• Energy Research

Energy harvesting from the environment becomes a valuable technology, especially for sea wave applications, in which it usually ends up wasted despite its potential to be harvested. Due to its wide availability and high energy density, piezoelectric energy harvesting (PEH) is becoming popular for flexible energy harvesting. This paper presents a flexible horizontal piezoelectric (FHP) energy harvester to harvest energy from the surface of sea wave. The harvester is made of bimorph piezoelectric devices; they are utilised to amplify and convert the collected mechanical vibrations into electrical power. A finite element model is established from ANSYS simulations to solve the iteration method by generating resonance frequency (fr). Then, Taguchi method, SN ratio and the ANOVA approach were used by considering the input variable of fr to estimate the optimum performance through control factors; number of blade, length and thickness. From the performance test result, it is proven that the higher numbers of blade including length, and minimum numbers of thickness significantly improve the significant level, α = 0.05% of ANOVA. Three prototypes are developed with approximate body dimensions through the resonance frequency perform and generate a 160.3 Hz on blade dimensions of 10 × 300 × 0.2 mm, with a piezoelectric (PZT) on its surface. This particular study shows that the potential of output power is generated from sea wave surface through a significant relationship between length, thickness, and blade design. This research develops a novelty for energy harvesting from flexible piezoelectric generator on sea wave application that could be easily install on offshore platform.

Although hybrid wind-biomass-battery-solar energy systems have enormous potential to power future cities sustainably, there are still difficulties involved in their optimal planning and designing that prevent their widespread adoption. This article aims to develop an optimal sizing of microgrids by incorporating renewable energy (RE) technologies for improving cost efficiency and sustainability in urban areas. Diverse RE technologies such as photovoltaic (PV) systems, biomass, batteries, wind turbines, and converters are considered for system configuration to obtain this goal. Net present cost (NPC) is this study's objective function for optimal sizing microgrid configuration. For demonstration, we assess the technical, economic factors, and atmospheric emissions of optimal hybrid renewable energy systems for Putrajaya City in Malaysia. The required solar radiation data, temperature, and wind speeds are collected from the NASA surface metrological database. From the quantitative analysis of simulations, the biomass-battery-based system has optimal economic outcomes compared to other systems with an NPC of around 1.07 M$, while the cost of energy (COE) is 0.118 $/kWh. Moreover, environmentally safe nitrogen oxide emissions, carbon monoxide, and carbon dioxide concentrations exist. The grid-tied RE technology boasts cost-effectiveness, with an NPC of 348,318 $ and a COE of 0.0112 $/kWh. This study aids decision-makers in formulating policies for integrating hybrid RE systems in urban areas, promoting sustainable energy generation.

This paper reviews on the function of Automatic Generation Control (AGC) as an intelligent mechanism in enhancing electrical power systems dynamic performance at various perturbations; by sustainin...

The purpose of this study is to assess the potential improvement in fuel economy and performance of a fuel-cell series hybrid electric vehicle (FCHEV) in combination with a supercapacitor (SC) by u...

Abstract Modern power system faces excessive frequency aberrations due to the intermittent renewable generations and persistently changing load demands. To avoid any possible blackout, an efficient and robust control strategy is obligatory to minimise deviations in the system frequency and tie-line. Hence, to achieve this target, a new two-degree of freedom-tilted integral derivative with filter (2DOF-TIDN) controller is proposed in this work for a two-area wind-hydro-diesel power system. To enhance the outcome of the proposed 2DOF-TIDN controller, its gain parameters are optimized with the use of a newly designed hybrid bat algorithm-harmony search algorithm (hybrid BA-HSA) technique. The effectiveness and superiority of hybrid BA-HSA tuned 2DOF-TIDN is validated over various existing optimization techniques like cuckoo search (CS), particle swarm optimization (PSO), HSA, BA and teaching learning-based optimization (TLBO). To further refine the system outcome in the dynamic conditions, several flexible AC transmission systems (FACTS) and superconducting magnetic energy storage (SMES) units are adopted for enriching the frequency and tie-line responses. The FACTS controllers like static synchronous series compensator (SSSC), thyristor-controlled phase shifter (TCPS), unified power flow controller (UPFC) and interline power flow controller (IPFC) are employed with SMES simultaneously. The simulation results disclose that the hybrid BA-HSA based 2DOF-TIDN shows superior dynamic performance with IPFC-SMES than other studied approaches. A sensitivity analysis is examined to verify the robustness of proposed controller under ± 25% changes in loading and system parameters.

Abstract This paper presents an equivalent electrical circuit model for a unit cell all-vanadium redox flow battery (V-RFB). The developed V-RFB model consists of an open-circuit cell potential (Ecell(ORP)) which is in series with an ohmic internal resistance and parallel with an n-Resistor–Capacitor (n-RC) network. The Ecell(ORP) represents an intrinsic relationship of the V-RFB state-of-charge (SOC), while the n-RC networks represent the polarization characteristic and dynamic behaviour of the V-RFB. The Ecell(ORP) and ohmic resistance parameters are obtained through a direct measurement of an experimental setup of 25 cm2 unit cell laboratory unit V-RFB, whereas the two pairs of RC network parameters are identified through a recursive algorithm of extended Kalman filter (EKF). The accuracy of this model is verified with different pulse voltages at a few values of SOCs. Ultimately, the model is validated with an experimental charge–discharge characterisation of V-RFB system. Suggestion for system improvement is highlighted.