Coordinated Optimal Power Flow for Integrated Active Distribution Network and Virtual Power Plants Using Decentralized Algorithm
Abstract : With the wide application of distributed energy technology in active distribution networks (ADNs), virtual power plants (VPPs) are introduced as a promising integration and management technology. To coordinate their operation schedule and ensure confidentiality, we establish a coordinated optimal power flow (OPF) model and propose an efficient decentralized algorithm based on multi-parametric quadratic programming and Benders decomposition. In feasible sub-problems, the quadratic exchanging functions are built, which greatly accelerates the convergence process. In infeasible sub-problems, feasible cut sets can be calculated based on benders decomposition. Besides, an effective relaxation method is developed to address degeneracy problem. To eliminate redundant feasible cut sets, a predetermined feasible region is constructed according to the characteristics of each VPP. The effectiveness of the proposed method is demonstrated via numerical tests using two cases of different scales. The results show that the proposed method converges much faster than some prevailing methods. Furthermore, the coordinated OPF has better fuel economy than conventional OPF scheme.
? The aforementioned SOP-based coordinated VVC problem cannot be solved by the existing method efficiently.
? In this section, using the linearization and conic relaxation, the original model is transmitted into an MISOCP model to realize a rapid and accurate calculation.
? It should be noted that there exists a relatively small gap between this solution and the solution to the original MINLP model, which is mainly caused by the conic relaxation deviation.
? As this paper considers a comprehensive objective function of the minimum total operational cost and voltage deviation, the conic relaxation results in a small gap between the two models.
? In order to solve the problem of safe operation and active management of high-permeability distributed power supply in distribution networks, active distribution network (ADN) technology has emerged as the time’s requirement.
? The optimal dispatching method has played an important role in promoting the consumption of renewable energy and has played a positive role in solving environmental problems.
? An online energy management based on the ADMM algorithm has been developed to address the high uncertainty issue in the networked microgrids dispatching, and the algorithm provides a less conservative schedule than the robust optimization-based approach.
• A time-series optimization model for coordinated VVC based on SOP is developed in this paper.
• The proposed model considers the cooperation of SOP and multiple regulation devices to eliminate voltage violations while minimizing the operation costs of ADNs.
• The Distflow branch model, proposed in , is used for modelling the distribution networks.
• By linearization and conic relaxation, the coordinated VVC problem is converted into an MISOCP model which can efficiently obtain the global optimal solution of the proposed formulation.
• Thus, through the proposed MISOCP formulation, a good quality solution with a relaxed optimality gap can be efficiently obtained.
? A linearized stochastic programming framework has been proposed to model the uncertainties of renewable energy sources, energy prices, load demands, and the integrated renewable energy sources and battery systems that are of higher importance to enhance management efficiency.
? The overall power supply pressure and the network losses of the ADN can be effectively reduced when operating in the bi-level distributed optimal dispatching mode. This makes the voltage quality of ADN performs better.
? It can effectively balance the power conflict between ADN and multi-stakeholder.
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