Keywords:Mixed-integer linear programming Renewable energy park Scheduling Virtual power producer a b s t r a c t In the energy management of the isolated operation of small power system, the economic scheduling of the generation units is a crucial problem. Applying right timing can maximize the performance of the supply. The optimal operation of a wind turbine, a solar unit, a fuel cell and a storage battery is searched by a mixed-integer linear programming implemented in General Algebraic Modeling Systems (GAMS). A Virtual Power Producer (VPP) can optimal operate the generation units, assured the good functioning of equipment, including the maintenance, operation cost and the generation measurement and control. A central control at system allows a VPP to manage the optimal generation and their load control. The application of methodology to a real case study in Budapest Tech, demonstrates the effectiveness of this method to solve the optimal isolated dispatch of the DC micro-grid renewable energy park. The problem has been converged in 0.09 s and 30 iterations.

This paper presents an electricity consumer characterization framework based on a knowledge discovery in databases (KDD) procedure, supported by data mining (DM) techniques, applied on the different stages of the process. The core of this framework is a data mining model based on a combination of unsupervised and supervised learning techniques. Two main modules compose this framework: the load profiling module and the classification module. The load profiling module creates a set of consumer classes using a clustering operation and the representative load profiles for each class. The classification module uses this knowledge to build a classification model able to assign different consumers to the existing classes. The quality of this framework is illustrated with a case study concerning a real database of LV consumers from the Portuguese distribution company.

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Triggered by the increased fluctuations of renewable energy sources, the European Commission stated the need for integrated short-term energy markets (e.g., intraday), and recognized the facilitating role that local energy communities could play. In particular, microgrids and energy communities are expected to play a crucial part in guaranteeing the balance between generation and consumption on a local level. Local energy markets empower small players and provide a stepping stone towards fully transactive energy systems. In this paper we evaluate such a fully integrated transactive system by (1) modelling the energy resource management problem of a microgrid under uncertainty considering flexible loads and market participation (solved via two-stage stochastic programming), (2) modelling a wholesale market and a local market, and (3) coupling these elements into an integrated transactive energy simulation. Results under a realistic case study (varying prices and competitiveness of local markets) show the effectiveness of the transactive system resulting in a reduction of up to 75% of the expected costs when local markets and flexibility are considered. This illustrates how local markets can facilitate the trade of energy, thereby increasing the tolerable penetration of renewable resources and facilitating the energy transition.Index Terms-Demand response, local electricity markets, microgrids, transactive energy, smart grids, stochastic optimization. NOTATIONIndices: e energy storage systems (ESSs) i distributed generation (DG) units l, m, s, t, v loads, markets, scenarios, periods, electric vehicles (EVs) Sets and subsets: Ω DG , Ω load set of DG units/loads Ω d DG ,Ω nd DG subset of dispatchable/non-dispatchable DG units Ω curt load ,Ω inte load subset of curtailable/interruptible loads Ω shift load subset of shiftable loads Parameters: C DG generation cost of DG unit (m.u./kWh) C ESS − ,C EV − discharging cost of ESS/EV (m.u./kWh) Ccurt,C inte ,C shift load curtailment/interruption/shift cost (m.u./kWh) C imb grid imbalance cost (m.u./kWh) M P electricity market price (m.u./kWh) Ne, N i , N l number of ESS/DG/loads Nm, Ns, Nv number of markets/scenarios/EVs Pcurt max maximum load reduction of Ω curt load (kW) P DG max/min maximum/minimum power of dispatchable DGs (kW) P DG nd forecast power of non-dispatchable DGs (kW) P ESS/EV + max maximum charge rate of ESSs/EV (kW) P ESS/EV − max maximum discharge rate of ESSs/EV (kW) P ESS max/min maximum/minimum energy capacity of ESSs (kWh) P EV max/min maximum/minimum energy capacity of EVs (kWh) P EV trip forecasted energy demand for EVs' trip (kWh) P load forecasted active power of loads (kW) P offer max/min maximum/minimum energy offer in markets (kW) P shift forecasted power of Ω shift load in T shift (kW) P shift max maximum load shifted of Ω shift load in T shift (kW) T number of periods T shift shift interval of Ω shift load T start shift /T end shift earliest/latest possible period for load shift of Ω shift load η EV + /EV − charging/discharging efficiency of EV...

a b s t r a c tIn competitive electricity markets with deep concerns for the efficiency level, demand response programs gain considerable significance. As demand response levels have decreased after the introduction of competition in the power industry, new approaches are required to take full advantage of demand response opportunities. This paper presents DemSi, a demand response simulator that allows studying demand response actions and schemes in distribution networks. It undertakes the technical validation of the solution using realistic network simulation based on PSCAD. The use of DemSi by a retailer in a situation of energy shortage, is presented. Load reduction is obtained using a consumer based price elasticity approach supported by real time pricing. Non-linear programming is used to maximize the retailer's profit, determining the optimal solution for each envisaged load reduction. The solution determines the price variations considering two different approaches, price variations determined for each individual consumer or for each consumer type, allowing to prove that the approach used does not significantly influence the retailer's profit.The paper presents a case study in a 33 bus distribution network with 5 distinct consumer types. The obtained results and conclusions show the adequacy of the used methodology and its importance for supporting retailers' decision making.