Analysis of smart inverter functions of decentralized grid-connected AC-stacked PV inverter architecture

The main objective of this paper is to analyze the feasibility of decentralized control approach in providing smart inverter functions for grid-tied AC-stacked PV inverter architecture. Decentralized controller allows fully distributed architecture both in terms of control and physical implementation of a PV system, resulting in higher reliability and potentially lower cost. In this paper, Relative Gain Array concept has been used to determine the best locally measured input-output pairing sets for designing the proposed decentralized controller. Proposed approach by sending supervisory commands to only one inverter minimize the required communications for controlling reactive power and mitigating harmonics. Detailed modeling and analysis are provided to show the feasibility of the proposed decentralized approach. Proposed decentralized control scheme is verified by offline simulation and real-time hardware-in-the-loop setup.