Annual risk assessment for system thermal overload

Thermal overload is a problem often encountered in real power systems. Under the new deregulated power market environment, utilities are more willing to carry out an accurate thermal overload risk assessment before making any facility planning decision than to purchase facilities based on a conservative judgement. They are more interested in the short term such as one year facility planning, than the long term planning. Therefore, we focus on the one year operational planning problem. The main difficulty of this problem lies with the amount of calculation and innumerable possibilities that have to be taken into account. This paper proposes a new method called segmentwise convolution method to calculate the thermal overload risk of every line at every hour in IEEE RTS'96 system. Several techniques are employed to facilitate our calculation. The analysis results are shown in this paper and explained. The method is shown to be efficient in evaluating thermal overload risk.