PRODUCTS CENTER
sao tome and principe Oil-immersed power transformer
Product Description
Detailed content
Product Structure and Process Features
The transmission and distribution system delivers electricity from distant power plants to users via regulated pathways. Electricity is transmitted through high-voltage transmission lines, and after being stepped down at multiple levels of substations, it finally becomes suitable for end-user consumption. Near the final electricity consumers, distribution transformers further reduce the voltage to an appropriate level. Transformers that lower the voltage to the operating range required by electrical equipment are called distribution transformers. These transformers are commonly used for everyday lighting as well as factory power supply, typically operating at low voltages of 0.4 kV or below. Distribution transformers are generally small in capacity, usually rated at 2,500 kVA or less, and their primary voltage ratings also remain relatively low—typically 35 kV or below. Unlike conventional oil-immersed transformers, our company’s fully sealed distribution transformers eliminate the traditional oil conservator tank. Instead, corrugated fins integrated into the transformer’s oil tank serve as both cooling and expansion/contraction elements, ensuring complete isolation of the transformer oil from the atmosphere. Distribution transformers come in two main types: step-down transformers with adjustable capacity and dual-voltage distribution transformers. The adjustable-capacity transformer features two distinct capacity settings, allowing it to adapt dynamically to varying load demands. By modifying the connection method of the high-voltage winding, switching between parallel and series configurations in the low-voltage winding, and fine-tuning individual tap positions, this type of transformer achieves seamless capacity adjustments without requiring excitation. Moreover, when transitioning from a higher to a lower capacity setting, the increased number of low-voltage windings significantly reduces the magnetic flux density in the iron core, leading to lower unit losses in the silicon steel laminations. As a result, both no-load losses and no-load current are minimized, effectively achieving energy-saving and loss-reduction benefits. The dual-voltage distribution transformer, on the other hand, offers two selectable voltage levels and can automatically adjust according to fluctuations in grid voltage. Similar to the adjustable-capacity model, its high- and low-voltage windings undergo switching between parallel and series connections, while tap position adjustments are managed by specialized non-excitation switches.
Features:
The distribution transformers are designed using CAD, ensuring performance that complies with IEC60076, GB1094, and GB/T6451 standards. The transformer core is made from cold-rolled grain-oriented silicon steel sheets, fabricated via an automated production line employing the Step-Lap jointing technique. The transformer tank features a corrugated design, manufactured on an automated production line provided by Germany’s GEOGE company. Both the surface pretreatment solution and the coating powder used are sourced from internationally recognized brands. After undergoing thorough pretreatment—including degreasing, pickling, phosphating, and electrophoretic processes—on an automated assembly line, the tank is powder-coated and subsequently cured at high temperatures, resulting in exceptional corrosion resistance for the transformer exterior. The transformer windings are wound using high-strength enameled wire (or paper-insulated wire), ensuring uniform ampere-turn distribution and a well-designed insulation structure, which collectively provide outstanding resistance to short-circuit forces. Additionally, the transformer core assembly adopts a maintenance-free, coreless design, while premium-grade acrylate rubber seals are utilized to effectively prevent both photo-oxidation and thermal aging.
Technical specifications:
1. Voltage Level: 10kV;
2. Voltage regulation method: No-load voltage regulation or on-load voltage regulation;
3. Tap range: ±5%, ±2 × 2.5%, or ±4 × 2.5%;
4. Capacity range: 30–25,000 kVA;
5. Frequency: 50Hz, 60Hz;
6. Single-phase, three-phase;
7. Connection group designation: Yyn0 or Dyn11 (or as per user requirements);
8. Short-circuit impedance: According to national standards or as per user requirements;
9. Operating Environment: Relative humidity up to 100%, with ambient temperature not exceeding 40°C (or as per user requirements);
10. Cooling method: AN;
11. Insulation Level:
①10kV-class products have a power-frequency withstand voltage of 35kV and an impulse withstand voltage of 75kV,
Company Address:
No. 9 Qianfeng North Road, Shiji Town, Panyu District, Guangzhou City
Follow us
Copyright © Guangzhou Yibian Electrical Equipment Co., Ltd. Urban sub station Power by 300.cn SEO