Abstract

In recent years, the participation of wind generator in primary load – frequency control of power systems has become imperative, especially in autonomous electric systems, due to the increased integration of the wind energy in the grid.

Ιn this diploma thesis, this phenomenon was studied and three models were developed. The first model which was a network represented by a single bus system and consisting of a hydro station, a wind generator and a load, was simulated in Matlab-Simulink. The second model was a small electric system, consisting of a synchronous generator, a wind generator and a load. This was developed in the lab of power systems with RSCAD and was implemented in Real Time Digital Simulator (RTDS). Finally, the last model, which was also developed in RSCAD and implemented in RTDS, was the medium voltage network of the small Greek island “Agios Eustratios (Ai Stratis)”.

The results concern four different operation strategies of the wind generator. The classic method that does not allow wind generator to contribute to frequency control, the contribution to the inertial response of the system, the pitch control deloading strategy and the combination of the two previous methods. Different scenarios concerning wind speed and load were examined for the above models as well as for all strategies.

Finally, the effect of wind speed on the system frequency was studied, by using measured wind speed inserted in the Real Time Digital Simulator.

Keywords: primary load – frequency control, variable speed – variable pitch wind turbine, permanent magnet synchronous generator (PMSG), Real Time Digital Simulator (RTDS), deloading strategy, pitch control, inertial response, combined control, hydro station, Ai Stratis.

Author: Nikolaos Katsoulakos

Responsible PhD: Panos Kotsampopoulos / kotsa@power.ece.ntua.gr

Supervising Professor: Nikos Hatziargyriou / nh@power.ece.ntua.gr

PDF: Full version (Greek) and Short version (English)