Agent-Based Simulation for Interconnection-Scale Renewable Integration and Demand Response Studies

This paper collects and synthesizes the technical requirements, implementation, and validation methods for quasi-steady agent-based simulations of interconnectionscale models with particular attention to the integration of renewable generation and controllable loads. Approaches for modeling aggregated controllable loads are presented and placed in the same control and economic modeling framework as generation resources for interconnection planning studies. Model performance is examined with system parameters that are typical for an interconnection approximately the size of the Western Electricity Coordinating Council(WECC) and a control area about 1/100 the size of the system. These results are used to demonstrate and validate the methods presented.

An Online Fault Detection Model and Strategies Based on SVM-Grid in Clouds

Online fault detection is one of the key technologies to improve the performance of cloud systems. The current data of cloud systems is to be monitored, collected and used to reflect their state. Its use can potentially help cloud managers take some timely measures before fault occurrence in clouds. Because of the complex structure and dynamic change characteristics of the clouds, existing fault detection methods suffer from the problems of low efficiency and low accuracy. In order to solve them, this work proposes an online detection model based on asystematic parameter-search method called SVM-Grid, whose construction is based on a support vector machine(SVM). SVM-Grid is used to optimize parameters in SVM. Proper attributes of a cloud system's running data are selected by using Pearson correlation and principal component analysis for the model. Strategies of predicting cloud faults and updating fault sample databases are proposed to optimize the model and improve its performance.In comparison with some representative existing methods, the proposed model can achieve more efficient and accurate fault detection for cloud systems.

Hybrid Petri Nets for Modeling and Analysis of Microgrid Systems

Hybrid Petri nets(HPNs) are widely used to describe and analyze various industrial hybrid systems that have both discrete-event and continuous discrete-time behaviors. Recently,many researchers attempt to utilize them to characterize power and energy systems. This work proposes to adopt an HPN to model and analyze a microgrid that consists of green energy sources. A reachability graph for such a model is generated and used to analyze the system properties.

The Oleic Acid Composition Effect on the Carboxymethyl Cellulose Based Biopolymer Electrolyte

Biopolymer electrolyte based on carboxymethyl cellulose has been prepared by doping with different concentration of oleic acid via solution casting technique. Fourier Transform Infrared spectroscopy was used to study the complexation between the salt and polymer. New peak was observed at 1710, 2850, 2920 cm-1. X-ray diffraction study reveals the amorphous nature of the biopolymer electrolyte. Impedance study shows the highest ionic conductivity, σ, was found to be 2.11 × 10-5 S·cm-1 at room temperature (303 K) for sample containing 20 wt.% of oleic acid and the biopolymer electrolyte obeys Arrhenius behaviour.

Effect of partial blockage of air duct outlet on performance of OWC device

The use of a Savonius rotor as turbine for an oscillating water column(OWC) is demonstrated.The effect of tuning the OWC using turbine duct blockage is also studied for different wave conditions.A horizontal turbine section OWC employing a Savonius rotor was tested by varying the opening of OWC exit(0%,25%,50%,75% and 100%) to study the behavior and performance of the device.The OWC model was tested at water depth of 0.29 m at frequencies of 0.8,0.9 and 1.0 Hz while the exit openings are varied.The static pressure,dynamic pressure,rotational speed of the Savonius rotor and the coefficient of power are presented as results.The OWC with exit opening of 25% showed greater performance in terms of rotational speed and CP compared to OWC with other exit opening percentages.This proves the ability of the OWC to be tuned by regulating flow in the turbine duct.

Materials for energy conversion

Advances in material science and engineering are critical to the development of economically viable technologies to address some of the grand socio-economic challenges of the twenty first century.Materials are at the core

A review on capacity sizing and operation strategy of grid-connected photovoltaic battery systems

Due to the fluctuation and intermittency of distributed PV generation,battery energy storage is required with higher renewable installation towards carbon neutrality.Thus,the photovoltaic battery(PVB)system receives increasing attention.This study provides a critical review on PVB system design optimization,including system component sizing and strategy improvement studies,from mathematical modeling,evaluation system establish-ment to feasibility and optimization studies.Several PVB simulation software packages are compared and eval-uated,and acknowledged system models are presented.The evaluation indicators are summarized from various aspects with cases of various evaluation systems combining different indicators or using the Pareto front for multi-criteria system designing.The PVB system feasibility study is analyzed from system configuration varia-tion,critical technical and economic parameter analyses,rule-based operation strategies to future expectations like large-scale energy storage profitability,grid parity,and energy community trading platform.The targets,methods,tariffand time resolution influences,and PVB system capacity optimization design recommendations are critically discussed.The research directions for system operation development and future expectations are analyzed from system feasibility,flexibility to resilience.The co-planning of PVB system capacity and operation design optimization makes the problem complicated,leading to relatively short time resolution but more flexi-bility to system operation strategy.This study could provide guidance and references to distributed PVB system future design and optimization studies.

