Total Supply Capability and Ideal Total Supply Capability for distribution system: Definition, model and algorithm

This paper proposes the definition, model and algorithm of two quantitative indices named the Total Supply Capability (TSC) and Ideal Total Supply Capability (ITSC) for distribution planning. The TSC of a distribution system is comparable to Total Transfer Capability (TTC) in transmission systems, which is defined as the maximum load it can serve under the N-1 guideline for distribution systems, taking into account the capacities of the substation transformers, network link topology, link capacity, and other constraints. The ITSC of a distribution system is the calculated TSC which considers capacities of tie lines are large enough. Mathematical models for TSC and ITSC are set up and procedures to calculate TSC and ITSC are presented. Based on TSC and ITSC calculation, a concept named Potential Supply Capability(PSC) is proposed, which depicts the “potential” or “hidden” TSC of the distribution system. Finally, TSC and ITSC calculation have been performed in a test system with promising results. The case study has shown that TSC and ITSC algorithms are efficient approaches to analyze and evaluate the existing distribution system.