1. The document presents a mathematical model of a photovoltaic (PV) module and grid-connected system using a three-phase multistring inverter with sinusoidal pulse width modulation (SPWM) control scheme.
2. The PV module is modeled using equations that account for factors like photocurrent, saturation current, series and shunt resistances, and temperature. The model is implemented in Simulink.
3. A three-phase multistring five-level inverter topology is proposed consisting of three PV strings connected to a common DC bus through DC-DC converters. SPWM control is used to generate switching signals and produce a five-level output voltage to reduce harmonics.