In distributed power electronic systems, DC-DC converters feed power to other downstream converters. When the downstream converters are... Show moreIn distributed power electronic systems, DC-DC converters feed power to other downstream converters. When the downstream converters are tightly regulated they tend to draw a constant amount of power from the source converter and exhibit dynamic negative resistance. This results in stability problems for the source converter. The negative-impedance instability is documented in literature and a novel nonlinear loop-cancellation feedback has been suggested as one of the solutions to overcome the destabilization effects of downstream converters representation by a constant power load. In this work we study the effect of this loop-cancellation feedback on the global behavior of the system, including the size of the stable region around the operating point. To perform this study we use a phase portrait technique that has been applied previously to study the global behavior of the distributed DC-DC power electronic systems. The large-signal averaged model of the converter is used to develop phase portrait. The basin of attraction of the stable operating point equilibrium is determined and the effect of variations int he grain of the nonlinear loop-cancellation feedback is examined. Comparisons of the size of the basin of attraction and the speed of recovery from perturbations from the equilibrium point are made. The case where the gain is zero refers to the nonlinear loop-cancellation being absent is included. M.S. in Electrical Engineering, May 2011 Show less
