Power Network Losses Probabilistic Analysis Considering Wind Power Output Characteristics

With the wind farms integrated to the power grid, the operation randomness and’ uncertainty of the power grid increases, which could also enhances the random variability of power network losses. The deterministic loss analysis methods that are widely used could not account for the effects of injection variations upon power losses. To make up the deficiencies mentioned above, it’s more suitable to apply the probabilistic loss analysis methods. By the probabilistic methods, we can get the fluctuation range and distribution of power losses instead of a certain value.Firstly, the impact of wind power characteristics on power losses is analyzed on the basis of power losses analysis theory. Caused by the random fluctuations of wind power, the power losses become more volatile and changeable, which may also comply with some kinds of probability distribution. Referring to the computational methods in probabilistic power flow, a probabilistic losses analysis method is proposed by using the cumulants, which could consider the fluctuation of injection power adequately in the analysis process. The proposed method is based on the linear power flow model. Given the probabilistic distribution of injection power, the cumulants of the network power losses can be get by taking advantage of the properties of independent cumulants. As there are correlations between two wind farms usually, we need to removes the correlation between node injection power variables. Finally, the power losses distribution could be calculated with the Cornish-Fisher expansion.The validity and rationality of the proposed method is validated on the modified IEEE 30-bus system by using the Matlab software in the end. The simulation shows that the proposed probabilistic losses analysis method has the advantages of high accuracy, quick calculating speed and strong practicality.