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—Solar photovoltaic (PV) arrays in portable applications are often subject to partial shading and rapid fluctuations of shading. In the usual series-connected wiring scheme, the residual energy generated by partially shaded cells either cannot be collected (if diode bypassed) or, worse, impedes collection of power from the remaining fully illuminated cells(More)
—The performance of a battery–ultracapacitor hybrid power source under pulsed load conditions is analytically described using simplified models. We show that peak power can be greatly enhanced, internal losses can be considerably reduced, and that discharge life of the battery is extended. Greatest benefits are seen when the load pulse rate is higher than(More)
—An actively controlled battery/ultracapacitor hybrid has broad applications in pulse-operated power systems. A converter is used to actively control the power flow from a battery, to couple the battery to an ultracapacitor for power enhancement, and to deliver the power to a load efficiently. The experimental and simulation results show that the hybrid can(More)
—A state space approach to the design of a maximum power point (MPP) tracking system for photovoltaic energy conversion is presented. The problem of optimal-power control of a nonlinear time-varying system is reduced to an ordinary problem of dynamic system stability in state space by applying MPP conditions in controller design. The resulting tracking(More)
Design or analysis of advanced power systems, involves knowledge in many disciplines. This paper introduces the Virtual Test Bed (VTB) computational environment for modeling, dynamic simulation and virtual-prototyping of such interdisciplinary systems. A basic feature of the VTB is that it allows experts to build models within their domain of expertise(More)
An ultracapacitor model with automatic order selection of complexity and automatic scaling of capacity is created in Virtual Test Bed platform for complex system simulation and prototyping. The order selection is based upon the variable simulation time step for appropriate level of details of the model, and automatically executed by the model itself,(More)
Satellite electrical power systems (SEPS) are strongly interdisciplinary, exhibit complex nonlinear behavior, and operate over a wide range of power levels. The Virtual Test Bed (VTB) provides a unified computational environment that allows rapid modeling, simulation and virtual-prototyping of such complex systems. VTB handles modeling in a comprehensive(More)