Fixed-point implementation of phase lead + resonant controllers for PV applications

This paper presents the implementation of a digital phase-lead plus resonant controller for photovoltaic (PV) applications using delta operator in a low-cost 16 bit fixed-point controller. The resonant controller is used to reduce the low frequency voltage ripple across the PV array in a step-up dc-dc converter for grid-connected PV applications. Delta operator is proposed to solve problems related to imprecise parameters representation in conventional shift operator implementation. Simulation and experimental results using shift and delta operators are presented to demonstrate the advantages of delta implementation form.