A contribution of demand response for the reliability of a power system

Reliability is a crucial issue in modern power systems, being, in simple words, the ability to continuously and efficiently supply loads without neglecting the quality of service while keeping the power grid stable. In general, reliability can be improved by using more reliable components (generators) or by adding redundancy, being this extra generation known as reserves. Insufficient reserve margin may originate instability and severe problems in power systems. Adequacy is related with the provision of sufficient generation resources to meet the demand and the reserves requirements. The higher the redundancy level the higher the costs, thus a trade-off between the reliability degree and the investment requirements is needed. In this work is investigated if controllable demand can be actively used as an alternative to generation units for guaranteeing adequate reliability indices in short term operation of power systems. The goal is assessing the feasibility of using demand side resources-controllable demand-instead of generation for improving the reliability indices. An evolution strategy has been implemented to design adequate control actions, to be applied over end-use loads, and their impacts on the reliability indices have been assessed. The obtained results showed that, when adequately designed, demand control actions can effectively contribute for a more reliable operation of the power system, being an alternative to the redundant generation in short term.