A Parallel Hybrid Excitation Flux-Switching Generator DC Power System Based on Direct Torque Linear Control

A parallel hybrid excitation flux-switching (PHEFS) generator dc power system is presented in this paper. The PHEFS topology is proposed to achieve good flux regulation capability of the system as well as capability of deexcitation at fault and avoid permanent magnet (PM) magnetic shortcircuit and demagnetization. In order to improve the system´s steady state and dynamic performance, a direct torque linear control (DTLC) scheme is proposed then. This DTLC scheme, which contains a voltage loop only and develops the direct linear relationship between the torque and sinusoidal value of the torque angle, can regulate the instantaneous torque directly and smoothly without current loop. The flux-weakening control of the DTLC scheme is also studied; the PHEFS generator system with excellent dynamic performance and lower flux and torque ripple has been achieved experimentally.