High efficiency power modules target demanding railway applications

February 11, 2016 // By Paul Buckley
Powerbox has launched two products in the company's railway DC/DC power converters ENAR150D series which aims to deliver more available power in slim packaging for railway demanding applications.

The products perform at 93% high efficiency, saving energy, reducing power dissipation and allowing more power available in confined environment. The new series includes an extensive set of accessories, simplifying power integration into trains and related vehicles.

Railway modernisation and introduction of new technologies such as On board WI-FI, GSM and LTE; Video systems and Telemetry require efficient and flexible power solutions.  The ENAR150D series combines high efficiency power switching and optimized topology to reduce component count by 25% compared to conventional topologies, contribute to improve the MTBF (Mean Time Between Failure) and to the long-term reliability. Developed for low profile applications and efficient conductive-cooling, the ENAR150D series employs the latest planar-on-board technology, improving power dissipation and robustness towards shocks and vibration. The ENAR150D24 and ENAR150D110 devices deliver 150 W output power, with a typical efficiency of 93% and are housed in slim packaging of 18.5 mm width.

Designed to operate from 24 VDC (16.8 – 30 VDC) or 110 VDC (77 – 137.5VDC), the ENAR150D24/2x12 and ENAR150D110/2x12 feature dual isolated 12 V outputs that can be combined in four different modes, independent, parallel, serial and symmetrical, to accommodate the final application requirements. In Independent mode, the two 75 W isolated outputs deliver 12 V / 6.25 A each. When connected in Parallel mode the output provides 150 W, 12 V / 12.5 A. If a higher output voltage is required to power intermediate bus voltage to embedded system, the Serial mode offers 24 V / 6.25 A. The fourth alternative, Symmetrical mode, provides a +/- 12V output, +/- 6.25 A with a common zero.

In cases where additional power is required, the ENAR150D series can be connected in parallel, without adding any external component, using passive current sharing technology.

The ENAR150D operates in a wide range of temperature, -40°C to +70°C. Under Class T2, the full power, 150 W, is delivered up to +55°C though with limited additional cooling the full power can maintained up to +70°C. For low cooling environment such as in Class TX, the output power can be maintained at 140 W from -40°C to +70°C.

Because 'Train-On-Time' is important, the railway industry requires high reliability. Low component count topology and thorough selection of reliable components contribute to an MTBF of 500,000 hours at +45°C ambient. The minimum technical lifetime is of 15 years at +45°C and 80% load level.

The ENAR150D24 and ENAR150D110 have a width of 18.5 mm, a height of 111 mm and a depth of 162 mm which makes it to fit into a large number of applications requiring low profile. The product is designed to fit into a 19 inch rack as specified in the IEC 60297-3. To facilitate insertion into rack systems (3U high / 4TE width), a front plate with complementary accessories can be added.

Operating within confined environments, without force air cooling, embedded electronics in trains and related vehicles require efficient cooling through conduction. The ENAR150D series is optimized for conduction cooling, if however additional cooling surface is required to interface the module to the infrastructure, the wall mounting kit allows the product to be fixed on the armature, improving conduction cooling.