Numerical calculation of the dynamic behaviour of electromagnetic actuators

The authors describe a numerical method for calculating the dynamic behavior of electromagnetic actuators supplied by voltage or current pulses of any waveform. Moving parts, eddy currents caused by the time variable, and the relative velocity to the field, as well as strong saturation of the ferromagnetic materials are taken into account. The numerical solution is based on the finite-difference method with acceleration of convergence and the time-stepping method. In order to always obtain a tridiagonal system matrix, even by impressed voltage, a double iterative solution is used. An application example is given for a system used in electromagnetic striking tools with a large displacement of the moving part