Comparative assessment of synchronous generators windings as a part of DC source connection schemes

The article deals with the schemes of DC sources based on a multiphase synchronous generator with excitation from permanent magnets and a rectifier. It evaluates various options for constructing circuits with the number of phases changing from two to ten along with the different generator windings connections, i.e. N-beam star and a closed ring of N sections. It is proved that, ceteris paribus compared to multiphase windings in terms of specific electric losses, windings with a small, i.e. 2 to 4, number of phases are preferable. The advantages of closed multiphase windings compared to open windings in terms of specific electric losses and maintaining output characteristics during single failures. Mathematical models were used to analyze the ripple of the rectifier output voltage for a different number of phases and various schemes of the windings connection, both in the normal mode and with the faulty rectifier diodes. The influence of the inductance of the generator winding on the value of voltage ripples is estimated. The authors make a conclusion that the closed windings are significantly more preferable as far as the rectified voltage ripples are concerned.