The versatility of anaerobic digestion (AD) as an effective technology for solving central challenges met in applied biotechnological industry and society has been documented in numerous publications ...over the past many decades. Reduction of sludge volume generated from wastewater treatment processes, sanitation of industrial organic waste, and benefits from degassing of manure are a few of the most important applications. Especially, renewable energy production, integrated biorefining concepts, and advanced waste handling are delineated as the major market players for AD that likely will expand rapidly in the near future.
The complex, biologically mediated AD events are far from being understood in detail however. Despite decade-long serious academic and industrial research efforts, only a few general rules have been formulated with respect to assessing the state of the process from chemical measurements. Conservative reactor designs have dampened the motivation for employing new technologies, which also constitutes one of the main barriers for successful upgrade of the AD sector with modern process monitoring instrumentation.
Recent advances in Process Analytical Technologies (PAT) allow complex bioconversion processes to be monitored and deciphered using e.g. spectroscopic and electrochemical measurement principles. In combination with chemometric multivariate data analysis these emerging process monitoring modalities carry the potential to bring AD process monitoring and control to a new level of reliability and effectiveness. It is shown, how proper involvement of process sampling understanding, Theory of Sampling (TOS), constitutes a critical success factor.
We survey the more recent trends within the field of AD monitoring and the powerful PAT/TOS/chemometrics application potential is highlighted. The Danish co-digestion concept, which integrates utilisation of agricultural manure, biomass and industrial organic waste, is used as a case study. We present a first foray for the next research and development perspectives and directions for the AD bioconversion sector.
This study presents a comprehensive survey on the reliability evaluation of the electrical network system. The impacts of integration of new and renewable energy sources (electric vehicle, energy ...storage system, solar, and wind) on the reliability of electrical power system (EPS) are discussed. The impacts of these renewable sources have merits/demerits when these sources are integrated with the conventional electric power system. However, the merits are predominant as it includes unlimited, free, and cost-effective resources. The recent researches depict that the uncertainties of renewable energy resources leads to the probabilistic and reliability analyses of EPS. EPS includes offshore and onshore wind farms, micro-grid, energy storage system, and other high voltage grids. It also contains the failure-prone components related to the power systems. For the accomplishment of these aspects, the handling methods of uncertainty parameters in generation, transmission, and distribution systems are discussed. The incorporation of electric vehicles, wind energy system, and energy storage system for reliability assessment is also discussed briefly. This study also presents the scope of a new research area for the researchers on the reliability assessment of renewable energy integrated power system.
Effect of HTL temperature on H/C ratio and heating value of bio-crude oil. Display omitted
► Hydrothermal liquefaction of two algae at subcritical and supercritical water conditions. ► Comprehensive ...analysis of bio-crude and solid residue samples. ► First report of nutrient values of algal biomass solid residues. ► Correlate H/C ratio and heating value of bio-crude with process temperature.
Six hydrothermal liquefaction experiments on Nannochloropsis salina and Spirulina platensis at subcritical and supercritical water conditions (220–375°C, 20–255bar) were carried out to explore the feasibility of extracting lipids from wet algae, preserving nutrients in lipid-extracted algae solid residue, and recycling process water for algae cultivation. GC–MS, elemental analyzer, FT-IR, calorimeter and nutrient analysis were used to analyze bio-crude, lipid-extracted algae and water samples produced in the hydrothermal liquefaction process. The highest bio-crude yield of 46% was obtained on N. salina at 350°C and 175bar. For S. platensis algae sample, the optimal hydrothermal liquefaction condition appears to be at 310°C and 115bar, while the optimal condition for N. salina is at 350°C and 175bar. Preliminary data also indicate that a lipid-extracted algae solid residue sample obtained in the hydrothermal liquefaction process contains a high level of proteins.
