The need of dc-dc switching converters for power supplies with high-voltage gains has increased in the recent years due to new applications in areas as renewable energy systems, transportation, industrial, medical, and others. A quadratic boost converter is a useful topology to obtain a step-up output voltage; however, a major drawback is the presence of a higher voltage stress over the active and passive switches. In this paper, a quadratic boost converter is combined with a voltage multiplier cell and an output filter to offer a high-voltage gain converter with nonpulsating input and output currents. The expressions for the capacitor voltages and inductor currents are given, as well as the corresponding ripples that allow the proper design of the converter. The bilinear switched, nonlinear averaged and linear averaged models are derived such that the dynamical behavior of the converter is analyzed and used to design a control strategy. A step-by-step procedure is given to tune up a current-mode controller. Experimental results are shown from a prototype, which delivers an output voltage of 220 V and an output power of 300 W. Step load changes between 20% and full load are applied to exhibit the robustness of switching regulator.

This work proposes an output voltage regulation scheme for a fuel-cell based power source. The proposed methodology relies on the design of a dynamic backstepping average current mode controller considering the combined fuel-cell stack and boost converter model. Also, an external loop for voltage regulation using a proportional-integral (PI) action is added. Moreover, to improve the robustness of the current loop, a load estimator using immersion-invariance (I&I) approach is designed. As a result, an adaptive backstepping controller ensuring asymptotic stability via a Lyapunov function is achieved. Finally, based on a 460 W testbench and a DSPACE platform, the closed-loop system performance is evaluated through experimental results. An appropriate output voltage regulation and robust behavior concerning to load variation and fuel-cell stack unregulated DC output voltage are exhibited.

In this paper, a passivity-based control (PBC) scheme for output voltage regulation in a fuel-cell/boost converter system is designed and validated through real-time numerical results. The proposed control scheme is designed as a current-mode control (CMC) scheme with an outer loop (voltage) for voltage regulation and an inner loop (current) for current reference tracking. The inner loop’s design considers the Euler–Lagrange (E-L) formulation to implement a standard PBC and the outer loop is implemented through a standard PI controller. Furthermore, an adaptive law based on immersion and invariance (I&I) theory is designed to enhance the closed-loop system behavior through asymptotic approximation of uncertain parameters such as load and inductor parasitic resistance. The closed-loop system is tested under two scenarios using real-time simulations, where precision and robustness are shown with respect to variations in the fuel cell voltage, load, and output voltage reference.

In this paper it is shown that the controller design methodology recently introduced by the authors to stabilize non-globally feedback linearizable triangular systems solves the long-standing problem of transient stabilization of multimachine power systems with non-negligible transfer conductances. The 3n-dimensional (aggregated) model of the n-generator system, with lossy transmission lines, nonlinear loads and excitation control, is considered. A nonlinear dynamic state-feedback control law that ensures, under some conditions on the physical parameters, global asymptotic stability of the operating point is constructed. To the best of the authors' knowledge only existence results-with the restrictive assumption of uniform inertia generators-are available to date for this problem. Simulation results of the New England benchmark system illustrate the performance of the proposed controller.