Analysis of Reactive Power Compensation Effect of a New Hybrid Excitation Brushless DC Generator

A new hybrid excitation brushless dc generator (HEBLdcG) is comprised of the structure-paralleled permanent magnet machine part and flux modulation machine part (FMMP). The reactive power compensation effect of the HEBLdcG is illustrated and investigated in this paper. It is shown that the operation modes of the FMMP are influenced by both, the field current and armature current. Based on this, the three ranges in terms of the field current are divided. Three typical operation states representatively selected in the three ranges are defined as the power-balance state, compensator state, and short-circuit state, respectively. The short-circuit current can be diminished on account of the reactive power compensation effect. Furthermore, the analysis of the short-circuit characteristics shows that the short-circuit characteristic curve-short-circuit output current versus field current-is not a straight line, due to the saturation of the d-axis flux path of the FMMP. And the HEBLdcG at -8-A field current features the lowest total loss at the short-circuit state. At last, a prototype HEBLdcG is manufactured and the experiments validate the simulations.