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Development and Challenge of Flexible Operation Technology of Thermal Power Units Under New Power System AI Introduction
Abstract：Under the background of “dual carbon”, new energy sources have begun to be connected to the grid on a large scale. However, the randomness and volatility of new energy generation significantly impact the power grid, making it urgent to build a new power system. As the cornerstone of the power system, traditional thermal power will transform into a basic security and system regulatory power supply, providing reliable capacity, peak regulation and frequency modulation and other auxiliary services. The flexible transformation of thermal power units has become an inevitable choice. The phased objectives, difficulties, and challenges of building a new power system were analyzed, along with the problems encountered in the flexible transformation of thermal power units at the present stage. Combined with thermal power operation data, the technical ways of configuring energy storage equipment for thermal power units were analyzed. The research shows that there are several issues in building a new power system, such as power system instability, difficulties in transforming traditional thermal power, high energy consumption, and environmental pressures. The flexibility transformation of thermal power units faces challenges such as insufficient peak regulation capacity, high operation costs, slow load response, high operation energy consumption, safety concerns, etc. The integration of thermal power and energy storage will bring better economic and environmental benefits.Keywords：new power system;thermal power units;subsynchronous oscillation;linear active disturbance rejection control;impedance model;direct-driven wind turbine;weak grid158|126|29<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15- Abstract：To promote the implementation of the “double carbon” policy and to manage the high volatility of new energy, the current requirements for deep peak shaving of thermal power units are getting higher and higher. Circulating fluidized bed (CFB) boiler units have inherent advantages under low load operation conditions. However, the ultra-low load operation below 20% still faces many difficulties, such as the stability of the fluidization in the furnace, the emission of nitrogen oxides, and the safety issues caused by local over-temperature in the furnace. This paper took the application of deep peaking technology of a 330 MW CFB boiler as an example and introduced the modification of the unit components, such as the coal conveying screening and crushing system, throttling rings of wind caps and lower secondary air pipes, etc. With the application of flue gas recirculation and other technologies, an 18% ultra-low load operation was successfully realized on this CFB boiler, and the NOx emission was also well controlled. The key points and difficulties of the ultra-low load operating technology of CFB unit were summarized. The potential problems caused by deep peaking operation were analyzed, and corresponding measures were proposed. The results of this study have an important engineering reference value.Keywords：coal-fired power unit;circulating fluidized bed (CFB) boiler;deep peak shaving;ultra-low emission;flue gas recirculation105|109|9<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15
Analysis on Thermoelectric Decoupling Technology Paths for Thermal Power Units Under the Background of Deep Peak-Shaving AI Introduction
Abstract：New energy power generation has the characteristics of large fluctuation and instability in output and power generation load. In order to solve the above problems brought by new energy units on the internet, a variety of thermoelectric decoupling modes was used to transform thermal power units,different technology paths were analyzed,and the potential of decoupling thermal power units and peak shifting capacity was explored. EBSILON professional software was used,and the peak load space under different thermoelectric decoupling schemes was evaluated and compared. The results show that the zero output thermoelectric decoupling transformation scheme of low pressure cylinder can improve the peak regulation capacity of the unit to the greatest extent. Under the original maximum heating load of 304.60 MW, the minimum power generation decreased by 172.21 MW, and the minimum power load rate decreased by 32.70%. Thermal power units after heat and power decoupling transformation can significantly improve the coordinated peaking ability of thermoelectric units and new energy units,and improve the stability of the overall power generation of power generation units.Keywords：thermal power units;heat and power cogeneration;thermo-electric decoupling;extraction heating;peak-load regulation95|271|4<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15Research on Combustion Stability of a 600 MW Subcritical Power Unit Under Long-Term Deep Peak Shaving AI Introduction
Abstract：Deep peak shaving of thermal power units is a crucial technique for integrating new energy sources and altering energy consumption patterns. A 600 MW sub-critical coal-fired unit was chosen as the subject of research, and long-term operation tests were conducted at 15% and 20% rated load respectively. The impact of different parameters on fire detection fluctuation was analyzed through parameter analysis. Additionally, a sliding window-based method for analyzing drum water level and furnace negative pressure wave characteristics was proposed for determining furnace combustion stability. The results of the tests indicate that with plasma combustion stabilization and a calorific value of approximately 20 kJ/g for Junger coal, two sets of coal mills can maintain long-term combustion stability at 15%-20% rated load for a 24-hour period. Furthermore, the analysis reveals that the coal volume change rate, coal volume distribution, and primary air volume are the primary factors influencing fire detection fluctuation. Overall, this study has provided valuable insights