Coordinated planning method of multiple micro-grids and distribution network with flexible interconnection

An Overview of Soft Open Points in Electricity Distribution Networks

“…To achieve a better performance of the operation of a distribution network and to reduce the overall cost, other electrical devices or smart technologies are often used with SOPs simultaneously. The electrical devices include but not limited to the switches of the network [74], DGs [75]- [77], energy storage [75], and capacitor banks [77]. Therefore, the states of the switches, the sites and sizes of DGs, energy storages and capacitor banks are also considered as decision variables in these articles.…”

“…The total investment/maintenance cost is usually converted into annual cost by timing the capital recovery factor or the present value factor [74]- [77]. Among the benefits summarized in Section III, power losses reduction can be easily converted into monetary value considering the price of electricity and is commonly considered as a term in the objective function of the optimization problem for SOP siting and sizing [74], [75]. In addition to the consideration of power losses, an alternative is to consider the cost of the electricity purchased from the upstream grid in the objective function [76], [77].…”

“…The optimal siting and sizing problem of SOPs can be formulated in a single-level [74], [75], [78] or a bi-level optimization model [76], [77]. Compared to the single-level optimization model, the bi-level one consists of an upper-level optimization model and a lower-level optimization model.…”

“…In [76], the bi-level optimization model is transformed into a single-level model based on the strong duality theory of conic optimization [79]. In [75], on the contrary, the single-level optimization problem is converted to an investment decisionmaking master problem with integer variables and an operation optimal sub-problem with continuous variables by the Benders decomposition method.…”

Distributed Energy System Feasibility and Supportive Energy Internet Technologies

“…As proposed by Jun et al [18], this method is possible on integrating energy generations, storage and loads interactions in isolated micro-gird. Yang et al [19] focused on the flexibility property of micro-grid, investigating how the flexible interconnection device (FID) could help optimize coordinating among multiple different micro-grid. Through the research, FID shows positive effective on controlling power flow, maintaining energy storage larger capacity and enabling high effective generator working status.…”