Analytical Method of the Analysis of Electromagnetic Circuits of Active Magnetic Bearings for Searching Energy and Forces Taking into Account Control Law

The work considers an analytical method for finding expressions of magnetic energy and forces in active magnetic bearings (AMBs), taking into account control laws. Such the expressions should be included into simulations of the rotor dynamics in AMBs. This method is based on constructing equivalent substitution schemes and applying the contour flow method to the analysis of magnetic circuits of AMBs. This allows to take into account scattering fluxes and magnetic resistances of sections of the AMBs magnetic circuits and ensures that the mathematical model is not critical in terms of the occurrence of “zero” gaps and currents. This expands its determination borders to almost the boundaries of the complete air gap. The practical applicability of the method was confirmed by designing the AMB for a laboratory rig of the rotor in a combined passive-active magnetic suspension. The reliability of the proposed method is confirmed by comparing the calculated and experimental force characteristics of the AMB and other data.