Multiobjective Reactive Power Planning Considering Load Margin

With our country's power grid construction developing toward large units, ultra-high voltage, ultra-long-distance transmission, and large grid, how to improve power transfer capability economically and effectively is attracting increasing attention. Therefore, considering economy and safety of power grid operation in the planning of reactive power devices has important significance for guiding the configuration of reactive power devices and improving operation level of power grid.This thesis begins by describing the basic theory of power system voltage stability, introducing various assessment index of power system voltage stability, and describing the most widely accepted load margin index and its solution methods in detail. The dangerous load increasing mode in the solution of load margin is studied and dangerous load increasing mode scheme which is fit for large real power system is formulated. Rapid identification and ranking methods for dangerous fault modes set are also studied. Finally, a multi-objective reactive power planning model considering load margin is established, which could optimize the losses of power grid and load margin under normal mode at the same time that considering stability constraints under fault mode, and predictor-corrector primal-dual interior point method and Pareto multy-objective method used to solve the proposed model together. The IEEE 14, IEEE 57 node example and a large provincial power grid in China are used to validate the effectiveness and practicality of the models and algorithms in this thesis.