Research On Capacity Allocation And Economy Of Distributed Photovoltaic-Energy Storage System Considering Power Loss And Voltage Leval

Distributed photovoltaic will be the focus of China's photovoltaic industry during “The 13 th Five-Year Plan”,accelerating the application of distributed photovoltaic is conducive to ease the energy crisis and environmental degradation.With the large-scale distributed PV accesses the distribution network,its volatility and randomness is bound to make the power quality problem more prominent and has an adverse effect on the power grid of the trend,voltage,loss and other aspects.The use of energy storage system can achieve the energy of time and space translation,the PV system can be controlled from the uncontrolled power supply combining with the energy storage system,thereby reducing its negative impact on the distribution network operation.How to optimize the capacity allocation of PV with the energy storage system and evaluate the economics of PV with the energy storage system is an important research topic in the photovoltaic,energy storage costs relatively expensive market environment.This paper analyzed the influence of distributed PV on power loss and system voltage when accessing to distribution network.On this basis a distributed optimization model of distributed photovoltaic-energy storage system was established considering power loss and voltage level,the output of the distributed photovoltaic-storage system was optimized under different load levels in the distribution network based on the genetic algorithm to solve the model.Then,the capacity of distributed energy storage system considering the cost economy under the requirement of minimum charge and discharge was configured,and the influence of different PV unit investment cost and energy storage battery cost on the capacity allocation of distributed photovoltaic-storage system was analyzed.Finally,the net income model and the economic evaluation index were constructed to evaluate the economy of distributed PV-energy storage system.The results showed that the proposed distributed PV-energy storage system capacity allocation method considering power loss and voltage level realized the minimum power loss of distribution network and increase of the voltage level,which achieved the goal of minimizing the cost of distributed PV-energy storage system,and the system had obvious economic benefits.This paper can provide reference for the capacity allocation of distributed PV system with energy storage.