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The modification of the physicochemical properties of sulfonated poly(arylene ether nitrile) (SPAEN) proton exchange membranes was demonstrated by poly(ethylene-co-vinyl alcohol) (EVOH) doping (named SPAEN-x%).

Iron and nitrogen co-doped carbon material (Fe/NC) is considered as a promising catalyst for oxygen reduction reaction (ORR) due to its excellent catalytic activity. However, it is still challenging to further reform the activity of ORR and oxygen evolution reaction (OER). Rare earth elements with unique orbital configuration and catalytic behavior are widely regarded as effective promoters to enhance the electrocatalytic activity of materials. Here, we successfully optimized the oxygen electrocatalytic activity of Fe/NC by the novel addition of Dy element, denoted as Dy2O3-Fe/NC. The resulting material shows excellent ORR/OER activity in 0.1 M KOH, with a half-potential (E1/2) of 0.914 V and an overpotential of 396 mV (at a current density of 10 mA cm-2). The excellent bifunctional electrocatalytic activity is derived from the close synergistic interaction between Fe and Dy, as well as the newly generated active sites of FeNx-Dy2O3. Zn-air battery assembled with Dy2O3-Fe/NC as cathode catalyst shows a high peak power density (225 mW cm-2) and long-term charge-discharge cycle stability.

Extensive efforts to enhance the oxygen evolution reaction (OER) catalytic performance of transition metal oxides mainly concentrate on the extrinsic morphology tailoring, lattice doping, and electrode interface optimizing. Nevertheless, little room is left for performance improvement using these methods and an obvious gap still exists compared to the precious metal catalysts. In this work, a novel "mixed-valent cobalt modulation" strategy is presented to enhance the electrocatalytic OER of perovskite LaCoO3 (LCO) oxide. The valence transition of cobalt is realized by ethylenediamine post reduction procedure at room temperature, which further induces the variation of magnetic properties for LCO catalyst. The optimized LCO catalyst with Co2+/Co3+ of 1.98% exhibits the best OER activity, and the overpotential at 10 mA cm-2 current density is decreased by 170 mV compared pristine LCO. Impressively, the ferromagnetic LCO catalyst can perform magnetic OER enhancement. By application of an external magnetic field, the overpotential of LCO at 10 mA cm-2 can be further decreased by 20 mV compared to that of under zero magnetic field, which arises from the enhanced energy states of electrons and accelerated electron transfer process driven by magnetic field. Our findings may provide a promising strategy to break the bottleneck for further enhancement of OER performance.

Layered Ni-rich LiNixMnyCo1-x-yO2 (NMC) materials are the most promising cathode materials for Li-ion batteries due to their favorable energy densities. However, the low thermal stability typically caused by detrimental oxygen release leads to significant safety concerns. Determining the pathways of oxygen evolution reaction is essential, as the ideal safety countermeasure is to break the reaction chain of thermal runaway. In this study, we demonstrate that two endogenous pathways of oxygen involved in strong exothermic reactions lead the NMC811|graphite pouch cell to an uncontrollable state, and we quantify the individual contribution of the pathways to thermal runaway. Approximately 41% of thermal-induced oxygen reacts aggressively with ethylene carbonate (EC) at the cathode/electrolyte interface with 16% heat generation, accelerating the self-heating rate and thereby further triggering thermal runaway. The residual oxygen that survives the reaction with carbonate spreads to the lithiated anode with major heat generation (65%), bringing the battery to the maximum destructive temperature during thermal runaway. By confirming the significant roles of EC and anode, a deeper understanding on battery fire was achieved. The revealed mechanism can help guide studies on stopping the two reaction pathways, allowing for the safer use of high-energy lithium-ion batteries in the future.

