In the framework of liberalized electricity markets, distributed generation and controllable demand have the opportunity to participate in the real-time operation of transmission and distribution networks. This may be done by using the virtual power plant (VPP) concept, which consists of aggregating the capacity of many distributed energy resources (DER) in order to make them more accessible and manageable across energy markets. This paper provides an optimization algorithm to manage a VPP composed of a large number of customers with thermostatically controlled appliances. The algorithm, based on a direct load control (DLC), determines the optimal control schedules that an aggregator should apply to the controllable devices of the VPP in order to optimize load reduction over a specified control period. The results define the load reduction bid that the aggregator can present in the electricity market, thus helping to minimize network congestion and deviations between generation and demand. The proposed model, which is valid for both transmission and distribution networks, is tested on a real power system to demonstrate its applicability.

SUMMARYThe nature and control of existing distribution networks limits the amount of distributed generation that can be connected. To increase the penetration of distributed generation a distribution management system controller (DMSC) can be used. The use of a DMSC requires a state estimator algorithm that provides an estimate of the network state in real time. In this paper, a state estimation algorithm based on the methods used on transmission networks is presented. The application of these methods into distribution networks requires existing measuring systems to be supplemented with the addition of new real-time measurements, and the use of load estimates.

No abstract