The removal efficiency of ammonia in denitrification downstream equipment, concentration and distribution mechanism of ammonia in fly ash and slurry were studied under the condition of high concentration of ammonia escaping from denitrification by selective catalytic reduction (SCR) in coal-fired power plants. Through sampling analysis of 350 MW and 600 MW units, the results show that: the escaping ammonia removal efficiencies of air preheater, electrostatic precipitator and wet desulphurization system are 3.37%-6.63%, 75.14%-83.28% and 36.36%-46.38%, respectively. The ammonia removal efficiencies of these downstream environmental protection equipment are high, and the ammonia concentration at chimney entrance decreases obviously compared with that at denitrification outlet. The ammonia content in fly ash is inversely proportional to the particle size of fly ash. Ammonia concentration in desulfurized flue gas increases with the increase of ammonia concentration in original flue gas. The removal efficiency of ammonia in desulphurization system decreases with the increase of slurry pH value. The results have great significance to the units’ environmental protection and economic running.

High temperature solid oxide electrolysis cell (SOEC) is a new type of high-efficiency electrochemical energy transfer device with high energy transfer efficiency, high reaction rate and wide application scenarios. It has enormous potential in the fields including production of low-cost green hydrogen and carbonaceous product with high added values. Nitrogen oxide treatment _{and ammonia synthesis may also be a promising direction of application. SOEC is expected to play an important role in the low-carbon transformation of energy, chemical industry, transportation and other fields. Based on the latest progress of SOEC in the fields of hydrogen production, oil production, nitride treatment and ammonia production, the development status of SOEC was systematically summarized, and the key directions for future development were prospected.}

Proton exchange membrane (PEM) water electrolysis is a green and sustainable method of hydrogen production. The development of efficient and economical electrocatalysts for anodic oxygen evolution reaction (OER) is the key to its large-scale commercialization. Iridium oxide catalysts supported by different manganese based oxide carriers (IrO _x /Mn₈O₁₀Cl₃, IrO _x /β-MnO₂ and IrO _x /α-MnO₂) were prepared by two-step synthesis method, and the content of iridium is about 55%. Compared with the commercial IrO₂ and other noble metal containing electrocatalysts, the synthesized catalysts have lower overpotential and higher current density. The overpotential of IrO _x /β-MnO₂ is only 228 mV at the current density of 10 mA/cm². The specific mass activity of IrO _x /Mn₈O₁₀Cl₃ reaches 916.7 A/g_Ir at 1.53V. The enhancement of OER activity is attributed to the abundant hydroxyl oxygen defects and Ir^III species on the catalyst surface. The rich crystalline-amorphous interface provides a large number of active sites for the reaction. The iridium oxide/manganese based oxide catalysts reported in this paper provide new insights for the development of efficient and economical catalysts for acidic OER.

Hydrogen energy has broad development prospects as a clean, carbon-free, flexible and efficient secondary energy and industrial raw material. Although the technologies of hydrogen production by water electrolysis, hydrogen storage and hydrogen supply have been relatively mature, the technology chain of hydrogen production-storage-supply is still in its infancy. It is of great importance to explore the technology chain in power system for the cooperative utilization of hydrogen energy and traditional electricity. This paper firstly introduced the basic principles, classifications, advantages and disadvantages of the technologies including hydrogen production by water electrolysis, hydrogen storage and hydrogen supply, and summarized the development of hydrogen production by water electrolysis, hydrogen storage and hydrogen supply technologies in the United States, Japan and the European Union. Then, the current status of above technologies in China was analyzed, and three possible application modes of hydrogen production by water electrolysis, hydrogen storage and hydrogen supply in power system in China were discussed. Finally, based on the current situation, the suggestions for promoting the development of hydrogen production by water electrolysis, hydrogen storage and hydrogen supply in power system in China were put forward, which provide a reference for optimizing the development of the whole technology chain of hydrogen energy production-storage-supply-use.

