Research On Application Of UPFC In Power System With Wind Farm

In recent years,the development momentum of wind power generat ion has been very rapid,and it has become one of the indispensable sources of electric energy in China.Due to the characteristics of unstable and frequent fluctuations in wind power generation,large-scale grid-connected wind farms bring many problems to the power grid safe and stable operation.As the most comprehensive device in the FACTS device,the UPFC can flexibly and conveniently improve the dynamic performance of the power system and improve its transient stability.Therefore,the application of UPFC in power systems with wind farms is of great significance for improving the utilization rate of wind energy and improving the operational stability of the system.This paper will focus on the UPFC's ability to improve the dynamic stability of wind power systems and its ability to control power flow.First of all,established UPFC mathematical model and carefully studied its control strategy.Because the traditional control strategy needs the accurate mathematical model of the controlled object,and the power system structure is complex and has the characteristics of nonlinear and strong coupling,it is not easy to establish its precise model.Therefore,based on the basic principle of UPFC and its traditional PI control method,a UPFC fuzzy control strate gy that can self-tuning parameters is studied and designed.It can be seen through simulation,this control strategy can more effectively improve the transient stability of traditional power systems than traditional PI control strategies.Secondly,the power flow control of UPFC power system containing wind farm is studied.Because the most significant function of the UPFC is the ability to regulate and control the distribution of power flow in the power system,and connect UPFC to the wind farm exit,it is used to control the line flow under the situation that the line breakage occurs and the wind farm has its output power fluctuate due to wind speed fluctuations.The simulation showed that,UPFC has a powerful power flow control function so that the power s ystem can always operate under a reasonable distribution of power flows,avoiding the occurrence of critical line overload conditions.Finally,the transient control ability of UPFC for wind power system containing power system is studied.SVG is a device that has been used for reactive power compensation at the exit of wind farms so far,and can also help improve the transient stability of power systems.UPFC also has good reactive power compensation performance and transient control performance.By comparing the transient control capabilities of UPFC and SVG,it can be concluded that UPFC is more effective in the transient control of power systems with wind farms.At the same time,the designed self-tuning parameter UPFC controller is applied to the transient control of the wind farm system.The simulation analysis shows that the designed control strategy can more effectively improve the transient performance of the wind farm containing power system.