Investigation On Small-signal Angular Stability Of DDPMSG

In recent years, with the more supporting policy on developing renewable energy,the capacity of wind power generation grows rapidly. Integration of large-scale wind power generations into grids is facing great challenges. Til now, many investigations are focusing onthe stability of system integrated with doubly-fed induction generator (DFIG),while seldom on direct-drive permanent magnet synchronous generator (DDPMSG).However,DDPMSG has obvious advantages compared with DFIG in many aspects and will be a future trend. Furthermore, investigations on small signal stability of power system integrated with DDPMSG is even more insufficient in contrast with investigations on transient stability and low voltage ride through (LVRT) capacity. Therefore, this paper aimed to analyse the impact of the small-signal angular stability with the integrated of permanent magnet synchronous machine into system .First, this paper briefly introduces the background and significance of this research,then the structure, control strategy, as well as the current situation and future development of direct-drive permanent magnet synchronous machine is declared. The researches of small-signal angular stability of PMSG integrated power system are overviewed. And then the complete mathematical model of direct-drive permanent magnet synchronous generator is given, and the complete 13 order linearized model is also obtained. On the basis of it, the simplified mathematical mode and its 5 order linearized model are obtained.Based on the idea that a direct-drive permanent magnet synchronous generator can be treated as a feedback ofpower system, this paper deduced the transfer function of direct-drive permanent magnet synchronous generator feedback controller. Withthe directly method of analysing small-signal angular stability analysis of a PMSG integrated power system, a indirect method is proposed in this paper, and the principle and process of proposed method is declared.Finally, based on the test system New England power system, the indirect method of analysing small-signal angular stability of PMSG integrated power system is validated.And the influences of parameters, location and the connection mode of PMSG on small-signal angular stability are analyzed.The research in this paperhas a practical significance of the simplified calculation of the small signal stability of direct-drive permanent magnet synchronous generator integrated power system, and has a certain reference value to study the influences of the parameters,location and connection modes of PMSG on the small-signal angular stability of a PMSG integrated power system.