Transient Stability Study And Control Strategy Of Power System With Large-scale Wind Farm Integration

Recent years,with the rapid development of wind power in China in,wind power generation has become a very important source of energy in our country.Although in recent years the rapid development of wind power,but there are still some problems need to be solved urgently.The wind power consumptive and the impact of wind power integration on power system stability is the two most prominent problems.Large-scale wind power integration can change the original structure and characteristics of the system.Thus,it's necessary to analyse the transient stability of power system which contains wind power,and to study the controlling strategy for improving the transient stability of power system.Based on EEAC(Extended Equal Area Criterion),this paper studies the transient stability of the power system which contains wind power system theoretically.Furthermore,based on the theoretical analysis results for the impact of wind power integration on the Transient Stability,this paper analyses the controlling strategy to improve the characteristics of power system which contains wind power.Frist of all,the principle and calculation process of the traditional Extended Equal Area Criterion are explained in this paper.Then,the structure and transient characteristics of DFIG are studied.It lays a foundation for the study of transient stability of wind power system.After this,this paper studies the transient stability of the power system which contains wind power system theoretically,proposes the calculation method for accelerating area,decelerating area and margin.Then,the proposed theoretical analysis method is evaluated on the basis of an example,the applicability and limitation of the method are also presented.Secondly,based on the theory presented in this paper,combined with the transient power angle diagram,the influence of wind farm integration on the transient stability of power system is further studied,and the specific situation of two kinds of wind power integration is analyzed.The one is the comparison of the impact of wind power and thermal power grid connected on the transient stability of the system under the same capacity;the two is the influence of different wind power penetration on the system transient stability.Finally,the conclusions are proved on the basis of simulation examples.Lastly,the control strategy for improving the transient stability of a wind power system is studied.Based on the extended equal area rule and the transient power angle curve,the factors affecting the transient stability of the wind power system are analyzed.Based on the analysis results,the method of reactive power compensation using SVG is proposed to improve the voltage of the grid connected to the wind farm during the transient period,and the control strategy of SVG is explained.Finally,an example is given to validate the feasibility of the proposed control strategy based on SVG.