|
US$299.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email.
NB/T 41007-2017: Power supply technical guidelines for AC electric arc furnace. Design of power supply
Status: Valid
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| NB/T 41007-2017 | English | 299 |
Add to Cart
|
3 days [Need to translate]
|
Power supply technical guidelines for AC electric arc furnace. Design of power supply
| Valid |
NB/T 41007-2017
|
PDF similar to NB/T 41007-2017
Basic data | Standard ID | NB/T 41007-2017 (NB/T41007-2017) | | Description (Translated English) | Power supply technical guidelines for AC electric arc furnace. Design of power supply | | Sector / Industry | Energy Industry Standard (Recommended) | | Classification of Chinese Standard | K04 | | Classification of International Standard | 29.020 | | Word Count Estimation | 13,127 | | Date of Issue | 2017-08-02 | | Date of Implementation | 2017-12-01 | | Quoted Standard | GB/T 2900.15; GB/T 2900.23; GB 5959.1; GB 5959.2; GB/T 10066.10; GB/T 10067.21; GB 50059; GB 50060; GB/T 50063; DL/T 5218; DL/T 5352; JB/T 9640; JB/T 10429 | | Regulation (derived from) | National Energy Board Bulletin 2017 No. 8; Industry Standard Filing Announcement 2017 No. 10 (Total No. 214) | | Issuing agency(ies) | National Energy Administration | | Summary | This standard specifies the design requirements for AC arc furnace power supply, total step-down substations, and AC arc furnace electrical systems. This standard applies to the power supply and distribution system of not less than 70t AC arc furnace powered by 330kV and below voltage levels. Other capacity AC arc furnaces can be implemented with reference to this standard. | NB/T 41007-2017: Power supply technical guidelines for AC electric arc furnace. Design of power supply
---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.
Power supply technical guidelines for AC electric arc furnace.Design of power supply
ICS 29.020
K04
Record number. 59882-2017
People's Republic of China Energy Industry Standard
AC electric arc furnace power supply technical guidelines
Power supply design
Published on.2017-08-02
2017-12-01 implementation
Published by the National Energy Administration
Content
Foreword I
1 Scope 1
2 Normative references 1
3 Terms and Definitions 1
4 power supply requirements 1
5 total step-down substation design requirements 2
6 Electric arc furnace (EAF) power design 2
6.1 Electric arc furnace installation power supply line 2
6.2 High-voltage power distribution unit 2
6.3 Electric arc furnace transformer 2
6.4 series reactor 3
6.5 Electric arc furnace device high current line 3
6.6 Protection, Measurement and Signaling 4
6.7 Equipment layout 4
6.8 Electrical Safety 4
7 Power design of ladle refining furnace (LF) 5
7.1 Ladle refining furnace (LF) unit power supply line 5
7.2 Ladle Refining Furnace (LF) Transformer 5
7.3 Other 5
Appendix A (informative) Main wiring diagram of typical electric arc furnace power supply system Figure 6
Appendix B (informative) Typical example of electric arc furnace power supply line Figure 7
Appendix C (informative) Typical example of power supply line for ladle refining furnace (LF) unit Figure 9
Foreword
This standard was drafted in accordance with the rules given in GB/T 1.1-2009.
This standard is proposed and managed by the National Voltage and Current Rating and Frequency Standardization Technical Committee.
This standard was drafted. China Metallurgical Jingcheng Engineering Technology Co., Ltd., China Metallurgical Saidi Engineering Technology Co., Ltd., China Machine Productivity Promotion
center.
The main drafters of this standard. Chen Qizhi, Liu Guangwen, Zhang Yuchuan, Zhu Leilei, Liu Juzhu, Liu Zhilian, Liu Jing.
AC electric arc furnace power supply technical guidelines
Power supply design
1 Scope
This standard specifies the design requirements for AC arc furnace power supply, total step-down substation and AC arc furnace power system.
This standard applies to the power supply and distribution system of AC arc furnace not less than 70t powered by 330kV and below. Other capacity
The AC arc furnace can be implemented with reference to this standard.
