Clustering of electrical generators in a multirotor wind turbine with inertia emulation

Abstract

An innovative control scheme of a multirotor wind turbine (MRWT) based on N parallel permanent magnet synchronous generators connected to a single back-to-back converter is presented, aiming at an overall cost and weight reduction of the system. This control solution is based on the MPPT mode of operation, to maximize power extraction when in below rated wind speed, together with standard vector current control. An inertia emulation controller was added to the model to provide primary frequency control to the network. Various simulations were carried out to validate the model considering five rotors. Furthermore, a comparison between the system behaviour and power extraction is performed against a MRWT with dedicated converters for each generator. Inertia emulation is also reproduced. Low voltage ride-through was validated by means of simulations. It was concluded that the clustering configuration is robust and might be a suitable solution for a MRWT.