Load management services in post-contingency control

Developments in market oriented electricity supply industries indicate that the competition is now penetrating further into the provision of system reserve, security, reactive power, etc. In the England and Wales electricity sector different reserve requirements are provided through competition, where not only generators but also large industrial users can offer their load reduction based services and participate in the provision of active reserve and load frequency control. Along this trend, this paper presents a method for determining an optimal security constrained economic dispatch that can incorporate load-management services and generation rescheduling capabilities in post-fault rearranging of transmission system power flows. This would allow the system to be operated with somewhat `relaxed´ security most of the time, without jeopardising the level of system security, and would result in a reduction of operating costs (uplift), and potentially, in postponing of transmission system reinforcement costs. The paper emphasises that the value of load management services, in terms of system security, is not only price, but also site and amount dependant. The proposed method enables the potential and value of load management services in uplift control to be evaluated, and therefore, it could be used as a base for commercial arrangements between transmission utilities and customers willing to sell their load management services