The pollution-free characteristics of hydrogen energy make it a necessary means to achieve the goals of “carbon peaking” and “carbon neutralization” in China. With the implementation of a series of related policies, the development of hydrogen energy is to enter the fast lane. Large scale storage and transportation of hydrogen energy with low energy consumption is a technical bottleneck that needs to be solved urgently at present. Hydrogen liquefaction with mixed refrigerant is an effective means to solve this problem. This paper made a statistical analysis of the current hydrogen liquefaction with mixed refrigerants. The basic technical routes of different researchers and the current hydrogen liquefaction process were summarized. Furthermore, the suggestions for the development of hydrogen liquefaction process with mixed refrigerants were put forward, to provide effective support for large-scale storage and transportation technology of hydrogen and accelerate the realization of large-scale commercial use of hydrogen energy.

A model of hundred kilowatt proton exchange membrane fuel cell (PEMFC) combined heat and power system was established in Aspen Plus platform, which was composed of fuel processing unit, heat recovery unit and PEMFC unit. The key equipment model of fuel processing unit was built according to the reaction kinetic parameters, while PEMFC stack adopted the custom model from Aspen Custom Modeler. This paper verified the accuracy of key equipment model and analyzed the effects of operating parameters on system performances under steady-state conditions. The results show that under the operation mode of determining heat by power, the feed of combustion natural gas or the steam-carbon ratio of reforming gas can be appropriately reduced to improve electrical efficiency and exergy efficiency of the system. In addition, the linkage valve on the pipeline from pressure swing adsorption (PSA) to PEMFC can be adjusted to increase the anode inlet pressure of the stack, so as to improve the power generation. However, it is not recommended to increase the cathode inlet pressure of the stack, which will lead to raise of auxiliary equipment power consumption and decline in net power efficiency. When the power is determined by heat, the opposite adjustment method can be adopted, and the exhaust temperature of combustion flue gas and PEMFC tail gas can be reduced to improve the system thermal efficiency. The study results provide reference for adjusting the operation parameters of PEMFC combined heat and power system to achieve appropriate thermo-electric output ratio.

Hydrogen energy is an important part of China's new energy system,and its market scale and application scenarios are also expanding. Under the guidance of various national policies,provinces and cities have issued relevant policies in the fields of fuel cell vehicles and other fields according to their regional characteristics,which has accelerated the pace of hydrogen energy commercialization to a certain extent. In terms of fuel cells and other aspects,this paper sorted out the national and local hydrogen energy policies,and analyzed the application fields of hydrogen energy,the policy points of the future development planning of provinces and cities,and the profit model. Finally,the corresponding suggestions and prospects were given for the current process of hydrogen energy commercialization,which provide a reference for improving the efficiency of hydrogen energy in the future.

The multi-energy complementary demonstra-tion projects of wind-solar-water-thermal-energy storage focuses on the development from the power side, and forms a complementary operation mode by using wind energy, solar energy, hydropower, coal to generate electricity. Multi-energy complementarity can effectively solve the problems of wind abandoning, light abandoning, water abandoning and power limiting, promote the absorption of renewable energy nearby, realize the stable delivery of electricity and improve the comprehensive utilization efficiency of energy. This paper summarized the connotation construction principles of multi-energy complementarity, detailed the development status and existing problems of the first batch of multi-energy complementarity demonstration projects, and analyzed in detail the development paths of different modes of multi-energy complementarity projects. This paper focused on the evaluation of wind and solar resources, new energy site planning, total installed capacity and optimal power ratio, optimal allocation of energy storage, coordinated control technology to ensure safety and stability and economic evaluation indicators of the project, so as to extract the general process and development mode suitable for the construction and promotion of multi-energy complementary projects. Finally, some summary and suggestions were put forward from the aspects of top-level design, market mechanism and operation management.

As a green and zero-carbon secondary energy, hydrogen is one of the key carriers for the development of energy transition and has become an important medium for energy interconnection. Hydrogen production by electrolytic decomposition of water is the main way to produce hydrogen in the future, which will promote the adjustment and transformation of energy structure. However, the development and industrial application of hydrogen energy technology in China is still at the initial stage. In addition, there are a lot of problems to be solved in the aspects of hydrogen energy production, storage and transportation, conversion and application industry chain. This paper analyzed the development status of green power hydrogen production technology, hydrogen storage and transportation technology, hydrogen application technology, and studied the typical scenarios of green electricity-hydrogen energy-multi-domain application and the key technologies of network coupling and integration. This work provides indicative ideas for the combination of hydrogen energy production, storage and application technology, and the development of application network in various areas.

