Analysis And Application Of Power Flow Balancing Based On Information Entropy

New energy and load fluctuation causes the change of power flows, and the characteristics of power flow change have direct impact on power grid security. Power flow balancing serves as an important characteristic of power flow change, which provides a new point of penetration for power flow analysis based power grid security operation research. Therefore, this thesis research on power flow balancing analysis and its application. Through the power flow characteristics analysis, this thesis establishes index to describe power flow transfer balancing under external power fluctuation, and researches evaluation methods and optimization methods for power grid security margin. This thesis researches mainly from the following two aspects. The first, evaluating the anti-interference of power system nodes and identifying the key components in power system operation under disturbance power contained environment. The second, researching the relation of power flow transfer characteristics and power system security load margin, and exploring the method for improving power grid security operation level through optimizing the power flow balancing.For the purpose of evaluating the anti-interference of power system nodes and identifying the key components in power system operation under disturbance power contained environment, the node disturbance power transfer balancing analysis method based on section information entropy is proposed. This thesis combines the information entropy and the practical power system operation characteristics, and proposes improved section information entropy. And by the combination of sensitivity analysis and the branch power margin, the node disturbance power transfer balancing evaluation index is established on the basis of the improved section information entropy. This evaluation index effectively describes the node injection power fluctuation transfer balancing degree on the system branches. The method proposed provides the basis for large-scale power system node anti-interference capability assessment, and provides reference for power system load management, error control of integrated wind power, and modern interactive power grid simultaneously.In order to reveal the relation of power flow transfer characteristics and power system security load margin, this thesis generalizes the power flow balancing analysis. This thesis researches the power flow transfer characteristics caused by the load change, and proposes the system power flow transfer balancing analysis methods based on real number information entropy. Firstly, this thesis analyses branch power flow transfer characteristics. Secondly, this thesis establishes system power flow transfer balancing index with the combination of real number information entropy and branch power margin in current system operation mode. And this index is applied for system security level assessment under the environment of changing load. This part of work lays the foundation of system security load margin improvement through adjusting the system operation mode.On the basis of system power flow transfer balancing analysis, this thesis researches the system optimal power flow balancing computing methods. This thesis establishes the optimal power flow balancing model with the objective function of maximization the system power flow transfer entropy. And this model is solved by the particle swarm algorithm to obtain the optimized system operation mode.This thesis researches the power system security problem in steady-state operation through the method of system power flow balancing analysis. The work in this thesis is aimed at establishing reasonable balancing indexes and providing new thinking and methods for fast identifying key nodes, assessing and optimizing power system operation security level. The power flow balancing analysis method based on information entropy proposed by this thesis is of high calculation efficiency, which provides strong support to the practical application of the research results. The theory and application reference for the improvement of modern power system operation security level by the research results of this thesis is expected.