Noble metal-free and highly efficient electrocatalytic materials with hierarchically porous structures continue to be studied for the oxygen reduction reaction (ORR) in microbial fuel cells (MFCs). We report bimetal-organic framework (bi-MOF)-derived nanocubic Swiss cheese-like carbons with a novel three-dimensional hierarchically porous structure (3D Co-N-C) prepared by utilizing cetyltrimethyl-ammonium bromide (CTAB) as a structure-directing agent to control the formation of a nanocubic skeleton, and silica spheres as a template to form a mesoporous structure. The elemental composition and chemical morphology of this material can be tuned through the Zn/Co ratio to optimize its ORR catalytic activity. The optimized 3D Co-N-C displays excellent ORR catalytic performance (half-wave potential as high as 0.754 V vs . reversible hydrogen electrode and diffusion-limiting current density of 5.576 mA cm−2) in 0.01 mol L−1 phosphate-buffered saline (PBS electrolyte), showing it can compete with the commercial 20 wt% Pt/C catalysts. The catalytic capability and long-term durability of 3D Co-N-C as an air-filled cathode electrocatalyst in an MFC device are tested, showing that the 3D CoNC-MFC can reach a high power density of 1257 mW m−2 and provide a competitive voltage during a periodic feeding operation for 192 h; these values are much higher than those of the Pt/C-MFC.

The rational design and construction of hierarchically porous nanostructure for oxygen reduction reaction (ORR) electrocatalysts is crucial to facilitate the exposure of accessible active sites and promote the mass/electron transfer under the gas-solid-liquid triple-phase condition. Herein, an ingenious method through the pyrolysis of creative polyvinylimidazole coordination with Zn/Fe salt precursors is developed to fabricate hierarchically porous Fe-N-doped carbon framework as efficient ORR electrocatalyst. The volatilization of Zn species combined with the nanoscale Kirkendall effect of Fe dopants during the pyrolysis build the hierarchical micro-, meso-, and macroporous nanostructure with a high specific surface area (1,586 m2·g−1), which provide sufficient exposed active sites and multiscale mass/charge transport channels. The optimized electrocatalyst exhibits superior ORR activity and robust stability in both alkaline and acidic electrolytes. The Zn-air battery fabricated by such attractive electrocatalyst as air cathode displays a higher peak power density than that of Pt/C-based Zn-air battery, suggesting the great potential of this electrocatalyst for Zn-air batteries.

On account of fossil energy depletion and the environmental crisis, Zn–air batteries with high energy density, eco-friendliness, and excellent safety have been considered as promising candidates for next-generation energy devices. The crucially important air cathode of the Zn–air battery undergoes gas-involving oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the discharging and charging steps, resulting in complicated reactions and sluggish kinetic processes at the solid–liquid–gas interface. Micropore-dominated metal–organic frameworks (MOFs) have been demonstrated as a promising precursor in the field of electrocatalysis. However, the microporosity of MOF derivatives severely impedes the mass and charge transfer for the ORR/OER. Hence, the rational design of a hierarchically porous structure for multiscale mass/electron transport channels is essential for bifunctional oxygen electrocatalysts derived from MOFs. In this review, the latest developments of hierarchically porous ORR/OER electrocatalysts derived from MOFs for Zn–air batteries are covered. First, we introduce the related fundamentals of rechargeable Zn–air batteries and focus on the electrochemical oxygen reactions occurring at the air cathode. Then, recent advances of hierarchically porous MOF derivatives for the ORR, OER, and Zn–air batteries are discussed in detail. Finally, the synthesis strategies of hierarchically porous MOFs and their derivatives are presented as well.

Electrochemical water splitting has wide applicability in preparing high-density green energy. The Proton exchange membrane (PEM) water electrolysis system is a promising technique for the generation of hydrogen due to its high electrolytic efficiency, safety and reliability, compactness, and quick response to renewable energy sources. However, the instability of catalysts for electrochemical water splitting under operating conditions limits their practical applications. Until now, only precious metal-based materials have met the requirements for rigorous long-term stability and high catalytic activity under acid conditions. In this review, the recent progress made in this regard is presented and analyzed to clarify the role of precious metals in the promotion of the electrolytic decomposition of water. Reducing precious metal loading, enhancing catalytic activity, and improving catalytic lifetime are crucial directions for developing a new generation of PEM water electrolysis catalysts. A summary of the synthesis of high-performance catalysts based on precious metals and an analysis of the factors affecting catalytic performance were derived from a recent investigation. Finally, we present the remaining challenges and future perspectives as guidelines for practical use.

