Home   Cart   Quotation   Policy   About-Us
www.ChineseStandard.net
SEARCH

GB/T 36551-2018 English PDF

US$919.00 · In stock
Delivery: <= 5 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB/T 36551-2018: Calculation methods for properties of concentric lay overhead electrical stranded conductors
Status: Valid
Standard IDUSDBUY PDFLead-DaysStandard Title (Description)Status
GB/T 36551-2018919 Add to Cart 5 days Calculation methods for properties of concentric lay overhead electrical stranded conductors Valid

Similar standards

GB/T 5585.2   GB/T 36102   GB/T 30552   GB/T 29324   GB/T 17937   

Basic data

Standard ID: GB/T 36551-2018 (GB/T36551-2018)
Description (Translated English): Calculation methods for properties of concentric lay overhead electrical stranded conductors
Sector / Industry: National Standard (Recommended)
Classification of Chinese Standard: K11
Classification of International Standard: 29.060.10
Word Count Estimation: 46,465
Date of Issue: 2018-07-13
Date of Implementation: 2019-02-01
Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration

GB/T 36551-2018: Calculation methods for properties of concentric lay overhead electrical stranded conductors


---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.
Calculation methods for properties of concentric lay overhead electrical stranded conductors ICS 29.060.10 K11 National Standards of People's Republic of China Calculation method for concentric stranded overhead conductor performance (IEC TR61597.1995, Overheadelectricalconductors-Calculationmethods Forstrandedbareconductors, MOD) Published on.2018-07-13 Implementation of.2019-02-01 State market supervision and administration China National Standardization Administration issued

Content

Foreword III 1 Scope 1 2 Normative references 1 3 symbols and abbreviations 1 4 current carrying capacity 3 5 AC resistance, inductive reactance and capacitive reactance 6 6 elongation of stranded wire 8 7 rated tensile strength of the wire 13 8 wire creep 13 9 strength loss 15 10 Calculation of the maximum disk length of the wire 16 Appendix A (informative) List of comparisons between this standard and IEC TR61597.1995 Appendix B (informative) List of technical differences between this standard and IEC TR61597.1995 and their causes Appendix C (informative) Example of calculation of conductor current carrying capacity under typical environmental conditions of IEC 22 Appendix D (informative) Calculation of conductor current carrying capacity under typical environmental conditions in China 24 Appendix E (informative) Calculation of resistance, inductance and capacitive reactance of wires 32 Reference 40

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009. This standard uses the redrafting method to modify the use of IEC TR61597..1995 "overall wire bare strand calculation method". This standard has been structurally adjusted compared to IEC TR61597.1995. Appendix A lists this standard and IEC TR61597. A summary of the numbering of chapters in.1995. There are technical differences between this standard and IEC TR61597.1995, and the terms involved in these differences have been passed on the outer side of the page. The vertical single line (|) in the blank position is marked, and Appendix B gives a list of the corresponding technical differences and their causes. This standard has made the following editorial changes. --- In line with the existing standard system, the standard name is changed to "the calculation method of concentric stranded overhead conductor performance"; --- In accordance with the requirements of GB/T 1.1-2009, the scope of the chapter added "this standard applies to GB/T 1179-2017 and NB/T 42060-2015 related performance calculations for overhead conductors". This standard was proposed by the China Electrical Equipment Industry Association. This standard is under the jurisdiction of the National Bare Wire Standardization Technical Committee (SAC/TC422). This standard was drafted by Shanghai Cable Research Institute Co., Ltd., Shanghai Zhongtian Aluminum Wire Co., Ltd., Jiangsu Hengtong Power Special Wire Co., Ltd. Company, Guangdong Yuanguang Cable Industry Co., Ltd., Jiangsu Tongguang Power Transmission Line Technology Co., Ltd., Far East Cable Co., Ltd., Shandong Huaneng Line Cable Co., Ltd., Zhengzhou Huali Cable Co., Ltd., Special Transformer Co., Ltd. Xinjiang Cable Factory, China Electric Power Research Institute Co., Ltd. Division, Shanghai Electric Power College, Shanghai National Cable Testing Center Co., Ltd. participated in the drafting. The main drafters of this standard. Xu Rui, Hu Yuanwei, You Weiren, Zhu Hongliang, Jiang Luzhen, Shi Haifeng, Xu Jing, Zhao Hui, Jiang Hongyi, Hu Zhengrui, Wang Jingchao, Zhao Wenbin, Wu Hao. Calculation method for concentric stranded overhead conductor performance

