On-load capacity regulating power transformer is one of the mainly-generalized new technical achievements of the State Grid Corporation of China. "Selection Guide for On-load Capacity Regulating Power Transformer" is prepared under the organization of the Production & Technology Department of State Grid Corporation of China in order to effectively guide the selection of on-load capacity regulating power transformer for company; this standard provides specific requirements for functions and technical indexes of on-load capacity regulating power transformer.
This standard is proposed and explained by the Production & Technology Department of the State Grid Corporation of China.
This standard is under the jurisdiction of the Ministry of Science and Technology of the State Grid Corporation of China.
Drafting organizations of this standard: China Electric Power Research Institute and China Electric Power Equipment Co., Ltd.
Chief drafting staff of this standard: Sheng Wanxing, Han Shaigen, Wang Jinli, Deng Hongfen, Xie Fang, Sun Yerong, Wang Furun, Fan Wenbo, Wu Yan and Guo Xianqing.
Selection Guide for On-load Capacity Regulating Power Transformer
有載調容配電變壓器選型導則
1 Scope
This standard specifies various technical requirements which shall be complied with upon manufacturing and selection of three-phase oil-immersed on-load capacity regulating power transformers (hereinafter referred to as "capacity regulating power transformer") with rated frequency of 50Hz, voltage grade of 10KV and rated capacity of 160 (50)~630(200)kVA.
This standard is applicable to 10KV power distribution system within the business area of the State Grid Corporation of China.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB 1094.1 Power Transformers - Part 1: General
GB 1094.2 Power Transformers - Part 2: Temperature Rise
GB 1094.3 Power Transformers - Part 3: Insulation Levels, Dielectric Tests and External Clearances in Air
GB 1094.5 Power Transformers - Part 5: Ability to Withstand Short Circuit
GB 1094.5 Power Transformers - Part 7: Loading Guide for Oil-immersed Power Transformers
GB 2536 Transformer Oils
GB 4208 Degrees of Protection Provided by Enclosure (IP Code) (IEC 60925-2001, IDT)
GB/T 6451 Specification and Technical Requirements for Three-phase Oil-immersed Power Transformers
GB/T 10230.1 Tap-changers - Part 1: Performance Requirements and Test Methods
GB/T 10230.2 Tap-changers - Part 2: Application Guide
GB/T 13384 General Specifications for Packing of Mechanical and Electrical Product
GB/T 15153.1 Telecontrol Equipment and Systems - Part 2: Operating Conditions - Section 1: Power Supply and Electromagnetic Compatibility (idt IEC 870-2-1:1995, MOD)
GB/T 17468 The Guide for Choice Power Transformers
JB/T 501 Test Guide for Power Transformers
DL/T 572 Operation Specification for Power Transformer
DL/T 597 Specification of Low-voltage Reactive Compensation Controls for Order
DL/T 698.1 Data Acquisition and Management System for Electrical Energy - Part 1: General Consideration
JB/T 3837 Identification Method of Transformers Product Type
JB/T 10088 Sound Level for 6kV~500kV Power Transformers
JB/T 10778 Three-phase Oil-immersed Adjusting Power Transformers
Q/GDW 200 Selection Guide for 10KV Regulating Capacity Power Transformer
IEC 60870-5-101 Transmission Protocols - Companion Standard for Basic Telecontrol Tasks
3 Terms and Definitions
For the purposes of this standard, the terms and definitions specified in GB/T 2900.1, GB 1094.1 and JB/T 10778 and those listed below apply.
3.1
Capacity regulating power transformer
The power transformer equipped with two different rated capacities and with the connection mode of high-voltage winding and low-voltage winding changed according to load change and can reliably operates under different rated capacity conditions.
3.2
On-load capacity regulating power transformer
The power transformer realizing capacity conversion under transformer excitation or load.
3.3
On-load capacity regulating tap-changers
A tap-changer capable of simultaneously changing the winding connection mode on high- and low-voltage sides of capacity regulating power transformer under capacity regulating power transformer excitation or load.
3.4
On-load capacity regulating controller
A control device capable of transferring relevant information and realizing the reliable conversion between high- and low-gear rated capacity operation modes through automatic detection and judgment according to actual loading condition of transformer under transformer excitation or load.
4 Product Model and Implication
For the formation of product model for capacity regulating power transformer, the low-gear rated capacity is written in parentheses, and other model compilation method meets the requirements of JB/T 3837, as shown below:
5 Technical Requirements
5.1 Basic requirements
5.1.1 Capacity regulating power transformers both before and after capacity regulating manufactured according to this standard shall meet the requirements of GB 1094.1, GB 1094.2, GB 1094.3, GB 1094.5 and GB/T 6451.
5.1.2 The rated capacity, voltage combination, connection symbol and performance parameter shall meet the requirements specified in Tables 1and 2.
