GB/T 45119-2024 Technical requirement for insulation monitoring of low voltage power system in power plants and substations
1 Scope
This document specifies the basic requirements, monitoring requirements, installation acceptance, operation and maintenance requirements for insulation monitoring of low voltage power system in power plants and substations.
This document is applicable to the design, selection, installation and use of insulation monitoring of low voltage AC and DC power systems in power projects such as power plants, substations and converter stations.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2423.1-2008 Environmental testing for electric and electronic products - Part 2: Test methods - Tests A: Cold
GB/T 2423.2-2008 Environmental testing for electric and electronic products - Part 2: Test methods - Tests B: Dry heat
GB/T 2423.5-2019 Environmental testing - Part 2: Test methods - Test Ea and guidance: Shock
GB/T 2423.10-2019 Environmental testing - Part 2: Test methods - Test Fc: Vibration (sinusoidal)
GB/T 2900.1 Electrotechnical terminology - Fundamental terms
GB/T 2900.33 Electrotechnical terminology - Power electronics
GB/T 4365 Electrotechnical terminology - Electromagnetic compatibility
GB/T 17626.2 Electromagnetic compatibility - Testing and measurement techniques - Electrostatic discharge immunity test
GB/T 17626.3 Electromagnetic compatibility - Testing and measurement techniques - Part 3: Radiated, radio-frequency, electromagnetic field immunity test
GB/T 17626.4 Electromagnetic compatibility - Testing and measurement techniques - Electrical fast transient/burst immunity test
GB/T 17626.5 Electromagnetic compatibility - Testing and measurement techniques - Surge immunity test
GB/T 17626.6 Electromagnetic compatibility - Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields
GB/T 17626.8 Electromagnetic compatibility - Testing and measurement techniques - Power frequency magnetic field immunity test
GB/T 17626.10 Electromagnetic compatibility - Testing and measurement techniques - Damped oscillatory magnetic field immunity test
GB/T 17626.18 Electromagnetic compatibility - Testing and measurement techniques - Damped oscillatory wave immunity test
DL/T 860 (All parts) Communication networks and system for power utility automation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2900.1, GB/T 2900.33 and GB/T 4365 and the following apply.
3.1
insulation monitoring
monitoring and measuring the insulation condition of low voltage AC and DC power supply system bus and branch circuit to ground
3.2
grounding resistance
insulation resistance to ground of bus or branch of AC and DC power system with ungrounded operation mode
3.3
balancing bridge
(Wheatstone) detection bridge composed of positive and negative equivalent artificial grounding resistance and DC bus grounding resistance. When the bus insulation is good or the resistance value of the grounding resistance is similar, the detection bridge is in balanced state
3.4
unbalanced bridge
invention relates to a bridge composed of (alternately) switched positive and negative artificial grounding resistors, and forms a detection bridge with a balance bridge resistance
3.5
signal injection method
method of inputting known AC, DC, square wave pulse and adaptive pulse signals into the branch, monitoring the corresponding grounding fault signal, detecting the grounding branch or locating the grounding point
4 Basic requirements
4.1 Working environment
Normal working environment of insulation monitoring equipment (hereinafter referred to as "insulation monitoring equipment") of low voltage AC and DC power systems in power plants:
a) The ambient temperature is -5°C~+40°C;
b) The daily average relative humidity shall not exceed 95%, the monthly average relative humidity shall not exceed 90%, and there is no condensation;
c) The altitude is not exceeding 2,000 m;
d) Good ventilation, no explosion hazard, no corrosive gas, and no mold;
e) There is no violent vibration source, no strong electromagnetic interference, and the external magnetic field induction intensity does not exceed 0.5 mT;
f) The horizontal acceleration of vibration does not exceed 0.3 g and the vertical acceleration does not exceed 0.15 g.
Note: Special environmental conditions shall be considered when formulating relevant standards for insulation monitoring equipment.
4.2 Electrical performance
4.2.1 Working power supply
4.2.1.1 The working power supply of insulation monitoring equipment shall be connected from the busbar through the protective appliance. DC input power supply shall be used when monitoring DC system; when monitoring the AC system, AC input power supply or DC input power supply shall be used, and AC and DC power supply shall not be input at the same time.
4.2.1.2 The DC input power supply shall work normally within the following ranges:
a) The voltage range of the 220 V power supply is 176 V~286 V;
b) The voltage range of the 110 V power supply is 88 V~143 V;
c) Ripple coefficient ≤ 5%.
4.2.1.3 The AC input power supply shall work normally within the following ranges:
a) The voltage range of the 380 V power supply is 304 V~456 V;
b) The voltage range of the 220 V power supply is 176 V~264 V;
c) The frequency range is 47.5 Hz~52.5 Hz;
d) The voltage is a sine wave, and the total harmonic content does not exceed 10%.
4.2.2 Dielectric capability
The electrical insulation performance of the following parts of the insulation monitoring equipment shall not be lower than the requirements in Table 1:
a) Between non-electrically connected live circuits;
b) Between each independent live circuit and the ground (metal frame);
c) Between the communication interface and the ground (metal shell of the chassis).
