Cascaded MPPT control with adaptive voltage controller applied to boost converters for PV applications

Abstract

Dc-dc boost converters have been widely employed at input stage of photovoltaic (PV) inverters. Since PV system dynamic depend on solar irradiance, temperature and operation point of I-V curve, its small-signal models changes significantly. Most applications of this converter apply a bulk input capacitance to reduce the impact of PV module's behavior on control system dynamics. However, conventional approaches cannot achieve fast dynamic response for any operation point using a current control strategy to limit the power processed by the converter. This manuscript proposes a cascaded control structure complying with all these requirements. It is composed of a non-linear current controller and an adaptive voltage controller with fast detection of the system model. Experimental results are carried out to validate the proposed technique.