Stability Analysis and Improvement Strategy of Doubly Salient Generator‐Based DC Electrical Power System for More‐Electric Aircraft

ABSTRACT

Constant power loads (CPLs) and electromechanical coupling between the auxiliary power unit (APU) and generator pose stability and dynamic performance challenges to more‐electric aircraft (MEA) electrical power systems (EPS). This paper develops a stability enhancement framework for a doubly salient electromagnetic generator (DSEG)‐based EPS to address both effects. A small‐signal impedance model is first established for the electrical source‐load cascaded system. Based on this model, a quasi‐proportional resonant (QPR) control strategy reshapes the source‐side impedance to mitigate the instability associated with the negative incremental impedance of CPLs. The analysis is then extended to the coupled APU‐DSEG system, with emphasis on the interaction between APU speed regulation and DSEG voltage control. A load current feedforward compensation method is introduced to reduce the resulting DC bus voltage fluctuations during load disturbances. DSEG prototype experiments and hardware‐in‐the‐loop (HIL) tests provide complementary validation of the generator model and proposed control strategies, demonstrating their effectiveness in suppressing voltage oscillations and improving transient performance.