1 Scope

This standard gives the performance of the overhead conductors and their calculation methods in GB/T 1179-2017 and NB/T 42060-2015. include. ---Wire current carrying capacity. calculation method and typical example; ---AC resistance, inductive reactance and capacitive reactance; ---Wire elongation. heat and stress-strain data; ---Wire creep; --- Loss of strength of the aluminum wire due to high temperature; --- Calculate the maximum length of the wire into a disk. This standard does not cover all methods and theories for calculating wire performance, but gives a simple method with a certain degree of accuracy. This standard applies to the calculation of the relevant performance of overhead conductors involved in GB/T 1179-2017 and NB/T 42060-2015.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article. Pieces. For undated references, the latest edition (including all amendments) applies to this document. GB/T 1179-2017 round wire concentric stranded overhead conductor (IEC 61089..1991, MOD) Galvanized steel wire for GB/T 3428 overhead stranded wire (GB/T 3428-2012, IEC 60888.1987, MOD) GB/T 17048-2017 Hard aluminum wire for overhead stranding (IEC 60889.1987, MOD) GB/T 17937-2009 Aluminum-clad steel wire for electricians (IEC 61232.1993, MOD) GB/T 23308-2009 Aluminum-magnesium-silicon alloy round wire for overhead stranding (IEC 60104.1987, IDT) GB 50545-2010 110kV~750kV overhead transmission line design specification NB/T 42060-2015 steel core heat-resistant aluminum alloy overhead wire IEC 61089.1991 round wire concentric stranded overhead conductor (Roundwireconcentriclayoverheadelectricalstandard Conductors)

3 symbols and abbreviations

3.1 Symbols and units The following symbols apply to this document. A wire cross-sectional area in square millimeters (mm2) AL aluminum wire cross-sectional area AG steel wire cross-sectional area B Width of the inner wall of the reel, in meters (m) D wire diameter in meters (m) D1, d2 reel side plate diameter and core diameter in meters (m) E wire overall elastic modulus in megapascals (MPa) EL aluminum wire elastic modulus EG steel wire elastic modulus f frequency in Hertz (Hz) F wire rated tensile force in Newtons (N) The pull of the FL aluminum wire in Newton (N) The tensile force of the FLH aluminum alloy wire part in Newton (N) Tension of the FG steel wire part I wire current in amperes (A) Relative stiffness of K1 steel wire to aluminum wire Kc creep coefficient Ke relative blackbody emission coefficient Kg stratum coefficient Kp wire forming factor KS wire and shield gap factor L wire maximum loading length in meters (m) Nu Nusselt number Pconv convection heat dissipation in watts per meter (W/m) Pj power loss in watts per meter (W/m) Prad radiates heat in watts per meter (W/m) Psol sunshine heat absorption in watts per meter (W/m) r wire radius in meters (m) Re Reynolds number Wire resistance at RT temperature T in ohms per meter (Ω/m) s Steven Bozeman constant (5.67×10-8W∙m-2∙K-4) Si solar radiation intensity in watts per square meter (W/m2) t time in hours (h) T temperature in Kelvin (K) T1 ambient temperature in Kelvin (K) T2 wire final equilibrium temperature in Kelvin (K) v Wind speed in meters per second (m/s) Winding volume on the Vdr reel, in cubic meters (m3) Xc capacitive reactance (MΩ·km) in megaohms, with a calculation interval of 0.3m Xi Inductive reactance (Ω/km) in ohms per kilometer, calculated radius 0.3m α resistance temperature coefficient in Kelvin (K-1) αL aluminum wire cross-section and overall cross-section ratio of the wire αG steel wire cross-section and overall cross-section ratio of the wire β wire linear expansion coefficient in units of Kelvin (K-1) βL aluminum wire linear expansion coefficient βG steel wire linear expansion coefficient Δx variable x increment ε strain (unit elongation) εL aluminum wire elastic strain εC creep and permanent strain εG steel wire elastic strain εT thermal strain Φ Creep calculation temperature (T) coefficient γ solar heat absorption coefficient λ The thermal conductivity of the air film in contact with the wire, in units of (W·m-1·K-1) Time (t) coefficient of μ creep calculation σ pressure in MPa (MPa) σL The minimum standard value of tensile strength of aluminum or aluminum alloy wire before twisting, in megapascals (MPa) Σ1% The stress at 1% elongation of the steel wire (aluminum-clad steel wire) in the core, in megapascals (MPa) Minimum standard value of tensile strength of σG pre-twisted steel (or aluminum clad steel wire) in megapascals (MPa) 应力 Creep calculation of stress (σ) coefficient 3.2 Abbreviations The following abbreviations apply to this document. CCC current carrying capacity (A) (currentcarryingcapacity) Geometric mean radius (m) of the GMR wire (geometricmeanradiusoftheconductor)

