POWER & ENERGY EFFICIENCY HANDBOOK
How to make dc/dc converters rugged Martin Tenhumberg | Traco Power
Design standards for rail transportation equipment are so severe that they are used as qualifications for products targeting other areas where ruggedness comes in handy. Here’s a quick overview of what these standards entail.
Sizing up EMC threats
In transportation, there is an emphasis on electronic systems in rail because of expanding safety, telemetry and infotainment systems. The move away from fossil fuels to electric drives also adds further opportunities for electronic control. By the nature of the application, electronic systems in trains are powered from a relatively noisy dc source. Voltage spikes, surges and drop-outs are common, along with radiated and conducted EMI from the highpower transmission systems. Shock and vibration are a constant stress and temperature extremes and swings are normal. The safety of passengers and staff is also of utmost concern. Designers must further consider the flammability of the materials used as well as the smoke and gas emissions that may result. Other markets face many of the same challenges. Industrial mobile systems, such as construction and material handling machinery and forklift trucks, also see harsh outdoor conditions. Similar requirements apply to equipment for protection and recovery services such as police and fire, snowplows, and electric vehicle charging stations. With no clear standards of their own, applications in these markets typically turn to existing, ruggedized equipment already designed and built to railway standards.
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DESIGN WORLD — EE NETWORK
Traco — P&EE HB 10-19.indd 20
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DC-DC Converter
Area C + 5V Signal processing area protected 0V against EM interferenece
Area B Pheripheral electronic area partly protected against EM Area A interference Inside vehicle with sources of major EM interference
Typical positioning of a DC/DC converter between EMC areas in a rail application. EN 50155 provides an example of physical EMC areas A, B and C in rail applications that guide system designers toward the appropriate level of EMI filtering.
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10/10/19 8:48 AM
