Fuzzified PI voltage control for boost converters in multi-string PV plants

This paper is concerned with the problem of the voltage control in a photovoltaic multi-string technology-based DC/DC boost converter. A new fuzzified PI regulator is proposed in order to adapt the voltage control to the non linear and time variant characteristics of the PV source. In particular the fuzzified PI controller parameters can be modified according to the variation of the system transfer function which is dependent on the actual PV source working point. The proposed solution allows to satisfy the control requirements of the boost converter in terms of stability of the closed loop control with the best dynamics in all possible operating conditions.