4 current carrying capacity

4.1 General The wire current carrying capacity (CCC) is the maximum steady-state current when the wire temperature rises under certain environmental conditions. The current carrying capacity is related to the type of wire, resistance, maximum allowable temperature rise, environmental conditions, and the like. 4.2 Heat balance equation According to the principle of heat balance in thermodynamics, when the heat, heat absorption and heat dissipation of the wire finally reach equilibrium, it can be expressed by the formula (1). Pj Psol=Prad Pconv (1) In the formula. Pj --- the heat generated by the Joule effect; Psol --- sunshine heat absorption on the surface of the wire; Prad --- radiant heat dissipation of the wire; Pconv---convection heat dissipation of the wire. Note. Magnetic heat gain, corona heat increase or evaporative heat dissipation is not considered in equation (1). 4.3 Calculation method For the calculation of each part of the formula (1), under the steady state conditions, the current commonly used calculation methods respectively obtain the bias between the current-carrying values. The difference is about 10%. 4.4 Joule effect The power loss Pj(W/m) can be calculated by the Joule effect according to equation (2). Pj=RTI2 (2) In the formula. RT --- wire resistance at temperature T in ohms per meter (Ω/m); I --- Wire current in amps (A). 4.5 Rizhao heat absorption Sunshine heat absorption, Psol (W/m), can be calculated according to formula (3). Psol=γDSi (3) In the formula. γ --- solar radiation endothermic coefficient; D --- wire diameter in meters (m); Si---sunshine intensity in watts per square meter (W/m2). 4.6 Radiation cooling Radiation heat dissipation, Prad (W/m), can be calculated according to formula (4). Prad=SπDKe(T42-T41) (4) In the formula. S --- Steven Bozeman constant (5.67 × 10-8W ∙ m-2 ∙ K-4); D --- wire diameter in meters (m); Ke---relative coefficient of blackbody; T2---the final equilibrium temperature of the wire in Kelvin (K); T1--- Ambient temperature in Kelvin (K). 4.7 convection cooling Only forced convection heat dissipation is considered here, Pconv(W/m), which can be calculated according to equation (5). Pconv=λNu(T2-T1)π (5) In the formula. λ --- the thermal conductivity of the air film in contact with the wire (assuming it is constant and equal to 0.02585 W·m -1 · K -1); Nu --- Nusselt number, which can be derived from equation (6). Nu=0.65Re0.2 0.23Re0.61 (6) In the formula. Re --- Reynolds number, can be derived from equation (7). Re=1.644×109vD T1 0.5T2-T1( )[ ]{ } -1.78 (7) In the formula. v --- wind speed, in meters per second (m/s); D --- wire diameter in meters (m); T1---ambient temperature in Kelvin (K); T2---The final equilibrium temperature of the wire in Kelvin (K). 4.8 Current carrying capacity (CCC) calculation method It can be seen from equation (1) that the steady current can calculate the current carrying capacity from equation (8). Imax= Prad Pconv-Psol( )/RT[ ] 1/2 (8) In the formula. RT—The wire resistance at temperature T in ohms per meter (Ω/m). Ρsol, Prad, and Pconv can be calculated by the formula (3), the formula (4), and the formula (5). 4.9 Determine the maximum allowable temperature of the aluminum wire Determining the maximum allowable temperature of the aluminum wire requires consideration of the economic optimization of the line loss, or the maximum allowable tensile strength loss of the aluminum wire. Incumbent In any case, the maximum allowable temperature should be confirmed and the appropriate margin should be retained. 