Dispatch Of Spinning Reserve And Frequancy Regulation Method Under Power-limited Condition Of Wind Generation

With the greenhouse problem and environmental problems worsening day by day,the adoption of new energy sources such as wind power instead of the original fossil energy sources is the future development trend and an objective requirement.Wind power as the most widely used and most studied form of power generation in new energy has become the mainstream of new energy power sources g radually.Because the wind generator adopts the doubly-fed asynchronous induction generator based on partial power converter,the rotor speed of the wind generator is decoupled from the frequency of the power grid.When the power grid is disturbed the wind generator can not be configured for rotation standby to reduce the frequency stability of the power grid.Disruption in the allocation of spin-back configuration is the most important to absorb wind power.In this paper the common methods of configuring spinning reserve when the power grid is disturbed are introduced.Firstly the additional torque control and virtual synchronous generator control are introduced.For the additional torque control the mechanism of its action on the electromagnetic power of the wind turbine is analyzed.The torque control mainly changes the electromagnetic power of the fan through three paths of rotor speed power angle and rotor voltage.Then starting from the equation of wind generator rotor motion through the analogy with the transient energy function of synchronous generator,Transient total energy is decided by introduced frequency derivative term.As for grid level,frequency derivative term seems to change the grid inertia.The introduction of frequency proportional term coefficient changed the grid damping and the simulation analysis verified the above conclusion.Aiming at the regional power system frequency modulation a distributed unit control structure with wind farms is established in this paper and three conditions to be met in the regional power network frequency adjustment are pointed out.An improved additional transfer control based on mode switching is proposed.The better configuration of rotating spares support for frequency stability while building a four-machine two-zone model to verify the accuracy of the method proposed in this article.This paper quantitatively analyzes the influence of power-limited operational condition of wind farm on the index of secondary frequency regulation and maximum penetration power of wind power,assuming that it will be able to reduce the pressure of synchronous generator in reserve capacity and fr equency regulation speed aspects as well as raise maximum penetration power of wind power;In order to study the allocation problem of secondary spinning reserve under power-limited operation of wind farm,the reserve optimization and the dynamic equivalent model consisted of equivalent synchronous generator and wind turbine are established,which is solved by MATLAB/Simulink.The optimization and simulate results show that the wind farm working in po wer-limited state will increase the stability of power grid and reduce spinning reserve.