The construction of anti-disaster backbone grid is of great significance to enhance the power supply capacity of power system under extreme natural disasters. Comprehensively considering economy and reliability, a planning method for anti-disaster backbone grid was proposed. The economy and reliability of the planning scheme were expressed as the strengthened cost and the benefit from loss reduction in life cycle. The objective function was to maximize the unit benefit from loss reduction of the original grid caused by the unit strengthened cost of backbone grid. Taking the network connectivity and safe operation of power system into account, a planning model for anti-disaster backbone grid was established. The model was solved by the improved crisscross optimization (ICSO) algorithm to find the optimal planning scheme. Finally, the effectiveness of the proposed method was verified by the simulation analysis of the IEEE 30-bus system.

Under the carbon peak goal and carbon neutral vision, offshore wind power has made great progress in China in recent years. The current development status and future planning of offshore wind power in China were analyzed, and the installed capacity of offshore wind power, new models and adopted technical routes were summarized. The paper focused on the basic type, anti-corrosion technology, and operation and maintenance technology of offshore wind power. The floating offshore wind power was the focus of basic type research. The operation and maintenance inspection and operation and maintenance management system was the focus of wind power operation and maintenance technology research. By analyzing the development status of offshore wind power, the main technical routes and advanced achievements of each technology were sorted out. Finally, based on the current domestic technology development status and demand, the future development trend of China’s offshore wind power was prospected.

With a large number of distributed energy resources connected to the grid,virtual power plants as a distributed energy management technology have received a lot of attention because of their flexibility,efficiency and sustainability. This paper briefly discussed the background of virtual power plants, analyzed the hot directions and emerging directions in virtual power plants,and introduced the composition and structure of virtual power plants. According to the different goals and functions of virtual power plants,virtual power plants can be divided into mission-driven virtual power plants, economy-driven virtual power plants and hybrid driven virtual power plants. On this basis, the different operation modes and different solution methods of different types of virtual power plants were further discussed. Finally,the future development prospects of virtual power plants were prospected.

Hydrogen energy storage is an important support for promoting global green low-carbon transformation and realizing “carbon neutrality” goal. After the “double carbon” goal was put forward, hydrogen energy storage has become a hot topic of social concern. The safety of hydrogen energy storage is one of the problems that must be focused on and solved first. Safety problems in four stages of hydrogen production, hydrogen storage, hydrogen transport and hydrogen use were summarized and analyzed, including hydrogen leakage and diffusion, hydrogen combustion and explosion, compatibility of hydrogen with metals. At the same time, the current status and development of hydrogen leakage detection sensor technologies were analyzed, and the urgent problems and future development directions of hydrogen leakage detection technologies were pointed out.

In order to cope with the increasing shortage of fossil fuels and a series of threats brought by global climate change, and achieve the goal of “dual carbon”, the proportion of renewable energy such as wind power and photovoltaic power in the grid has been continuously increased. However, the renewable energy power generation is random and uncontrollable, and the access location is scattered, which increases the difficulty of safe and stable operation of the power system. The introduction of virtual power plant (VPP)provides a feasible path for the above problems. The concept and classification of VPP was summarized and expounded. Moreover, the main differences between VPP and microgrid were compared. The existing researches from the perspectives of coordinated control, resource aggregation and optimal scheduling, and participation in the electricity market were analyzed and summarized. Taking the blockchain and digital twin technologies as examples, the applications of digital technologies in VPP were analyzed. Finally, the development prospects of VPP suitable for China’s national conditions and the challenges that may be faced in the future were pointed out.

With the massive access to renewable power generation and the advancement of the marketization process, the development prospects of virtual power plants that can give full play to the value of flexible resources have gradually emerged. In the process of virtual power plant participation in the market, the formulation of its market trading strategy needs to be challenged by the market mechanism. On the other hand, the market trading is closely related to the optimal scheduling of resources. The adjustable capacity of the internal resources, uncertainty, load behavior and other characteristics bring challenges to the development of trading strategy. This paper focused on the challenges and problems faced in the market transactions of virtual power plants, and summarized the market strategies adapted to the market mechanism. The key technologies required to deal with the formulation of the strategies, such as uncertainty handling, bid analysis methods, and virtual plant management methods were analyzed and reviewed, in order to provide a reference and a direction for the future research on virtual power plants.

