The study for the distributed energy storage（DES） planning of distribution system including photovoltaic power generation and distribution system system based on cost-benefit optimization is proposed.The power supply profit

peak power generation benefit

loss reduction efficiency

efficiency of extending the operation time of power susspy system

CO

2

emission and reactive support efficiency are subject to the normalization of optimal net present value（NPV）

discounted payback period（DPP） and b

enefit-cost ratio（BCR） and a comprehensive DES planning cost-benefit target model is set up.In addition

the DES optimization planning is combined with the improvement load power factor and power supply voltage quality.At the same time

in view of the the key factors of indirect influence of the reactive power output of photovoltaic power generation

the influence of the permeability of photovoltaic power generation in the distribution system and the number of planned DES units on the cost-benefit evaluation objective function of DES planning are studided on the basis of the probability distribution function of solar irradiance.The simulation experiment on 33 node system is performed on the basis of the planning strateg.Finally

it is shown by the expeinmental simualtion data that the proposed optimal configuration strategy can make the total NPV maximum and

at the time of improving power load factor and volateg quality

can obtain the optimnal position and and capacity planned by the DES unit.