The proportional integral derivative (PID) controller is one of the most robust and simplest configuration controllers used for industrial applications. However, its performance purely depends on the tuning of its proportional (K_P), integral (K_I) and derivative (K_D) gains. Therefore, a proper combination of these gains is primarily required to achieve an optimal performance of the PID controllers. The conventional methods of PID tuning such as Cohen-Coon (CC) and Ziegler–Nichols (ZN) generate unwanted overshoots and long-lasting oscillations in the system. Owing to the mentioned problems, this paper attempts to achieve an optimized combination of PID controller gains by exploiting the intelligence of the whale optimization algorithm (WOA) and one of its recently introduced modified versions called improved whale optimization algorithm (IWOA) in an automatic voltage regulator (AVR) system. The stability of the IWOA-AVR system was studied by assessing its root-locus, bode maps, and pole/zero plots. The performance superiority of the presented IWOA-AVR design over eight of the recently explored AI-based approaches was validated through a comprehensive comparative analysis based on the most important transient response and stability metrics. Finally, to assess the robustness of the optimized AVR system, robustness analysis was conducted by analyzing the system response during the variation in the time constants of the generator, exciter, and amplifier from −50% to 50% range. The results of the study prove the superiority of the proposed IWOA-based AVR system in terms of transient response and stability metrics.

Reusing waste cooking oil (WCO) as fuel in compression ignition (CI) engine offers a sustainable solution for energy scarcity and environmental protection. WCO and n-pentanol ternary blends deliver are attractive prospects in utilization as bio-components and recycled components to moderately substitute diesel fuel. The current study intends to investigate the performance and emission characteristics of a single cylinder CI engine, having constant load at a uniform speed of 1300 rpm, using diesel-waste cooking oil n-pentanol blends. Blends chosen and analogized with diesel oil as reference fuel and their contents were the following: (1) D95-WCO5 (95%vol. diesel, WCO5%vol. waste cooking oil, (2) D65-WCO20-Pe15 (65%vol. diesel, 20%vol. waste cooking oil, and 15%vol. n-pentanol) and (3) D60-WCO20-Pe20 (60%vol. diesel, 20%vol. waste cooking oil and 20%vol. n-pentanol). The experimental results revealed that with the DF95-WCO5 blend the BSFC improved by 0.32%. However, with the addition of n-pentanol as a ternary blend; DF65-WCO20-Pe15 and DF60-WCO20-Pe20 resulted in improvements of 0.49% and 0.68% respectively. The BTE for DF95-WCO5 increased by 38.7%, while the increase was 39.2% for DF65-WCO20-Pe15 and 39.6% for DF60-WCO20-Pe20, which was less, as compared with diesel fuel. The lowermost level of CO discharge was achieved when the engine was fueled with DF65-WCO20-Pe15 and DF60-WCO20-Pe20, due to the highest level of saturation. CO₂, in the cases of DF65-WCO20-Pe15 and DF60-WCO20-Pe20, increased, as compared to diesel fuel under the same engine operating conditions. However, the binary blend DF95-WCO5 resulted in decreased CO₂ as analogized to diesel, because of incomplete combustion of the fuel. During experimental work it could be observed that the DF95-WCO5 binary blend produced higher Particulate material (PM-1, PM-2.5, PM-7 and PM-10) emissions, compared to DF100. Moreover, with the addition of n-pentanol as a ternary blend in the ratio of 15 to 20%, emission was further reduced. This indicated that direct exertion of WCO in engines must be promoted, as it is an impressive choice for waste recapture.

The increasing penetration of Distributed Generators (D.G.) into the existing power system has brought some real challenges regarding the transient response of electrical systems. The injection of D.G.s and abrupt load changes may cause massive power, current, and voltage overshoots/undershoots, which consequently affects the equilibrium of the existing power system and deteriorate the performance of the connected electrical appliances. A robust and intelligent control strategy is of utmost importance to cope with these issues and enhance the penetration level of D.G.s into the existing power system. This paper presents a Modified Particle Swarm Optimization (MPSO) algorithm-based intelligent controller for attaining a desired power-sharing ratio between the M.G. and the main grid with an optimal transient response in a grid-tied Microgrid (M.G.) system. The proposed MPSO algorithm includes an additional parameter named best neighbor particles (rbest) in the velocity updating equation to convey additional information to every individual particle about all its neighbor particles, consequently leading to the increased exploration capability of the algorithm. The MPSO algorithm optimizes P.I. parameters for transient and steady-state response improvement of the studied M.G. system. The main dynamic response evaluation parameters are the overshoot and settling time for active and reactive power during the D.G. connection and load change. Furthermore, the performance of the proposed controller is compared with the PI-PSO-based MG controller, which validates the effectiveness of the proposed M.G. control scheme in maintaining the required active and reactive power under different operating conditions with minimum possible overshoot and settling time.

Long-term engine running has been the subject of extensive research on the deterioration of engine oil. In contrast, it is not fully clear what effect synthetic and biofuels will have. Modern engines, traditional fuels and lubricants should be used to provide a research basis for characterizing novel fuel-related phenomena in engines. This study makes an effort to characterize how lubricating engine oil behaves over the course of its service life using data on friction and wear. Every 20 hours, oil samples from the engine were obtained to evaluate its chemical makeup. On a reciprocating test rig, friction and wear measurements were taken. Kinematic viscosity, density, and wear metals such as cadmium (Cd), cobalt (Co), and lead (Pb) were measured for the lubricant oil analysis. In general, n-pentanol aids in the reduction of engine wear debris, contamination, and lubricating oil oxidation. According to the findings of this study, a D60WCO20Pe15 ternary combination can be used in a diesel engine without any alteration. The sound pressure level (SPL) increased by 7.8 dB at engine speed of 1300 RPM in the case of the DF95WCO5. However, when compared to base line, the average SPL of D60WCO20Pe15 ternary blend was 4.3 dB lower.