Product Overview

The company introduces advanced European technology and optimizes the design of epoxy resin-impregnated dry-type transformers through patented technology and specialized software. The core of the product uses high-quality cold-rolled oriented silicon steel sheets, manufactured by the automatic core production line of GEORG, Germany, employing a step-lap process. This greatly improves the no-load performance of the core. The coil is made with epoxy resin from Huntsman, USA, and the coil impregnation process is completed using the vacuum impregnation equipment from HEDRICH, Germany. The resin has good permeability and no bubbles, resulting in low partial discharge. The high and low-voltage coils are tightly matched with strong structural strength, ensuring high short-circuit and vibration resistance. This product has a lifespan of 30 years or more under normal operating conditions, and during its service life, the coil surface will not crack due to temperature changes.

Product Features

• Low Noise and Low Loss

1.The noise source of the transformer comes from the core. Our company applies Germany GEORG’s step-lap core automatic production line, the first of its kind in China, and the Step-Lap new process, which improves the internal magnetic circuit distribution of the core and reduces noise.

2.High-quality silicon steel sheets are used, and a lower magnetic flux density is selected to keep the core away from saturation, reducing harmonics in the core, thereby lowering noise and no-load loss.

3.All clamping parts are equipped with silicone rubber and elastic components to buffer and reduce amplitude, lower noise, and the surface of the core is treated to provide sound insulation.

• Flame Retardant and Environmentally Friendly

1.The solid insulation made of high-quality resin has high electrical strength (breakdown voltage not less than 34kV/mm), and the partial discharge is low, controlled within ≤5pC.

2.The resin materials used in dry-type transformers produce minimal heat when burned (about 65mJ/kg), making them self-extinguishing and flame-retardant. They will not produce toxic or harmful gases under high heat, nor will they generate electric arcs due to short circuits.

3.The coil does not absorb moisture, and the surface of the core is cured, making the transformer reliable in environments with relative humidity up to 100%. Intermittent operation does not require moisture removal.

4.Dry-type transformers also feature strong overload capacity, good thermal stability, small size, lightweight, easy installation, and no maintenance. They are widely used in high-rise buildings, commercial centers, airports, stations, docks, subways, factories, and underground substations.

• Forced Cooling

Dry-type transformers can use natural air cooling (AN) or forced air cooling (AF). With natural air cooling (AN), under normal conditions, the transformer can continuously output 100% of its rated capacity. With forced air cooling (AF), under normal conditions, the transformer’s short-term output capacity can increase by 30%, suitable for various emergency overload or intermittent overload operations.

• Temperature Control System

The temperature control system consists of a temperature controller and a Pt100 platinum resistance temperature sensor installed at the hottest point of the product. The temperature controller has temperature display and control functions, showing and controlling the temperature of each phase of the transformer. If the winding temperature becomes too high due to overload or fault, the temperature controller will issue an alarm signal. When the winding temperature exceeds the safety value, it will send a trip signal. When forced air cooling is used, the temperature controller automatically starts and stops the fan according to the winding temperature. The transformer’s winding and core temperature monitoring can be provided as per user requirements, with 4~20mA analog output or RS485 computer interface to meet modern power operation automation management needs.

• Protective Shell

The protection level of the shell is classified according to GB4028 standards. IP20 protects against objects larger than 12mm in diameter entering the shell, providing a safety barrier for live parts. IP23 protects against water droplets entering at angles within 60° from the vertical (after adopting IP23 shell, the cooling ability of the transformer is reduced, and the capacity drops by approximately 5%).

Product Application Fields

Dry-type transformers are typically used indoors. They are mainly used in high-rise buildings, hospitals, airports, stations, subways, large supermarkets and shopping centers, cinemas, schools, and other places with special importance and fire protection requirements. Due to the strong short-circuit resistance, low maintenance, high operational efficiency, compact size, and low noise, dry-type transformers are commonly used in fire-resistant and explosion-proof locations.

Main technical data of dry-type distribution transformer