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China National Electric Wire & Cable Imp./Exp. Corp. |
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CNEW is export agency of Xian XD Transformer Co. Ltd. Their transformers is erected in most of CNEW’s substation project. In 2003 CNEW supplied 410kV/33kV-250MVA transformer to Germany, that was the first ultra high voltage transformer exported to Germany from China
Xian XD Transformer Co. Ltd.. is the largest base for manufacturing complete sets of ultra-high voltage AC transmission and transformation equipment in China. Xian XD Transformer Co. Ltd... is the largest base for manufacturing complete sets of ultra-high voltage DC transmission and transformation equipment in China. Xian XD Transformer Co. Ltd.. is the largest base for researching and developing complete sets of ultra-high voltage AC & DC transmission and transformation equipment in China , and is appointed by the state as the national profession center responsible for the quality supervision, examination and test. Xian XD Transformer Co. Ltd.. is the largest base for exporting complete sets of ultra-high voltage AC & DC transmission and transformation equipment in China.
Since it started design in 1978 and manufactured the first batch of 500 kV power transformer in China in 1980, Xian XD Transformer Co. Ltd.. has supplied the worldwide customers with various types of large transformers including 500 kV step-up transformers and auto-transformers, etc. With the constant development in past twenty years, Xian XD Transformer Co. Ltd.. has accumulated rich experiences on design and manufactrue of 500 kV power transformer, and had a reliable ability to manufacture high quality of the products to meet the requirements of customers.
Started to research and manufacture 330 kV power transformer in 1970s, Xian XD Transformer Co. Ltd.. has successively provided many step-down transformers, communication transformers and generator transformers of SFP9-370MVA/330kV, SSP7-360MVA/330kV, OSFPSZ9-240MVA/330kV for the northwest 330kV network in China. The capacity of 330kV made by Xian XD Transformer Co. Ltd.. occupies above 60% of total capacity of 330kV transformer in China. Xian XD Transformer Co. Ltd. has become the main supplier of 330kV transformers inside the country.
In 1969, Xian XD Transformer Co. Ltd.. produced its first 360MVA/220 kV power transformer for Danjiangkou hydroelectric power plant in Hubei province that was the largest transformer in China at that time. Since then, Xian XD Transformer Co. Ltd.. has for more than thirty years been making unremitting efforts to improve the technology of 220 kV power transformers and has already developed to be a leading supplier in the country. By extensively applying the structure of full folding plate of pressed arch-type tank of 110 kV power transformer to 220kV power transformer, Xian XD Transformer Co. Ltd.. makes the structure of 220 kV products more reasonable and more compact and the outward appearance substantially novel and unique, which wins excellent reputation in the market. Besides, this structure is more convenience for customers in the aspects of assembling and lifting core for check on site.
Based on the digestion and absorption of the importing technique, Xian XD Transformer Co. Ltd.. designs and manufactures series of 110kV power transformers with the characters of low loss, low noise, good ability of withstanding short-circuit and high operating reliability. New series of 110kV power transformers by Xian XD Transformer Co. Ltd.. have various types of structures that will be suitable for the requirements in different installing environment, such as city network, agriculture network, indoor and outdoor, etc. Since 1992, Xian XD Transformer Co. Ltd.. has provided the customers nearly 700 units of new series of 110kV products among which 300units have been exported to Malaysia, Thailand, Indonesia, Indian, China Hong Kong special administrative region and so on.
Generator transformer used in power station Generator transformer is the key equipment for electric power generation and power transmission. The generator transformer, designed and manufactured by Xian XD Transformer Co. Ltd.., fully complies with requirements of power design with its excellent performances of low loss, low noise, low partial discharge, good ability of short-circuit withstand, and reliable operation. The voltage class covers a range from 110 kV to 500 kV with the biggest capacity of 420 MVA for three-phase transformer. Xian XD Transformer Co. Ltd.. also provides single-phase generator transformer and various types of combined transformers capable of overcoming harsh transportation conditions. Xian XD Transformer Co. Ltd.. can provide varied products to match all kinds of thermal power sets and water power sets, such as 200MW, 250MW, 300MW and 600MW, etc. Among them, two new types of generator transformers of SFP10-370 MVA/220 kV and SFP9-420 MVA/220 kV have passed the appraisal for new products given by the National Machinary Department and the National Power Department. The specification and the performance of SFP10-400 MVA/500 kV power transformer have reached to the leading level in the world. SFP-160 MVA/420 kV transformer exported to lraq is so far the product with the highest voltage level amon all exported transformers in China, with its technical level has ranked in the international leading list.
Double split transformer used in power station In order to meet the requirements of power stations for safety electric generation, Xian XD Transformer Co. Ltd.. specially designs and manufactures the radial double split transformer with low voltage, which enhances the ability of short circuit withstand of the transformer and the starting/spare transformer used in power station. The voltage class covers a range from 35 kV to 220kV with a range of the capacity from 31.5 MVA to 63 MVA. Recently, Xian XD Transformer Co. Ltd.. has developed 50 MVA/330 kV axial double-split low voltage starting/spare transformer. And now Xian XD Transformer Co. Ltd.. Transformer is continuously working on the development of 330kV radial double split transformer.
Operating characteristics of low voltage transformer High short-circuit impedance between two LV windings, but the respect impedances between two LV windings and HV winding are equal and low. Split factor K is more than 4.5 normally Small unbalance between turns and good ability of short-circuit withstand. One of windings can work separately with high reliability. HV winding is located between two LV windings with balance force, which enhances the ability of shortcircuit withstand.
The transformers are in accordance with National Standards IEC. The voltage regulation range is 10 4 2.5% kV for 10kV class and 35 3 2.5% for 35kV class. Voltage regulation is effected by adjusting the on-load tap-changer on the high voltage side. Adjustment can be made manually or motor-operated, and in the latter case automatic regulation is also possible through additional devices. Such transformers can keep the output voltage on the secondary side at a required stable level. The tank wall of more than 35kV 3150kVA transformer is made into a corrugated shape. Thus, mechanical strength is much improved, and weldding work reduced, and the outlook appearance is improved too. Therefore they are widely used in places where requirment on voltage quality is emphasized, such as institutes, buildings, hotels, hospital and factories. These transformers are new products and have better economy in operation.
FEATURES OF PRODUCTS The SC9-Z type transformer we producted is low-noise low-loss cast resin dry-type transformer. Due to excellent design, high material quality, scientific formulation, and strict processing and quality control, the transformers can boast to have the following outstanding characteristics: HV winding with cupper thread and LV winding with cupper thread or cupper foil are wound and reinforced by glass-fibre and then cast with resin under vacuum. After curing, windings with high mechanical strength, substantially no partial discharge, and consequently high reliability can be obtained. Flame-proof, self-extinguishing and no pollution. The epoxy resin and insulating materials used for windings are self-extinguishing and will not burn continuously by an electric arc. No toxic gas will be given out when the resin is burned. Good adaptability to environment. The windings will not absorb moisture and the core and frame are sealed with a special anti-rust protective coating. The transformer
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