New-Tech Europe | May 2017

Calculating the Ideal Power Inductance for Energy-Efficient Applications

Alexander Gerfer, Ranjith Bramanpalli, Jochen Baier, WURTH

The of devices with power supply units is essentially influenced by the inductor. To calculate the ideal power inductance, a solution has been found that reduces losses in core materials: a simple online tool that accurately determines AC losses. Successful energy-efficient device- design depends largely on the power supply unit and therefore on the composition of its individual components. So, when selecting these components - such as inductors (coils or rather inductances), for temporary energy storage for example - it is important to understand their loss and heat behavior. By introducing new materials and calculating AC losses using various calculation models, the energy-efficiency

reach their limits. A new tool from Würth Elektronik eiSos based on a metrological approach, helps the developer determine the most accurate data to date for DC and AC current losses in power inductors within the application environment. Reduction of core material losses By introducing new iron alloy group material compositions, Würth Elektronik eiSos has further reduced core material losses for high current power inductors. Its component range WE-MAPI combines the optimal use of inductance and current carrying capacity with low internal losses thanks to clever material selection and manufacturing technology. Conventional coils typically use enamelled copper wire wound around

ideal power inductance for energy- efficient applications can be measured and ascertained. Whilst linear regulators were the most widely used voltage regulators in the past, switch mode power supplies are now predominantly found in modern power electronics. The continuous reduction in processor voltages has played its part in this. Just a few years ago, switching frequencies of up to 300 kHz were widespread. Nowadays modern switching controllers usually have frequencies of 800 kHz or more. Switching losses, on one hand, but also power inductor losses, on the other, are important aspects in the design of switching power supply units. The latter can be influenced by the materials-mix. Conventional calculations of core losses using the Steinmetz-equations, quickly

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