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 2nd 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.