Characteristics of a linear induction tachometer - A 3D moving conductor Eddy current problem

The performance of a linear induction tachometer is calculated and compared with experimental tests. The machine is modelled in three different ways, representing three levels of idealisation. Results from a Fourier harmonic analysis are compared with those of 2D finite elements and a full 3D finite element solution. The flux paths are highly three dimensional, so the machine does not lend itself well to two dimensional modelling. Consequently, the 3D predictions are closest to the test results.