دانلود رایگان مقاله مدل سازی کامل نیروگاه بادی گذرای الکترومغناطیسی

abstract

This paper presents a modelling methodology to analyse the impact of wind farms in surrounding networks. Based on the transient modelling of the asynchronous generator, the multi-machine model of a wind farm composed of N generators is developed. The model incorporates step-up power transformers, distribution lines and surrounding loads up to their connection to the power network. This model allows the simulation of symmetric and asymmetric short-circuits located in the distribution network and the analysis of transient stability of wind farms. It can be also used to study the islanding operation of wind farms.

10. Conclusion

Wind generators have been modelled in terms of the Quadrature-Phase Commutator full transient model, with six electrical state-variables, and two more mechanical. The electrical network from the wind farm common busbar up to the point of common coupling has also been modelled in state-space. Delta-wye connection of the transformer at the wind farm common busbar has also been integrated in the overall model, and rated values of the generators have also been verified. The approximation of aggregated modelling of Squirrel Cage Induction Machines has been discussed in detail, providing the physical meaning of aggregated parameters and variables. The aggregated induction generator works in an average operating point corresponding to average rotor speeds and average stator voltages. But this modelling approach is only valid when all the generators have similar angular speeds. Generalization of this modelling could mask the real evolution of each wind generator that might be very different to the evolution of the re-scaled machine. Steps needed for the simulation of the overall system have been specified. The multi-machine model and the aggregated approximation share the same simulation structure. As a consequence, it is quite straightforward to simulate both models in the same platform. An alternative simplified multi-machine model for validation of the proposed full transient model has been developed. This model is based on the formulation of the impedance matrix of the overall network, as used for the fault analysis problem. The model is simulated according to the particular slip of each generator. Compari-son between results of the full transient model and those of the simplified one shows that, in general, both models predict the same pseudo steady-state behaviours.