Improve Market Efficiency with Topology Configuration: Ex-Ante and Ex-Post

Electricity markets are operated upon reliable power system operation, where physical resources and financial transactions are committed based on variable market and system inputs. System operators need to ensure transmission reliability at all times. Transmission outages occur daily to allow reliability maintenance and integration of network upgrades. Outage windows vary with the complexity of work scopes and are constrained by various system conditions, such as applicable outage seasons, conflictions with concurrent outages, etc. Operation planning engineers usually perform ex-ante congestion management analysis to evaluate the impact of transmission outages on system security and market efficiency during the outage window, and provide recommendations on outage scheduling and congestion management. Transmission outages may induce high market operation cost when outage windows are not be able to be "optimized" and congestion occurs. In real-time operation, operators have proved the effectiveness of applying "no-cost" switching to relieve congestion when network topology configuration is applicable. Ex-post market efficiency analysis has been studied to provide operation strategy review to the operators, an effort in perfect dispatch. Ex-ante market efficiency analysis of outages faces market and operational uncertainties. Common factors include outage location and scope, outage duration, flexibility of outage rescheduling, potential confliction with concurrent outages, weather and seasonal conditions during the outages, etc. Operators need to develop robust and effective market simulation cases and tool sets to predict the impacts on production cost, congestion revenue, and other market efficiency indicators. Heuristic approaches are often applied due to the inexplicit nature of these types of studies. After-the-fact review on congestion management with no-cost transmission switching is an applicable approach in real-time operation review. However, ex-post market efficiency assessment of long duration outages or topology configuration could be a challenging task. Market input variations due to the occurred topology changes are also hard to define, which are crucial to quantify market efficiency change with outage rescheduling, or topology reconfiguration. This panel will review the above challenges with practices.