Dynamic modelling and robust regulation of a no-storage wind-diesel hybrid power system

Abstract High penetration autonomous wind-diesel energy systems should normally comprise at least two dynamic energy control devices. The first device maximizes the power output of the wind turbine, while keeping it wihin mechanical design limits; the second is added to the conventional regulator of the diesel for continuous adaptation of plant output to the requirements of the consumer. This paper deals with the design of robust regulators for the second requirement. Highly detailed linear dynamic models are first derived for the three modes of operation of a basic system comprising one wind turbine and one diesel unit (D, W/D and W). Numerical analysis of these operating modes provides a better understanding of the unregulated system and allows for development of a systematic design procedure for the PID regulators required to smooth the frequency. Taking a system with 20% and 100% wind-energy penetration, the robustness of this supplemental regulation is then demonstrated by investigating its performance with respect to rejection of disturbances due to load demand and wind.