New energy storage is an important technology and fundamental equipment for building a new electric power system, an important support for achieving the goals of carbon peaking and carbon neutrality, and also a development focus for emerging strategic industries. In light of typical situations, such as a lack of station site resources and large-scale access to distributed new energy for power supply on a sea island, new energy storage is proposed to solve power supply capacity or quality problems in local areas and to replace or postpone power transmission and distribution investment. Considering the different life cycles of energy storage and power grid facility projects, we proposed an assessment method for the substitution effect of alternative energy storage on power grid functions based on the annual cost method and measured its cost-effectiveness under typical application scenarios.

Different from the traditional concrete mixing procedure, the innovative post-filling coarse aggregate concrete (PFCC) reduces the cost of pumping concrete by increasing the coarse aggregate content and reducing the usage of cement. Previous studies have shown that PFCC enhances the compressive strength, elastic modulus, and flexural strength of concrete. In this paper, the shear behavior of 13 post-filling coarse aggregate concrete beams and 3 control beams was tested to determine the relationships between the shear performance of the beam and the post-filling coarse aggregate ratio, concrete strength grade, shear span ratio and stirrup reinforcement ratio. The results showed that the ultimate shear capacity of beam specimen increases first and then decreases with the increase in post-filling coarse aggregate ratio, reaching the maximum at 15% post-filling ratio. The results also indicated that the ultimate shear capacity of the beam increases with the increase in concrete strength grade and stirrup ratio. However, experimental results exhibited that the ultimate shear capacity decreases as the shear span ratio increases. This study provides a reference for the application of post-filling coarse aggregate concrete in engineering practice.

Practical application of Li-S battery is limited by the fast capacity decay and low coulombic efficiency caused by the shuttling phenomenon. Modification of the battery separator to impart the separator with ionic sieving property is an effective strategy to alleviate the shuttling phenomenon. In this study, perfluorinated sulfonic acid (PFSA) ionomers with different equivalent weight (EW) values are used to modify the commercial polyethylene separator, and the electrochemical performance of these separators is systematically investigated. Our results show that the separator modified using PFSA ionomer with a low EW value of 830 shows optimal battery performance owing to its unique structure of the ionic cluster. The Li-S battery with this modified separator shows an initial discharge capacity of 1352 mAh g−1 and a retained capacity of 931.6 mAh g−1 after cycling 100 times at 0.2 C, which demonstrates the effectiveness of this modification strategy. Furthermore, the correlation between the properties of PFSA ionomers and the electrochemical performance of the modified separator unveiled in this study may provide insight for the rational design of advanced separator for battery applications.

The development of highly active and cost-efficient electrocatalysts toward oxygen reduction reaction (ORR) is essential for widespread application of polymer electrolyte fuel cell (PEFC). In the present work, hierarchically structured porous Co-Zn-N-C electrocatalyst is prepared by using soft templated bimetallic-organic framework precursors. The as-synthesized hierarchically porous catalyst presents outstanding ORR onset-potential (0.88 V vs. RHE), half-wave potential (0.78 V vs. RHE), and diffusion limiting current density (5.73 mA cm−2), that is similar to that at commercial Pt/C catalyst in acidic electrolyte. It is found that the hierarchical porous architecture is important for its excellent catalytic activity and further testifies that the hierarchically porous electrocatalyst also exhibits superior single PEFC performance with a power density of 412 mV cm−2. The present work provides not only a facile and low cost strategy toward the preparation of hierarchically porous materials, but also inspires an approach for enhancing the ORR electrocatalytic activity of MOF-derived materials.