Piezoelectric Energy Harvesting Systems play a vital role in energizing microelectronic devices with the low‐frequency operation. Here, a novel piezoelectric energy harvesting device has been ...developed for low power electronic devices. The developed Piezoelectric Energy Harvesting Systems consists of a cantilever with poles projecting outwards and the cantilevers one end is connected to the wind‐catcher, and another end is connected to the torsional spring. The developed Piezoelectric Energy Harvesting Systems signifies its application in energizing microelectronic devices. The cantilever is placed inwards to the piezoelectric crystal stack. When the wind strikes, a vortex is created in the windcatcher, which oscillates the cantilever and generates stress in the piezoelectric crystal stack to develop electric energy. The output voltage obtained from the Piezoelectric Energy Harvesting Systems does not affect any input frequency of the piezoelectric crystal. The result obtained shows that the developed Piezoelectric Energy Harvesting Systems generates 120–200 eV with 2.9 × 1016–4.84 × 1016 Hz frequency considering an elementary charge unit as 40 for a variable wind flow of 4–9 m/s. This research aims to develop an efficient wind‐based Piezoelectric Energy Harvesting Systems for low powered microelectronic devices.
Clean and environment-friendly energy harvesting are of prime interest today as it is one of the key enablers in achieving the Sustainable Development Goals (SDGs) as well as accelerates social ...progress and enhances living standards. India, the second-most populous nation with a population of 1.353 billion, is one of the largest consumers of fossil fuels in the world which is responsible for global warming. An ever-increasing population is projected until 2050, and consequently, the energy demand in the upcoming decades will be co-accelerated by the rapid industrial growth. The Ministry of New and Renewable Energy (MNRE) with the support of National Institution for Transforming India (NITI) Aayog is working to achieve the Indian Government's target of attaining 175 GW through renewable energy resources. Many Indian states are currently increasing their renewable energy capacity in an objective to meet future energy demand. The review paper discusses in-depth about the three Indian states, namely Karnataka, Gujarat, Tamil Nadu, which pioneers the renewable energy production in India. The global energy scenario was discussed in detail with Indian contrast. Further, the barriers to the development of renewable energy generation and policies of the Indian government are discussed in detail to promote renewable energy generation throughout India as well as globally since the challenges are similar for other nations. This study analyzed various prospects of the country in renewable energy which has been done in a purpose to help the scholars, researchers, and policymakers of the nation, as it gives an insight into the present renewable energy scenario of the country.
With the increasing penetration of renewable energy sources in the power system, the power electronic inverters are widely used to interface with the grid, which will reduce the inertia of the power ...system. This study proposes ancillary inertial service from single-phase rooftop solar photovoltaic (PV) based inverter to the grid. The inertia emulation control technique transforms the behaviour of inverter like a synchronous generator under power imbalances. A hybrid energy storage system consisting of battery and supercapacitor (SC) has been connected at the DC bus to take care of the variability in PV output power and load fluctuations. The SC absorbs/injects the fast-varying power and provides the inertial response to arrest the frequency deviation and battery charges/discharges to bring back the frequency to the nominal value. Real-time simulation is carried out to test the system behaviour for different operating conditions using OPAL-RT 5700.
Summary
Torque ripple and harmonics in permanent magnet synchronous motor (PMSM) cause negative impacts on its speed control and overall efficiency. In this article, an Elman neural network ...(ENN)‐controlled feedback linearization‐based direct torque control strategy has been proposed to mitigate torque ripples and undesirable harmonics of PMSM. In this approach, the stator flux, stator flux position, and developed torque are used to generate a switching pulse to the impedance source inverter employing ENN controller. By changing the switching pattern of the impedance source inverter through modifying the pulse width modulation using the proposed control strategy. It is possible to control the armature current of the PMSM at various orders and corresponding time harmonics under different operating conditions. The outstanding aspect of the proposed control strategy is that it boosts the inverter operation and reduces the requirement of the DC‐DC converter in boosting. For evaluating the performance of the developed control strategy, an extensive simulation study has been conducted in the MATLAB/Simulink environment, and experimental analysis is carried out using the Xilinx‐FPGA kit.
