风电机组多状态出力模型的准确建立是含风电机组配电网可靠性评估的关键。基于风速历史数据由近及远影响逐渐减弱的特性,提出一种新的风速分布预测模型,即风速分布预测的指数平滑模型。在指数平滑模型建立中,以风速预测值与实测值间的绝对误差最小为目标函数构造并确定平滑系数最优取值,从而建立风电机组多状态出力模型。通过同ARMA、Weibull分布等风速模型的比较,验证了指数平滑方法建立风电机组多状态出力模型的精确性与高效性。将该方法应用于IEEERBTS测试系统BUS6的配电网可靠性评估,并与已有方法进行对比,表明该方法在可靠性评估计算精度上具有一定的优势。
Building an accurate multi-state output model of wind turbine generators (WTG) is a key element in the system reliability evaluation of electrical distribution networks (EDN) containing WTGs. This paper proposes an exponential smoothing method to forecast the wind speed distribution based on the fact that the closer to the current wind speed, the greater the wind speed has an influence on the wind speed distribution. The optimal smoothing factor of the proposed model is formulated as an optimization problem with the objective function of minimizing the sum of absolute errors between the predicted and statistic wind speeds, which can be used to accurately build the WTG multi-state output model. Compared with the ARMA and Weibull methods for wind speeds, the proposed model provides more accurate and efficient results. The case studies on the IEEE BUS6 EDN show that the proposed wind speed model has the advantage in the accuracy of EDN reliability evaluation compared with the traditional wind speed models.