Equivalent voice-coil models for real-time computation in electromagnetic actuation and sensor applications

This paper presents a method to derive equivalent models to characterize the magnetic field of a multi-layer (ML) voice coil. Two equivalent models are discussed. The first reduces the number of wire layers to a minimum. To offer some intuitive insights, a detailed derivation of an equivalent single layer (ESL) model is given in this paper. The second models the ML coil as an equivalent PM, the magnetic field of which has a closed-form solution. The equivalent models are validated by investigating the effects of coil geometry on the modeling errors, and by comparing the computed forces against published data. As illustrated with a number of examples in this paper, the field and force calculations which do not increase with the number of current loop-turns offer a number of advantages in real-time applications.