Performance improvement of start-up system for small scale autonomous wind system

This paper proposed an enhanced start-up system for small scale autonomous wind turbines based on doubly fed induction generator. The improvement is evidenced by the decrease of the magnetizing current transient which does not exceed the rated rotor current value Three points are investigated to ensure fast and smooth start-up process: firstly the startup algorithm that guarantee to effectively reach stable system functioning, secondly the proposed topology which includes a supercapacitor as a supplementary source, that can be disconnected once wind system boots and thirdly the use of predictive controllers that ensures fast resuming turbine operation. An energy management system is developed to monitor the power flow and to enhance storage devices lifetime by reducing the battery current ripple. Proposed model and control strategy of each system component, as well as start-up process actions are described in detail. The effectiveness is validated by numerical simulation.