More electricity utilities will participate in the investment and operation of private distributed generations (DGs) while the local power company is responsible for the reinforcement of lines and DGs

as well. How to achieve the maximum benefits among various utilities

including the power company

is a task in the expansion planning of distribution networks. To solve the market-oriented planning problem

virtual peer to peer (P2P) trading is integrated and modeled in the new expansion planning of distribution networks. First

virtual market transaction optimization among prosumers is formulated. Second

the distributed regional marginal price (DLMP) is calculated by the optimal operation model

which contributed to the network usage charge (NUC) and then integrated in the expansion planning model. Case studies are performed and indicate the integrated P2P transaction strategy could improve local load consumption

while reducing the load rate of lines

as well as the electricity cost of users. Besides

the total planning cost paid by the power company could be saved via prosumers' investment and P2P transactions and the factors affecting power company's profit are also classified in multi-investor planning of distribution networks.