• Nonlinear dynamics and bifurcation analysis in two models of sustainable development 

      Angulo, Fabiola; Olivar, Gerard; Osorio A., Gustavo; Velásquez, Luz S. (UPC. Cátedra Unesco de Sostenibilidad, 2009-12)
      Article
      Accés obert
      We show in this document two mathematical models of development. Namely, we state two systems of nonlinear differential equations with state variables which regard to ecosystem, social and economic dimensions. We analyze ...
    • Study of Chaos in the buck Converter 

      Fossas Colet, Enric; Olivar, Gerard (Institute of Electrical and Electronics Engineers (IEEE), 1996-01)
      Article
      Accés obert
      A dc-dc buck converter controlled by naturallysampled, constant-frequency pulsewidth modulation in continuous conduction mode gives rise to a great variety of behavior, depending on the values of the parameters of the ...
    • Técnica ZAD aplicada a un convertidor "buck": análisis de estabilidad y de transición al caos 

      Angulo García, Fabiola; Fossas Colet, Enric; Olivar, Gerard (Comité Español de Automática, 2005-10)
      Article
      Accés obert
      En este trabajo se presentan algunos resultados obtenidos al analizar el convertidor buck controlado mediante un modulador de anchura de pulsos (PWM) centrado. El ciclo de trabajo se calcula obligando a que una salida, ...
    • Transition from periodicity to chaos in a PWM-controlled buck converter with ZAD strategy 

      Angulo García, Fabiola; Fossas Colet, Enric; Olivar, Gerard (World Scientific Publishing, 2005-10-31)
      Article
      Accés obert
      The transition from periodicity to chaos in a DC-DC Buck power converter is studied in this paper. The converter is controlled through a direct Pulse Width Modulation (PWM) in order to regulate the error dynamics at zero. ...