Optimal Control Strategy for Distributed Energy Resources in a DC Microgrid for Energy Cost Reduction and Voltage Regulation

Abstract

Distributed energy resources (DERs), including renewable energy resources (RESs) and electric vehicles (EVs), have a significant impact on distribution systems because they can cause bi-directional power flow in the distribution lines. Thus, the voltage regulation and thermal limits of the distribution system to mitigate from the excessive power generation or consumption should be considered. The focus of this study is on a control strategy for DERs in low-voltage DC microgrids to minimize the operating costs and maintain the distribution voltage within the normal range based on intelligent scheduling of the charging and discharging of EVs, and to take advantage of RESs such as photovoltaic (PV) plants. By considering the time-of-use electricity rates, we also propose a 24-h sliding window to mitigate uncertainties in loads and PV plants in which the output is time-varied and the EV arrival cannot be predicted. After obtaining a request from the EV owner, the proposed optimal DER control method satisfies the state-of-charge level for their next journey. We applied the voltage sensitivity factor obtained from a load-flow analysis to effectively maintain voltage profiles for the overall DC distribution system. The performance of the proposed optimal DER control method was evaluated with case studies and by comparison with conventional methods.

Optimization Models under Uncertainty in Distributed Generation Systems: A Review

“…LP/MILP Solver Simulation Platform [19] CPLEX AIMMS [17,21,22,36,53,58,65,84,86,99,115,117,134,136,142,151,154,157,176] GAMS [37,44,83,96,101,[128][129][130]156,160,161,170,179] MATLAB [20,90,118,133,167] IBM [116] Gurobi GAMS [43] MATLAB [82] Python [145,166] Intlinprog MATLAB [46,57,70] Other/Unspecified GAMS [42,66,104,114,…”

Electric Vehicle Battery Storage Concentric Intelligent Home Energy Management System Using Real Life Data Sets

“…al [32] adopts a multi-objective method to make the EV charging and discharging more cost-effective by considering both the economy and user's preference. An RESs-integrated iEMS employed by Abdalla et al and Trinh et al [15,33] has adopted the moving sliding-window concept, which is called the receding horizon model predictive control or rolling horizon [6], to enhance the adaptability of scheduling algorithms. Additionally, Wu et al [34] introduce a unique machine learning-based energy management technique for a hybrid electric bus with an emphasis on thermal safety and battery deterioration.…”

State of the Art of Low and Medium Voltage Direct Current (DC) Microgrids

“…Apart from the selection regarding the interface with the main grid and the design of the topology for the connection of all the components included in the DC MG, it is essential to determine the control strategies according to which the total system will operate. The field of control strategies regarding these special structures has gained attention over the past few decades, which has led to the rise of advanced control algorithms, creating a mixture of different approaches presented in the worldwide literature [49][50][51][52][53][54]. Overall, control strategies deal with stability and protection issues, power balance, smooth transition regarding transient occurrences (e.g., black start), synchronization, optimization of various objectives (e.g., cost), market participation, etc.…”

“…Energies 2021, 14, x FOR PEER REVIEW 12 of 26 algorithms, creating a mixture of different approaches presented in the worldwide literature [49][50][51][52][53][54]. Overall, control strategies deal with stability and protection issues, power balance, smooth transition regarding transient occurrences (e.g., black start), synchronization, optimization of various objectives (e.g., cost), market participation, etc.…”