Research On Multi-objective Intelligent Optimal Dispatching Of Active Distribution Network

Active distribution network is a distribution network with internal distributed energy,active control and operation ability.With the large-scale access of distributed power to distribution network,especially random wind energy,the energy flow in distribution network is constantly changing,and a series of problems are brought,such as harmonic pollution and reverse power flow.The problems of transmission,three-phase unbalance,voltage fluctuation,loss increase and so on,therefore,it is very important to analyze and study the optimal dispatching algorithm of active distribution network,and to realize the economy,environmental protection and efficiency of power grid dispatching by planning the output of the components involved in the dispatching of distribution network.In this thesis,the mathematical model of the output of each component participating in the optimal dispatch of active distribution network is studied.Considering the harmonic pollution caused by DG in the active distribution network,the flower pollination algorithm(FPA)is used to solve the problem in order to ensure the power quality.Furthermore,considering the contribution of stochastic energy sources such as wind energy,three objectives of economy,environmental protection and efficiency are established.Quantum flower pollination algorithm(QFPA)is used to solve the multi-objective optimal scheduling problem of active distribution network.The specific work is as follows:1.The output model of each unit structure related to the optimal dispatching strategy of active distribution network is studied.The output modes of wind farm,photovoltaic unit and energy storage system are mainly studied,and the mathematical model is established.Weibull distribution is used to describe wind speed and Coulomb counting method is used to calculate the instantaneous state of charge(SOC)of energy storage battery.2.Aiming at the power quality(PQ)problem caused by the harmonic problems caused by the inverters in BES and DG participating in active distribution network,this thesis establishes an optimal dispatching model with the additional network loss caused by harmonics as the objective,power quality,system security and energy storage constraints as constraints,and flower pollination algorithm as the solution.3.The multi-objective optimal dispatching problem of active distribution network is studied.The three objectives of economy,environment and efficiency are chosen to represent the different requirements for power system operation,besides considering power flow constraints,unit constraints,node voltage constraints and load balancing constraints.Quantum behavior is introduced into flower pollination algorithm to improve it.Flower pollination based on quantum behavior is proposed to solve multi-objective optimal scheduling problem.