Operational Performance and Stability Analysis of a Three-Phase Grid-Connected PV Inverter

This paper presents a detailed analysis of the performance and operational stability conditions of a three-phase commercially available grid-connected PV inverter. The presented analysis covers the development of the PV system model, including related electrical circuits and control systems. The operation of the PV inverter is considered for different voltage supply conditions (sinusoidal or distorted grid voltage and variation in grid impedance), as well as for various inverter output powers. The obtained results are validated by measurements, indicating operating conditions under which considered PV inverter may become unstable.