Theoretical study and experimental validation of a Wind Energy Conversion System control with three-level NPC converters

This paper presents a theoretical study, a numerical simulation and an experimental validation of a Wind Energy Conversion System (WECS) control by using a back to back three-level NPC converter. In this context, the WECS, which is based on Doubly Fed induction Generator (DFIG), has been briefly described, and its hierarchical control system with a three-level NPC back-to-back converter has been detailed. The Rotor Side Converter (RSC) controls the power flow from the stator of the DFIG to the grid by controlling the rotor currents of the DFIG. The Grid Side Converter (GSC) ensures the regulation of the DC voltage to the desired value, and regulates the power flow from the rotor of the DFIG to the grid by controlling the filter currents. The overall WECS has been numerically simulated and validated experimentally. Both of simulation and experimental results confirm the validity of the control by using a three-level NPC converter.