Research on Verification Method of Motor Startups in Nuclear Power Plants Based on Topology Recognition

There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive software to solve this problem,and the experience of engineers is not accurate enough.Therefore,this paper developed a method and system for the startup calculation of group motors in nuclear power plants and proposed an automatic generation method of circuit topology in nuclear power plants.Each component in the topology was given its unique number,and the component class could be constructed according to its type and upper and lower connections.The subordination and topology relationship of switches,buses,and motors could be quickly generated by the program according to the component class,and the simplified direct power flow algorithm was used to calculate the power flow for the startup of group motors according to the above relationship.Then,whether the bus voltage is in the safe range and whether the voltage exceeds the limit during the startup of the group motor could be judged.The practical example was used to verify the effectiveness of the method.Compared with other professional software,the method has high efficiency and low cost.

Quantification of CO_(2) Emissions from Three Power Plants in China Using OCO-3 Satellite Measurements

Coal-fired power plants are a major carbon source in China. In order to assess the evaluation of China's carbon reduction progress with the promise made on the Paris Agreement, it is crucial to monitor the carbon flux intensity from coal-fired power plants. Previous studies have calculated CO_(2) emissions from point sources based on Orbiting Carbon Observatory-2 and-3(OCO-2 and OCO-3) satellite measurements, but the factors affecting CO_(2) flux estimations are uncertain. In this study, we employ a Gaussian Plume Model to estimate CO_(2) emissions from three power plants in China based on OCO-3 XCO_(2) measurements. Moreover, flux uncertainties resulting from wind information, background values,satellite CO_(2) measurements, and atmospheric stability are discussed. This study highlights the CO_(2) flux uncertainty derived from the satellite measurements. Finally, satellite-based CO_(2) emission estimates are compared to bottom-up inventories.The satellite-based CO_(2) emission estimates at the Tuoketuo and Nongliushi power plants are ~30 and ~10 kt d^(-1) smaller than the Open-Data Inventory for Anthropogenic Carbon dioxide(ODIAC) respectively, but ~10 kt d^(-1) larger than the ODIAC at Baotou.

Virtual Power Plants for Grid Resilience: A Concise Overview of Research and Applications

The power grid is undergoing a transformation from synchronous generators(SGs) toward inverter-based resources(IBRs). The stochasticity, asynchronicity, and limited-inertia characteristics of IBRs bring about challenges to grid resilience. Virtual power plants(VPPs) are emerging technologies to improve the grid resilience and advance the transformation. By judiciously aggregating geographically distributed energy resources(DERs) as individual electrical entities, VPPs can provide capacity and ancillary services to grid operations and participate in electricity wholesale markets. This paper aims to provide a concise overview of the concept and development of VPPs and the latest progresses in VPP operation, with the focus on VPP scheduling and control. Based on this overview, we identify a few potential challenges in VPP operation and discuss the opportunities of integrating the multi-agent system(MAS)-based strategy into the VPP operation to enhance its scalability, performance and resilience.

Increasing the Efficiency and Level of Environmental Safety of Pro-Environmental City Heat Supply Technologies by Low Power Nuclear Plants

In connection with the current prospect of decarbonization of coal energy through the use of small nuclear power plants (SNPPs) at existing TPPs as heat sources for heat supply to municipal heating networks, there is a technological need to improve heat supply schemes to increase their environmental friendliness and efficiency. The paper proves the feasibility of using the heat-feeding mode of ASHPs for urban heat supply by heating the network water with steam taken from the turbine. The ratio of electric and thermal power of a “nuclear” combined heat and power plant is given. The advantage of using a heat pump, which provides twice as much electrical power with the same heat output, is established. Taking into account that heat in these modes is supplied with different potential, the energy efficiency was used to compare these options. To increase the heat supply capacity, a scheme with the use of a high-pressure heater in the backpressure mode and with the heating of network water with hot steam was proposed. Heat supply from ASHPs is efficient and environmentally friendly even in the case of significant remoteness of heat consumers.

