110kV Class Power Transformers

General The110kV class low loss transformers are developed by Huapengour workshop through years of service experience and careful analysis of the advantages and disadvantages of the transformers of different manufacturers, both domestic and abroad, and are featured by low loss, low partial discharge, low noise, high strength against short circuit, and high reliability in service. Its outstanding performance has won high reputation throughout China, and the world, and are highly appreciated by experts of the circle. Transformers can be made with welded tank cover and/or flange , Thus obviated from the necessity of lifting out the active part for inspection after arrival on site. Partial discharge level: apparent discharge < 80pC at 1.5 times rated voltage. Noise level : below 58 dB for transformers 63MVA and below with AN cooling Losses: no-load loss 30% lower than specified by GB/T 6451-1995 Reliability: no damage or oil leakage have been found in transformers in service up to the present Short-circuit withstand capability: Our SZ9-31500/110,SSZ-50000/110 transformers successfully passed short-circuit test in National Transformer Quality Inspecting and Testing Center, and in CESI Laboratory of Italy. Winding 1. Partially interleaved continuous winding is used for HV winding to improve its behavior under lightning impulse, because of its more uniform voltage distribution. 2. All the spacers and vertical strips are rounded at corners, in order to obtain a more reliable insulation structure. 3. Zig-Zag directional flow is provided inside the windings, so that all parts of the windings are better cooled, resulting in lower winding temperature rise, and specifically lower hot-spot temperature, thus the insulation life of the transformer is prolonged. 4. Separate regulating windings are provided for both the 110kV high voltage and the 35kV medium voltage side, so that a more balanced ampere-turn is obtained in spite of tap-changing, the short-circuit withstand capability is thus promoted. Radially, the windings of a phase assembly are tight-fit, little space is left between the core and the low-voltage cylinder, and between the windings. All the vertical strips and cylinders are thoroughly dried before assembly, so that a tight phase assembly can be finally obtained. Core 1. High permeability grain oriented high quality cold-rolled sheets are used for the fabrication of core. The sheets are cut on automatic cutting line made by Georg Co. of Germany or Soenen Co. of Belgium. The burrs are controlled within 0.02mm. 2. The core is stacked without stacking the upper yoke, the upper yoke sheets are placed into position after the winding blocks are mounted on the core. The joints of the core sheets are mitred 45°joint with step-lap. The stacked core is pressed under even pressure and the edge of the sheets are painted with epoxy resin, so that a straight, robust, integral structure is obtained, helping to reduce core loss and noise. 3. Wooden strips are driven into the space between core and LV cylinder. The yoke is kept tightened by epoxy-resin impregnated glass tape, while the lower yoke is pressed against the wall of the lower tank through threaded bolts. The active part of the transformer is in addition kept in position by devices at three places between the upper yoke and the tank cover in such a way that the active part cannot be displaced during transportation. Tank and Accessories 1. Corrugated tank improves the mechanical strength of tank and saves welding work. Wide gauge steel plate is used wherever it is mandated, to further reduce welded seams, eliminate ad much as possible the source of oil leakage. 2. And to the sealing surfaces are machined, and high quality heat and oil resistant material are used as gaskets. 3. Double groove, double sealing structure are used at the tank flange, the inner gasket is protected by the outer gasket from atmospheric effect including the effect of ultraviolet light, to prolong the life of the sealing system and to ensure its reliability as much as possible. 4. Stainless steel is used for the control cabinet as well as for the conduits of secondary wiring, so that the appearance is more pleasant-looking. Accessories 1. Because of the good relationship maintained and constant interchange of ideas with all the qualified sub-suppliers, requirements of our customer can be satisfied to the utmost extent. 2. With our patented cooling fan, transformers with forced air cooling can be made at a noise level below 63dB. 3. High efficiency radiators are developed and made by workshop itself. These radiators are purchased by other transformer manufacturers too, among them is the Toshiba Transformer Works at Nagoya for their 110kV transformers. Wind-cold Equipment Equipment body 　 　   Transformers for 300,500,600MW generator set:       The generator transformers of our company have been continuously improved in design and manufacturing technology, and achieved international level, the product meets GB(Chinese National Standard)and IEC standard. We have full ability to design and manufacture generator transformers of three phase unit and single phase bank for power station. 　   SF-75MVA/110KV main transformer   SFP-370000KVA/535KV main transformer       DFP-270MVA/5253 for power plant SFP-430MVA/242KV main transformer       OSFPS-150MVA/345KV SFP-360MVA/525KV transformer for power plant       SFP-370MVA/242KV main transformer ODFPSZ250000MVA/500kv the connect transformer