Stability analysis on the DC Power Distribution System of More Electric Aircraft

The local DC power distribution system (PDS) of a more electric aircraft is one of the cores of the electric power transmission. Generally, the PDS is made up of small power subsystems designed on their own stand-alone operation. But the interaction between the subsystems (sources and loads) induces some problems of stability. This paper compares the different stability behaviours of two load models: resistive load and constant power load. Some tests for the two load models at different operating points are carried out and the results are compared. The small signal theory and the impedance criterion GMPM (gain margin phase margin) are used to analyse the stability of each system. At conclusion, some statements are expressed to contribute to such electric interconnected systems stability.