Comparative stability study of DC current control strategies for a droop-controlled PMSG system

In presence of tightly regulated power electronic converters and motor drives in the more electric aircraft (MEA), stability is a great concern for the electrical power system (EPS) in the MEA. The DC electrical power distribution system (EPDS) of the MEA is one of the core architecture for electrical power transmission. DC transmission cables are also taken into account since it cannot be neglected in such low voltage microgrid. Proper active power is regulated by DC current control for the active rectifier. Both the output current of the active rectifier and the current after the capacitor can be used as feedback variable of the controller. This paper undertakes the comparative stability study on the DC current feedback approaches for droop-controlled PMSG system. The mathematical model and corresponding linearized model around the equilibrium point are developed. The state-space matrix is derived and the layout of the eigenvalues is shown for different methods respectively. The analysis is verified by time domain simulation results in Matlab/Simulink.