Under the carbon trading mechanism, virtual power plants (VPP) aggregating distributed energy resource (DER) to participate in electricity market (EM) trading will help new energy consumption and improve environmental benefits. This paper constructed a multi-agent VPP model including wind turbine, photovoltaic power, controllable distribution generation, stored energy, and flexible load, and formulated bidding strategies for each entity participating in the electric energy market (EEM) and peak regulating market (PRM). The EEM and PRM examples showed that participating in peak regulating bidding by VPP could achieve the maximum benefits of VPP and reasonable distribution of the interests among DER members. Moreover, this paper introduced the carbon trading mechanism, analyzed the correlation between changes in carbon trading price and wind and solar consumption rate, carbon emissions and VPP benefits, and further explored the impact of carbon sink resource trading on electricity price, output and energy demand change rate. It provided a basis for the ecological protection compensation mechanism of carbon sink value, and also provided a reference for the price transmission effect of carbon market (CM) on EM under the coordination of electricity-carbon market and the optimization design of CM price mechanism.

The new energy is connected to the distribution network in the form of distributed generation, which brings uncontrollability, randomness and volatility to the system. With the help of modern power electronics, information and communication and automatic control technologies, the active distribution network with flexibility and controllability has become a development trend. The active distribution network planning is one of the major research fields in recent years. Based on the research results in this field at home and abroad, the research contents and methods of active distribution network planning were summarized, analyzed and prospected. The basic structure of the active distribution network was described, and the characteristics of the components of the distribution network were introduced. According to the different control variables, the planning models of active distribution network were classified, the optimization objectives in the model were summarized. The commonly used model solving algorithms and their advantages and disadvantages were analyzed and summarized. Through the discussion of key issues, the development trend of active distribution network in the future was analyzed.

Offshore wind power is a kind of green energy, which has attracted more and more attention. The anti-corrosion technology of offshore wind power facilities has become a current research hotspot. This paper first expounded the corrosion mechanism of equipments in the marine environment, and then introduced the commonly used anti-corrosion technologies for offshore wind power facilities, including the anti-corrosion coatings, cathodic protection, reserved corrosion allowance method, etc. Then, combined with an example, the anti-corrosion technology of thermal spraying and mineral grease coating in the new anticorrosion method in splash area were introduced emphatically. Finally, it briefly described the anti-corrosion detection and maintenance means of wind power facilities. It also introduced the corrosion protection methods used in Guishan wind power project in Zhuhai, Guangdong, which has been built into grid connected power generation in China, in order to provide some suggestions for improving the anti-corrosion level of offshore wind power.

The development of industry has brought a large amount of CO₂ emissions. In the process of achieving the goal of carbon peak and carbon neutralization, carbon dioxide capture, utilization and storage (CCUS) technology is an indispensable key technology. The carbon capture method with high technology maturity at this stage and great development potential in the future is post combustion carbon capture technology, mainly including solvent absorption, adsorption, membrane method and cryogenic distillation. The development and industrial application of the four most commonly used carbon capture methods were briefly introduced, and the industrial applicability of several methods was analyzed, especially the chemical absorption method and physical adsorption method, which are most widely used in large-scale carbon capture projects currently running. Chemical absorption method, adsorption method and membrane carbon capture technology have great development potential in the future, which can quickly promote the achievement of the goal of double carbon and help the near-zero emission of carbon.

Virtual power plant has become an important means to promote the construction of new power system and achieve the goal of “double carbon”. The intelligent operation management and control platform of virtual power plant effectively realizes the management and monitoring of flexible and adjustable resources in virtual power plant. The intelligent operation management and control platform of virtual power plant was described from the perspective of system framework and comprehensive functions. Firstly, the energy ecosystem of virtual power plant was analyzed and summarized based on framework of operation management and control, and market participation of virtual power plant. The intelligent operation management and control platform of virtual power plant was analyzed based on characteristics of platform system framework and platform structure framework. Then, the comprehensive functions of intelligent operation management and control platform of virtual power plant were analyzed from three aspects of functional structure blueprint, functional physical structure and functional scenario application.

