Calculation of global magnetic forces using analytical and finite element solutions

Magnetic circuit analysis and finite element solutions are used to predict the force variation of a magnetic actuator under changes in position. Advantages and limitations of the analytical approach are highlighted. The performance analysis evaluates force values using the methods of Maxwell stress tensor, virtual work with one and two solutions, and compares these forces with those obtained by the more precise method of weighted Maxwell stress tensor. Results agree with reference values to within a few percent. Quick and easy to implement, the single solution virtual work direct-energy approach brings insight into the analysis of magnetic field energy storage and related force production.