A review of offshore wind farm layout optimization and electrical system design methods

There is more wind with less turbulence offshore compared with an onshore case,which drives the development of the offshore wind farm worldwide.Since a huge amount of money is required for constructing an offshore wind farm,many types of research have been done on the optimization of the offshore wind farm with the purpose of either minimizing the cost of energy or maximizing the total energy production.There are several factors that have an impact on the performance of the wind farm,mainly the energy production of wind farm which is highly decided bythe wind condition of construction area and micro-siting of wind turbines(WTs),as well as the initial investment which is influenced by both the placement of WTs and the electrical system design,especially the scheme of cable connection layout.In this paper,a review of the state-of-the-art researches related to the wind farm layout optimization as well as electrical system design including cable connection scheme optimization is presented.The most significant factors that should be considered in the optimization work of the offshore wind farm is highlighted after reviewing the latest works,and the future needs are specified.

Convex optimization of virtual storage system scheduling in market environment

Due to the popularization of distributed energy resources(DERs),the aggregated prosumer effect excels a general energy storage system characteristic.Virtual energy storage system(VESS)concept is proposed hereby that mimics an actual storage unit and incorporates the same charging(consumer)and discharging(producer)modes.It is possible to provide ancillary services via VESS by exploiting the flexibility and thus much research has been proposed on the optimization of the VESS scheduling.In general,the charging and discharging efficiencies of VESS are different and there can be only one status at a time slot.To achieve the optimal schedule while considering the constraints above,binary terms should be introduced into the optimization problem which end up with a nonconvex problem.In this paper,a complimentary mathematical proof is given for the convexification of this mixed-integer linear programming(MILP)problem so that the linear programming(LP)method can be applied instead if the objective function is linear.The proposed proof is validated through a case study and the simulation results show the effectiveness of the proposed method.