Sensorless vector control of PMSG for variable speed wind energy applications

This paper presents a sensorless control scheme for a permanent magnet synchronous generator (PMSG) in variable speed wind energy conversion system (WECS) applications. The rotor speed is estimated using recursive least square estimation (RLSE) algorithm using a simple equation which requires only the knowledge of rotor flux. A programmable low pass filter (PLPF) is implemented to obtain the rotor flux. The concept is analyzed in a wind speed sensorless variable speed direct drive PMSG WECS wherein the MPPT controller does not require the knowledge of wind speed, air density or mechanical parameter of the WECS. The machine side and grid side converters are vector controlled in rotor flux reference frame and grid voltage reference frame respectively. Results show good estimation accuracy.