In decentralized power distribution networks, single-phase transformers offer significant advantages as distribution transformers. They can reduce the length of low-voltage distribution lines, decrease line losses, and improve power supply quality.
This transformer adopts an energy-efficient wound core design and is mounted on poles in a suspended configuration. It features a compact size, requires minimal infrastructure investment, and reduces the low-voltage power supply radius. These attributes effectively lower the transformer’s no-load loss and no-load current. Furthermore, it can reduce the length of low-voltage distribution lines, decrease line losses, and enhance power supply quality, potentially reducing low-voltage line losses by over 60%. It is suitable for rural power grids, remote mountainous areas, scattered villages, agricultural production, lighting, and power applications. It can also be used for energy-saving renovations in pole-mounted distribution lines for railways and urban power grids.
Structural Features
Windings: The high-voltage winding is made from high-quality polyurethane-enameled round copper wire, while the low-voltage winding uses paper-insulated cable wire. Interlayer insulation employs pre-coated adhesive paper, which melts at a specific temperature during the drying process, creating adhesion. As the temperature further increases, it solidifies, reliably bonding the adjacent layers of the winding into a solid unit. This prevents conductor displacement and ensures the safety and reliability of the insulation structure.
Core: The core is a single-phase wound core made from grain-oriented silicon steel or amorphous alloy steel strips. This ensures the magnetic flux path aligns with the grain orientation of the silicon steel, fully utilizing the material’s superior magnetic properties. The no-load loss is far below standard requirements. The core is securely bonded with specialized core固化漆 (curing varnish), further effectively reducing transformer noise levels.
Tank: A cylindrical, fully sealed tank is used, enhancing operational reliability and requiring no maintenance during normal operation.
Other Features:
One (or two) high-voltage bushings, extending from the tank cover, contain current-limiting fuses internally.
One (or two) lightning arresters are installed on the tank wall, with their terminals connected near the high-voltage bushing outlets via copper straps.
A secondary circuit breaker switch is fitted inside the tank, with an external operating handle, overload reset, and signal light mounted on the tank wall.
Low-voltage bushings extend from the tank wall. Terminal X2 is equipped with an earthing device. One end of the single high-voltage winding is brought out through the high-voltage bushing, and the other end is grounded.
Our company’s single-phase pole-mounted distribution transformers are primarily developed for export projects. Customizable capacities range from 3 to 333 kVA, with input voltages of 33000/30000/17321/13800/7620/6930/6350V, and frequencies of 50 Hz or 60 Hz. They comply with standards such as IEEE C57, ANSI C57, IEC 76, and GB 10318.
Standards Compliance
GB 1094.1-1996 “Power Transformers – Part 1: General”
GB 1094.2-1996 “Power Transformers – Part 2: Temperature Rise”
GB 1094.3-2003 “Power Transformers – Part 3: Insulation Levels, Dielectric Tests, and External Clearances in Air”
GB 1094.5-2003 “Power Transformers – Part 5: Ability to Withstand Short-Circuit”
JB/T 10317-2002 “Technical Parameters and Requirements for Single-Phase Oil-Immersed Power Transformers”