In order to promote the utilization of clean and renewable energy such as solar energy and hydrogen energy, and better integrate it with virtual power plant technology, aiming at the coupling system of photovoltaic power station and electrolytic water hydrogen production, the operation mode of large-scale aggregate resources was constructed and the relevant economic analysis considering the initial investment of resources was carried out. At the same time, combined with the analysis of the annual output data of the actual photovoltaic power station project, it was discussed that when this kind of coupling resources were used as virtual power plant resources, while supporting the new power system and promoting the consumption of new energy, it could maintain and continuously optimize its own economy. The operation mode optimization elements, equipment function characteristics and market conditions worthy of attention were pointed out, which provided a reference for related research.

Hydrogen fuel cells, as the energy supply device, have received a lot of attention because of their high energy density and low carbon emission characteristics. However, due to the insufficient hydrogen refueling infrastructures, the hydrogen cost is high, and the dynamic response of hydrogen fuel cells is poor. Therefore, the hybrid power system of rechargeable battery and hydrogen fuel cells is generally used to supply energy to vehicles such as unmanned aerial vehicles (UAV), cars, and others. The energy management strategy of hybrid power system has an impact on the parameters of system dynamic response, economy and battery life. So the selection and design of energy management strategy are crucial to hybrid power system. This paper introduced the working principle of hydrogen-electricity hybrid power system and its energy supply methods. Besides, the current status of application and research progress of different energy management strategies for various application scenarios were summarized according to different control objectives. Finally, this paper presented the challenges of hybrid energy management strategies and outlooks their future development direction.

Focusing on the goal of carbon peak and carbon neutrality, the low-carbonization of the whole link of energy power system (i.e., source-network-load-storage) faces new requirements and challenges. The high proportion of renewable energy generation has become an inevitable trend. Considering the impact of the uncertainty of renewable energy generation on the safe and stable operation of the power system, the use of virtual power plant (VPP) with multi-energy complementary characteristics is a favourable way to solve this problem. Therefore, an optimal scheduling strategy of multi-energy complementary VPP was proposed. Firstly, taking into account the coupling relationship between multiple energy sources, a VPP operation mechanism that takes into account the entire source-grid-load-storage chain was constructed. Secondly, according to the proposed operation mechanism, a multi-energy complementary optimal dispatching model with low carbon economy as the goal was proposed to promote the consumption of renewable energy by coordinating the dispatching of various types of devices. Finally, the effectiveness of the proposed strategy was verified by simulating and analyzing a reference case of a multi-energy complementary VPP including renewable energy generation in a region.

Supercritical carbon dioxide(S-CO₂) Brayton cycle has great development potential in the field of efficient utilization of clean energy represented by fourth-generation nuclear energy and solar energy. A reasonable and reliable control strategy is the key to ensure the safe, stable, efficient and flexible operation of the S-CO₂ Brayton cycle system. This paper summarized the characteristics of S-CO₂ Brayton cycle control, and summarized and compared the S-CO₂ Brayton cycle control strategies under different application scenarios. The results show that the key control strategies of S-CO₂ Brayton cycle include running state control, impeller machine control, heat source control, etc. The variable load control strategies mainly include volume control, turbine bypass control, turbine inlet throttle control, compressor speed control, etc. The analysis results provide a reference for the selection of S-CO₂ Brayton cycle control strategies in related power generation fields.

In order to obtain the online monitoring information of boiler furnace temperature field in thermal power plant quickly and accurately, a temperature field reconstruction algorithm of acoustic tomography (AT) based on deep neural network (DNN) was proposed. After normalizing the measured values, combined with principal component analysis (PCA) dimension reduction, a fully connected network was constructed to distinguish the peak type. Moreover, DNN and BP neural network were built to predict the normalized slowness value and its maximum value, respectively. Finally, the temperature field distribution was reconstructed. Four typical temperature field models were simulated by using this method. The results show that the reconstruction quality of DNN algorithm is better than that of Tikhonov regularization algorithm and conjugate gradient algorithm. In addition, the average relative error and root mean square error of reconstructed image are less than 0.36% and 0.85% respectively.

