Stability Analysis And Control Of Power System With Wind Farm

Due to both environmental and energy crisis,green energy sources,such as wind and water,are now placed under the spotlight on the world's energy stage.Wind energy in particular has seen a great increase in its production capacity.However,the randomness in fluctuations of wind powered sources cause instability in its output power.Joining wind farms to existing electrical network system disturbs load flow analysis,as wind power generation differs greatly from traditional power generation methods.Discussions and analysis of such network in this thesis is laid out as follows:Thesis conducts analysis on the mathematical models for wind powered asynchronous generators and doubly fed induction generators.Weibull probability distribution is used to reflect fluctuation characteristics of wind speed under real operating conditions.And proposed methods are simulated using actual grid data from specific areas in Yunnan Province.Power system analysis software packages(Power System Analysis Toolbox,PSAT)is used in building a grid model for this thesis.A number of key static parameters are established from performing load flow analysis on above mentioned grid data.Weak nodal points are identified by analyzing boundary conditions as well as power angle elastic coefficient method,which is inspired by first order relationship in Hook's law.Grid data from Yunnan is simulated using two above mentioned methods to segregate weak regions in its electrical network.Classic genetic algorithm(GA)performs poorly when grid is subjected to severe disturbances and instability failures.Due to its slow convergence,classic GA is ill suited as an instantaneous reactive power compensation method.This paper proposes a new piecewise accelerated genetic algorithm for instantaneous reactive power compensations under voltage instability and power angle instability conditions to restore network to a transient stable state.