for implementing long-term, deep peak regulation of similar units. The research results can provide a reference for long-time limit depth peak regulation of the same type of units.Keywords：thermal power units;deep peak shaving;flame detector fluctuation;combustion stability;correlation analysis78|109|0<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15- Abstract：In order to study the influence of the heat storage coefficient of the furnace side evaporation section and superheating section on the primary frequency modulation capacity of the thermal power unit under the deep modulation working conditions, a refined simulation model suitable for the thermal power under the deep modulation working condition was built, based on the typical model in the transient stability program PSD-BPA, and the control logic of the thermal power unit under the actual furnace-machine coordination mode. The correctness of the model was verified by the actual primary frequency modulation data of a DC furnace with a rated power
Research on Dry-Wet Conversion Strategy of Supercritical Thermal Power Units Under Deep Peaking Condition AI Introduction
Abstract：To seek applicable dry-wet conversion mode in deep peaking condition, two different dry-wet conversion strategies were performed on two supercritical thermal power units to study the dry-wet conversion under coordinated control mode and its impact on the system stability. The results show that both strategies could realize the dry-wet conversion under coordinated control mode and further deep peaking could proceed via the dry-wet conversion. Moreover, the dry-wet conversion could be conducted either by co-control of coal and water or by feedwater control, yet the coal-water ratio varied. During the dry-to-wet process, affected by the two strategies, the system stability (the temperature and pressure of the main steam) is changed from dry state to wet state. In contrast, the system stability for both strategies is proved qualified under the conversion from wet state to dry state.Keywords：thermal power units;deep peaking;dry-wet conversion;coordinated control;system stability141|155|3<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15- Abstract：By analyzing the change laws of flue gas temperature, steam temperature and working fluid mass flow during a power failure accident in a 660 MW power plant, the change laws of heat load in dense phase zone, transition zone and dilute phase zone over time were obtained. On this basis, a 700 MW ultra-supercritical circulating fluidized bed (CFB) boiler was taken as the research object, the calculation model of flow and heat transfer in water wall after power failure accident was established, and a calculation program for the transient characteristics of the water wall was developed based on the Fortran language. The dense phase zone, transition zone and dilute phase zone were analyzed, respectively. Through calculation, the change laws of the thermal parameters such as water wall metal temperature and working fluid temperature after power failure accident were obtained. The calculation results show that, after the power failure accident, the maximum water wall metal temperature at the outlet of dense phase zone is 558.6 ℃, and the maximum water wall metal temperature at the outlet of dilute phase zone is 579.6 ℃. Therefore, there is no need to equip emergency water supply pump to ensure the safety of the water wall after power failure. The research results can provide guidance for power plants to deal with power failure accidents of ultra-supercritical CFB boilers.Keywords：ultra-supercritical;circulating fluidized bed (CFB) boiler;power failure;heat load;water wall62|58|3<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15
Modeling and Dynamic Characteristic Analysis of Combustion Process of Biomass Vibrating Grate Furnace AI Introduction
Abstract：In order to explore the combustion characteristics of the biomass vibrating grate furnace and realize the control and optimization of the unit combustion process, the mechanism model of the grate combustion process was established through the analysis of the biomass fuel characteristics and combustion mechanism. Moreover, the dynamic change of the grate fuel amount was studied, and the key parameters such as furnace temperature and flue gas oxygen content were predicted. The influence of periodic vibration of grate on combustion state in furnace was discussed. The results show that the amount of fuel in the grate is related to the current feed rate and fuel burning rate. The fuel has a large storage capacity on the grate, which leads to a large delay between the fuel burning and the current feeding. The predicted values of furnace temperature and flue gas oxygen content can follow the measured values well, and their changes are in accord with the combustion characteristics. The periodic vibration of the grate will cause the periodic change of the combustion state in the furnace. When the grate vibrates, the fuel combustion speed, furnace temperature, furnace pressure will increase, and the oxygen content of the flue gas will be reduced. As the vibration of the grate stops, these parameters return to the steady state level.Keywords：thermal power;biomass direct combustion power generation;grate furnace;combustion characteristics;dynamic characteristics45|168|2<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15Energy Storage Configuration Considering the System Wind Power Reserve Capacity Under High Wind Power Permeability AI Introduction