The energy crisis and environmental issues are becoming more severe due to the long-term consumption of fossil fuels. Therefore, novel energy-conversion devices with high energy density and environmental friendliness are expected to provide reliable alternatives to traditional fossil-based energy systems. However, because of the inevitable use of costly precious metals as the electrode catalysts for such devices, their popularization is seriously hindered. Transition metal nitrides (TMNs) exhibit similar surface and adsorption properties to noble metals because the atomic distance between metal atoms increases and the d-band center of metal atoms downshifts after nitrogen atoms enter the metal lattice. TMNs have become one of the best electrode materials to replace noble metal-based electrocatalysts in next-generation energy-storage and energy-conversion devices. In this review, the recent developments in the electrocatalytic application of TMNs are covered. First, we discuss the structure and activity origin of TMNs and introduce the common synthesis methods for the preparation of TMNs. Subsequently, we illustrate the applications of mono-metallic TMNs and multi-metallic TMNs in oxygen-reduction reaction, oxygen-evolution reaction, and bifunctional oxygen reduction and evolution reactions. Finally, we summarize the challenges of TMNs encountered at the present stage, and expect their future development.

Flows of two immiscible liquids through inclined pipes are often encountered in industrial processes. The interfacial characteristics in inclined pipes are of significance for understanding the mechanism of flow pattern transition and modeling the flow parameters. This paper developed a novel experimental technique to access the interface characteristics of liquid-liquid flows, during which optical and electrical methods were successfully combined by matching the refractive index and conductivity of the flows. A planar laser-induced fluorescence (PLIF) system was set up with a continuous laser and high-speed camera. Organic and aqueous phases were chosen to match refractive indices. The liquid-liquid interface in the middle of the pipe could be clearly visualized by the PLIF system. Meanwhile, two conductance parallel-wire array probes (CPAPs) were designed to reconstruct the liquid-liquid interfaces at upward and downward pipe cross-sections. The performances of the CPAP were validated using the PLIF results and employed to investigate the liquid-liquid interfacial structures. The interfacial shape and its instability were uncovered using the reconstructed interfaces by the CPAPs.

Gas-liquid two-phase flows are characterized by complicated temporal-spatial structures, such as large Taylor bubbles occurring periodically, unstable huge waves and randomly distributed gas bubbles. Wire-mesh sensor (WMS) is a very popular tomography technology for multiphase flows. The existing WMS, however, fails to visualize the distributed gas bubbles with small sizes. The real-time detection of small-scale bubbly flows still presents significant challenges. In this study, we propose a new conductance wire-mesh sensor (WMS) system operated in a differential measurement mode to realize the visualization of bubbly flows. An experiment of gas-water flows is mimicked to validate the WMS responses. A comparison of differential and non-differential measurement modes in visualizing the gas bubbles has been conducted. By using the differential measurement mode, the WMS visualizations present a good agreement with the flow images recorded by a high-speed camera and indicate a higher accuracy in the gas holdup measurement of bubbly flows.

Development of noble metal-free catalysts with great electrocatalytic performance and stability is of importance for electrochemical energy conversion and storage devices. Herein, we reported the synthesis of trifunctional catalysts with three-dimension (3D) hierarchically porous nitrogen-doped carbon framework with Ni-Co dual metal-involving and carbon nanotubes growth derived from nickel metal-organic framework. The as-synthesized catalyst exhibited better oxygen reduction reaction performance under both neutral and basic conditions compared with commercial Pt/C catalysts. Under basic electrolyte, the oxygen evolution reaction performance of the synthesized catalyst was comparable to that of commercial IrO2 catalysts and reasonable hydrogen evolution activity was achieved compared with reported non-noble metal-based catalysts. The assembled microbial fuel cell using the as-prepared material as the air electrode exhibited a maximum power density of 1971.2 mW m−2 and could steadily operate for more than 250 h of feed period. Furthermore, the Zn-air battery fabricated with the obtained catalyst showed excellent power density and rechargeability, which were superior to that of a Zn-air battery using Pt/C/IrO2 as the air electrode. We anticipate that the results described here can provide a new idea for design of multifunctional electrocatalysts for energy conversion and storage devices.

