Stability of distributed power supply systems

A comprehensive stability analysis of a distributed power system (DPS) is performed. The possible performance degradation and stability problems caused by the loading effect of cascaded converters are analyzed. The effect of impedance overlap on the system and individual subsystems is examined.

By applying the loop gain analysis technique, a forbidden region for the polar plot of the ratio of impedances at the interface between cascaded subsystems is determined. A method of transforming the forbidden region into a load impedance specification for a given source impedance is developed. The method guarantees system stability and minimal performance degradation of the DPS, while allowing impedance overlap at the interface.