Start-up system design for small scale autonomous DFIG wind turbine

Autonomous wind systems are becoming promising since they provide new and innovative solutions to non-electrified areas. Start-up procedures for this wind systems requires some care to ensure electricity availability, to ovoid overloads and to reduce electrical and mechanical stress that affect lifetime of system components. In this context, this paper deals with an enhanced start-up system for small scale autonomous wind systems based on doubly fed induction generator. With the proposed start-up system, transient magnetizing current value is maintained under rated rotor current value to ensure smooth start-up process. Start-up algorithm guarantees the reach of a stable system functioning. Suggested topology, that includes a supercapacitor as a supplementary source, can be disconnected once wind system boots. Predictive controllers are used to ensure fast response. An energy management system is developed to monitor power flow. Considered model and control strategy of each system component, as well as start-up process are presented. Simulation results prove the effectiveness of the proposed start-up system.