Research For Probabilistic Load Flow Of Power System Under The Background Of Incorporating Renewable Energy

With the shortage of resources and environmental pollution,the renewable new energy is developed and utilized in recent years.Solar energy and wind energy with its widely distributed,non-pollution,safe and other advantage,has received more attentions in recent years.However,the PV power and wind power appears unstable and intermittent,which brings influence on the electric power system.Probabilistic load flow calculation is based on the probability theory.It can analyze the influence of the power of renewable energy on the node voltage and branch power,which is important preliminary planning of renewable energy,power system operation and scheduling.Firstly,the mathematical research foundation of probabilistic power flow calculation is introduced.Combining the Cumulants and Gram-Charlier expansion theory of random variable can reduce the computation burden of the process of convolution.Then,the stochastic power flow model for power system with renewable energy by using the Cumulants and Gram-Charlier expansion theory is proposed.The relativity of output power of renewable energy is analyzed based on modified Nataf Transformation.And the random branch outage is considered by using the compensation of wattless power.Finally,using the actual running data of HeZe Power Grid,the probabilistic power flow calculation is done based on the proposed method.The influence of relativity of output power of renewable energy and random branch outage on probabilistic power flow.Contrasting to the Monte Carlo Simulation proves the validity and rapidity of the proposed method.