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Basic requirements
4.1 Working environment
4.2 Electrical performance
4.3 Communication and others
5 Test requirements
5.1 Classification
5.2 Functional indexes
5.3 Main way
6 Installation acceptance
6.1 Inspection
6.2 Arrangement
6.3 Acceptance
7 Operation and maintenance
7.1 Operation
7.2 Maintenance
Annex A (Normative) Environmental adaptability and electromagnetic compatibility requirements
Annex B (Informative) Insulation monitoring of low voltage DC ungrounded systems
Annex C (Informative) Insulation monitoring of low voltage AC ungrounded systems
Annex D (Informative) Insulation monitoring of low voltage AC grounding systems
Bibliography
電力廠站低壓用電系統的絕緣監測技術要求
1范圍
本文件規定了電力廠站低壓用電系統的絕緣監測的基本要求、監測要求、安裝驗收和運行維護等要求。
本文件適用于發電廠、變電站、換流站等電力工程低壓交直流用電系統絕緣監測的設計、選型、安裝和使用。
2規范性引用文件
下列文件中的內容通過文中的規范性引用而構成本文件必不可少的條款。其中,注日期的引用文件,僅該日期對應的版本適用于本文件;不注日期的引用文件,其最新版本(包括所有的修改單)適用于本文件。
GB/T 2423.1-2008 電工電子產品環境試驗 第2部分:試驗方法試驗A：低溫
GB /T 2423.2-2008 電工電子產品環境試驗 第2部分: 試驗方法 試驗B:高溫
GB/T 2423.5-2019 環境試驗 第2部分: 試驗方法 試驗Ea和導則: 沖擊
GB/T 2423.10-2019 環境試驗 第 2 部分: 試驗方法 試驗Fc : 振動(正弦)
GB/T 2900.1 電工術語 基本術語
GB/T 2900.33 電工術語 電力電子技術
GB / T4365 電工術語 電磁兼容
GB / T 17626.2 電磁兼容 試驗和測量技術 靜電放電抗擾度試驗
GB / T 17626.3 電磁兼容 試驗和測量技術 第 3 部分: 射頻電磁場輻射抗擾度試驗
GB / T 17626.4 電磁兼容 試驗和測量技術 電快速瞬變脈沖群抗擾度試驗
GB / T 17626.5 電磁兼容 試驗和測量技術 浪涌(沖擊)抗擾度試驗
GB / T 17626.6 電磁兼容 試驗和測量技術 射頻場感應的傳導騷擾抗擾度
GB / T 17626.8 電磁兼容 試驗和測量技術 工頻磁場抗擾度試驗
GB / T 17626.10 電磁兼容 試驗和測量技術 阻尼振蕩磁場抗擾度試驗
GB / T 17626.18 電磁兼容 試驗和測量技術 阻尼振蕩波抗擾度試驗
DL / T860 (所有部分) 電力自 動化通信網絡和系統
3術語和定義
GB / T2900.1、 GB / T2900.33、 GB / T4365 界定的以及下列術語和定義適用于本文件。
3.1
絕緣監測 insulation monitoring
監視及測量低壓交、直流電源系統母線和支路對地絕緣狀況。
3.2
接地電阻grounding resistance
采用不接地運行方式的交、直流電源系統母線或支路的對地絕緣電阻。
3.3
平衡橋balancing bridge
一種 正、負極等值人工接地電阻與直流母線接地電阻構成的(惠斯通)檢測電橋, 在母線絕緣良好或接地電阻阻值相近時檢測電橋處于平衡狀態。
3.4不平衡橋unbalanced bridge
一種由(交替)投切的正、負極等值人工接地電阻構成的電橋, 并與平衡橋電阻構成檢測電橋。
3.5
信號注入法 signal injection method
用已知交流、直流、方波脈沖以 及自 適應脈沖的信號輸入在支路中, 監測對應產生的接地故障信號, 偵測接地支路或定位接地點的方法。
4基本要求
4.1工作環境
電力廠站低壓交直流用電系統絕緣監測設備(以下簡稱“絕緣監測設備”)的正常工作環境:
a )環境溫度為 -5 ℃ ~+40 ℃ ;
b ) 日平均相對濕度不超過 95% , 月 平均相對濕度不超過 90% , 無凝露;
c )海拔不超過 2 000 m ;
d )通風良好, 無爆炸危險, 無腐蝕性氣體, 無霉菌;
e )無劇烈振動源, 無強電磁干擾, 外磁場感應強度不超過 0.5 mT ;
f )振動水平加速度不超過 0.3 g , 垂直加速度不超過 0.15 g 。
注: 特殊環境條件在制定相關絕緣監測設備標準時考慮。
4.2電氣性能
4.2.1工作電源
4.2.1.1絕緣監測設備的工作電源應從母線上經過保護電器引 接。 用于監測直流系統時應采用直流輸入電源; 監測交流系統時應采用交流輸入電源或直流輸入電源, 不應采用交直流電源同時輸入。
4.2.1.2直流輸入電源應在以下范圍內正常工作:
a)220 V 電源電壓范圍為 176 V~286 V ;
b) 110 V 電源電壓范圍為 88 V~143 V ;
c)紋波系數 ≤5% 。
4.2.1.3交流輸入電源應在以下范圍內正常工作:
a )380 V 電源電壓范圍為 304 V~456 V ;
b ) 220 V 電源電壓范圍為 176 V~264 V ;
c )頻率范圍為 47.5 Hz~52.5 Hz ;
d )電壓為正弦波, 總諧波含量不超過 10% 。
4.2.2絕緣性能
絕緣監測設備的下列部位的電氣絕緣性能應不低于表 1 的要求:
a )非電連接的各帶電電路之間;
b )各獨立帶電電路與地(金屬框架)之間;
c )通信接口 對地(機箱金屬外殼)之間。
4.3通信及其他
5檢測要求
5.1分類
5.2功能指標
5.3主要方式
6安裝驗收
6.1檢查
6.2布置
6.3驗收
7運行維護
7.1運行
7.2維護
附錄A（規范性）環境適應能力和電磁兼容要求
附錄B（資料性）低壓直流不接地系統的絕緣監測
附錄C（資料性）低壓交流不接地系統的絕緣監測
附錄D（資料性）低壓交流接地系統的絕緣監測
參考文獻
