Study On Transient Stability And Coordinated Control Of Long-Distance Transmission Grid Containing High Proportion Of Wind Power

In order to improve the transmission ability of wind power for grid, the operating characteristics of long-distance transmission grid containing high proportion of wind power and the characteristics of grid-connected wind power are analyzed, the new influence on transient stability and stable control owing to high proportion of wind integration on sending power grid of Eastern Area of Inner Mongolia (long-distance transmission grid) is researched according to the actual situation of northeast China power grid. In this test, wind power modeling, transient stability and stable control are emphatically researched.First of all, wind turbine model, control system model, rotor model, wind-power model have been modeled practically. To solve the accuracy of simulation in simple impedance equivalence, a new node equivalent method for wind farms has been set up. Not only the electrical relationship of node voltage and appendance, but also the electric property relationship between grids connected point and each node within wind farms have been considered effectively in this method, which is applied in modeling the wind farm group to set up the simulated system in electric power system by PSASP. Model parameters have been amended by using turbine LVRT testing data. Equivalent model of wind farm group has been revised through wind farm short-circuit testing data. The results have proved that the simulation model can meet the requirement of electromechanical transient simulation of large power grid, and lay a theoretical foundation for further research.Then this paper studies the optimization control theory of H-P equation and puts forward a new coordinated control method to improve transient stability for thermal power in long-distance transmission grid. This method focuses on the optimization of fast valving control and cutting generator, aiming at two kinds of optimization control set up the state space equation and solving process. Combined with network configurations and thermal power plant parameter of northeast grid, Optimized for fast valving control. The traditional "plan" fast valving control change into based on unit stability parameter changes from time to time optimal control,and simulation results proved the fast valving control is effective to improve the transient stability of long-distance transmission grid; Apply this new coordinated control method to optimize cutting generator control, Cutting generator measures solving optimal control problem is attributed to the set of cutting time and cutting generator number, Through the simulation of the actual data, prove this method effectively and feasible to improve power transmission capacity.Study on the optimization control theory of H-P equation, Combine actual character about long-distance power grid transient stability, and put forward a new thermal power generating unit coordinated control method about quadratic performance index for the unit stability parameter in long-distance power transmission grid. This method is mainly reflected in the optimizing control of fast valving and cutting generator, aiming at two kinds of optimizing control, setting up the own state space equation and solving process. Combined with power network configurations and thermal power plant parameters of northeast grid eastern region of Inner Mongolia, deduce for fast valving optimizing control, making the traditional "plan type" fast valving control change into based on unit stability parameter changes optimal control from time to time, and simulation results prove that the fast valving control is effective to improve the transient stability of long-distance transmission grid. Apply thermal power generating unit coordinated control method based on H-P equation to deduce the cutting generator coordinated control, making coordinated control problem due to the critical cutting machine quantity and the unit to remove time to calculate, and through the simulation of the actual data, not only proves this new method is effective about solving unit critical mute time, but also proves taking cutting measures is available to improve the ability for conveying wind power in long-distance power transmission grid.Combine the characteristics of key nodes voltage with the correlation between power angle and voltage stability, put forward installing dynamic reactive power compensation device in the adjacent node of long-distance transmission system oscillation center to improve transient stability. The technical measures improve the supporting capacity of dynamic reactive power in transient oscillation process; improve the level of transient voltage stability and power angle stability level. Simulate long-distance transmission system in the Eastern Area of Inner Mongolia of Northeast Power Grid to verify the effectiveness of the technical measure.