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 2900.15 Electrotechnical terminology transformers, transformers, voltage regulators and reactors
GB/T 2900.23 Electrotechnical terminology industrial electric heating device
GB 5959.1 Safety of electric heating devices - Part 1. General requirements
Safety of electric heating devices - Part 2. Particular requirements for electric arc furnace installations
GB/T 10066.10 Test methods for electric heating devices - Part 10. Direct electric arc furnace
GB/T 10067.21 Basic technical requirements for electric heating devices - Part 21. Large-scale AC electric arc furnace
GB 50059 35kV~110kV substation design specification
GB 50060 3~110kV high voltage power distribution unit design specification
GB/T 50063 Electric device electrical measuring instrument device design specification
Technical specification for DL/T 5218 220kV~750kV substation design
DL/T 5352 high voltage power distribution unit design technical specification
JB/T 9640 electric arc furnace transformer
JB/T 10429 ladle refining furnace transformer
3 Terms and definitions
GB/T 2900.15, GB/T 2900.23, GB 5959.2, GB/T 10066.10 and GB/T 10067.21 and the following
Terms and definitions apply to this document.
3.1
Electric arc furnace transformer secondary side voltage regulation voltageregulationofEAFtransformer
The electric arc furnace transformer usually adopts three kinds of voltage regulation methods. variable magnetic flux voltage regulation, pre-autotransformer voltage regulation and series transformer voltage regulation.
The secondary side voltage of the arc furnace transformer is adjusted within a certain range to meet the needs of the smelting process. The latter two ways can achieve electric arc furnace change
The secondary side voltage regulation steps of the press are equal.
4 power supply requirements
4.1 The total step-down substation that supplies the electric arc furnace should be powered by two independent high-voltage power supplies.
4.2 In the engineering feasibility study stage, the power quality of the common connection point (PCC point) of the arc furnace should be pre-evaluated. The result should be
Meet the requirements of relevant national standards.
5 total step-down substation design requirements
5.1 The total step-down substation should use special step-down transformer or special busbar isolated from other power users to supply power to the arc furnace transformer.
For the main wiring of the electric arc furnace power supply system, see Figure A.1 in Appendix A.
5.2 The design shall comply with the relevant provisions of GB 50059 and DL/T 5218.
5.3 The capacity of the dedicated step-down transformer shall be greater than the sum of the capacity of the arc furnace transformer to which it is supplied. The capacity and structure should consider the electric arc furnace
Transformer load cycle, shock overcurrent value, negative sequence and harmonic current.
5.4 The selection of the cross section of the power supply conductor for the EAF transformer shall take into account the effects of overload and harmonic current of the EAF transformer.
5.5 The power quality control device should be installed near the AC arc furnace workshop.
5.6 The neutral point of the medium voltage system of the transformer to the arc furnace transformer should be grounded with low resistance.
6 Electric arc furnace (EAF) power design
6.1 Electric arc furnace device power supply line
6.1.1 The power supply system of a single electric arc furnace should be powered by line-transformer mode. The design of the high voltage switch unit of the electric arc furnace should be simplified.
Single and easy to operate. The typical design of the electric arc furnace power supply line is shown in Figure B.1 in Appendix B.
6.1.2 Isolation switch and grounding switch should be provided at the front end of the reactor or electric arc furnace transformer (without reactor).
6.1.3 The conductor current capacity of the power supply line of the electric arc furnace device and the rated current of the electrical equipment should be greater than the overload capacity of the electric arc furnace transformer.
Current value.
6.1.4 On the primary side of the electric arc furnace transformer, measures should be taken to limit the operation of overvoltage, and zinc oxide should be installed between the three phases and each relative ground.
A lightning damper and a RC absorption device should be installed in the opposite direction.
6.1.5 The electric arc furnace transformer shall be equipped with a voltage absorbing capacitor on the secondary side. If there is a third winding drawn, it shall be led in the third winding.
A zinc oxide surge arrester or a RC absorption device is provided at the source.
