This paper presents an analytical model for prediction of on load magnetic field in slotted surface mounted permanent magnet radial flux synchronous machines. This technique can either be used in the case of internal or external rotor radial-field machines topologies. The machine model is formulated in polar coordinates and accounts explicitly for the stator windings current waveform and effect of stator slotting. Results from this analytical model are compared to corresponding finite element analyses. This analytical model is then coupled to electrical circuit equations to study the behaviour of a PM synchronous alternator connected to a power rectifier.