Dynamic Reactive Power Optimization Method For Distribution Network With DG

In recent years,many countries have vigorously developed distributed generation.Distributed DG grid-connected provides many benefits,such as reducing power loss at load side,improving system voltage distribution and improving stability and reliability of power system.However,the impact of distributed generation on power production,transmission and distribution is also obvious,especially in the planning,design,operation and operation of distribution network.Especially the problem of voltage control is urgent.Unlike the discrete regulation characteristics of the main transformer and capacitor in the traditional distribution network,the output of DG is continuous and smooth,and its strong intermittence and randomness are also different from the traditional generators,which bring many difficulties to the reactive power optimization problem with DG.This paper takes the active distribution network with distributed generation as the research object,aiming at comprehensively studying the voltage and reactive power situation and control problems after DG grid-connected through theoretical analysis and simulation,and ultimately improving the DG permeability and voltage quality of the active distribution network.(1)The influence of DG grid connection on power flow,voltage and loss of active distribution network is analyzed.Taking wind power generation and photovoltaic generation as typical examples,under the constraints of the radial network topology of distribution network,the operation principle of DG and its voltage and reactive power characteristics are introduced.From the point of view of power flow calculation,the influence of DG grid-connected on voltage,reactive power and network loss is analyzed.Finally,the statistical index of DG operation is studied.(2)A voltage and reactive power control partition method for active distribution network is proposed.In order to reduce the complexity of voltage and reactive power control in distribution network with DG,a voltage and reactive power partition method for active distribution network with DG grid connection is proposed.From the perspective of clustering,this method uses FCM method,combines the structural characteristics of distribution network,and uses genetic algorithm to partition voltageand reactive power control.On this basis,the observability index of central node and controllability index of central node are accurate.The central bus in a given area.(3)A dynamic reactive power optimization method for active distribution network with DG is proposed,which coordinates capacitors,main transformers and DG in a day to ensure the quality of voltage and reactive power,reduce network losses and improve the permeability of DG.The performance of the dynamic reactive power optimization method proposed in this paper is tested with 69 bus distribution system in City X,Province J.