Research On High Permeability Distributed Photovoltaic Absorption Evaluation Method

When large-scale distributed photovoltaic is connected to the grid,there are problems such as mismatch between installed capacity and power demand,insufficient local absorption space,and non-synchronous of photovoltaic construction and distribution network construction.The problem of light abandonment in the development of distributed photovoltaic has not been properly dealt with.The randomness,fluctuation and intermittent nature of photovoltaic power generation further increase the difficulty of grid connection absorption.In order to solve the problem of distributed photovoltaic absorption further,the following research work has been carried out in this dissertation.Firstly,the characteristics of grid connected operation of distributed photovoltaic are studied by theoretical analysis.The research on the characteristics of distributed photovoltaic grid connection laid the foundation for the later establishment of photovoltaic probability model.Secondly,according to the uncertainty characteristics of photovoltaic power generation and the regular characteristics of load changes,combined with theoretical knowledge such as probability theory,mathematical statistics,and Gram-Charlier expansion series,the power-side model and the load-side model are established respectively.The basic concepts of probabilistic power flow calculation are studied In this dissertation,a probabilistic power flow calculation method considering source-load uncertainty is proposed.IEEE 14 and IEEE 30 distribution network structures are used for simulation verification.The accuracy and speed of semi-stationary method and Monte Carlo method are compared and analyzed from two aspects of calculation accuracy and calculation time.The state information of the whole distribution network is obtained through probabilistic power flow calculation,which provides technical support for distributed photovoltaic consumption.Then,for three typical consumption modes of points,lines,and areas of the distribution network,the three-dimensional indicators of penetration,dispersion,and distribution are used to describe the evaluation method of distributed photovoltaic access status in the distribution network.Considering the impact of high-penetration distributed photovoltaic access on the distribution network,a distributed photovoltaic consumption assessment method is proposed.This dissipative evaluation method takes the minimum network loss as the objective function and uses particle swarm optimization to analyze the case of IEEE 14 and IEEE 30 distribution network structures.Through this method,the optimal capacity and access location of distributed photovoltaics can be obtained.Finally,according to the overall function of the distributed photovoltaic access distribution network decision support system,the architecture and functional requirements of the distributed photovoltaic access distribution network decision support system are proposed.Based on the distributed photovoltaic consumption method,the core algorithm of the distributed photovoltaic access distribution network decision system is developed under the JAVA platform,which can provide guidance for distributed photovoltaic planning work in the distribution network.