Non-precious materials have been considered as promising bifunctional catalysts towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In the present work, a three dimensional (3D) Co-N co-doped hollow carbon sphere (HCS) electrocatalyst is synthesized at room temperature by the aid of a facile preparation method. The as obtained Co-N co-doped catalyst exhibits excellent catalytic activity towards both ORR and OER due to its high surface area and to 3D hollow architecture. For the ORR, the catalyst shows more positive onset-potential (of ∼0.962 V vs. RHE) and larger diffusion limiting current density (5.55 mA cm −2 ) compared with benchmark Pt/C catalyst in alkaline medium. Moreover, the as synthesized catalyst exhibits low potential (1.720 V vs. RHE) at the current density of 10 mA cm −2 and small Tafel slope (81 mV dec −1 ) for OER. In addition, the catalyst exhibits remarkable methanol tolerance and good long-term stability under working conditions. This strategy provides a facile and effective method for the preparation of non-noble metal catalysts with 3D hollow structure for energy conversion and storage applications.

The use of nanoscale metal–organic frameworks (MOFs) as drug delivery vehicles has attracted considerable attention in tumor therapy. In this study, novel biocompatible MOF-based nanocarriers were used as part of a facile and reproducible strategy for precision cancer theranostics. Both diagnostic (Mn2+) and therapeutic compounds (doxorubicin, DOX) were incorporated into the multifunctional MOF-based nanocarriers, which exhibited high colloidal stability and promoted T1-weighted proton relaxivity and low-pH-activated drug release. The obtained MOF-based nanocarriers exhibited significantly high cellular uptake and efficient intracellular drug delivery into cancer cells, which resulted in high apoptosis and cytotoxicity, in addition to effectively inhibiting the migration of 4T1 breast cancer cells. Moreover, the MOF-based nanocarriers could intensively deliver diagnostic and therapeutic agents to tumors to enable precise visualization of the nanocarrier accumulation and accurate tumor positioning, diagnosis, and imaging-guided therapy using magnetic resonance imaging (MRI). In addition, the functional MOF-based nanocarriers exhibited effective ablation of the primary breast cancer, as well as significant inhibition of lung metastasis with a high survival rate. Therefore, the developed nanocarriers represent a viable platform for cancer theranostics.

A novel method to prepare iron and nitrogen co-doped carbon nanotubes (Fe-N-CNT) is proposed, based on catalytic pyrolysis of waste plastics. At first carbon nanotubes are produced from pyrolysis of plastic waste over Fe-Al2O3; then Fe-CNT and melamine are heated together in inert atmosphere. Different co-pyroysis temperatures are tested to optimize the electrocatalyst production. Working at a high doping temperature improved the degree of graphite formation and promoted the conversion of nitrogen to a more stable form. Compared with commercial platinum on carbon, the electrocatalyst obtained from pyrolysis at 850 °C, showed remarkable properties, with onset potential of 0.943 V vs RHE and half-wave potential of 0.811 V vs RHE and even better stability and anti-poisoning. In addition, zinc-air batteries tests were also carried out and the optimized catalyst exhibited high maximum power density.

Accurate channel modelling is crucial for network performance analysis, particularly when considering unmanned aerial vehicles (UAVs). Measurement campaigns involving UAVs have shown that the path loss between UAVs and terrestrial base stations (BSs) is highly dependent on the UAV height, rendering previous line-of-sight (LoS) probability models inaccurate. In this paper, the coverage probability, average ergodic rate and area spectral efficiency are theoretically investigated based on a more realistic channel model, with height dependent LoS probabilities. Our results show that the long tail of the LoS probability function in UAV networks has an important performance impact on sparse networks where the BS density is low. Our new findings also show that the coverage of UAV-enabled networks may continuously decrease with the UAV density, since the LoS probability slowly declines with the link range.

