Probabilistic OPF Incorporating Uncertainties in Wind Power Outputs and Line Thermal Ratings

This paper considers two important aspects of the operation of modern power supply systems, which are evaluated in terms of uncertainties that should be incorporated into the standard power \pmbflow analysis. The first aspect is the evaluation of uncertainties due to significantly increased penetration levels of unpredictable renewable energy sources, which is illustrated on the example of an actual UK wind farm (WF). The second aspect is the use of line dynamic thermal rating (DTR), instead ofof static thermal rating, where the evaluated uncertainties are illustrated using the manufacturers' specifications of commonly used UK transmission overhead lines for typical UK weather conditions. The presented analysis demonstrates that there are complex correlations between the line DTRs and WF power outputs, as both are strongly impacted by the variations in wind speeds and wind directions. These variations and related uncertainties are modeled using suitable analytical PDF and CDF formulations and then incorporated in the probabilistic optimal power flow (POPF) analysis, allowing for a more accurate assessment of the risk of line overloading. The POPF is solved using Monte Carlo simulation approach and illustrated on a modified version of a widely used IEEE 14-bus network.