Analysis of a new compound-excited doubly salient brushless DC generator with power tracking rectification

A new compound-excited doubly salient brushless dc (DSBLDC) generator with power tracking rectification is proposed, which is constituted by a doubly salient electromagnetic machine (DSEM) with split field windings and a simple switched-mode rectifier. The configuration and operation principle are introduced. The inductance features of the generator are analyzed for the utilization of series field winding in switched-mode rectifier. Then the performance with the power tracking rectification method for variable speed operation is investigated by finite element (FE) analysis. The comparison between the proposed generator with power tracking rectification and conventional rectification is conducted, and the results show that the output power for low speed operation is improved substantially and the required field power is reduced. A 20kW prototype is designed and constructed. The preliminary experimental result agrees well with the simulated data. The new DSBLDC generator, with merits of simple configuration and flexible control, is a promising option for the automotive onboard power generation system.