Salp swarm algorithm-based fractional-order PID controller for LFC systems in the presence of delayed EV aggregators

• Published in: IET electrical systems in transportation Vol. 10; no. 3; pp. 259 - 267
• Main Authors: Babaei, Farshad, Lashkari, Zahra Bahari, Safari, Amin, Farrokhifar, Meisam, Salehi, Javad
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.09.2020
• Subjects: ancillary services market; control system synthesis; controller effectiveness; delayed EV aggregators; delays; electric vehicles; electric vehicles battery; EV aggregator notion; EV participation; EVs aggregator; fewer frequency variations; FOPID controller; fractional‐order PID controller coefficients; frequency control; frequency control service; frequency variation signal; integral absolute error; integral time absolute error; LFC performance; LFC system; load demand; load frequency control systems; load regulation; mean absolute error indicators; power generation units; power system control; random behaviour; Research Article; salp swarm algorithm‐based fractional‐order PID controller; settling time; three‐term control; time‐varying delay; time‐varying systems; two‐area LFC systems; time-varying systems; electric vehicles; power generation units; ancillary services market; salp swarm algorithm-based fractional-order PID controller; electric vehicles battery; load frequency control systems; random behaviour; EV aggregator notion; LFC performance; frequency variation signal; EV participation; frequency control service; mean absolute error indicators; EVs aggregator; controller effectiveness; settling time; load regulation; integral time absolute error; load demand; three-term control; time-varying delay; integral absolute error; fewer frequency variations; control system synthesis; frequency control; delayed EV aggregators; two-area LFC systems; LFC system; FOPID controller; delays; power system control; fractional-order PID controller coefficients
• ISSN: 2042-9738; 2042-9746; 2042-9746
• DOI: 10.1049/iet-est.2019.0076

Electric vehicles (EVs) battery has the ability to enhance the balance between the load demand and power generation units. Random behaviour of owners and EVs low capacity are some factors that develop the EV aggregator notion to increase the EV participation in the ancillary services market. In the presence of EVs aggregator, the frequency control service is capable of causing time-varying delay in load frequency control (LFC) systems. Owing to the dependency of controller effectiveness on its parameters, these parameters should be designed optimally in order to have a better result in an LFC system in the presence of time-varying delay. Therefore, a salp swarm algorithm (SSA) is utilised to adjust the fractional-order proportional integral derivative (PID) (FOPID) controller coefficients. Also, some evaluations are performed about the proposed LFC performance by an integral absolute error, integral time absolute error and mean absolute error indicators. In this study, both single and two-area LFC systems containing EVs aggregator with time-varying delay are simulated and analysed. The results indicate that the proposed controller has fewer frequency variations in contrast to other controllers presented in the case studies. Moreover, it is concluded that the FOPID controller could significantly decrease the overshoot and settling time of the frequency variation signal.