6.2 High-voltage power distribution unit
6.2.1 The design shall comply with the relevant provisions of GB 50060 and DL/T 5352.
6.2.2 The circuit breaker on the high voltage side of the EAF transformer shall have frequent operation capability and shall be controlled on the main console. Circuit breaker, isolation
The switch and grounding switch shall be provided with an interlock that prevents misoperation.
6.3 Electric arc furnace transformer
6.3.1 The design shall comply with the relevant provisions of JB/T 9640.
6.3.2 The capacity and overload capacity of the EAF transformer shall be in accordance with the power requirements of the process system; the optional primary voltage shall be subject to technical economy.
After comparison, it is determined; the voltage of the secondary side of the arc furnace transformer and the voltage regulation of the secondary side of the arc furnace transformer should conform to the production process.
Requirements.
6.3.3 The electric arc furnace transformer shall adopt the on-load voltage regulation mode. When the primary side voltage of the transformer exceeds 35kV, it is better to use series transformer
Pressure mode or pre-autotransformer voltage regulation mode; for a primary voltage 220kV, the capacity of more than 120MVA arc furnace transformer,
It is advisable to use a pre-autotransformer voltage regulation method.
6.3.4 The recommended value of the voltage level on the secondary side of the EAF transformer should be selected according to Table 1.
Table 1 Recommended values for the voltage level of the secondary side of the EAF transformer
Transformer capacity/MVA 50~90 ≥90
Voltage series/15~17 17~23
Note. For the electric arc furnace in the modern “three-in-one” process, the transformer can be appropriately reduced without affecting the service life of the transformer on-load tap changer.
The number of stages of the secondary side voltage.
6.3.5 The electric arc furnace should adopt the electric arc furnace transformer with equal voltage regulation step, and confirm the voltage adjustment level difference according to the transformer capacity.
The value should be selected according to Table 2.
Table 2 Recommended values for the voltage difference of the secondary side of the EAF transformer
Transformer capacity/MVA 50~90 ≥90
Voltage level difference/V 20~35 25~40
6.3.6 The constant power section of the secondary voltage of the EAF transformer shall meet the requirements of the main melting period and the rapid heating period for high-power supply, and the electric arc furnace shall be changed.
The constant current section of the secondary voltage of the press should meet the requirements of temperature regulation and heat preservation during the arcing and refining period. Constant power section of secondary voltage of electric arc furnace transformer
The recommended number of series should be selected according to Table 3.
Table 3 Recommended values of secondary voltage constant power stage series of electric arc furnace transformer
Transformer capacity/MVA 50~90 ≥90
Constant power section voltage series/6~9 9~12
Note. For the electric arc furnace in the modern “three-in-one” process, more constant power gears should be set, accounting for 40%~50% of the total number of gears. If the electric arc furnace bears
More refining and heat preservation tasks can reduce the constant power section gear appropriately, but it should not be less than 25% of the total gear.
6.4 series reactor
6.4.1 The design shall comply with the relevant provisions of JB/T 9640.
6.4.2 The series reactor should be iron core type and should be equipped with overvoltage protection device. When using the electric arc furnace device power supply line code in Appendix B
For the example diagram, the reactor should be installed close to the EAF transformer.
6.4.3 Series reactors shall be provided with intermediate taps that can change the reactance value as required by the process. The tap position should be set from 4 to 6 files, which can be totaled.
The reactance value is evenly distributed among the gear positions; or the average distribution is 40% or more of the total reactance value, and the gear position is not set below 40%.
6.5 Arc furnace device high current line
6.5.1 The design shall comply with the relevant provisions of GB 10067.21.
6.5.2 The secondary side of the EAF transformer shall be sealed with a triangle. Large arc furnaces should be sealed inside the transformer or at the front end of the water-cooled cable.
6.5.3 The unbalance factor of the three-phase impedance of the high-current line of the electric arc furnace device shall not exceed 5%.
6.5.4 The dynamic stability check of the conductor shall be included in the increased electromagnetic force at the intersection of the busbar and the turn. The distance between the conductor supports should be resonant
check.
