In order to plan the access scheme of flexible multi-state switch（FMSS） scientifically and rationally

we propose a decision-making method for two-step FMSS optimization access

in which the large scale of distribution network

a wide variety of optional locations

and the complex calculation of comprehensive benefit are taken into account. Firstly

a screening method for FMSS access location is proposed based on the external characteristics of the grid. Then

a comprehensive evaluation index and a calculation method are established based on its property and economics from the perspective of asset performance evaluation

including cost and economic benefits

reliability

voltage quality

as well as acceptance capacity for distributed generation. After the uncertainty of subjective analysis and inadequate information are taken into account

a multi-indicator decision model for FMSS access scheme is established using grey correlation analysis method. Finally

three improved IEEE 33 nodes are taken as a topological structure to determine optimal access scheme for three-port FMSS by two-step decision-making method

whose evaluation values are checked through relative nearness degree. The results show the FMSS access scheme is affected by voltage quality

network loss

reliability

and the validity and practicability of this model are verified.