On Reactive Power Injection Control of Distributed Grid-tied AC-stacked PV Inverter Architecture

In this paper, two different Reactive Power Injection (RPI) methods for a fully distributed PV inverter architecture are investigated. RPI methods are parts of ancillary service requirements for modern PV systems to play a more active role in grid regulation and control in future high penetrated PV generation networks. The main objective of this paper is to demonstrate and test RPI methods on a panel-level AC-stacked PV-inverter string which is controlled with distributed control scheme with minimum communication requirements and propose a combined RPI method. Effectiveness and feasibility of distributed control architecture and RPI methods are verified by experimental results during normal operation and voltage disturbance conditions using a lab-scale PV inverter string setup.