6.5.5 The setting of the brackets, protective shutters, casings, armor, fasteners and adjacent metal parts of the electric arc furnace conductor shall be selected
Reduce induction heat.
6.6 Protection, measurement and signalling
6.6.1 The design shall comply with the relevant provisions of GB/T 50063 and GB 10067.21.
6.6.2 The arc current of the arc furnace electrode regulator should be directly measured by setting the Rogowski coil at the secondary side outlet of the transformer.
6.6.3 When the electric arc furnace transformer adopts the series transformer voltage regulation mode, the current transformer can be installed in the third winding (series voltage regulating winding)
The secondary side current should be converted to a ratio and should be in phase.
6.6.4 The primary side detection circuit of the electric arc furnace transformer shall be equipped with an ammeter, a voltmeter, an active power meter capable of detecting the maximum demand, active power and
Reactive energy meter. The electric arc furnace console should be equipped with a meter that displays the electrode current and phase voltage. The range of the above ammeter and power meter should be considered
The condition of the electric arc furnace overload.
6.6.5 The electric arc furnace shall be set with the following contact signals.
a) energizing and de-energizing signals on the high voltage side of the electric arc furnace transformer;
b) electric arc furnace transformer voltage gear indication signal;
c) an indication signal of the reactor gear position;
d) arc voltage signal per phase of the electric arc furnace;
e) oil circulation system fault signal;
f) fault signal of the electric arc furnace transformer water or wind cooling system;
g) operating the power supply voltage loss signal;
h) Other signals required by the process.
6.7 Equipment layout
6.7.1 The design shall comply with the relevant provisions of DL/T 5352, GB 50059 and GB 50060.
6.7.2 The electric arc furnace should be equipped with a separate high-voltage switch room, and the reactor should be installed close to the transformer. The reactor can be set at the front end of the high voltage switch
A separate reactor room and cable connection is preferred.
6.7.3 The electric arc furnace transformer should be close to the electric arc furnace under the condition of ensuring the maintenance space to shorten the length of the large current line of the electric arc furnace device.
The height of the transformer can be raised.
6.7.4 The electric arc furnace transformer room should be equipped with a space for loading oil or filtering oil.
6.7.5 An oil sump with a capacity of 100% transformer oil or a facility for discharging oil to a safe space shall be provided.
6.7.6 The electric arc furnace shall be provided with an operation room and shall be controlled by a console. The elevation of the floor of the operating room and the position of the observation window and console should
It enables the operator to observe the action of the machine being operated and the condition before the furnace. The arc furnace energization operation should be controlled on the main console. control
The room should take measures to prevent smoke from entering.
6.7.7 The electric arc furnace shall be provided with a low voltage and control room. The power equipment and control equipment below 1000V may be installed in the control room.
6.7.8 The electric arc furnace mechanism to be operated by the furnace shall be provided with operating equipment beside the furnace.
6.8 Electrical safety
6.8.1 The design shall comply with the relevant provisions of GB 5959.1 and GB 5959.2.
6.8.2 The electric arc furnace device should be grounded reliably, the grounding resistance should be no more than 4 Ω; in the high soil resistivity area, it should be no more than 10 Ω.
6.8.3 For static charges that endanger the safety of personnel or the normal operation of the device, grounding, shielding and other restraining measures should be taken and adequate protection should be maintained.
distance.
6.8.4 The electric arc furnace shall be provided with interlocking measures to ensure maintenance and operational safety requirements.
6.8.5 Indicators for energizing and de-energizing should be installed in the operating area of the EAF.
6.8.6 When the electric arc furnace is tilted to the pouring site, the sound and light signals that can be heard and seen by the personnel in the pouring site should be set.
6.8.7 Warning signs or fences to prevent personnel from entering should be provided under the EAF platform and under the water-cooled cable.
7 electric design of ladle refining furnace (LF)
7.1 Ladle refining furnace (LF) unit power supply line
7.1.1 The typical design of the power supply line is shown in Figure C.1 in Appendix C.
7.1.2 Other design contents can be implemented with reference to the relevant content of the electric arc furnace power supply line.
