An energetic based method leading to merged control loops for the stability of input filters

In most of applications, power converters are controlled to allow their output current/voltage to follow the required reference values. For DC/DC and DC/AC converters, the control must take into account their input voltage, which must be rejected. In such conditions, the converters can be modeled as negative impedance, causing the instability of their feeding 2^nd order input filter. This paper presents an original method for the stabilization of the input filter. A merged control scheme is defined using an Energetic based method. A first control scheme is defined to control the output current. A second independent control scheme is defined to control the filter stability. Both control loops are merged using a weighing criterion. Simulation results are provided and the stability issue is discussed.