 20840.1-2010 and GB/T 20840.6-2017, this The documents are numbered in the following format. --- The numbering of chapters, articles, figures, tables and notes starts from 1001; ---Appendices are numbered 10A, 10B, etc. Low power passive current transformer (passive LPCT) is based on passive technology, does not contain any active electronic components, and the output is the same as the primary current. A signal proportional to the primary current is used, such as an iron core coil with an integrated shunt resistor as a current-to-voltage converter (primary converter), or an output proportional to the primary current. A signal proportional to the derivative of the current, such as an air-core coil (Rogowski coil). This document does not include air-core coils with active integrators. According to the general block diagram given in Figure 601 of GB/T 20840.6-2017, the low-power passive current transformer does not use an active primary converter (i.e., does not use any active electronic components), so no primary power supply is required. In addition, no secondary converter or secondary power supply. Figure 1001 shows a general block diagram of a low power passive current transformer. The components required for low power passive current transformers are determined by the technology used. The transmission cable or a The secondary converter is not essential for low power passive current transformers. The derivative type LPCT solution uses only the air core coil as the primary transformer. The transmission cable is used as the transmission system. When using this technology, the primary converter is not considered. The proportional LPCT solution will The iron core coil is used as a primary sensor, the load resistor is directly connected to the coil output as a primary converter, and the transmission cable is used as a transmission system. Figure 1001 General block diagram of a single-phase low-power passive current transformer Instrument transformers Part 10.Low power passive current transformers Supplementary technical requirements for transformers1 ScopeThis document specifies the terms and definitions, ratings, design, and Supplementary technical requirements for design and structure, testing and consultation, bidding and ordering instructions, etc. This document is applicable to the rated frequency of 15Hz~100Hz, used for measuring and protecting electrical measuring instruments or relay protection devices. And a multi-purpose newly manufactured analog output passive LPCT with both measurement and protection functions. This document does not apply to electronic current transformers with digital outputs or using any type of active electronic component technology. NOTE 1.5.6.1003 gives the accuracy requirements necessary for passive LPCTs used in gas measuring instruments. NOTE 2.5.6.1004 gives the accuracy requirements necessary for passive LPCTs used in relay protection devices, especially for currents up to several times the rated current. In addition, the transient accuracy of the passive LPCT during a fault is given if required. Accuracy. Note 3.Passive LPCTs have only analog voltage outputs (for digital outputs or using any type of active electronic components, refer to the technical reference GB/T 20840.8). Such a passive LPCT may include a secondary signal cable (transmission cable). Appendix 10C gives the use of air-core coils (Ro Appendix 10D gives the working principle of the derivative type LPCT using an integrated shunt resistor. Working principle of LPCT.2 Normative referencesThe contents of the following documents constitute the essential clauses of this document through normative references in this document. For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to This document. Chapter 2 of GB/T 20840.6-2017 and the following supplements are applicable. GB/T 762 standard current level (GB/T 762-2002, IEC 60059.1999, MOD) GB/T 20840.1 Transformers Part 1.General Technical Requirements (GB/T 20840.1-2010, IEC 61869-1.2007, MOD) GB/T 20840.6 Transformers Part 6.Supplementary general technical requirements for low power transformers (GB/T 20840.6-2017, IEC 61869-6.2016, MOD)3 Terms and definitionsThe terms and definitions defined in GB/T 20840.1 and GB/T 20840.6 and the following supplements and modifications apply to this document. 3.1 General Definitions 3.1.613 Transmission system 3.1.613 of GB/T 20840.6-2017 and the following supplements are applicable. NOTE 1001.For passive LPCTs, the transmission system is only the transmission cable. ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 20840.10-2025_English be delivered?Answer: Upon your order, we will start to translate GB/T 20840.10-2025_English as soon as possible, and keep you informed of the progress. 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