Three-phase single-stage boost inverter for direct drive wind turbines

In this paper, a new power electronics interface topology for Direct Drive Wind Turbines (DDWTs) to improve the system reliability and with a potential to decrease the size of the Permanent Magnet (PM) generator is presented. In the proposed topology the grid-side Voltage Source Converter in a traditional DDWT is replaced by a three-phase single-stage boost inverter. This enables the use of a low-voltage generator and thus allows design of a smaller sized generator. The current source inverter topology of the boost inverter also enables elimination of the dc-bus electrolytic capacitors. In this paper, a detailed reliability analysis of the existing power electronic interface along with that of the developed interface is presented. The control technique used for the system is described. The validity of the proposed system is supported by set of MATLAB/Simulink simulations on the closed-loop grid-tied system.