Parameter deviation effect study of the power generation unit on a doubly-fed induction machine-based shipboard propulsion system

To lower the difficulty of fault protection, a doubly-fed induction machine based shipboard propulsion system (DFIM-SPS) that is partially power decoupled is presented. In such an intrinsically safe SPS architecture, a synchronous generator (SG) is employed for power generation, and the accuracy of the parameters of power generation unit (PGU) plays an important role in SPS stable operation. In this paper, the PGU parameter deviations are studied to evaluate the effects on system performance. The models of salient-pole SG, type DC1A excitation system (EXS) and DFIM are illustrated first. Besides, the corresponding control scheme is explained. For the 16 important parameters of PGU, up to 40% of parameter deviations are applied to implement parameter sensitivity analysis. Then, simulation studies are carried out to evaluate the parameter deviation effects on system performance in detail. By defining three parameter deviation effect indicators (PDEIs), the effects on the PGU output variables, which are the terminal voltage and output active power, are studied. Moreover, the increasing rates of PDEIs with different degrees of parameter deviations for the key parameters are analyzed. Furthermore, the overall system performance is investigated for the two most influential PGU parameters. This paper provides some vital clues on SG and EXS parameter identification for DFIM-SPS.