This article investigates the combined analysis of load frequency control (LFC) and Automatic voltage regulation (AVR) for two-area hybrid system. Classical PID controller is habituated as secondary controller. A novel differential evolution artificial electric field algorithm (DE-AEFA) is proposed in this paper to tune controller parameters. Initially, DE-AEFA algorithm is applied to test system 1 comprising two-area non-reheat thermal turbines. Later on, the study is extended to combined model named test system 2 to investigate combined LFC and AVR problem. Further, the system is extended to the incorporation of HVDC link with the existing AC tie-line in parallel. System dynamic performance is predominantly enhanced by AC/DC rather than only AC tie-line. The proposed scheme robustness is demonstrated by conducting sensitivity analysis.

This paper made an attempt to put forward the comparative performance analysis of different energy storage devices (ESDs), such as redox flow batteries (RFBs), superconducting magnetic energy storage (SMES) device and ultra-capacitors (UCs), in the combined frequency and voltage stabilization of a multi-area interconnected power system (MAIPS). The investigative power system model comprises two areas, and each area consists of the power-generating sources of thermal, hydro and gas units. The intelligent control mechanism of fuzzy PID was used as a secondary controller optimized with a hybridized approach of the artificial electric field algorithm (HAEFA) subjected to the minimization of integral time absolute error (ITAE) objective function. However, the superiority of fuzzy PID in dampening the deviations of combined load frequency control (LFC) and automatic voltage regulator (AVR) responses was revealed upon comparison with conventional PI and PID. Further, the LFC-AVR combined analysis was extended to incorporate different ESDs one after the other. The simulation results reveal the efficacy of incorporating ESDs with the LFC-AVR system and the supremacy of RFBs in damping out the fluctuations in frequency and voltage.

This paper introduces a new-fangled coordinated control mechanism for simultaneous stabilization of frequency and voltage in multi-area system. A new differential evolution- artificial electric field (DE-AEFA) algorithm is suggested for fine tuning of classical PID as regulator. Viability of DE-AEFA based control scheme is established by counterpointing its dynamic responses with other algorithms and also tested on a widely accepted test system of dual area thermal plant with turbines of non-reheat structure. Further, the dynamic responses of the considered system has been examined by placing interline power flow controller (IPFC) in tie-line and redox flow batteries (RFBs) in both the areas. This investigation depicts the superiority of IPFC and RFBs in mitigating frequency, tie-line and voltage deviations by coordinating with the proposed controller. It is deduced that the proposed coordinated control strategy is highly efficient and surpasses prevalent approaches. Eventually, sensitivity analysis is performed to test control strategy robustness.

This paper puts forward the implementation of an intelligent type II fuzzy PID (T2-FPID) controller tweaked with a water cycle algorithm (WCA), subjected to an error multiplied with time area over integral (ITAE) objective index for regularizing the variations in frequency and interline power flow of an interconnected power system during load disturbances. The WCA-based T2-FPID is tested on a multi-area (MA) system comprising thermal-hydro-nuclear (THN) (MATHN) plants in each area. The dynamical behavior of the system is analyzed upon penetrating area 1 with a step load perturbation (SLP) of 10%. However, power system practicality constraints, such as generation rate constraints (GRCs) and time delays in communication (CTDs), are examined. Afterward, a territorial control scheme of a superconducting magnetic energy storage system (SMES) and a unified power flow controller (UPFC) is installed to further enhance the system performance. The dominancy of the presented WCA-tuned T2-FPID is revealed by testing it on a widely used dual-area hydro-thermal (DAHT) power system model named test system 1 in this paper. Analysis reveals the efficacy of the presented controller with other approaches reported in the recent literature. Finally, secondary and territorial regulation schemes are subjected to sensitivity analysis to deliberate the robustness.

Power availability from renewable energy sources (RES) is unpredictable, and must be managed effectively for better utilization. The role that a hybrid energy storage system (HESS) plays is vital in this context. Renewable energy sources along with hybrid energy storage systems can provide better power management in a DC microgrid environment. In this paper, the optimal PI-controller-based hybrid energy storage system for a DC microgrid is proposed for the effective utilization of renewable power. In this model, the proposed optimal PI controller is developed using the particle swarm optimization (PSO) approach. A 72 W DC microgrid system is considered in order to validate the effectiveness of the proposed optimal PI controller. The proposed model is implemented using the MATLAB/SIMULINK platform. To show the effectiveness of the proposed model, the results are validated with a conventional PI-controller-based hybrid energy storage system.

This paper presents a novel tuning approach of the secondary controller in combined load frequency control and automatic voltage regulator of the interconnected power system considering communication time delays (CTDs). Traditional PID is used as a regulator and optimal gain values are rendered with new combined optimisation of the differential evolution-artificial electric field algorithm. The efficacy of the presented algorithm is tested on the two-area reheat thermal plant, which is widely utilised in the literature, and also on some standard benchmark test functions. Moreover, the secondary regulator is not enough to sustain the stability under large disturbances and due to CTDs. Therefore, to dampen the system oscillations further, an interline power flow controller (IPFC) and redox flow batteries coordinated control strategy is implemented. However, the impact of CTDs on the combined model is also analysed. The combined model is subject to random power demand to validate the robustness of the proposed coordinated control scheme. Abbreviations: LFC: load frequency control; DTUs: distant terminal units; DE: differential evolution; CTDs: communication time delays; AVR: automatic voltage regulation; RFB: sedox flow battery; ESD: energy storage device; ISE: integral square error; AEF: artificial electric field; ACE: area control error.