Transformers for railway engineering

Supplying the track electric circuits is carried out for the reasons of operational safety is usually conducted by means of separation transformers, the parameters and structure of which are adjusted to changeable and difficult working conditions.
Mostly they are used for supplying the devices of automatic line blockades, heating the railway crossovers and supplying the railway traffic control systems.
Transformers supplying the devices of automatic line blockades:
These transformers supply the devices for railway traffic control.

Description: Linia kablowa – Cable line

ELHAND transformer, type ET3KOL-16kVA, intended for supplying blockade lines.

The automatic line blockades are used by the Polish Railways (PKP) on the lines with high traffic intensity. They allow to achieve the increase in track flow capacity on the tracks where such devices for railway traffic control are installed. Moreover, due to its structure, they ensure the safety of the railway traffic to a much greater extent than the line devices used in railway engineering in the past. However, the condition for all this is the provision
of failure free supply. For this purpose, the industrial control system circuits are used to form the entire set together with supply transformers.
The supply is executed by the isolating transformers of ET3KOL type. The transformers are installed at both ends of the supply line. This guarantees the reserve for the blockade supply should one of them fail to operate. It is the control systems that steers the respective sequence for combining the transformers. The three-phase isolating transformers in the ET3KOL railway version are adjusted to operation in any climate zone due to their special enclosure and highly effective vacuous impregnation. Due to overvoltage limiters in combination with strengthened insulation, the transformers are resistant to switching overvoltages and lightning surges. Large overvoltage resistance from the supply side during atmospheric discharges reduces the amount of damages to the track electronics used in the track-vehicle impact elements. The application of these transformers allow to reduce the costs of exploitation (the necessity of transmitters repair is eliminated.

Transformers supplying electric heating systems for railway crossovers (EOR):
The transformers supplying the systems for heating railway crossovers (EOR) are untypical isolating transformers, adjusted for operation in the environment with very high humidity and considerable annual and daily temperature amplitudes. They usually operate in the sets of a few transformers, isolating the circuits of electric heaters for heating railway crossovers. These are usually non-service systems, placed in wells or
boxes on the verges of track line. They operate within the range of ambient temperature from -40OC to +10OC. However, they can operate with 20% durable current overload without any harm to transformer insulation. Additionally the transformers are coated with resin, which makes them water-resistant and entirely resistant to the presence of any water that may appear in the box in which they are installed. As opposed to toroidal transformers their inrush currents are small and they have been limited at the design stage. The transformers may be protected against short-circuits with excess current switches S301 with C type characteristics.

ELHAND transformer intended for supplying the crossovers heating systems, type ET1KOLŻ-2,5kVA.

Transformers supplying the railway traffic control circuits:
These transformers play a responsible role in the devices for railway traffic protection.
Their technical parameters must meet the requirements of EN(IEC)61558 standard as well as sharpened requirements of branch standards regarding no-load current, resistance to short-circuits and overloads and working temperatures.
Our company produces the transformers intended for supplying the railway control systems with power from 40 to 500 VA, type ET1KOL.

ELHAND transformer intended for supplying the railway traffic control systems, type ET1KOL-0,70 kVA.