Polyethylene (PE) membranes coated with nano-Al2O3 have been improved with water-dispersed poly(p-phenylene terephthamide) (PPTA). From the scanning electron microscope (SEM) images, it can be seen that a layer with a honeycombed porous structure is formed on the membrane. The thus-formed composite separator imbibed with the electrolyte solution has an ionic conductivity of 0.474 mS/cm with an electrolyte uptake of 335%. At 175 &deg, C, the assembled battery from the synthesized composite separator explodes at 3200 s, which is five times longer than the battery assembled from an Al2O3-coated polyethylene (PE) membrane. The open circuit voltage of the assembled battery using a composite separator drops to zero at 600 s at an operating temperature of 185 &deg, C, while the explosion of the battery with Al2O3-coated PE occurs at 250 s. More importantly, the interface resistance of the cell assembled from the composite separator decreases to 65 &Omega, Hence, as the discharge rate increases from 0.2 to 1.0 C, the discharge capacity of the battery using composite separator retains 93.5%. Under 0.5 C, the discharge capacity retention remains 99.4% of its initial discharge capacity after 50 charge&ndash, discharge cycles. The results described here demonstrate that Al2O3/PPTA-coated polyethylene membranes have superior thermal stability and ion diffusion.

Hierarchical nanostructured materials, which possess the porous structure of multiscale porosities on different pore diameters from micro-, meso- to macropores based on International Union of Pure and Applied Chemistry, are much desired to present the synergistic attractive advantages of each scale of hierarchical pores in the development of catalysis, adsorption, separation, energy, and biochemistry. The use of hierarchical nanostructured materials as oxygen reduction reaction (ORR) electrocatalysts is advanced to increase specific surface area for active sites dispersion and exposure as well as enhance reactants/products transfer. However, complex and costly templateincorporated methods and relatively uncontrollable template-free methods motive us to develop novel and efficient preparation methods. Herein, recent developments and synthesis strategies that have been made in the field of hierarchical nanostructured materials as well as their application for ORR electrocatalysts are reviewed.

With the popularization of heat network and application of Combined Heat and Power (CHP) units, the coupling between power system and thermodynamic system becomes deeper and deeper. With the increasing penetration of intermittent distributed generations (DGs) and continuous fluctuation of power loads and heat loads, uncertainty analysis is needed to study the possible variation interval of the operation state of integrated energy system. In this paper, the models of power system, district heating network and coupling components are built firstly. Then, the affine algorithm is introduced into multi-energy flow analysis to deal with uncertain factors including load fluctuation and DG output. Finally, the case study proves that the affine algorithm for multi-energy flow calculation can calculate the lower and upper bounds of state variables of integrated energy system under uncertainty, which include the pipe mass flow rates in district heating network and the bus voltages in power system.

With the increasing coupling of the power distribution system and the natural gas system, they will affect each other. The influence of natural gas system on power distribution system is enormous especially when the gas turbine generations dominate the power generation. This paper firstly builds the interval arithmetic model of natural gas system under uncertainty. With this model the instability of the gas sources and the deviation on gas load prediction are considered. Then the modeling of power distribution system and coupling parts are also presented. Secondly, a modified coupling power and natural gas flow calculation method based on interval arithmetic is presented taking into account the uncertainties of natural gas system. Finally, the test case that combines a modified IEEE 13- bus three-phase unbalanced power distribution system and a 11- node natural gas system is employed to demonstrate the influence of the uncertainty of natural gas system on power distribution system.

