Double-Side Voltage-Behind-Reactance Model of Main Machine in Aircraft Wound-Rotor Synchronous Starter-Generator Considering Saliency Factor Change and Equivalent Iron Loss Resistance

Research on control strategies of aircraft wound-rotor synchronous starter-generator relies on accurate simulation models. The field current of the main machine is provided by the main exciter through rotating rectifier. This brushless excitation structure requires that the main machine model has the function that both stator and rotor windings can directly connect with electronic components. Large changes of armature current can cause the saliency factor of the main machine to change obviously. In addition, iron loss is significant for the research on efficiency optimization control strategies. In this paper, the characteristics of the saliency factor and iron loss of the main machine operating under different conditions are analyzed. A constant-parameter double-side voltage-behind-reactance model of the main machine considering the equivalent iron loss resistance and the change of saliency factor is derived and established. The accuracy of the proposed model is verified through the computer studies.

I. Introduction

With the development of more electric aircraft (MEA), the integrated starter-generator (ISG) has received extensive attention as its key technologies. Several electrical machines are considered for ISG system, such as asynchronous machine, permanent magnet synchronous machine (PMSM) and switched reluctance machine (SRM), among which wound-rotor synchronous machine has great competitiveness because of its high reliability, mature structure and generation technologies [1], [2].