Reliability considerations for switched mode power supplies for use in railway applications

The use of switched mode power supplies in trackside and railway applications is considered, with particular emphasis on the selection process for determining long-term high reliability. Key words: reliability, switched mode power supplies, isolation, regulators NOTATION core area maximum flux density of core material capacitance applied voltage switching frequency input ground output ground input current output current stacking factor of core material inductance number of primary turns resistance ground resistance load resistance differential temperature between case and ambient input voltage input line voltage output voltage ground voltage