In a smart grid environment, we study coalition formation of prosumers that aim at entering the energy market. It is paramount for the grid operation that the energy producers are able to sustain the grid demand in terms of stability and minimum production requirement. We design an algorithm that seeks to form coalitions that will meet both of these requirements: a minimum energy level for the coalitions and a steady production level which leads to finding uncorrelated sources of energy to form a coalition. We propose an algorithm that uses graph tools such as correlation graphs or clique percolation to form coalitions that meet such complex constraints. We validate the algorithm against a random procedure and show that, it not only performs better in term of social welfare for the power grid, but also that it is more robust against unforeseen production variations due to changing weather conditions for instance.
Cooperation in wireless networks allows single antenna devices to improve their performance by forming virtual multiple antenna systems. However, performing a distributed and fair cooperation constitutes a major challenge. In this work, we model cooperation in wireless networks through a game theoretical algorithm derived from a novel concept from coalitional game theory. A simple and distributed merge-and-split algorithm is constructed to form coalition groups among single antenna devices and to allow them to maximize their utilities in terms of rate while accounting for the cost of cooperation in terms of power. The proposed algorithm enables the users to self-organize into independent disjoint coalitions and the resulting clustered network structure is characterized through novel stability notions. In addition, we prove the convergence of the algorithm and we investigate how the network structure changes when different fairness criteria are chosen for apportioning the coalition worth among its members. Simulation results show that the proposed algorithm can improve the individual user's payoff up to 40.42 as well as efficiently cope with the mobility of the distributed users. The power consumption schemes of consumers is an important issue in energy management process in smart grid. The non-cooperative methods which are always considered cannot achieve the maximized performance for consumers and networks. In this paper, we propose a cooperative power consumption scheme for consumers based on coalition formation game, which is suitable for the general electricity markets in smart grid. The advantage is that it can utilize the cooperative relationships among each other for payment savings and meanwhile take the social welfare into consideration. It is realized according to the pricing model used by power provider, the welfare function of the consumer coalitions, as well as the coalition formation algorithm based on the modified Pareto order which are proposed in this paper. Simulation results show that a stable consumers' partition can be formed in the concerned area and the higher utility for consumers and social welfare can be obtained comparing with the non-cooperative methods.