Table 1 Technical Parameters of Type S11-M.ZT On-load Capacity Regulating Power Transformer
Rated capacity
kVA High voltage
kV High-voltage tapping range
% Low voltage
kV Connection symbol No-load loss W Load loss W Short-circuit impedance % No-load current
%
160(50)
10
10.5
11
±5
0.4
Dyn11 (Yyn0) 280(130) 2310(870)
4.0 1.6 (0.8)
200(63) 340(150) 2730(1040) 1.5 (0.7)
250(80) 400(180) 3200(1250) 1.4 (0.7)
315(100) 480(200) 3830(1500) 1.4 (0.7)
400(125) 570(240) 4520(1800) 1.3 (0.6)
500(160) 680(280) 5410(2200) 1.2 (0.6)
630(200) 810(340) 6200(2600) 4.5 1.1 (0.5)
Notes:
1 The parameter in parentheses refers to that with low capacity.
2 Technical parameters of other connection groups and corresponding technical parameters, where regarded as non-preferred, shall be negotiated between the user and the manufacturer.
3 Power transformers with high-voltage tapping range of ±2×2.5% or other tapping range may be provided as required by the user.
Table 2 Technical Parameters of Type S13-M.ZT On-load Capacity Regulating Power Transformer
Rated capacity
kVA High voltage
kV High-voltage tapping range
% Low voltage
kV Connection symbol No-load loss
W Load loss
W Short-circuit impedance
% No-load current
%
160(50)
10
10.5
11
±5
0.4
Dyn11 (Yyn0) 200(100) 2310(870)
4.0 1.4 (0.7)
200(63) 240(110) 2730(1040) 1.4 (0.7)
250(80) 290(130) 3200(1250) 1.2 (0.6)
315(100) 340(150) 3830(1500) 1.2 (0.6)
400(125) 410(170) 4520(1800) 1.0 (0.5)
500(160) 480(200) 5410(2200) 1.0 (0.5)
630(200) 570(240) 6200(2600) 4.5 0.8 (0.4)
Notes:
1 The parameter in parentheses refers to that with low capacity.
2 Technical parameters of other connection groups and corresponding technical parameters, where regarded as non-preferred, shall be negotiated between the user and the manufacturer.
3 Power transformers with high-voltage tapping range of ±2×2.5% or other tapping range may be provided as required by the user.
5.1.3 For the capacity regulating power transformer, positive deviations of no-load loss and load loss are not allowed.
5.1.4 The design, manufacturing, inspection and etc. of elements and components of capacity regulating power transformer shall meet those specified in relevant standards and regulations.
5.1.5 The transformer oil used for capacity regulating power transformer shall meet the requirements of GB 2536 while the oil used for on-load capacity regulating tap-changers shall meet the relevant requirements of GB/T 10230.2.
5.1.6 The sound level of capacity regulating power transformer shall meet the requirements of JB/T 10088.
5.1.7 During the switching process between high and low capacity for capacity regulating power transformer, the power supply continuity on low-voltage side shall be maintained; the duration of switching overvoltage generated on low-voltage side shall be less than 10ms and shall not affect the safe and stable operation of electrical equipment on low-voltage side.
5.2 Safety requirements
5.2.1 The design, manufacturing and inspection of elements and components of capacity regulating power transformer shall meet those specified in relevant standards and regulations.
5.2.2 Fully-sealed structure shall be adopted for the oil tank of capacity regulating power transformer, the oil tank may be corrugated oil tank, the oil tank with elastic panel-type radiator or the internally inflated oil tank etc.
5.2.3 Safety protection devices
a) The capacity regulating power transformer shall be equipped with pressure relief valve which shall be capable of releasing pressure reliably where the pressure in the oil tank reaches the safety limit, however, no transformer oil shall overflow;
b) The capacity regulating power transformer shall ensure that the pressure relief valve doesn’t operate at the maximum ambient temperature under the maximum permissible load state; the transformer oil level shall be able to ensure the insulation for each part reliably where the transformer has not been put into operation or at the minimum ambient temperature;
c) The capacity regulating power transformer shall be equipped with transformer oil level display device which shall reliably observe the oil level indication where at the maximum ambient temperature under the maximum permissible load state, or at the minimum ambient temperature and the transformer has not been put into operation;
5.2.4 The capacity regulating power transformer should be equipped with a tube socket used for thermometer, and the tube socket shall stretch into the transformer oil by 120mm±10mm.
5.3 Technical requirements for on-load capacity regulating tap-changers
5.3.1 Functional requirements
5.3.1.1 On-load capacity regulating tap-changers shall be provided with the function of simultaneously adjusting the winding connection mode for the high- and low-voltage sides of capacity regulating power transformer, and the non-simultaneity of three phase is less than or equal to 4ms.
5.3.1.2 The switching for on-load capacity regulating tap-changers shall be completed within 20-40ms, and the power supply continuity at low-voltage side shall be maintained.
5.3.2 Performance requirements
5.3.2.1 The rated capacity of on-load capacity regulating tap-changers is not less than the maximum capacity of transformers.
5.3.2.2 The electrical life and mechanical life of on-load capacity regulating tap-changers is not less than 50000 times and 100000 times respectively.
5.3.2.3 The working power supply of on-load capacity regulating tap-changers is AC 220V/AC 380V, the permissible deviation is -20~20%, and the operating power supply side shall be equipped with switching current-limiting device.
5.3.2.4 On-load capacity regulating tap-changers must be equipped with channel for pressure relief.
5.3.2.5 Other performance requirements shall comply with GB/T 10230.1.
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Product Model and Implication
5 Technical Requirements
6 Test
7 Type Selection Method
8 Marking, Packaging, Transportation and Storage
9 Installation, Operation and Maintenance
10 Delivery Documents and Information Required to be Provided during Bidding
