An Improved DC-Link Voltage Control Method for Multiple Grid Connected Converter in Direct Drive Wind Power Generation System

Abstract

In order to reduce the current of each IGBT and reduce the harmonic current into the grid, a multiple AC-DC-AC full-scale converter which is suitable for high power direct drive wind power generation systems is adopted. The reasons of DC-link voltage fluctuation of the grid connected converter are analyzed. An improved DC-link voltage control method for multiple grid connected converter in direct drive wind power generation systems is proposed in this paper to limit the fluctuation range of the DC-link voltage. The instantaneous generator power and grid voltage feedbacks are used to improve the dynamic response of the DC-link voltage. Simulation and experimental results verify the analysis and the conclusion.