7.2 Ladle Refining Furnace (LF) Transformer
7.2.1 The design shall comply with the relevant provisions of JB/T 10429.
7.2.2 The ladle refining furnace transformer shall be determined after technical and economic comparison, and the primary voltage, secondary voltage and voltage regulation mode shall be in accordance with the process system.
Claim.
7.2.3 On-load voltage regulation should be adopted.
7.2.4 The ladle refining furnace transformer shall determine the secondary voltage according to the requirements of the ladle refractory life, smelting process, heating rate and so on. generally
Next, the thickness of the process slag can shield the arc to obtain the maximum arc length, and thereby determine the highest secondary voltage. In addition, the arc voltage should be higher than
70V.
7.2.5 Transformer taps with equal voltage difference should be used. The voltage level difference should be set to 10V~20V, and the number of stages should be set to 7~13.
7.2.6 The design of the transformer tap of the ladle refining furnace shall be set with constant power section and constant current section voltage. Constant power section voltage should meet the conditions of the furnace
The rapid temperature rise requirement of good time, the constant current section voltage should meet the requirements of steel liquid insulation. The constant power section tap voltage should be set to 3 to 5 levels, constant
The current segment tap voltage should be set to 5 to 8 levels.
7.3 Other
High-voltage power distribution equipment, high-current lines, protection measurement and signal, equipment layout, electrical safety requirements for ladle refining furnace
Related items.
Appendix A
(informative appendix)
Main wiring diagram of typical electric arc furnace power supply system
The main wiring of a typical electric arc furnace power supply system is shown in Figure A.1.
2 back 330kV (or 220, 110, 66kV) power supply, quoted from the regional power grid
Figure A.1 Typical electric arc furnace power supply system diagram
Appendix B
(informative appendix)
Typical example diagram of electric arc furnace power supply line
A typical example of a power supply line for an electric arc furnace unit is shown in Figure B.1.
Figure B.1 Typical example diagram of the electric arc furnace power supply line
Description.
1---incoming disconnecting switch;
2---voltage transformer;
3---high voltage circuit breaker;
4---current transformer;
5---transformer room isolation switch;
6---Resistance-capacitor absorber;
7---Zinc oxide arrester;
8---series reactor;
9---Electric arc furnace transformer;
10---voltage limiting capacitor;
11---Royce coil and integral circuit;
12---secondary voltage transformer.
Note. When the reactor of the electric arc furnace device is not equipped with a reactor, a lightning arrester and a RC absorption device shall be installed between the electric arc furnace transformer and the operating circuit breaker;
When the reactor of the electric arc furnace device power supply line is set between the operation circuit breaker and the electric arc furnace transformer, the reactor and the transformer should be installed as close as possible.
A lightning arrester and a RC absorption device shall be provided between the reactor and the operating circuit breaker.
Figure B.1 (continued)
Appendix C
(informative appendix)
Typical example of power supply line for ladle refining furnace (LF) unit
A typical example of a power supply line for a ladle refining furnace (LF) unit is shown in Figure C.1.
Figure C.1 Typical example of the power supply line of the ladle refining furnace (LF) unit
Description.
1---incoming disconnecting switch;
2---high voltage circuit breaker;
3---current transformer;
4---voltage transformer;
5---transformer room isolation switch;
6---Resistance-capacitor absorber;
7---Zinc oxide arrester;
8---Electric arc furnace transformer;
9---voltage limiting capacitor;
10---Royce coil and integral loop;
11---Secondary voltage transformer.
Figure C.1 (continued)
Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of NB/T 41007-2017_English be delivered?Answer: Upon your order, we will start to translate NB/T 41007-2017_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time. Question 2: Can I share the purchased PDF of NB/T 41007-2017_English with my colleagues?Answer: Yes. The purchased PDF of NB/T 41007-2017_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+ countriesQuestion 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 [email protected]. 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.
|