Metastability of Pulse Power Loads Using the Hamiltonian Surface Shaping Method

Pulse loads on an electric ship are becoming more prevalent as ship component technologies move to more electric power. However, these pulse loads, such as electromagnetic aircraft launch systems, rail guns, lasers, and radar all can have a destabilizing effect on the ships power distribution network. Typically these types of loads are modeled as constant power and are analyzed for stability with small-signal models and techniques. However, small-signal methods are insufficient for pulse power load stability. This paper will present a brief overview of small-signal methods. Then a large signal metastable analysis method based on a Hamiltonian surface shaping and power flow control methodology based on the average-mode model of dc-dc converters will be presented. The results show that the nonlinear time-variant load pulses create nonlinear limit cycles and dynamics. The stability of the limit cycles can be assessed through a comparison of the power generated versus power dissipated in the system. Simulation, hardware-in-the-loop, and hardware experimental results will be presented.