Dynamical optimal real-time AGC reserve dispatch strategy and unit selection for frequency regulation

When sudden insufficient power supply occurs that will cause frequency drop quickly, and this could lead to a complete network collapse. Automatic generation control (AGC) is one of the important auxiliary services that play an important role in satisfying the large load changes or other disturbances, maintaining system frequency stability, keeping tie-line transaction security and enhancing the safety of the power system. The system must have a certain level of AGC frequency regulation reserve (FRR) to ensure system security. Furthermore, different AGC unit has different aspects, such as response rate, capacity, price and location that will have different influences on frequency security, the safety of transmission lines and system operating economy. So, Independent System operator (ISO) must evaluate different AGC effects, purchase and dispatch AGC FRR in scientific way. This paper provides the scientific bases for calculating necessary AGC FRR, guiding the operator to dispatch and select AGC FRR, allocating them among AGC FRR provider to provide emergent FRR following a generation deficiency. The optimal is the maximization of the utility's social welfare. Simulation results of IEEE 30-bus 6-machine test system illuminate the proposed methodology.