Prescribed Time Consensus Optimal Strategy For Economic Dispatching Of Smart Grid

As a crucial problem in the operation and control of smart grid,economic dispatch is particularly important in energy management.Reasonable and effective completion of dispatching task brings a great impact on improving the economic benefits of smart grid.Distributed economic dispatching is a new generation dispatching strategy,which can adjust the generator’s state flexibly and improve energy utilization efficiency.In addition,as an important indicator to evaluate system’s performance,the convergence rate that directly affects system’s operation quality.The usual convergence time includes asymptotic time convergence,finite time convergence and fixed time convergence.The convergence time of the asymptotic time strategy is infinite,the convergence time of the finite time strategy depends on system’s initial conditions,the convergence time of the fixed time strategy is affected by system’s other parameters,so it is urgent to study the convergence strategy which can be set arbitrarily and meet the actual demand.Based on the consensus theory of multi-agent systems,the paper studies the distributed prescribed time convergence strategy for economic dispatch of smart grid under different constraints,different communication topologies and different economic scheduling models,which can realize arbitrary time convergence of dispatch algorithm.The main contents and innovative works are as follows:Firstly,for the economic dispatch problem of smart grid with supply-demand balance equation constraints,a distributed prescribed time consensus economic dispatch algorithm is proposed.The algorithm solves the problem that the convergence time of generators depends on the system’s initial conditions or other parameters in the process of economic dispatch but cannot be set in advance.Finally,the superiority of the proposed algorithm is verified by MATLAB numerical simulations.Secondly,for economic dispatch problem of smart grid only consider the constraints of supply and demand balance equation,a distributed prescribed time consensus economic dispatch algorithm under power constraints is proposed.By introducing two auxiliary variables to design algorithm,which can solve the problem that the generators cannot realize prescribed time stability due to its own power capacity constraints.Finally,the effectiveness of the proposed algorithm is verified by numerical simulations under strongly connected directed graphs.Thirdly,for the cost function of economic dispatch is only a non-convex ideal model,a distributed prescribed time consensus economic dispatch algorithm with valve point effect is proposed.The algorithm is designed by using piecewise linearization approach approximately to deal with incremental cost function,which can solve the dilemma that the generators cannot obtain the consensus optimal solution in the prescribed time so that the generators under the influence of valve point effect can achieve stability in the prescribed time.Finally,the feasibility of the proposed algorithm is verified by numerical simulations under directed balance graph.