Seasonal Performance of Solar Power Plants in the Sahel Region: A Study in Senegal, West Africa

The main objective of this study is to evaluate the seasonal performance of 20 MW solar power plants in Senegal. The analysis revealed notable seasonal variations in the performance of all stations. The most significant yields are recorded in spring, autumn and winter, with values ranging from 5 to 7.51 kWh/kWp/day for the reference yield and 4.02 to 7.58 kWh/kWp/day for the final yield. These fluctuations are associated with intense solar activity during the dry season and clear skies, indicating peak production. Conversely, minimum values are recorded during the rainy season from June to September, with a final yield of 3.86 kWh/kW/day due to dust, clouds and high temperatures. The performance ratio analysis shows seasonal dynamics throughout the year with rates ranging from 77.40% to 95.79%, reinforcing reliability and optimal utilization of installed capacity. The results of the capacity factor vary significantly, with March, April, May, and sometimes October standing out as periods of optimal performance, with 16% for Kahone, 16% for Bokhol, 18% for Malicounda and 23% for Sakal. Total losses from solar power plants show similar seasonal trends standing out for high loss levels from June to July, reaching up to 3.35 kWh/kWp/day in June. However, using solar trackers at Sakal has increased production by up to 25%, demonstrating the operational stability of this innovative technology compared with the plants fixed panel. Finally, comparing these results with international studies confirms the outstanding efficiency of Senegalese solar power plants, other installations around the world.

The Application of Intelligent Lighting in Thermal Power Plants

With the rapid development of electronic information technology,the Internet of Things(IoT),Internet technology,and modern communication technology,people are demanding higher standards for the building environment.Especially in modern large-scale buildings with high levels of industrialization,lighting systems should also be optimized accordingly.This article explores the application path of intelligent lighting in thermal power plants for reference.

Exploration of Construction Organization for Maintenance of Steam Turbine Equipment in Thermal Power Plants

The continuous development of the power industry has had a positive impact on thermal power plants,helping them maintain a good production form.In the use of steam turbine equipment in thermal power plants,to prolong its lifespan and avoid safety hazards,it is necessary to pay attention to strengthening maintenance and construction organization,better implementing effective organizational work,and effectively applying steam turbine equipment to ensure the sustainable development of thermal power plants.This article discusses the concept of equipment maintenance from the perspective of steam turbine equipment in thermal power plants,analyzes the current situation of equipment maintenance,and proposes a specific construction organization to provide a reference for steam turbine equipment maintenance.

DSS Scheme for Operation Optimization Problem on Power Plants

Based on the target analysis of the operation optimization for power plants, a novel system scheme called operation optimization decision support system (OODSS) is brought forward. According to the structure and design thinking of decision support system (DSS), the overall structure of the OODSS is studied, and the scheme of the sub systems in the OODSS such as the user interface system, the problem processing system, the database system, the model base system, the expert system (ES) and the data mining sy...

Considerations on FGD in Coal-Fired Power Plants

Aiming at issues on flue gas des-ulfurization facing coal-fired power plants inChina, such as process selection, whetheradopting flue gas desulfurization (FGD) or not,qualification of flue gas desulfurization en-gineering company, the localization of technicalequipment, charge for SO2 emission andnormalized management, this article makes acomprehensive analysis and puts forwardconstructive suggestions. These will providesome references for those being engaged in fluegas desulfurization in coal-fired power plants.[

ISSUES AND SUGGESTIONS ON LEVYING SO_2 EMISSION GHARGES TO THERMAL POWER PLANTS

This paper analyzes 9 essentials in trial collecting SO2 emission charges based on the relevant legislative policies, summarizes and analyzes the actual practices of collecting and using SO2 emission charges in power industry, and combining the status of power system reform, puts forward some recommendations about reasonably collecting and using SO2 emission charges and prompting power plants to take measures of desulfurization.

Progress and prospects of innovative coal-fired power plants within the energy internet

The development of electrical engineering and electronic, communications, smart power grid, and ultra-high voltage transmission technologies have driven the energy system revolution to the next generation: the energy internet. Progressive penetration of intermittent renewable energy sources into the energy system has led to unprecedented challenges to the currently wide use of coal-fired power generation technologies. Here, the applications and prospects of advanced coal-fired power generation technologies are analyzed. These technologies can be summarized into three categories:(1) large-scale and higher parameters coal-fired power generation technologies, including 620/650/700 oC ultra-supercritical thermal power and double reheat ultra-supercritical coal-fired power generation technologies;(2) system innovation and specific, highefficiency thermal cycles, which consist of renewable energy-aided coal-fired power generation technologies, a supercritical CO_2 Brayton cycle for coal-fired power plants, large-scale air-cooling coal-fired power plant technologies, and innovative layouts for waste heat utilization and enhanced energy cascade utilization;(3) coal-fired power generation combined with poly-generation technologies, which are represented by integrated gasification combined cycle(IGCC) and integrated gasification fuel cell(IGFC) technologies. Concerning the existing coal-fired power units, which are responsible for peak shaving, possible strategies for enhancing flexibility and operational stability are discussed. Furthermore, future trends for coal-fired power plants coupled with cyber-physical system(CPS) technologies are introduced. The development of advanced, coal-fired power generation technologies demonstrates the progress of science and is suitable for the sustainable development of human society.