Experimental and numerical investigation of a solar eductorassisted low-pressure water desalination system

Greenhouse solar-energy driven desalination technology is potentially well suited for supplying water and small scale irrigation in remote and/or rural areas, and for avoiding over-exploitation of available water resources. The efficiency and productivity of these systems are however low, in part because the heat of evaporation has to be transferred as waste heat to ambient air during condensation. In order to maximize energy regeneration during condensation we propose an educator based system that lowers the evaporation process temperature by reducing pressure. The feasibility of the educator assisted passive solar desalination system is investigated using a detailed computational fluid dynamics analysis complemented by experiments. The study focuses in particular on the ability of the new design to lower the required evaporation temperature and thereby reduce the energy intensity of the process. Two configurations, with open and closed educator, are investigated and a detailed analysis of the thermofluid processes is presented. The configuration with a closed educator installed outside the evaporation chamber shows very promising performance. The proposed system can maintain the maximum temperature and pressure in theevaporation chamber below the desirable temperature and pressure thresholds （30 ℃ and 5 kPa）. The analysis and experimental data also show it is possible to further reduce energy requirements by reducing the motive water flow rates.

Biomass-derived nitrogen self-doped porous activation carbon as an effective bifunctional electrocatalysts

The strategy of adopting cheap precursors or abundant resources,which can be obtained directly from nature,is a simple and excellent method of introducing accessible research into environmentally friendly development.Moreover,this is also an urgent requirement for the sustainable development of green technology.Herein,we introduce a simplistic and expandable method to prepare metal-free biomassderived nitrogen self-doped porous activation carbon(N-PAC) with large specific surface area(S_(BET)=1300.58 m^(2)/g).Moreover,the manufactural electrocatalysts exhibit prominent oxygen reduction reaction(ORR) performance in all PH values.As compared with the commercial Pt/C catalyst,the N-PAC/800 with a positive onset potential at 10 mA/cm^(2)(0.93 V),half-wave potential(0.87 V),and limiting current(6.34 mA/cm^(2)) bring to light excellent catalytic stability,selectivity,and much-enhanced methanol tolerance.Furthermore,the prepared electrocatalysts possess considerable hydrogen evolution reaction(HER) performance with a less onset potential of 0.218 V(acidic medium) and0.271 V(alkaline medium) respectively,which can show similar catalytic activity across the whole pH range.Such bifunctional electrocatalyst,with excellent electrocatalytic properties,resource-rich,low cost,and environmental-friendly,hold a promising application in energy conversion and reserve.

Preparation,characterization and thermophysical properties investigation of A70/polyaniline nanocomposite phase change material for medium temperature solar applications

The ever-present demand for energy from various application in industrial and domestic processes has led to the consumption of fossil fuel at a rapid rate with adverse effect due to global warming.This study focuses on the thermal energy storage aspect intended for medium temperature applications.A novel composite A70 and PANI was prepared and characterized.The study investigates the composites thermophysical and optical properties.Differential Scanning Calorimetry and Transient Hot Bridge measured thermal storage capacity and thermal conductivity of the composite,respectively.The heat storage capacity of the composite remained stable within 4%whereas a highest rise of 11.96%in thermal conductivity was measured.The composites thermal,chemical,and physical stability were analysed from Thermogravimetric Analyser,Fourier Infrared Transform,and Scanning Electron Microscope,respectively.The composites were thermally stable up to a temperature of 250°C.No chemical reaction occurred between the nanomaterial and base PCM matrix.The microscopic visuals did not show any considerable change in the microscopic structure of the material.In the case of optical properties,the composites showed significant reduction in transmittance of solar spectrum with respect to pure A70.The maximum decrement in transmission was around~89%compared to A70.As the composite prepared were thermally stable till 250°C,hence may be utilized for solar thermal and low concentrated photovoltaic application but not limited to these.