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A master's thesis from Aalborg University
Book cover


Impact of Turbine Converter Control on Wind Farm with DC Collection Grid

Authors

;

Term

4. term

Publication year

2018

Submitted on

Pages

94

Abstract

This thesis presents a control strategy for a DC/DC resonant converter for offshore WT application. The main objective is to obtain fast and accurate power tracking. The control architecture is based on a feedforward developed by linearization of the power to frequency equations. The method used contains an algorithm that obtains the right switching frequency from a look-up table in order to follow the reference power. Results obtained by simulation on a lossless 10MW converter show a good performance on the whole operating range during power and output voltage steps. Moreover, the controller is able to reject output voltage harmonics and has a proper set-point tracking bandwidth. The validation of the control structure is performed on a 10kW and 5kV output voltage laboratory setup. Experimental results reflect a favorable matching but arise further issues such as: proper MV measurement, non-idealities and output choke impact. Furthermore, the need of a low gain compensator in parallel is necessary to avoid steady-state error when the resolution of the feedforward is reduced.