High Efficiency DC-DC Converter For Light-Rail and Industrial Applications

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The device is capable of powering low to high loads at a high efficiency and complies with a large range of environmental conditions

A wide variety of electrically powered traction systems are used in rapid transit systems around the world. Most metros operate from DC power either at 750VDC with a third rail, or 1.5kV with a third rail or from an overhead catenary. 750VDC is very common in light rail, powering both the rolling-stock equipment as well as trackside signalling systems. The same voltage is also used in industrial equipment and applications such as mining.

Now the challenges are increasing due to demanding railway and industrial applications. To solve this, the new ENR500D, a 750VDC input DC-DC converter by Powerbox can be implemented, which provides high efficiency of 95 per cent across the low to high load range. Its switching stage is based on an enhanced resonant topology that is combined with the latest MOSFET technology and high-performance magnetics.

The ENR500D has a nominal input voltage of 750VDC and operates within a range of 500 to 900VDC. The nominal output voltage is set to 48VDC, though it can be adjusted up to 60VDC. Nominal output power is 500W constant across the temperature range of -40 to +70 degrees Celsius in natural cooling conditions. Designed to reduce energy consumption, at no load the ENR500D input power is less than 5W.

Environmental Compliance

Complying with the European Standard EN 50124-1, Macro-environmental conditions (PD1 to PD4B), these power converters can be part of a hermetically sealed equipment varying from no ventilation up to forced ventilation using clean filtered air from outdoors and requiring a flexible, robust design that can meet a large range of environmental conditions.

The ENR500D also has ingress protection to IP20 and input to output double reinforced isolation.

In accordance with EN50124-1, rated impulse voltage of 4.4kV, the input to output has double reinforced insulation of 1000V, with a clearance 8.0mm, creepage ISO Class I and 10.0mm, ISO Class II 14.2mm.

In railway applications, robustness is a must and the ENR500D is enclosed in an aluminium chassis with the integral heatsink. It measures 163 x 230 x 80mm. For reliability and availability, all printed circuit boards have a protective coating.

As designed for a large range of light-rail and industrial applications, the ENR500D can be modified to offer other output voltages such as 12V, 24V or any other required by the system designer. Different output powers can also be provided in optimised mechanical formats.