Research On Distributed Fixed Time Control Strategy For Transient Stability Of Smart Grid

With the high penetration of renewable energy sources and the integration of other new technologies such as new energy vehicles and demand-side management,the operation of power systems has become more flexible and variable.At the same time,the addition of these new technologies will continue to make the smart grid stable operation conditions more demanding and thus more important for studying the stable operation of the smart grid.When the grid is disturbed,the main methods to keep the system running smoothly using conventional generators are: fast excitation control,governor control and power system excitation stabilizer,but these control methods cannot participate in the regulation during the initial transient stabilization of the fault.In this paper,we design a controller to regulate the energy storage systems(ESS)installed on the generator side with fast action characteristics to improve the transient stability of the grid in order to compensate for the slow action of the generator regulation system.The research of this paper is focused on.First,in the context of modern power grid integration information network,a transient stability control strategy based on the fixed-time consistency algorithm of multi-intelligent system is proposed to address the shortcomings of the traditional power system transient stability control method and the problem that the fault duration of smart grid affects the transient stability control.The strategy first establishes "neighbor generators" for each generator through the power system communication topology modeling method,and designs a distributed fixedtime controller using the local information of the generator and its neighbor generators to restore the stable operation of the system within a fixed time by controlling the energy storage device after the disturbance.estimating the system stabilization time brings great convenience.Secondly,this paper further considers the constraints on the actual transient stability control of the smart grid,such as the capacity limitation of the output of the external energy storage device,the input time delay of the controller,the external disturbances and the uncertainty of the fault duration.Therefore,the design of transient stabilization controller must overcome these constraints in order to make the grid operation more stable and reliable.In this paper,based on the fixed time consistency approach for multi-intelligent systems,the nonlinear terms in the generator dynamics equations and external disturbances are offset,and the system model with controller input delay is transformed into a control model without explicit input delay in the controller design process based on Artsein transformation.When the grid is disturbed,the energy storage device is controlled in the control loop to absorb or inject active power to stabilize the system in a fixed time.Finally,the stability analysis of the strategy is carried out by constructing the Lyapunov function and using the knowledge of graph theory to derive the time bound of the stable system.The controller is also put into the New England 39-node test system to further verify the advantages of the controller performance in terms of interference immunity.