Time Series Power Flow and Contingency Analysis with Weather Adjusted Line Ratings: A Synthetic WECC Case Study

This paper presents a framework to evaluate the impact of weather adjusted line ratings (WALR) under diverse generation and loading conditions, utilizing a time series model. Hourly power flows and contingency analysis are conducted on the synthetic 10,000-bus Western Electricity Coordinating Council (WECC) system over the span of a year identifying overloads and critical contingencies. Hourly WALR are then calculated using inputs such as ambient temperature, wind speed and direction, and solar radiation. The sensitivities of these weather inputs on transmission line ratings are also evaluated. Simulation results showed that weather conditions can significantly impact the rating of a transmission line, and that strategic use of WALR can effectively alleviate thermal overloads. The proposed methodology provides valuable insights into the transmission system and enables planning and operations engineers to propose reliable and cost-effective mitigation solutions. The paper further discusses the practical challenges associated with the implementation of WALR and provides recommendations for overcoming these obstacles.