Leaching Behavior of Fly Ashes from Power Plants

The Yanzhou mine district, located in southwestern Shandong Province, is about 1300 km2 with more than 8×109tons of proved coal reserves and there are 10 big power plants in this area. A large amount of coal ashes, which are regarded as waste materials, have been stockpiled in the area and have influenced the environment of the mine district. In this paper, analysis of fly ash samples from three power plants is carried out, the enrichment and concentration of trace elements, Pb, Zn, Cu and As, in coal ashes are analyzed, and petrological and mineralogical characteristics and chemical compositions of coal ashes are studied. The aim of this work is to provide basic scientific data for utilization of ashes and reduction of environmental pollutions.

Cause Analysis and Countermeasure of Gypsum Rain in Coal-fired Power Plants

Focusing on the phenomenon of gypsum rain while wet desulphurization(WFGD) were adopted in coal fired power plant without GGH, the paper studied and put forward the solutions : (1) desulfurization facilities related equipment modification;(2) optimal operation of existing desulfurization facilities.

Output power analyses for the thermodynamic cycles of thermal power plants

Thermal power plant is one of the important thermodynamic devices, which is very common in all kinds of power generation systems. In this paper, we use a new concept, entransy loss, as well as exergy destruction, to analyze the single reheating Rankine cycle unit and the single stage steam extraction regenerative Rankine cycle unit in power plants. This is the first time that the concept of entransy loss is applied to the analysis of the power plant Rankine cycles with reheating and steam extraction regeneration. In order to obtain the maximum output power, the operating conditions under variant vapor mass flow rates are optimized numerically, as well as the combustion temperatures and the off-design flow rates of the flue gas. The relationship between the output power and the exergy destruction rate and that between the output power and the entransy loss rate are discussed. It is found that both the minimum exergy destruction rate and the maximum entransy loss rate lead to the maximum output power when the combustion temperature and heat capacity flow rate of the flue gas are prescribed. Unlike the minimum exergy destruction rate, the maximum entransy loss rate is related to the maximum output power when the highest temperature and heat capacity flow rate of the flue gas are not prescribed.

A Special Issue:“Key Technologies of Virtual Power Plant and Distributed Energy Resources”for Global Energy Interconnection

The increasing penetration of renewable and distributed energy resources(DERs)is transforming the power grid into a new type of clean and low-carbon power system.However,the uncertainty and volatility of DERs have also brought severe challenges to the secure and reliable operation of the power systems.In order to successfully integrate renewable DERs,virtual power plant(VPP)has emerged as a new technique for coordinating demand-side DERs,which has drawn significant attention from industry and academia.

Overview of Past, Present and Future Marine Power Plants

In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.

Environmental life cycle assessment of Indian coal-fired power plants

Coal is the backbone of the Indian power sector. The coal-fired power plants remain the largest emitters of carbon dioxide, sulfur dioxide and substantial amounts of nitrogen oxides, which are associated with climate and health impacts. Various CO2 mitigation technologies （carbon capture and storage--CCS） and SO2/NOx mitigation technologies （flue gas desulfurization and selective catalytic reduction） have been employed to reduce the environmental impacts of the coal-fired power plants. Therefore, it is imperative to understand the feasibility of various mitigation technologies employed. This paper attempts to perform environmental life cycle assessment （LCA） of Indian coal-fired power plant with and without CO2, SO2 and NOx mitigation controls. The study develops new normalization factors for India in various damage categories, using the Indian emissions and energy consumption data, coupled with the emissions and particulate emission to come up with a final environmental impact of coal-fired electricity. The results show a large degree of dependence on the perspective of assessment used. The impact of sensitivities of individual substances and the effect of plant efficiency on the final LCA results is also studied.