This work elaborates Elman neural network‐controlled adaptive combined feedback linearization‐based direct torque control strategy for an PMSM drive.
The switching pattern of the impedance source inverter is generated by the developed control strategy.
The proposed control strategy mitigates the torque ripple and undesirable harmonics of the PMSM.
Experimental results reveal the performance of the developed feedback linearization‐based direct torque control strategy. The experimental setup consists of FPGA kit (Spartan 6‐xc6slx75t‐csg484) through which switching pulse is generated through the HDL coding generated using Xilinx generator.
PMSM torque ripple minimization strategy.
SUMMARY
This work articulates the hybrid photovoltaic‐wind power system development for water pump applications. The proposed control scheme is based on modified Artificial Bee Colony (ABC)‐based on ...Maximum Power Point Tracking (MPPT) algorithm.. On power circuit part, the single CUK converter‐fed induction motor driven a centrifugal pump and has been employed, which improves the system overall performance. The proposed MPPT control provides the smooth propagation of the motor operation as well as forces the photovoltaic system to operate always in maximum power point (MPP) region. Further, the modified ABC algorithm strengthens searching competency and has been employed for the achievement of local optimal maximum power point (MPP) under partial shade conditions with high accuracy and zero oscillation around MPP region when compared with other optimized algorithms. Particle swarm optimization‐space vector pulse‐width modulation (PSO‐SVPWM) was adapted for the inverter; control with standard v/f control is implemented in this work for better speed regulation and reduction in total harmonic distortion. Moreover, the power balance of the integrated hybrid system to the DC bus has been discussed with practicality. This article also explains the comparison of different MPPT algorithms and includes PSO, ant colony optimization, firefly algorithm, and ABC under fast‐changing environmental conditions. In the case of classical ABC method, only one scout bee is responsible to achieve the local maximum. The proposed modified ABC has been used to improve searching capacity, with the addition of scout bees. Experimental results are presented and reveal that the modified ABC algorithm performs 7.5 times faster than the standard PSO technique. Prototype model in hardware setup is developed with MATLAB/Simulink interfaced with dSPACE DS 1104.
This study introduces a type of solid-state transformer (SST) for solar power station design and an energy management strategy (EMS) for the SST. The purpose of this study is to design a real ...efficient EMS for the photovoltaic-assisted charging station in smart grid ancillary services and apply the optimal decision method. Also, the energy bound calculation (EBC) model is proposed to find the upper and lower bounds of flexible sources. Also, taking into account the EBC results and the power order from the aggregator, a charge power allocation algorithm is designed to distribute the power of flexible electric vehicles (EVs). With the help of a case study and laboratory analysis, the proposed EMS strategy is effective in real-time energy management and is suitable for practical applications. The obtained results show the stable performance in the calculation of the energy range and real-time power allocation which improves the efficiency of the photovoltaic-based charging station. Also, the SST improves the operation of charge stations for supplying the sustaining power.
A hybrid microgrid-powered charging station reduces transmission losses with better power flow control in the modern power system. However, the uncoordinated charging of battery electric vehicles ...(BEVs) with the hybrid microgrid results in ineffective utilization of the renewable energy sources connected to the charging station. Furthermore, planned development of upcoming charging stations includes a multiport charging facility, which will cause overloading of the utility grid. The paper analyzes the following technical issues: (1) the energy management strategy and converter control of multiport BEV charging from a photovoltaic (PV) source and its effective utilization; (2) maintenance of the DC bus voltage irrespective of the utility grid overloading, which is caused by either local load or the meagerness of PV power through its energy storage unit (ESU). In addition, the charge controller provides closed loop charging through constant current and voltage, and this reduces the charging time. The aim of an energy management strategy is to minimize the usage of utility grid power and store PV power when the vehicle is not connected for charging. The proposed energy management strategy (EMS) was modeled and simulated using MATLAB/Simulink, and its different modes of operation were verified. A laboratory-scale experimental prototype was also developed, and the performance of the proposed charging station was investigated.
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