Validation study of mathematical model for brushless, capacitor-excited single phase synchronous generator

A method for the design and optimization of a capacitor-excited, single-phase brushless synchronous generator is presented. The method utilizes an equivalent model for the single-phase machine having two balanced quadrature stator phases, (armature and exciter) and unbalanced loads. The two stator windings are balanced when appropriate turns ratio transformations are applied to the windings. Expressions are derived for fundamental and harmonic current amplitudes and phases using a d q machine model which includes rotor damper windings and saturation characteristics based on two-reaction theory. The resulting model includes sufficient detail to calculate the self-excitation condition under various loads for a given machine geometry. The model is incorporated into a spreadsheet design program. Experimental data from various machine designs are compared with the results of the design program. The machines studied have varying air gaps, sizes and pole numbers. Both measured and calculated results shed light on design issues such as the tradeoffs between self-excitation and output waveform quality