Operating beyond today´s PV curves: Challenges and potential benefits

Accounting for system-level voltage-related operating problems represents a rather complex challenge. We first suggest that today´s practice based on the use of PV curves in large power grids neither guarantees feasible power transfer nor enables the most economic utilization of real power. To overcome this problem, the use of a full-blown AC Optimal Power Flow (AC OPF) to support utilization and delivery of real power is proposed. This leads to a combined adjusting of real power generation and voltage generator settings of the Automatic Voltage Regulators (AVRs) and T&D voltage-controllable equipment such as on-load tap changing transformers (OLTCs) and shunt capacitor banks. We illustrate the proposed approach on the small IEEE 14 bus power system and on large ERCOT and PJM systems. We present a comparison of today´s PV-curve-based management of voltage-related delivery problems and the proposed full-blown AC OPF.