Joint scheduling of frequency control reserves and energy dispatch for islanded power systems

In this paper, we propose a framework to jointly schedule energy and frequency control reserves in islanded systems, taking into account the system dynamic response. In islanded power systems, the control of system frequency differs considerably comparing to large interconnections, and dynamic models are employed to study the system behaviour. We suggest a way of incorporating relevant aspects of the dynamic response in an optimal power flow formulation, which in addition to including dynamic constraints also accounts for transmission, generation and security constraints. The applicability of the method is demonstrated on the Swiss power system under a special, critical case where the Swiss system is disconnected from the remaining European grid and energy shortage is a concern. We show that the proposed framework can be successfully applied for the operational planning and allows for a secure and reliable power system islanded operation.