The severe mortality and morbidity of myocardial infarction requests appropriate and accurate detection. Considering pathological profile of the acidic myocardial infarction microenvironments, herein, the low pH-sensitive albumin nanocomposites with MnO

Polyethylene (PE) membranes coated with nano-Al2O3 have been improved with water-dispersed poly(p-phenylene terephthamide) (PPTA). From the scanning electron microscope (SEM) images, it can be seen that a layer with a honeycombed porous structure is formed on the membrane. The thus-formed composite separator imbibed with the electrolyte solution has an ionic conductivity of 0.474 mS/cm with an electrolyte uptake of 335%. At 175 °C, the assembled battery from the synthesized composite separator explodes at 3200 s, which is five times longer than the battery assembled from an Al2O3-coated polyethylene (PE) membrane. The open circuit voltage of the assembled battery using a composite separator drops to zero at 600 s at an operating temperature of 185 °C, while the explosion of the battery with Al2O3-coated PE occurs at 250 s. More importantly, the interface resistance of the cell assembled from the composite separator decreases to 65 Ω. Hence, as the discharge rate increases from 0.2 to 1.0 C, the discharge capacity of the battery using composite separator retains 93.5%. Under 0.5 C, the discharge capacity retention remains 99.4% of its initial discharge capacity after 50 charge–discharge cycles. The results described here demonstrate that Al2O3/PPTA-coated polyethylene membranes have superior thermal stability and ion diffusion.

Reliability evaluation is of crucial importance for the planning, designing and operating of electricity-gas-heat integrated energy system. However, the traditional reliability evaluation of electricity-gas-heat integrated energy system was mainly considered from the perspective of the energy suppliers and the user’s subjective experience of energy consumption was not considered in the past. From the user's perspective, this paper firstly establishes the reliability modeling of electricity-gas-heat integrated energy system considering various energy forms of electricity, natural gas and heat, complex coupling relations and multi-energy storage. Secondly, the indexes of user's severity perception degree of energy consumption faults and user's satisfaction degree of energy consumption are introduced in order to describe user's experience of energy consumption. For the side of users and user groups, the reliability evaluation indexes of energy consumption are proposed, including the reliability evaluation indexes of electricity consumption, the reliability evaluation indexes of gas consumption and the reliability evaluation indexes of heat consumption. Finally, the reliability evaluation method of electricity-gas-heat multi-energy consumption based on Markov chain Monte Carlo method is proposed. In the case study, the traditional reliability evaluation indexes of energy supply and the proposed reliability evaluation indexes of energy consumption are compared in order to illustrate the importance of user’s experience of energy consumption and the effectiveness of the proposed method.

In order to improve the reliability of integrated energy system, the station-grid co-planning model and its solution method are proposed. The planning model considers the constraints of distribution network, gas distribution network, heat distribution network and energy station, and aims at minimizing the total planning cost within the planning period including investment cost, maintenance cost and reliability cost. It realizes the optimal planning for the types and locations of energy supply sources, distribution pipelines, energy stations and energy storage devices, such as electricity storage devices, gas storage devices, heat storage devices and cooling storage devices. The model is a mixed integer quadratic programming problem, which is solved by Gurobi. The case study uses the modified electricity-gas-heat integrated energy system to analyse the system planning scheme and planning cost under two scenarios. The results show that the proposed model can reasonably plan the integrated energy system and further improve the reliability of the integrated energy system.

Power system, natural gas system, and thermal system are traditionally managed by different types of companies, resulting in information islands among different systems. In order to break the information islands phenomenon and realize the unified management of electric-gas-heat integrated energy system, this paper thoroughly analyses the composition and characteristics of the electricity-gas-heat integrated energy system and extends the common information model by using object-oriented modeling concept based on the IEC 61970 to meet the needs of integrated energy systems, such as multi-energy flow calculation, optimal scheduling, and operational control. The complete extended model of natural gas system, thermal system, coupling links and multi-energy storage systems is built. In addition, the attributes of key classes in the electricity-gas-heat integrated energy system are described, such as the classes of natural gas source, natural gas transporting unit, natural gas pipeline, natural gas load, motor-driven compressor, power-to-gas unit, power-to-heat unit, natural gas storage system, thermal storage system and hydrogen storage system. The extended common information model of electricity-gas-heat integrated energy system is built under the Rational Rose platform and an example verification is carried out to generate XML file and partial code of header file and source file in order to test the rationality of the extended common information model.