4.10 Calculated value of current carrying capacity Through the formula (8), the current carrying capacity of any wire under certain conditions can be calculated. Appendix C gives the calculated current carrying capacity for some wire sizes under typical conditions recommended in GB/T 1179-2017. These bars Changes in the components (especially wind speed and ambient temperature) will result in a change in the current carrying capacity, which needs to be recalculated according to equation (8). ---The speed of the transverse wind (90° on the line), v=1m/s; ---Sunlight intensity, Si=900W/m2; --- heat absorption coefficient, γ = 0.5; --- Blackbody radiation coefficient, Ke = 0.6; ---The final equilibrium temperature of the wire, T2 = 353K and 373K (corresponding to 80 ° C and 100 ° C); --- Ambient temperature, T1 = 293K (corresponding to 20 ° C); --- The frequency is 50Hz (the corresponding values at 60Hz are very close, the difference is within 2%). Appendix D gives the calculated current carrying capacity of some wire sizes under typical environmental conditions selected by domestic power engineering. These conditions Changes (especially wind speed and ambient temperature) will result in a change in the current carrying capacity, which needs to be recalculated according to equation (8). ---The speed of the transverse wind (90° on the line), v=0.5m/s; ---Sunlight intensity, Si=1000W/m2; --- heat absorption coefficient, γ = 0.9; --- Blackbody radiation coefficient, Ke = 0.9; ---The final equilibrium temperature of the wire, T2 = 343K, 353K and 363K [corresponding to 70 ° C, 80 ° C and 90 ° C (or 150 ° C)]; --- Ambient temperature, T1 = 308K (corresponding to 35 ° C); --- The frequency is 50Hz. 5 AC resistance, inductive reactance and capacitive reactance 5.1 General The resistance of a wire is a function of wire material, length, and cross-sectional area and is affected by wire stranding. In order to calculate more accurately, The resistance of the wire also depends on the change in current and frequency. Wires with a resistance greater than 0.02 Ω/km are given in GB/T 1179-2017. The nominal value of the DC resistance at 20 °C. DC resistance at other temperatures can be calculated by DC resistance and temperature coefficient of resistance at 20 °C inferred. Due to the skin effect, the current density is unevenly distributed on the wires, which increases the surface resistance of the wires. AC at a given temperature T The resistance can be calculated from the DC resistance and the temperature T on the basis of considering the skin effect. Two other important influencing factors caused by AC resistance are capacitive reactance and inductive reactance, which can be divided into two parts. the first part is at 0.30m. The magnetic flux in the radius is caused; the second part is generated from the radius of 0.30 m to the equivalent circuit of the wire. Appendix E gives the first part Inductive and capacitive values. 5.2 AC resistance The AC resistance is calculated from the DC resistance at the same temperature. The DC resistance of the wire rises with increasing temperature and is linear Department, can be calculated by equation (9). RT2=RT1 1 αT2-T1( )[ ] (9) In the formula. RT2---DC resistance at temperature T2; RT1---DC resistance at temperature T1; α --- Temperature coefficient of resistance at temperature T1. GB/T 1179-2017 and IEC 61089.1991 give the DC resistance of the wire corresponding to RT1 at 20 °C. The materials involved are The temperature coefficient of resistance at 20 ° C is as follows. ---L type hard aluminum wire. α = 0.00403K-1; ---L1 type hard aluminum wire. α = 0.00407K-1; ---L2 type hard aluminum wire. α = 0.00410K-1; ---L3 type hard aluminum wire. α = 0.00413K-1; ---LHA1, LHA2 type aluminum alloy wire. α = 0.00360K-1; ---LHA3 type aluminum alloy wire. α = 0.00390K-1; ---LHA4 type aluminum alloy wire. α = 0.00380K-1; ---NRLH1 type heat resistant aluminum alloy wire. α = 0.00400K-1; ---NRLH2 type heat resistant aluminum alloy wire. α = 0.00360K-1; --- LB various types of aluminum-clad steel wire resistance temperature coefficient is given in Appendix A of GB/T 17937-2009. According