Research On Photovoltaic Access Capacity Of Distribution Network Based On Time Series Production Simulation

Photovoltaic power generation has developed rapidly in the distribution network due to its advantages of less geographical restrictions and high building integration rate.However,with the increasing of PV permeability,the pressure of intermittence and randomness on power system frequency modulation cannot be ignored.On the other hand,the load and photovoltaic output in the distribution network often have similar time-varying characteristics.If we can make good use of this correlation and reasonably plan the photovoltaic grid connected capacity,it may alleviate the problem of photovoltaic frequency modulation from the root.From the perspective of sequential production simulation,this paper studies the photovoltaic access capacity planning of the distribution network by establishing a load and photovoltaic output timing model.Firstly,the time series characteristics of common load curves are analyzed,and it is pointed out that the load at each time point of the same day is in a similar position in the annual data.Based on this,a time series load modeling method is proposed.By substituting a random number of 01 uniform distribution sampling into the inverse function of cumulative distribution function of load data at each time point,the simulation results of daily load time series are obtained.It is proved that the model has the advantages of wide applicability and high accuracy by comparative analyzing actual examples.Secondly,the influencing factors of photovoltaic output are analyzed,and the deterministic and stochastic parts of photovoltaic output are described by the uncovered day output and uncovered coefficient respectively.The weather types of historical data are classified by K-means clustering with clear coefficient and abrupt coefficient as indicators,and the distribution models of various weather uncovered coefficient are established.Based on the analysis of the relationship between the load and the output without shading,a simulation method of photovoltaic sequential production is proposed.The practical example verifies that the method can effectively reproduce the timing characteristics of photovoltaic output.Finally,based on the time series production simulation of load and photovoltaic output,a photovoltaic grid connected capacity planning model is built by using the mixed integer linear programming method.Its goal is to minimize the comprehensive generation cost,including generation cost,environmental cost,frequency modulation cost and light abandonment penalty.The effectiveness of the model is verified by a practical example.Based on the model,the capacity planning results of different load types are analyzed,and the influencing factors of the optimal photovoltaic access capacity are determined,including the frequency modulation capacity of power system,the frequency modulation demand of load and photovoltaic,and the timing correlation degree of negative load photovoltaic output.the effect of time series production simulation on photovoltaic grid capacity planning is analyzed.The results show that the capacity planning model based on time series production simulation can fully consider the synergy between load and photovoltaic output,and the capacity planning results are more optimistic.