Research On Requency Features And High-frequency Generator Tripping In The Power Grid Including Wind Power

The intrinsic characteristics of wind power make wind power generations not provide stable and reliable electrical energy for power grid as regular generations.With the percentage of wind generation in power grid increasing,the influence of wind power output volatility to power grid frequency stability will be more and more significant.In large-scale interconnected power grid,the negative effect of wind power tend to be submerged,and it is difficult to cause people's attention.However,the local sending grid once separates with the main power grid,the isolated net will not only face a serious high frequency problem but also be disturbed by severe wind power.In order to solve the frequency stability problems of the power grid with wind power,this paper researched into frequency characteristic and high-frequency generator tripping of the local power grid with a high wind power penetration.At first,through analyzing the characteristics of wind turbines and the features in transmitting to the local grid,this paper built the models of wind turbines and wind farms,and simulated analysised the running disparities between wind turbines and regular generations in a high frequency condition.We knew from the simulation result that wind power farms transmitted to the local grid can weaken the frequency of the system,and make the frequency deviation and variation increasing.Then,it analyzed the influence of doubly-fed wind power generator's variable speed constant frequency control mode to frequency characteristic from the aspects of power system frequency,and simulating studyed the importance of Low Voltage Ride Through,high frequency protection and the excess capacity exited of power system to the isolated net system frequency stability.In the end,based on a wind-hydro power system,this paper put forward a method which controls the excess power and wind power output level to design the high-frequency generator tripping.Then a high-frequency generator tripping scheme for a local power grid is proposed.The scheme can adapt to all the way to run within the scope of the excess power and wind power output,and it is a good prospect for engineering application.