to the temperature coefficient of resistance at 20 ° C, the corresponding DC resistance of the wire at each final equilibrium temperature can be calculated. Due to the "skin effect", the AC resistance of the conductor is higher than the DC resistance. The reason for this phenomenon is that the inside of the conductor will pass more The flux linkage causes the inductance inside the conductor to be higher than the inductance at the outer surface. Due to the voltage drop across any length of the conductor over the entire cross section They must be equal, thus concentrating the current on the outer surface of the conductor, increasing the effective resistance. The method used to calculate the AC-DC resistance ratio is quite correct. Appendix E gives the AC resistance value calculated based on the typical method. For composite wires (Lx/Gxy wires) containing steel cores, the magnetomotive force is unbalanced due to the opposite stranding direction of adjacent layers, in the steel core The magnetic flux changes with current, causing the AC-DC resistance ratio to change with current, especially when the number of aluminum lines is odd. Although the magnetic effect on a single layer of Lx/Gxy wire may be significant, the magnetic effect on the 3-layer wire is not very noticeable, but does not affect Calculation of AC resistance values for these types of wires. 5.3 Inductive reactance The inductive reactance of the wire is calculated from the flux generated by the current flowing through the wire. To simplify the calculation, according to the commonly used 0.3m radius Division, the resistance can be divided into two parts. a) produced by a magnetic flux in the radius of 0.3 m (accurate value is 0.3048 m); b) Generated by a magnetic flux from a radius of 0.3 m to the equivalent loop of the conductor. Where part a) is the geometric coefficient (a function of the wire size) and part b) depends only on the phase-to-phase distance between the conductor and the transmission line. Part a) is calculated as follows, and part b) can be found in the ready-made technical literature. To calculate the inductive reactance of a wire within a radius of 0.3 m, the geometric mean radius (GMR) of the wire must be calculated first, as in equation (10). GMR=0.5DKg (10) In the formula. GMR --- the average geometric radius of the wire in meters (m); D --- wire outer diameter in meters (m); Kg --- Strand coefficient (ratio of radius). The stranding factor "Kg" depends only on the type and geometry of the conductor (number of conductor layers and number of single wires). Table 1 shows the different twisted shapes The value of "Kg" is calculated. Table 1 Twist layer coefficient "Kg" value for inductive reactance calculation Aluminum steel Number of layers in the root layer Strand coefficient Kg Aluminum steel Number of layers in the root layer Strand coefficient Kg 6 1 1 - a 45 3 7 1 0.7939 18 2 1 - 0.7765 54 3 7 1 0.8099 7 1 - - 0.7256 72 4 7 1 0.7889 ......
Image     

Tips & Frequently Asked Questions:

Question 1: How long will the true-PDF of GB/T 36551-2018_English be delivered?

Answer: Upon your order, we will start to translate GB/T 36551-2018_English as soon as possible, and keep you informed of the progress. The lead time is typically 3 ~ 5 working days. The lengthier the document the longer the lead time.

Question 2: Can I share the purchased PDF of GB/T 36551-2018_English with my colleagues?

Answer: Yes. The purchased PDF of GB/T 36551-2018_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.

Question 3: Does the price include tax/VAT?

Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countries

Question 4: Do you accept my currency other than USD?

Answer: Yes. If you need your currency to be printed on the invoice, please write an email to Sales@ChineseStandard.net. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.