Wide-area Damped Coordinated Control Of Grid-connected Wind Power System Considering Time Delay

In order to promote the sustainable development of China’s economy and society and the rational allocation of natural energy resources,the interconnection of regional power grids is advancing rapidly.With the large-scale wind turbine connected to the grid,the influence of various uncertain factors on its stability is increasing.It is difficult for the local controller designed by local signal to restrain the low frequency oscillation in interconnected power system.The development of wide area measurement system provides strong support for wide area damping control.However,due to the delay in transmission channel,and when multiple damping controllers are put into the system at the same time,the interaction between controllers will also affect the control effect.Therefore,it is of great practical and theoretical significance to discuss the coordinated damping control of grid connected wind power system with time delay effect to suppress the low-frequency oscillation of the grid.In this paper,firstly,the mathematical model of doubly fed asynchronous wind turbine is explained in detail,and the influence of communication delay on the damping effect of additional active control of doubly fed wind turbine is analyzed by using the damping torque method,and verified by time-domain simulation,which lays a theoretical foundation for the subsequent additional damping control of wind power grid connected system.Then,the wide area additional damping controller of doubly fed wind farm is designed,which has strong robustness but does not depend on the accurate mathematical model of the controlled object.Combined with the advantages of progressive memory recursive least square method,the effect of uncertain time delay on the stability of the system is effectively reduced.Finally,considering the damping control of synchronous generator and the interaction between different control loops in the power system,and considering the influence of time delay,a damping coordinated control strategy for wind power grid connected system is proposed based on auto disturbance rejection control and particle swarm optimization algorithm,and the effectiveness of the control strategy is verified by relevant simulation examples.