With the advancement of the national goal of “double carbon”, the hydrogen production by electrolytic water will usher in explosive growth, among which the topology and control of power supply is of great significance to improve the efficiency of hydrogen production system. This paper took the topology of isolated DC/DC hydrogen production power supply as the main line to sort out and analyze, and summarized and analyzed the structures, advantages and disadvantages of single-stage, two-stage, parallel and multi-port DC/DC isolated hydrogen production power supply according to different application scenarios. The analysis shows that the full-bridge resonant converter and the control scheme considering the temperature, pressure and hydrogen/oxygen cross-osmosis feedback of the electrolytic cell will become the development trend of high-power large-scale hydrogen production power supply which can adapt to wide range and strong fluctuation. Moreover, the isolated three-port DC/DC conversion power supply will become the distributed integrated electric-hydrogen coupling development mode in the future. The research of this paper aims to provide theoretical reference for the further research of hydrogen production by electrolytic water.

With the gradual increase in the proportion of new energy, energy storage technology, as an auxiliary new energy grid, has attracted wide attention. Hydrogen energy storage and fuel cell technology have been listed as strategic energy technologies in China, and have been actively applied in the market and enterprise development. Hydrogen production from electrolytic water can stabilize the fluctuation caused by the connection of renewable energy to the grid and help the power grid to cut peak and frequency modulation. As a power generation device to improve energy conversion rate, fuel cell has the advantages of low noise and no pollution, it is one of the effective ways to absorb renewable energy. This paper made a comparative analysis of the development status and advantages of the existing energy storage technologies, the key technologies and research directions of hydrogen energy storage system were introduced emphatically, and the commercial development of hydrogen energy storage was prospected.

Under the background of energy complementarity and low-carbon economy, virtual power plant (VPP) is an effective carrier for achieving optimal allocation of regional resources and new energy consumption. At the technical level,the CO₂ recycling through carbon capture power plant (CCPP) and power-to-gas (P2G) conversion devices was realized, a CCPP-P2G coupling model was established, and a price based demand response model considering user satisfaction on the load side was introduced. In terms of low-carbon policy, the ladder carbon trading mechanism was introduced into VPP to constrain carbon emissions. Then, with the goal of minimizing the total cost, a low-carbon economic dispatch model for VPP was established. By setting different scheduling scenarios for comparison, the effectiveness of the model in low-carbon economy operation of VPP was verified, and the impact of carbon trading parameters on the carbon emissions and costs of VPP was explored through sensitivity analysis. The results show that the model has guiding significance for VPP low-carbon economic scheduling.

This paper analyzed the localization status of key components and systems in offshore wind turbines such as blades, spindles, electrical systems, and control systems.In view of the localization weaknesses existing in the components and systems of offshore wind turbines, the localization of blades, main bearings, converters and programmable logic controller (PLC) was carried out by using the ideas of theoretical analysis, material/component selection, component development, test verification and overall assembly, and 5 MW offshore wind turbines were assembled with the developed localization components and systems. The localization rate of the unit was more than 95%. The results show that most of the components and systems of offshore wind turbines have the conditions for localization, but some technologies, such as blade design, still rely on imports, and a few core components are still missing in China.

In order to solve the problem of uneven ammonia injection in selective catalytic reduction (SCR) de-NO _x system of coal-fired power plant, a precise ammonia control optimization method was proposed by combining the intelligent feed-forward cascade control technology with the partition control technology. In the intelligent feed-forward process, the improved one-dimensional convolution neural network model with higher prediction accuracy was used to predict the NO _x mass concentration at the inlet of the SCR reactor, which was used as the intelligent feed-forward control signal to realize the fast and accurate control of the NO _x mass concentration under the whole working condition of the unit. In the partition control process, the single sub area and multi-point synchronous sampling measurement technology and equalization control strategy were combined to realize the precise control of ammonia injection in each partition. The proposed optimization method has been applied to several coal-fired power plants. The operation results show that the precise control of ammonia injection amount is realized under the whole working conditions of the unit. The NO _x mass concentration at the outlet section of SCR reactor is uniformly distributed. The ammonia consumption is obviously reduced and the economic benefit is significant.

