Research On Quasi Steady State Simulation And Frequency Control Method Of Power Systems Integrated With Wind Power Generations

As environmental issues have been paid more and more attention,wind power generations which hold the advantages of sustainability and pollution-free become one of the research focuses.The impact of integration of large scale wind power generations on power system stability is more and more obvious.Currently,the DFIGbased wind turbines are widely used in power grids which are connected to the grid through the power electronic devices.The power generated by wind turbines can not respond to the change of system frequency.Therefore,with the increasing penetration of wind power,the system frequency stability will be greatly affected.In this paper,the issue of long term frequency stability of wind power system is studied:Firstly,this paper introduces the research background and significance,the development status of domestic and foreign wind power generations,the dynamic simulation model and frequency control methods with both wind power generations and demand side response involved.By taking the factors of AGC control and load change characteristics into consideration,the paper studies quasi steady state time domain simulation method which is suitable for the analysis of interaction of large-scale wind power generations and system frequency stability.The method simpli fies the system simulation model and the simulation speed is improved obviously.Then,the ways of how the wind turbines and demand side response can be involed in frequency regulation are studied.In this paper,the virtual inertia frequency control and primary frequency control of wind turbines are taken into account.The demand side response frequency regulation is similar to the primary frequency regulation of the conventional unit.By considering the relationship among four aspects which are maximum frequency deviation,the rate of change of frequency,the reserve capacity of thermal power plants and the reserve capacity of the wind power plants,this paper puts forward a coordinated control method and through which the parameters of wind and thermal power plants in together with demand side response can be dynamically tuned.Finally,by taking a practical system in Inner Mongolia as an example,the effectiveness of the proposed coordinated frequency control method is verified by using quasi steady state simulation method.It is shown that the results of quasi-steadystate model are close to the simulation results of the detailed model while the quasi-steady-state simulation speed is 20-30 times of the simulation speed of the detailed model.The simulation results show that the proposed method can satisfy the system requirements and make the demand side take part in the frequency regulation with less power which improve the system operating efficiency.