The Planning Method Of Distributed Photovoltaic Power Considering Power Quality

With the rapid development of smart grid technology,more and more new energy or low-loss distributed power generation(DG)access to the distribution network.The change of solar radiation intensity affects the output of distributed photovoltaic power source,so that it has randomness and volatility.When the distributed PV power access to the system,it will change the system’s original topology and trend,affect the power quality of the power grid.With the increasing popularity of distributed photovoltaic power generation in the distribution network,the power quality of the distribution network will seriously affect the safe and economical operation of the power grid.So it is necessary to take into account the power quality assessment in the grid planning phase when the distributed photovoltaic access to the grid.In this paper,the influence of distributed PV access grid on voltage deviation,voltage fluctuation,harmonics and three-phase unbalance is analyzed theoretically,and the simulation is carried out with IEEE-33 node as an example.Next,a comprehensive evaluation method of power quality based on data envelopment analysis is introduced.The power quality of distributed PV access point is evaluated by this method,and compared with other comprehensive evaluation methods,the data envelopment analysis method is verified.Then,an optimal method of distributed PV power supply based on improved particle swarm optimization(PSO)is proposed.Based on the maximum capacity of distributed PV capacity,the improved particle swarm optimization algorithm is used to calculate the access location and capacity of the distributed PV power source,and the validity of the proposed method is verified by IEEE-33 node as an example.Based on the effectiveness of the optimization of the distributed PV power supply model which is solved by the improved particle swarm optimization(PSO)and the comprehensive evaluation method of data envelopment analysis,the planning method of distributed photovoltaic power considering power quality is proposed.This method first deals with the trend analysis and calculation of the planning area.According to the PV development needs of the planned area,the access point of the power quality standard is selected,the set of access points is determined,and the gray-Markov chain prediction model is used to predict the output of the PV power to be planned.Next,the improved particle swarm optimization(PSO)algorithm is used to solve the optimal configuration model of PV power supply considering power quality constraints.The access point and access capacity of PV power supply access network is obtained.Then,the power quality assessment of each access point in the access scheme is evaluated by the power quality assessment method of data envelopment analysis(DEA).If the power quality evaluation index of the access point in the access scheme is unqualified,the amendment measures will be given to ensure a distributed PV power access planning with good power quality can be obtained.In this paper,the actual calculation of three-phase equilibrium and three-phase imbalance is carried out,and the feasibility of the proposed method is verified by an actual 10kV line and IEEE-33 node three-phase unbalanced system.