Research on Sensorless Control Based Back-to-Back Converter for Direct-Driven WECS

The development of back-to-back full power converter based direct-driven wind energy conversion system (WECS) using permanent magnet synchronous generator (PMSG) is very fast, and the sensorless control applied in WECS has been paid much attention for its low cost, high reliability and good capability to interference and poor environment compared with conventional encoder. Based on analysis to the principle of back- to-back converter for direct-driven VSCF WECS, the PLL based sensorless control strategy is adopted to determine the speed and phase of the PMSG. The experimental results prove that the back-to-back converter using sensorless control based on PLL has good performance. Therefore the validity of the proposed strategy is verified, which illustrate that the conventional encoder can be substituted by sensorless control for direct-driven WECS.