Effect of Uncertainties in Parameters of Load Model on Dynamic Stability Based on Probabilistic Collocation Method

Among the main electric components in power systems, load models have great effect on power system time- domain dynamic simulations. However, owing to the characteristics such as time-variation, randomness and so on, it is difficult to construct load model. In addition, in order to analyze the uncertainties, Monte-Carlo method is often used to estimate the probability density function of the desired output, which requires many sample data obtained from repeated simulations, therefore the uncertainty studies on power system stability are few. This paper studies the effect of the uncertainties of dynamic load proportion on power system dynamic stability based on Probabilistic Collocation Method (PCM). It could be concluded that using the proposed method the desired output is directly described as a polynomial in the uncertain parameter of the system. Consequently, high calculation accuracy could be reached by low-dimensionality polynomial functions and fewer time-domain simulations. Cases study verifies the validity of the proposed method.