Indirect boost matrix converter and low‐voltage generator for direct drive wind turbines

Abstract

Here, a new topology for direct drive wind turbines (DDWTs) with a new power electronics interface and a low-voltage generator is presented. In the presented power electronics interface, the grid-side converter is replaced by a boost current source inverter (CSI) which eliminates the required dc-bus capacitors, resulting in an increase in the system lifetime. The inherently required dc-link inductor for this topology is eliminated by utilising the synchronous inductance of the permanent magnet synchronous generator. The control technique used for the developed DDWT is described here. The boost CSI enables conversion of a low dc voltage to a higher line-to-line voltage creating an indirect boost matrix converter, and thus, enabling the implementation of a low-voltage generator. This further enables a reduction in the number poles required in direct drive wind generators. The feasibility of the proposed generator-converter topology for DDWTs and its controllers are verified through simulations and experimental results on a laboratory scale 1.5 kW, 240 V set-up.