Wire Thickness Effect in Wound Coils

This application note presents the effect of wire thickness to accuracy of electromagnetic simulation of wound coils. Two classes of examples will be discussed. The first class of examples relates to straight wound coils while the other class refers to toroidal wound coils.

The wound coil simulation examples will be used for direct comparison of physically identical coils modeled in WIPL-D using two modeling approaches – using wires or using plates. When using wires, a coil model is very easy to build as WIPL-D Pro helix built-in object can be used. However, a wire coil model applies thin wire approximation meaning that the current distribution does not change along the circumference of the wire but it changes only along the wire axis. Due to the approximation, simulations are very fast, but the accuracy could be compromised. The aim of this application note is to investigate if the thin wire model can be used when simulating the coils. Building the more accurate wound coil model with the plates, where the all components of the current are taken into account is more demanding.

The two wound coil models yield almost identical results although the completely different models have been used. Therefore, the thin wire approximation can be applied to coil wire objects without compromising the accuracy. The approximation significantly reduces simulation time and computer requirements. However, the thin wire coils model becomes less reliable as the frequency and winding density is increased.

Computer used in this application is regular desktop PC. All presented models of the coils are simulated efficiently. The wire coil models run in seconds, while the plate coil models run in minutes.

Section: Low Frequency

For full version of the document, please check the following pdf.