Component proximity effects in high density and high switching speed power converters

High density high switching frequency power converters component interactions become an important issue. Compact power units do not have the luxury separating sensitive components and functions at desired distances apart. High switching frequency converters need to be designed with components as close as possible to each other with short track lengths to reduce unwanted parasitic effects. This creates a coupling effect between components reducing the component efficiency and increasing the noise pollution problem. The coupling effect need to be reduced to acceptable levels by placing and rotating components in optimal positions increasing the performance of the system. A few papers have been published on the topic showing complex analysis of stray magnetic fields from inductors and capacitors and possible design guidelines optimising placement of components. Complex structures such as multiple components combined with the enclosure and even mounting structures are more difficult to analyse. Simulating the latter, an electromagnetic simulation tool based on computational electromagnetic techniques called FEKO was used for analysing structural influences on component placement. Trace loops and trace positions can also be analysed and optimally designed with FEKO. A Helmholtz coil test bed according to MIL-STD-461-E was manufactured to verify the results obtained. The Helmholtz coil is actually an alternative method testing for radiated magnetic field susceptibility. The same device can be used for testing component and structure interference influences. Different components, such as inductors, capacitors and semiconductors can be positioned and rotated in the Helmholtz magnetic field to quickly verify the least susceptible angle of the component.