Heavy metal pollution in desulfurization wastewater from coal-fired power plants has huge potential harm to the environment. Among them, the problem of heavy metal ions such as Pb²⁺, Cd²⁺ and Cr³⁺ is particularly prominent. Efficient and targeted removal of relevant heavy metal ions is a huge challenge for wastewater purification. For this reason, sulfur-doped porous carbon materials were prepared by template method to selectively remove heavy metal ions from wastewater with electro-adsorption. The results show that the removal efficiency of Pb²⁺, Cd²⁺ and Cr³⁺ in wastewater can still reach 99% after 5 cycles. The electric adsorption experiment was carried out for the actual desulfurization wastewater from a coal-fired power plant in northern China, the mass concentrations of Pb²⁺, Cd²⁺ and Cr³⁺ could be effectively reduced to less than 0.2 μg/L. Through structural, morphological and electrochemical characteri-zation, it is found that S/PC₃ has excellent ion transport channels (mesoporous ratio is 91.06%) and electrochemical performance (117.3 F/g, 1 A/g). At the same time, the appropriate sulfur doping amount improves the site activity of sulfur-doped carbon materials, and makes the sulfur atoms (Lewis soft base) with heavy metal ions (Lewis soft acid) combine.

Virtual power plant (VPP) is a new type of operation mode. It can effectively aggregate a large number of demand side resources and formulate effective dynamic aggregate control strategies to achieve power complemen-tation in different time and space of the power grid and improve the flexibility of power grid control and the economy of the system. From the perspective of power grid dispatching, this paper analyzed the characteristics of typical power grid demand response behavior, and proposed the demand response capability indexes and the classification and aggregation method of VPP. Then, a multi-source VPP regulation model was constructed, and the results supported the hierarchical and regional complementary regulation of VPP response resources. Finally, taking a park as a case, the rationality of VPP control strategy and the scientificity of multi-source VPP control were analyzed. The results show that the overall dynamic control strategy can guide the VPP to give full play to the demand response value in a scientific and reasonable way, and promote the stable load of power grid and the safe and stable operation of the system.

In order to effectively remove CO from hydrogen-rich gas, cobalt-based nano-particle catalyst supported on nitrogen-doped ordered mesoporous carbon was prepared and characterized by X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS) and thermogravimetry-mass spectrometry (TG-MS). The effects of nitrogen doping on the self-reduction behavior of the catalyst and CO methanation reaction performance were studied. The characterization results show that the nitrogen atoms introduced into the mesoporous carbon skeleton are mainly used as the nucleation sites of cobalt oxide, which have a strong interaction with the oxide carrier, and greatly improve the dispersion of cobalt species. Thus, small nano-cobalt particles with uniform particle size are formed, which significantly promote self-reduction reaction and thereby improve the reduction degree of the catalyst. The catalyst evaluation results show that, compared with the mesoporous carbon carrier without doping, the CO removal efficiency of the catalyst doped by nitrogen is much higher.

The CO₂ emissions of China power industry is the main source of CO₂ emissions. The CO₂ emissions of thermal power plants account for the largest proportion in the power industry. Under the goal of “double carbon”, CO₂ accounting technology can realize the intuitive judgment of CO₂ emissions in thermal power plants, provide important support for CO₂ emission reduction in thermal power plants, promote thermal power plants to participate in carbon trading, and drive regional economic development. Combined with domestic and foreign policies, the implementation progress of the current general CO₂ accounting methods was discussed. The problems existing in the CO₂ accounting methods of thermal power plants based on carbon accounting and supplemented by carbon monitoring were summarized. The key and difficult points of the application of CO₂ accounting technology in thermal power plants were analyzed. Finally, the development and application of CO₂ accounting technology in thermal power plants were prospected.

Aiming at the problems of low efficiency, low level of intelligent operation and low level of data informatization application encountered in the current substation equipment test operation, a mobile laboratory platform based on grid cloud data management was developed. This paper focused on the theoretical process of the result judgment of the expert analysis system embedded in the mobile laboratory platform. Combined with the practical application cases of transformer differential protection after operation, according to the test results of low-voltage short-circuit impedance method, capacitance method, frequency response characteristic method, transformation ratio and direct resistance test, the reliability of the embedded expert analysis system to analyze the winding deformation caused by the short circuit impact of the transformer was illustrated. Finally, according to the results of the dismantling inspection after returning to the factory, the validity of the platform in the field application was further verified.

