Derivation of a magnetic equivalent circuit model for analysis and design of claw-pole alternator based automotive charging systems

In this research, magnetic equivalent circuit (MEC) analysis is used to establish the dynamic response of a claw-pole alternator. Specifically, the machine geometry and winding layout are used to derive a circuit that relates magnetomotive force (currents) to flux in each part of the machine. Using winding flux linkages as inputs, the magnetic flux and magnetic scalar node potentials throughout the machine are determined using standard DC electric circuit analysis. Repeated solution of the circuit over several rotor positions provides a means to study the harmonics introduced by concentrated stator windings, stator and rotor slots, and localized saturation (stator or rotor). The advantage of this technique over a finite element approach is that engineering judgment is used to establish the circuit of sufficient detail to portray only the salient magnetic properties. Thus, the dimension of the nonlinear equations that must be solved at each time step is much smaller than in a finite element model. Results obtained using the MEC approach in the simulation of an automotive charging system are presented and compared with those predicted using existing design software --Abstract, page iii