Steady-state and dynamic properties of boost-power-stage converter in photovoltaic applications

Dc-dc interfacing of photovoltaic (PV) modules into the downstream system is usually done by using a boost-power-stage converter with an added input capacitor. Its dynamic properties are often assumed to be equal to those of a conventional boost converter. The input voltage of the converter is most often feedback controlled to achieve maximum power transfer in PV applications, which actually changes the converter to be a current-fed converter. This paper will show that the boost-power-stage converter with an added input capacitor has thoroughly different dynamic properties than those of the conventional voltage-fed boost converter. The effect of input-side control on the output impedance and the mode of the output port are also discussed.