With the increase of new energy penetration, the power balance and frequency stability problems brought by its randomness, intermittency and volatility has become increasingly serious. It is difficult to cope with these problems only by traditional centralized power plants. Flexible resources in the power systems should also bear a part of the responsibility for the balance of power and energy. Virtual power plant (VPP) can aggregate a large number of distributed flexible resources with different characteristics, participate in the electricity markets as a whole and accept the dispatch of the grid, and provide important support for the real-time power balance of the power systems. The development of VPPs should be based on a large number of flexible resources, advanced communication and dispatching/control technologies, and efficient business models and good market policies. The operation of VPPs can be attributed to the energy flow of the energy network, the information interaction of the information network and the value transfer of the value network. Therefore, based on the three-layer network architeciture of “energy-information-value”, the operation modes and control schemes of different types of VPPs were analyzed, and the idea of “three flow separation-convergence” for VPP architecture design was proposed. The findings provide useful guidance for the design, construction and operation of VPPs.

The increasingly frequent extreme weather has a more serious impact on the electro-thermal coupling system. Resilience is a core indicator that measures the system’s ability to withstand extreme events, reduce the impact of failures,and recover quickly. To enhance the ability of the electro-thermal coupling system to withstand extreme disasters,a two-stage three-layer resilience enhancement strategy of combined heat and power-virtual power plant (CHP-VPP) considering thermal inertia was proposed. In the first stage, the system was reconstructed based on the minimum spanning tree theory with the goal of minimizing the cost of tie switches. In the second stage,aiming at minimizing the operating cost,the optimal decisions under the worst failure scenario was formulated based on distributionally robust optimization theory. The column and constraint generation algorithm was used for iterative solutions. A CHP-VPP test system was built based on an IEEE 33-bus system and a 6-node thermal system. The simulation results show that the proposed method can effectively enhance the resilience of CHP-VPP to cope with extreme disasters.

To achieve carbon peaking and carbon neutrality goals and improve energy efficiency, new energy plays a major role in China strategic deployment. However, as centralized photovoltaic is located in desert areas, photovoltaic power transmission has become a bottleneck problem. Battery transportation technology provides new possibilities for the existing problems of desert electric energy transmission. Firstly, from the perspective of desert centralized photovoltaic transmission mode, this paper focused on the actual operation of the existing desert photovoltaic transmission and analysed the working principle of battery transportation technology. Then, the differences such as investment cost, transmission capacity, and ability to cope with desert climate were compared between traditional desert photovoltaic transmission and battery transportation technology. Finally, the advantages of battery transportation technology, such as low construction cost and strong ability to deal with desert climate were summarized and the limitations were also discussed.

The energy saving and emission reduction transformation of thermal power enterprises can reduce the coal consumption of thermal power supply, and then effectively reduce the growth of carbon dioxide emissions, which is of great significance to achieve the goal of carbon peak and carbon neutralization. Taking a 630 MW unit as an example, the system units of four waste heat utilization schemes (low-temperature economizer scheme, secondary low-temperature economizer scheme, bypass flue scheme and turbine boiler coupling scheme) were compared, and the key technical parameters and power saving effect were compared and analyzed. Moreover, a reference for the upgrading and technical transformation of energy conservation and emission reduction in China’s power industry was put forward. The results show that the exhaust gas temperature is reduced to 90 ℃, The coal consumption rate of power supply is reduced by 1.88 g/(kW⋅h) in the low-temperature economizer scheme, 2.16 g/(kW⋅h) in the secondary low-temperature economizer scheme, 2.29 g/(kW⋅h) in the bypass flue scheme, and 2.66 g/(kW⋅h) in the turbine boiler coupling scheme.

Accurate power load forecasting is conducive to ensuring the safe and economic operation of the power system. Aiming at the problems of low prediction accuracy and long time consuming of the current prediction algorithms, an improved deep learning (DL) short-term load forecasting model based on random forest (RF) algorithm and rough set theory (RST), namely RF-DL-RST, was proposed. Firstly, based on historical data, the model used RF algorithm to extract the key features that affected the load forecasting. Then, the key features and historical load data were trained as the input and output items of deep neural network (DNN), and the prediction results were corrected by RST. After that, the rough set method was used to revise the prediction results. Finally, the simulation was verified by an example. The results show that the prediction accuracy of the model is higher than that of a single DNN model and a model without RST revised.