Research On Large-Scale Offshore Wind Power Connection Mode And Its Comprehensive Evaluation Method

With the increasing construction scale of wind power and gradually growing permeability,wind power not only brings a lot of clean energy for the power system,but also brings considerable unstable factors,which is directly related to the security and stability of power system.Therefore,it is very important to study the wind power access problem in the design and planning stage to ensure the economy and security of the power system,and scholars at home and abroad have launched a series of related research on large-scale offshore wind power connection mode and its comprehensive evaluation method.In this context,the effects of different large-scale offshore wind power connection modes was studied on two aspects: the power system capacity of wind power accommodation,the security and stability of the power system,and the paper also focuses on large-scale comprehensive evaluation method of offshore wind power connection mode.The main work includes the following three parts:Firstly,this dissertation analyzed the power balance and peak-load balance after the large-scale offshore wind power accessed in Jiangsu Province,and established single point connection topology,two-point connection topology,three-point connection topology of large-scale offshore wind power,and the wind power capacity of different types of wind power connection mode were compared.The results show that,the more the wind power connection points are,the stronger the wind power capacity of the power system is.Secondly,the influence of different connection modes of large-scale offshore wind power on the power flow,static security level,short-circuit current level,dynamic stability and power quality of Jiangsu power system is analyzed.The results show that,the less the offshore wind power connection points are and the more concentrated the connection mode is,the higher the short-circuit current level is.From the point of view of power flow,static security level,dynamic stability and power quality,the more offshore wind power connection points are,the better the connection mode is.Finally,the decision-making index system of wind power connection mode was established,including 7 criteria: maximum access capacity,steady-state flow distribution,transient stability,dynamic stability,static security,short-circuit current levels and economy.And the optimal decision-making method of wind power connection mode was studied.The results show that,three-point connection mode is better than two-point connection mode,and two-point connection mode is better than single-point access method,which is based on the subjective and objective weighting method.In the system of the comprehensive evaluation method of wind power connection mode that established in this paper,the more the connection points are,the better the wind power connection mode is.At last,the results are analyzed to confirm the rationality and applicability of the index system and decision-making method.