Loading...
Modulación, modelación y control para un convertidor de potencia bidireccional aislado
Citations
Altmetric:
Abstract
En esta investigación se desarrollaron un esquema de modulación, el modelo promedio y una estructura de control para un convertidor de potencia CA-CC bidireccional aislado. Como primera medida se analizaron las condiciones necesarias para que el convertidor presentara un desempeño muy bueno. Es decir, que mostrara un factor de potencia alto, una transferencia eficiente de energía y bajas pérdidas por conmutación, entre otros. Teniendo en cuenta los efectos del nuevo esquema de modulación en el funcionamiento del convertidor se identificaron las variables de estado a usarse en el modelo promedio de señal grande. Este modelo representa la dinámica lenta del convertidor, la cual se puede aproximar linealmente alrededor de una órbita de operación para obtener el modelo de señal pequeña. A partir de este último se pueden derivar las funciones de transferencia para diseñar los lazos de control. Para validar el modelo promedio obtenido se efectuaron simulaciones en SABER, tanto para el modelo promedio como para el conmutado, en lazo abierto y en lazo cerrado. Allí se observa que el modelo promedio de señal grande concuerda muy bien con el modelo conmutado y que el primero puede utilizar para predecir el funcionamiento del convertidor.
In this research, a modulation scheme, an average model and a control structure for an isolated AC-DC bidirectional power converter were developed. As an initial measure, the necessary conditions for the converter to present very high performance, i.e. high power factor, efficient energy transfer, and low commutation losses among others. Taking into consideration the effects of the new modulation scheme upon converter operation the state variables to be used in the large-signal averaged model were identified. This model represents the converter’s slow dynamics and can be linearly approximated around an operating orbit to obtain a small-signal model. From this the transfer functions to design the control loops can be derived. In order to validate the model derived in this work, SABER simulations were performed for both average and switching models in open loop and closed loop. The average model agreed very well with the switching model, and that the average model can predict the converter behavior.
In this research, a modulation scheme, an average model and a control structure for an isolated AC-DC bidirectional power converter were developed. As an initial measure, the necessary conditions for the converter to present very high performance, i.e. high power factor, efficient energy transfer, and low commutation losses among others. Taking into consideration the effects of the new modulation scheme upon converter operation the state variables to be used in the large-signal averaged model were identified. This model represents the converter’s slow dynamics and can be linearly approximated around an operating orbit to obtain a small-signal model. From this the transfer functions to design the control loops can be derived. In order to validate the model derived in this work, SABER simulations were performed for both average and switching models in open loop and closed loop. The average model agreed very well with the switching model, and that the average model can predict the converter behavior.
Description
Date
2007