Rugged High-Power Railway Converters Compliant with EN 50155 Standards

Whether on a train, track, or station, power supplies used in railway applications are regularly exposed to extremely harsh conditions while also being required to operate accurately and reliably. These products are expected to last decades, with extreme working conditions including heat, cold, shock and vibration, mechanical impact, and EMI—all of which can seriously damage the electronic assemblies of power converters.

Rugged power converters capable of withstanding these harsh conditions are essential in railway system design. To qualify for use in railway systems, power supplies must meet the highest standards for shock and vibration, fire protection, thermal performance, EMI/ESD, weight, safety, and reliability.

Today, several stringent international standards regulate railway applications. Some of these include:

• EN 50155 - Electronic equipment used on rolling stock
• EN 61373 - Shock and vibration tests
• EN 50121-3-2 - Electromagnetic Compatibility (EMC)
• EN 45545-2 - Fire Protection on Railway Vehicles

EN 50155, for instance, is a well-established performance standard for electronic equipment used in rolling stock (all rail vehicles that move, including locomotives, passenger wagons, light rail vehicles, and freight trains). It defines minimum requirements for input voltage range, electrical isolation, operating temperature range, shock and vibration, humidity, and EMC, while also specifying equipment reliability and expected operational life. In many cases, electronic equipment used on rolling stock is expected to operate for more than 20 years, necessitating comprehensive environmental testing. EN 50155 also mandates normal operating temperature tests, as well as thermal cycling, dry heat, and damp heat tests.

EN 61373 specifies requirements for testing equipment intended for use on railway vehicles that may experience vibration and shock due to operational conditions. EN 50121-3-2 addresses the emission and immunity aspects of EMC for electrical and electronic apparatus intended for railway rolling stock. To ensure maximum safety in the event of a fire, all materials used in rail vehicles must comply with European standard EN 45545-2.

With over 40 years of experience in developing and manufacturing leading standard and custom power converters, RECOM has expanded its portfolio of EN 50155-certified power supplies. RECOM offers customized power solutions up to 10kW for railways, alongside a broad range of AC/DC and DC/DC converters.

Various supply voltages have emerged for DC/DC converters in railway systems over the last few decades. Standard voltage ratings include 24VDC, 36VDC, 48VDC, 72VDC, 96VDC, and 110VDC. The latest EN 50155 version defines seven standardized DC voltages, with 110VDC most common for long-distance trains, while 24VDC to 48VDC is more typical on light rail, trams, and trolleys. To meet nominal 24, 48, or 110VDC input requirements, many railway application developers select 4:1 converters, such as the RP20-FR and RP40-FR series, which cover the nominal input voltage range including transients, with three different input voltage versions. Recent RECOM innovations provide railway designers with converters covering an even wider input voltage range using a single module.

The company’s latest 100W and 200W DC/DC converters from the RPA100E-W and RPA200H-RUW families feature a broad 10:1 input range, accommodating all common voltage ratings in a single module. With ultra-wide input from 14.4VDC to 156VDC, these DC/DC converters are suitable for any railway design without concern for voltage tolerances, dips, or local supply variations. RECOM also offers isolated and regulated 12V or 24VDC outputs with consistently high efficiency up to 90% across the full input voltage and load range. Featuring a metal baseplate, these converters operate over a wide temperature range from -40°C to +97°C.

The RP40Q-RUW and RP60Q-RUW series extend the ultra-wide input to a 12:1 range, from 14 to 185VDC, offering designers even more flexibility. Housed in standard quarter-brick cases with threaded inserts for secure mounting in high shock and vibration environments, these converters provide reinforced isolation at 3VDC, regulated 5VDC, 12VDC, 15VDC, 24VDC, and 48VDC outputs with sense and trim pins. They are CE marked, EN 50155 and EN 45545-2 certified, and backed by a three-year warranty.

RECOM's expanded DC/DC converter portfolio from 8W to 240W offers the broadest range of EN 50155-certified products on the market. These railway-certified series feature compact case sizes delivering power densities up to 4.5W/cm³, among the highest available today. RECOM has also developed the RMD plug-and-play series for higher power railway applications, providing 150W to 500W output with five input ranges covering 14.4V to 170VDC, fully tested to EN 50155 and ready as complete solutions.

In AC/DC applications, RECOM has developed three-phase AC input battery chargers with active power factor correction (PFC) and full railway standard compliance. Available in 3.2kW (SA3200 series) and 5kW (SA5000 series) ratings, these converters can be cascaded to generate up to 20kW. The SA3200 series also operates with DC input up to 800V. Output ranges include 24VDC up to 110VDC (and intermediate ratings of 36/48/72/96VDC).

For AC supply applications, RECOM offers inverter families, such as the ID250 series, delivering single-phase or multiphase output voltage or current with nominal inputs of 24V, 48V, 72V, or 110VDC. Output options include single-phase 200-240VAC or 50-156VAC for the 48V input version. These series comply with railway application standards and are typically used for passenger sockets or driver consoles.

Globally, as railway networks expand to meet growing transportation demands for workers, tourists, and industry, the need for rugged, standards-compliant power supplies continues to rise. As a leading provider of high-performance power solutions, RECOM is a reliable source for a broad range of rugged, standards-compliant DC/DC and AC/DC converters and DC/AC inverters.

RECOM offers a comprehensive portfolio of rugged EN 50155-compliant power converters, including turnkey solutions for numerous railway applications. From low-power modules (8W–240W) to 10kW power supplies, RECOM provides a range of standard and custom solutions for all railway power needs.