Delay effects on the limit cycling behavior in an H-bridge resonant inverter with zero current switching control strategy

Celebrado en Tarragona del 2-6 de septiembre de 2018.In this paper, bifurcations of limit cycles in a H-bridge LC resonant inverter under a zero current switching control strategy with delay in the switching action are analyzed. Mathematical analysis and numerical simulations show that the delay can degrade the quality of the oscillations and even inhibit them.Agencia Estatal de Investigación DPI2017- 84572-C2-1-RFondo Europeo de Desarrollo Regional DPI2017- 84572-C2-1-RMinisterio de Ciencia e Innovación MTM2015-65608-PJunta de Andalucía Consejería de Economía y Conocimiento P12-FQM-165

Nonlinear dynamic modeling and analysis of self-oscillating H-bridge parallel resonant converter under zero current switching control: unveiling coexistence of attractors

This paper deals with the global dynamical analysis of an H-bridge parallel resonant converter under a zero current switching control. Due to the discontinuity of the vector field in this system, sliding dynamics may take place. Here, the sliding set is found to be an escaping region. Different tools are combined for studying the stability of oscillations of the system. The desired crossing limit cycles are computed by solving their initial value problem and their stability analysis is performed using Floquet theory. The resulting monodromy matrix reveals that these cycles are created according to a smooth cyclic-fold bifurcation. Under parameter variation, an unstable symmetric crossing limit cycle undergoes a crossing-sliding bifurcation leading to the creation of a symmetric unstable sliding limit cycle. Finally, this limit cycle undergoes a double homoclinic connection giving rise to two different unstable asymmetric sliding limit cycles. The analysis is performed using a piecewise-smooth dynamical model of a Filippov type. Sliding limit cycles divide the state plane in three basins of attraction, and hence, different steady-state solutions may coexist which may lead the system to start-up problems. Numerical simulations corroborate the theoretical predictions, which have been experimentally validated.Postprint (author's final draft

Suppression of undesired attractors in a self-oscillating H-bridge parallel resonant converters under zero current switching control

Resonant converters under zero current switching control strategy can exhibit coexistence of attractors, making it difficult the startup of the system from zero initial conditions. In this paper, the problem of multiple coexisting attractors in parallel resonant converters is addressed. Appropriate modifications of the switching decision with the aim of converting undesired attractors into virtual ones are proposed. A suitable control signal is generated from the state variables of the system and used to adjust the switching decision. Numerical simulations corroborate the proposed solutions and the simplest one was finally verified by measurements from a laboratory prototype.Postprint (author's final draft

Delay effects on the limit cycling behavior in an H-bridge resonant inverter with zero current switching control strategy

In this paper, bifurcations of limit cycles in a H-bridge LC resonant inverter under a zero current switching control strategy with delay in the switching action are analyzed. Mathematical analysis and numerical simulations show that the delay can degrade the quality of the oscillations and even inhibit them.Postprint (author's final draft

Analysis of a bidirecctional coupled-inductor Cuk converter operating in sliding mode

Analytic models for a bidirectional coupled-inductor Cuk converter operating in sliding mode are described. Using a linear combination of the converter four state variable errors as a general switching surface, the expression for the equivalent control is derived and the coordinates of the equilibrium point are obtained. Particular cases of the general switching surface are subsequently analyzed in detail: 1) surfaces for ideal line regulation, 2) surfaces for ideal load regulation, and 3) surfaces for hysteretic current control. Simulation results verifying the analytical predictions are presented.Peer Reviewe