Research On Frequency Dynamic Characteristics Of Power System Integrated With Wind Power

With the development of wind power generation technology,the penetration of wind power in power system gradually increases.It has become an inevitable trend that wind turbines gradually replace traditional thermal power units.China’s large wind power base is gradually connected.With wind power penetration rates rising,a series of influence will be produced to power system.One of the main effect is caused by power system inertia decreases,and thus influencing the dynamic characteristics of the actual power system frequency,even threaten the system safe and stable operation.Therefore,it is of great significance to study the influence of large-scale wind power grid on the dynamic characteristics of power system.At present,there are few researches on the influence mechanism of high permeability wind power grid on power system frequency and how to evaluate the frequency dynamic characteristics of power system.Aiming at the above deficiencies,this paper will carry out the following research:(1)This paper summarizes the power system load,generator frequency static characteristic.This paper introduces the theory of dynamic characteristics of power system frequency and contains only the inertial response of the power system and conventional unit primary frequency control theory,Using frequency response assessment model of generators with spare capacity combining,this paper further analyzes the influencing factors of power system frequency response.(2)In the case of wind power turbines participating in the power system frequency modulation scenario,a simplified model of dynamic frequency assessment of power system is proposed.By studying the model,a brief calculation method for the frequency response of power system is proposed.The analytical formula of frequency response index of power system is derived.The influence of wind power on the frequency modulation of wind power is analyzed.Results show that the virtual inertia control and droop control can improve power system frequency response characteristic,but the wind turbines participating in the different ways of frequency modulation have various indicators to power system.(3)The time domain simulation of the detailed electromechanical transient model with large-scale wind power is very time-consuming.In order to solve this problem,this paper summarized measure several important indexes on the basis of power system frequency response.In this paper,a high penetration of wind power system dynamic frequency response prediction model is proposed.Using this model,the frequency response behavior of power system can be evaluated quickly.The system correlation parameter polymerization method and the error of the method are given.Using IEEE10 machine 39 node system,this paper compares frequency response index calculation results and calculation efficiency of the time domain simulation model and the evaluation model to verify the proposed frequency response evaluation efficiency and correctness of the model.It is of great significance to the operation and planning of power system.The evaluation model can improve the efficiency of power system frequency evaluation.