Enhanced graph-based fault diagnostic system for nuclear power plants

Scheduled maintenance and condition-based online monitoring are among the focal points of recent research to enhance nuclear plant safety.One of the most effective ways to monitor plant conditions is by implementing a full-scope,plant-wide fault diagnostic system.However,most of the proposed diagnostic techniques are perceived as unreliable by operators because they lack an explanation module,their implementation is complex,and their decision/inference path is unclear.Graphical formalism has been considered for fault diagnosis because of its clear decision and inference modules,and its ability to display the complex causal relationships between plant variables and reveal the propagation path used for fault localization in complex systems.However,in a graphbased approach,decision-making is slow because of rule explosion.In this paper,we present an enhanced signed directed graph that utilizes qualitative trend evaluation and a granular computing algorithm to improve the decision speed and increase the resolution of the graphical method.We integrate the attribute reduction capability of granular computing with the causal/fault propagation reasoning capability of the signed directed graph and comprehensive rules in a decision table to diagnose faults in a nuclear power plant.Qualitative trend analysis is used to solve the problems of fault diagnostic threshold selection and signed directed graph node state determination.The similarity reasoning and detection ability of the granular computing algorithm ensure a compact decision table and improve the decision result.The performance of the proposed enhanced system was evaluated on selected faults of the Chinese Fuqing 2 nuclear reactor.The proposed method offers improved diagnostic speed and efficient data processing.In addition,the result shows a considerable reduction in false positives,indicating that the method provides a reliable diagnostic system to support further intervention by operators.

IoT-Enabled Plant Monitoring System with Power Optimization and Secure Authentication

Global food security is a pressing issue that affects the stability and well-being of communities worldwide.While existing Internet of Things(IoT)enabled plant monitoring systems have made significant strides in agricultural monitoring,they often face limitations such as high power consumption,restricted mobility,complex deployment requirements,and inadequate security measures for data access.This paper introduces an enhanced IoT application for agricultural monitoring systems that address these critical shortcomings.Our system strategically combines power efficiency,portability,and secure access capabilities,assisting farmers in monitoring and tracking crop environmental conditions.The proposed system includes a remote camera that captures images of surrounding plants and a sensor module that regularly monitors various environmental factors,including temperature,humidity,and soil moisture.We implement power management strategies to minimize energy consumption compared to existing solutions.Unlike conventional systems,our implementation utilizes the Amazon Web Services(AWS)cloud platform for reliable data storage and processing while incorporating comprehensive security measures,including Two-Factor Authentication(2FA)and JSON Web Tokens(JWT),features often overlooked in current agricultural IoT solutions.Users can access this secure monitoring system via a developed Android application,providing convenient mobile access to the gathered plant data.We validate our system’s advantages by implementing it with two potted garlic plants on Okayama University’s rooftop.Our evaluation demonstrates high sensor reliabil-ity,with strong correlations between sensor readings and reference data,achieving determination coefficients(R2)of 0.979 for temperature and 0.750 for humidity measurements.The implemented power management strategies extend battery life to 10 days on a single charge,significantly outperforming existing systems that typically require daily recharging.Furthermore,our dual-layer security implementation utilizing 2FA and JWT successfully protects sensitive agricultural data from unauthorized access.

GRU-integrated constrained soft actor-critic learning enabled fully distributed scheduling strategy for residential virtual power plant

In this study,a novel residential virtual power plant(RVPP)scheduling method that leverages a gate recurrent unit(GRU)-integrated deep reinforcement learning(DRL)algorithm is proposed.In the proposed scheme,the GRU-integrated DRL algorithm guides the RVPP to participate effectively in both the day-ahead and real-time markets,lowering the electricity purchase costs and consumption risks for end-users.The Lagrangian relaxation technique is introduced to transform the constrained Markov decision process(CMDP)into an unconstrained optimization problem,which guarantees that the constraints are strictly satisfied without determining the penalty coefficients.Furthermore,to enhance the scalability of the constrained soft actor-critic(CSAC)-based RVPP scheduling approach,a fully distributed scheduling architecture was designed to enable plug-and-play in the residential distributed energy resources(RDER).Case studies performed on the constructed RVPP scenario validated the performance of the proposed methodology in enhancing the responsiveness of the RDER to power tariffs,balancing the supply and demand of the power grid,and ensuring customer comfort.