Reserve Requirements to Efficiently Manage Intra-Zonal Congestion

The security-constrained unit commitment problem schedules power generators to minimize cost subject to operating constraints. Reserve requirements ensure that reserve is available to re-balance the system following a contingency but do not guarantee reliability in congested systems where reserve activation is limited by transmission constraints. Operators improve reserve deliverability by limiting power flows and controlling the location of reserves. Zones are used to address inter-zonal congestion but operators lack efficient ways to handle intra-zonal congestion. We propose dynamically relating minimum reserve levels to transmission stress in a computationally efficient approach that complements existing reserve models from the literature. Analysis on the IEEE RTS 96 test case demonstrates the approach can mitigate intra-zonal congestion more economically than traditional reserve policies.