PROJECT TITLE :

Single-Stage Three-Phase Grid-Tied PV System with Universal Filtering Capability Applied to DG Systems and AC Micro grids - 2017

ABSTRACT:

This paper proposes a single-stage 3-part four-wire grid-connected photovoltaic (PV) system operating with a twin compensating strategy and feedforward management loop (FFCL). Besides injection of active power into the grid, the PV system operates as a unified power quality conditioner (UPQC), suppressing load harmonic currents and compensating reactive power. Furthermore, regulated, balanced, and harmonic-free output voltages are provided to the load. Since the PV-UPQC relies on a twin compensation strategy, the series converter operates as a sinusoidal current supply, whereas the parallel converter operates as a sinusoidal voltage supply. Thus, seamless transition can be achieved from the interconnected to the islanding operation modes, and vice versa, without load voltage transients. Moreover, to beat issues related to sudden solar irradiation changes, fast power balance involving the PV array and also the grid is obtained, since the FFCL acts on the generation of the series inverter current references. Consequently, the dynamic responses of each inverter currents and dc-bus voltage are improved. Detailed analysis involving the active power flow through the inverters is performed permitting correct understanding of the PV-UPQC operation. Experimental results are presented to evaluate both dynamic and static performances of the PV-UPQC tied to the electrical distribution system.