GB/T 20840.99-2025Instrument transformers - Part 99: Glossary (English PDF)

Foreword

This 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 99 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: Ferroressonance in substations with electromagnetic voltage transformers;

--- Part 103: Application of transformers in power quality measurements.

This document is modified to adopt IEC 61869-99:2022 "Transformers - Part 99: Terminology".

The technical differences between this document and IEC 61869-99:2022 and their reasons are as follows.

--- Added the term and definition of "3.1.3 Voltage sensor" to conform to the actual situation in my country;

--- Change "transformers are designed to" to "transformers for DC applications having at least one of the following functions.", in "measuring DC Add "(including significant harmonics)" after "current and/or DC voltage", change "with or without AC component" to "withstand DC voltage" Pressure" to make the definition more precise (see 3.2.1);

--- Add the term and definition of "3.2.11 Electromagnetic voltage transformer" to conform to the actual situation in my country;

--- Adjust the definition to "winding to which the measured current or voltage is applied" (see 3.2.27);

--- The Chinese name of the term adds "measuring current transformer" and the English name adds "formeasuringCT" (see 3.5.27).

In line with my country's actual situation;

--- The Chinese name of the term has been added with "protective current transformer", the English name has been added with "forprotectiveCT", and the definition of "accurate the symbol "KALF" is added after "Limit coefficient" (see 3.5.28) to conform to the actual situation in my country;

--- The Chinese name of the term adds "(for transformer)" and the English name adds "(forIT)" (see 3.5.42) to conform to the actual situation in my country Condition;

Actual situation;

--- "relative to the rated primary short-circuit current peak" (see 3.5.51) has been added to the definition to conform to the actual situation in my country;

The following editorial changes were made to this document.

---Replace the international documents in the "Source" and "Note" of some terms and definitions with Chinese standards;

--- Deleted "Note 2.In some countries (such as the United States), a conductor is used instead of the neutral point (grounding system corner) for grounding" (see 3.1.7);

--- In Note 1, adjust "(e.g., calculated neutral point current)" to "e.g., calculated neutral point current (self-generated zero-sequence current)" (see 3.1.12);

--- Adjust the "LPCT" in the note to "single-phase LPCT" (see 3.1.16);

--- Adjust the "LPVT" in the note to "single-phase LPVT" (see 3.1.17);

--- Adjust "between two points" to "output terminal" (see 3.1.21);

--- Deleted "temperature sensor" in the example (see 3.2.23);

--- Adjust the source of the term (see 3.4.10);

--- Delete "Note 1.For digital signals, the rated transformation ratio is 1" (see 3.5.5);

--- Adjust "expressed as a percentage (%)" in Note 1 to "expressed as a percentage of the root mean square value of the primary current (%)" (see 3.5.9);

--- The expression "iepsilon=kr×is-ip" is added to the definition (see 3.5.50);

--- Correct "primary current" in Note 3 to the symbol tn to "primary voltage" (see 3.5.56);

--- Correct "ysrmng" in the symbol description of item b) in Note 1 to "ysrmng(n)" (see 3.5.59);

--- Add Note 2 and adjust the square root in the expression in 3.5.68 to extend to the entire expression (see 3.5.67 and 3.5.68);

--- Correct "a) and b)" in the diagram symbol description in Note 1 to "a and b" (see 3.5.80);

--- A Chinese index arranged in phonetic notation has been added to the appendix.

Introduction

The purpose of formulating the transformer standard is to establish a set of optimal evaluation criteria for the transformer, from raw material selection, design, production, etc.

GB/T 20840 aims to establish the requirements for 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 supplementary technical requirements applicable to various types of DC voltage transformers.

Fill in the 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 mechanism 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 personnel engaged in product design, production, testing and use can operate more clearly and accurately, thus providing it lays the foundation for the design and manufacture of high-quality products, better promotes trade, exchanges and technical cooperation, and provides the normal operation of my country's power grid.

Assure.

This document deals with terms and definitions related to GB/T 20840 (all parts).

The structure of the term list in this document is not in the order of the product standard series, but in a logical order based on the concept hierarchy.

That is, start with the most general concepts and then move on to more specific concepts.

Instrument transformers Part 99: Terminology

1 Scope

This document defines terms and definitions specific to instrument transformers.

This document applies to the field of transformers covered by GB/T 20840 (all parts). Unless otherwise specified, in this document, all peripheral Periodic charges are considered to be RMS values.

2 Normative references

This document has no normative references.

3 Terms and definitions

The following terms and definitions apply to this document.