Research On Multi-objective Reactive Power Optimization Operation Of Distribution Network With Distributed Generation

The global recognition of the concept of sustainable development and environmental protection has increased the speed of energy transition and the development of renewable energy.The development of clean energy(mainly solar and wind energy)and the continuous increase in grid penetration have effectively alleviated the energy crisis,but the uncertainty and unpredictability of its output have affected the operation of the grid.Therefore,rational handling of uncertainties in the distribution network and effective handling of the impact of distributed power grid connection are the prerequisites for the stable operation of the power grid,as well as an important factor and research focus for the future development of clean energy.This paper studies the impact of distributed power generation(DG)grid-connected operation,and optimizes the operation of the distribution network through reactive power compensation.First,introduced distributed power,and analyzed the impact of DG grid connection on the distribution system.Secondly,by analyzing the relationship between environmental changes and DG output,combined with the actual operating conditions,the probability model of DG and load is established,and the three-point estimation method is used to solve the calculation for the probabilistic power flow..In order to solve the correlation problem between the input variables,the algorithm is improved by the Nataf transformation,and the Gram-Charlier series expansion is used to find the accurate probability density function of the variable.Finally,the system simulation The improved algorithm was verified.Then,the distribution network after DG was connected to the grid was reconstructed.Combining the uncertainty and probability constraints of DG and load,starting from the system's active power loss expectation,voltage stability index and reactive power compensation equipment investment,a static reactive power optimization model of the DG distribution network is established.The improved bee colony algorithm is used to solve the model.Using Pareto optimal solution to deal with correlation problem.It is verified by simulation calculation.Finally,in order to simulate the actual operating conditions more accurately,modified the static reactive power optimization model,the restriction on the number of operations of the equipment was increased,and a dynamic reactive power optimization model that took into account the correlation was established.And use time-sharing decoupling to simplify the model.Through simulation calculation,analysis and verification of the established model and correlation effects provide theoretical guidance for actual optimization operation.