Circuit models for electrical machines served the E.E. community well (and our civilization!) for decades. In the hands of the skilled practitioner of circuit theory, they can become more accurate than they have any right to be. Take for example the induction motor (my preference-maybe an ocd thing!). Because of transformer action causing current to be induced in the rotor, it's modeled by a transformer! A few strategic resistances and reactances are put into the transformer circuit to leach off power due to eddy currents in iron cores, flux leakage, etc. Performance- just a few percentage points off! But still off and always will be. Circuit elements are static and cannot possibly subsume the physical process of the motor motion.This book gives methods which are true to the physical construct of the machine and its operating physics. The programming/computer graphic savvy engineer could possibly develop his own simulation software from it's contents and run it on a gamer's laptop.Magnetic flux density (B field vector) is approximated by finite elements (more accurate with finer mesh-you'll use the magnetic vector potential or rather find it in finite elements-B is the curl of this). Flux lines (vector field trajectories or integral curves of B) are plotted by using Euler's method or Runge-Kutta. All can be displayed on the pc screen for various time intervals.Torque calculation is found using either virtual work or Maxwell's stress tensor(J.D.Jackson's text Classical Electrodynamics Third Edition for this) for induction motors. A Newton torque equation can be used in conjunction with this for rotor angular speed estimate(tricky for induction though). I recommend this book be bundled with a more qualitative design book like Design of Rotating Electrical Machines. Also you might bundle it with Finite Elements for Electrical Engineers for a more thorough presentation of finite elements. I should also like to add Analysis of Electric Machinery and Drive Systems (IEEE Press Series on Power Engineering) as this is the chief reference for reference-framing which is used to take account of motion as well as to simplify integrals, mutual inductances, etc. This in itself contains a significant portion of the operating physics. For elementary examples of its use see my review of Inductance: Loop and Partial and the update in this review (it's really just the rotation group).This all is to say that you can get all that circuit models offer and more (like nonlinearities) with these methods which use conventional physical and mathematical reasoning. No contrivances or ad hocs needed here.The reviewed book and those books linked in this review contain all the E&M and motor concepts you'll ever need for this type of analysis/design, assuming some basic circuit and mechanics knowledge.