Limits of the frequency response for the analysis of ripple-based controllers

Advanced control techniques like V2, Vout hysteresis or V2Ic can strongly reduce the required output capacitance in PowerSoC converters. Techniques to analyze power converters based on the analysis of the frequency response are not suitable for ripple-based controllers that use fast-scale dynamics to control the power stage. This paper proves that the use of discrete modeling together with Floquet theory is a very powerful tool to model the system and derive stable region diagrams for sensitivity analysis. It is applied to V 2Ic control, validating experimentally that Floquet theory predicts accurately subharmonic oscillations. This method is applied to several ripplebased controllers, providing higher accuracy when it is compared with other techniques based on the frequency response. The paper experimentally validates the usefulness of the discrete modeling and the Floquet theory on a 5 MHz Buck converter with a V 2Ic control.

Staatsbibliothek zu Berlin: un espacio para la democracia

Documentar los momentos principales del proyecto de la Biblioteca Estatal de Berlín. Hans Scharoun y Edgar Wisniewski. Tres hipótesis y su verificación. Fenomenología; Husserl, Heidegger, Ortega y Gasset y Merleau-Ponty. Kulturforum, desarrollo histórico; Baumgarten, Fahrenkamp, Gutbrod, Scharoun, Wisniewski, Hilmer&Sattler, Stimmann, Düttmann. Textos centrales de Scharoun , 1957; textos centrales de Adolf Arndt. Documentar proyectos colaterales; concurso Amerikagedenk Bibliothek, Philharmonie, Wolfsburg. Propuestas de Werner Düttmann. Encuentro con Wisniewski; croquis iniciales… Concurso Staatsbibliothek; Scharoun, Gutbrod, Bornemann, Spengelin, Ruegenberg, Kramer, Pfau, Seitz, Krahn, Deilmann. Acta del jurado. Plantas publicadas del proyecto 1964, 1967, 1979. Textos centrales de Ulrich Conrads y Edgar Wisniewski, 1978 y 1979. Scharoun-Feininger, una teoría de Matthias Schirren. Fotografías momento de la inauguración, 1978 y en la actualidad. Bibliografía actualizada a 2015. ABSTRACT To document key moments of the project of the State Library in Berlin. Hans Scharoun and Edgar Wisniewski. Three hypotheses and its verification. Phenomenology; Husserl, Heidegger, Ortega y Gasset and Merleau-Ponty. Kulturforum, historical development; Baumgarten, Fahrenkamp, Gutbrod, Scharoun, Wisniewski, Hilmer & Sattler, Stimmann, Düttmann. Main texts of Scharoun, 1957; central texts of Adolf Arndt. To document side projects; contest Amerikagedenk Bibliothek, Philharmonie, Wolfsburg. Werner Düttmann proposals. Meeting with Wisniewski; initial sketches ... Staatsbibliothek competition; Scharoun, Gutbrod, Bornemann, Spengelin, Ruegenberg, Kramer, Pfau, Seitz, Krahn, Deilmann. Brief of the competition‘s jury. Drawing’s Project published 1964, 1967, 1979. Ulrich Conrads and Edgar Wisniewski central texts, 1978 and 1979. Scharoun-Feininger, a theory of Matthias Schirren. Photography time of the inauguration, 1978 and today. 2015 updated bibliography.

Accurate Analysis of Subharmonic Oscillations of V^2 and V^2Ic Controls Applied to Buck Converter

V2Ic control provides very fast dynamic performance to the Buck converter both under load steps and under voltage reference steps. However, the design of this control is complex since it is prone to subharmonic oscillations and several parameters affect the stability of the system. This paper derives and validates a very accurate modeling and stability analysis of a closed-loop V2Ic control using the Floquet theory. This allows the derivation of sensitivity analysis to design a robust converter. The proposed methodology is validated on a 5-MHz Buck converter. The work is also extended to V2 control using the same methodology, showing high accuracy and robustness. The paper also demonstrates, on the V2 control, that even a low bandwidth-linear controller can affect the stability of a ripple-based control.