A Continuous Calculation Method Of Static Security Analysis Based On Probabilistic Power Flow

In recent years, with the rapid development of the economic growth and the industy, the power system is showing us lots of new features. Larger scale and more complicated structure is making power grid one of the most complicated artificial networks. In such a case, more and more uncertain factors, which contain the output of generators, load power, parameters of the grid and so on, will occur. Traditional power system static security analysis algorithms are generally based on deterministic power flow calculation methods. However, in such a grid containing numerous uncertaintis, a new static security analysis algorithm combined with probabilistic power flow is worth considering. Meanwhile, in order to adapt to the continuous changes of the system state, it’s meaningful for us to research the continuous calculation methods of static security analysis.On the basis of the traditional power system static security analysis, this paper introduces a new static security analysis algorithm combined with probabilistic power flow method based on Latin hypercube sampling. At the same time, against the continuous changes of the system state, this paper proposes a continuous calculation method of static security analysis based on probabilistic power flow. Firstly, a probabilistic power flow method based on Latin hypercube sampling is analysed. It is applied to the grid with wind farms. Moreover, respectively, it’s researched in two different cases, in which random variables are independed or associated. Secondly, DC power flow model and sensitivity method of static security analysis are studied. Using a new contingency ranking method which considering the uncertainties of a literature, this paper proposes a new static security analysis sensitivity method combined with probabilistic power flow. Thirdly, the balance of the fluctuation flows in probabilistic power flow calculation is researched. Through introducing dynamic power flow to probabilistic power flow method, the malpractice of traditional power flow calculation methods is solved. Last but not least, the fluctuation of wind power output and the unit ramp rate are studied. A new dynamic power flow considering ramp rate is proposed. And based on it, a continuous calculation method of static security analysis is introduced. Of course, all the algorithms above are tested to be right with examples based on MATLAB platform.