Evaluation of wheeling and nonutility generation (NUG) options using optimal power flows

The application of optimal power flow for the evaluation of wheeling and nonutility generation (NUG) related options is presented. Both wheeling and NUG options affect vital attributes such as system security, voltage profile, losses, and VAr reserves. These options put a strain on the existing transmission system and may restrict economic utility dispatching. Optimal power flows may be used to determine the best control settings to accommodate wheeling or NUG options so as to maintain system security while minimizing losses or production cost. Short-term marginal wheeling costs may be derived using optimal power flows. Case studies involving the Northeast Utilities and IEEE test systems are presented. These cases show that optimal power flows can be used effectively to address a broad range of wheeling or NUG related planning issues