Abstract：The high proportion penetration of the wind power weakens the inertia and frequency regulation capacity of the power system. The energy storage system (ESS) is widely used in the inertia support and frequency regulation of the power grid with the characteristics of rapid response and stable output. Firstly, the rated speed and active power output of the doubly fed induction generator (DFIG) were taken as constraint conditions, and the optimal power reservation coefficient was set based on the rotor overspeed control to divide the wind speed range of the DFIG participating in the system frequency modulation. On this basis, considering the frequency support capacity of the system, a coordinated frequency modulation method of the DFIG and the ESS was proposed. Based on the analysis of the ESS active power output and system steady-state recovery process, the dynamic frequency regulation characteristics of the ESS under the control strategy of the virtual synchronous machine were described, so as to realize the optimal configuration of the control parameters of the ESS under different working conditions and different support requirements. Simulation results show that the proposed method can make full use of the frequency modulation capacity of the DFIG while ensuring the frequency modulation requirements of the system, optimize the configuration results of the ESS parameters, realize the smooth output of the ESS, and improve the frequency support ability of the system.Keywords：wind power generation;energy storage system;doubly fed induction generator;rotor overspeed control;virtual synchronous generator;power reserve coefficient88|205|17<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15Droop Control Strategy of Distributed Photovoltaic Reactive Power Considering Probability Distribution AI Introduction
Abstract：Distributed photovoltaic access to the distribution network has gradually become a trend, but the large-scale distributed photovoltaic grid connection will cause serious power flow reversal, resulting in out-of-limit voltage and network loss increase. Aiming at the out-of-limit voltage problem generated by distributed photovoltaic access to distribution network, a distributed photovoltaic reactive power droop control strategy considering the probability distribution was proposed. Firstly, the influence of probability distribution of photovoltaic output on the current active power of different photovoltaic units of photovoltaic power plants was considered, and the available reactive capacity of each photovoltaic inverter was evaluated and calculated. Then, the reactive power droop coefficient was adjusted according to the current available reactive capacity of each photovoltaic unit, and the reactive power support capacity of the photovoltaic power station was maximized without sacrificing active power. Finally, the effectiveness of the proposed control strategy was verified by PSCAD/EMTDC simulation software.Keywords：distributed photovoltaic;out-of-limit voltage;photovoltaic probability distribution;reactive power and voltage control;droop control137|381|23<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15Study on Double Phase-Locked Loop on the Synthetic Inertia Control of Offshore Wind Farm Frequency Regulation AI Introduction
Abstract：To build the new power system with the main body of new energy, the offshore wind farm (OWF) is an important part and has been rapidly developed in coastal cities. However, the large-scale OWFs also reduce the inertia of power systems, which significantly decreases the anti-disturbance capability of system frequency Therefore, a synthetic inertia control strategy for OWF based on dual phase-locked loops (PLL) was proposed. First, the influence mechanism of PLL on virtual inertia of wind turbine was theoretically analyzed for variable parameter PLL. And the variation rule of wind turbine inertia support capacity and system frequency response characteristics with parameter changing PLL was explored. Then, the double PLL based OWF frequency regulation strategy was proposed through analyzing the negative effect of primary frequency regulation characteristics caused by the variable parameter of PLL. Finally, the effectiveness of the proposed frequency regulation strategy was verified though simulations. The results show that the proposed method has significant advantages in frequency response speed and frequency measurement noise suppression.Keywords：offshore wind farm;synthetic inertia control;frequency regulation strategy;new-type power system;phase-locked loop41|209|10<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15
Flexible Power Generation Technology
Development and Application of Test System for Ball Joints of Parabolic Trough Solar Collector AI Introduction
Abstract：The ball joint is a key component of a parabolic trough solar collector. To address the problems of operation sticking and heat conduction oil leakage in ball joints, a performance test system was developed. The system can perform accelerated life tests of ball joints in rotational, angular, or rotational-angular motion, and at temperature up to 393 ℃ and pressure up to 4.1 MPa. Using thermal conductivity oil as heat transfer fluid, performance tests of the ball joints were conducted under working conditions of 393 ℃ and 2.3 MPa, as well as under varying temperature and pressure conditions. The torque characteristics and sealing performance of the ball joint over a simulated 12-year lifespan were analyzed. Furthermore, the stability and reliability of the test system were verified through the test process, and the control and measurement accuracy of key technical parameters met the operational requirements. This test system provides technical support for the performance assessment of ball joints.Keywords：solar thermal power generation;parabolic trough solar collector;ball joint;test system;torque characteristic;seal performance;accelerated life;performance testing61|78|0<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15A Two-Modal Weather Classification Method and Its Application in Photovoltaic Power Probability Prediction AI Introduction
Abstract：Weather classification is an indispensable preprocessing step in photovoltaic (PV) power prediction. A new two-modal weather classification methods based on PV power clustering was proposed to finely depict the uncertainty of PV power output. Both PV power data and meteorological data were considered for weather classification, providing a novel and effective path for PV power prediction. In addition, data fusion technology was used to extract relevant information from both numeric weather prediction (NWP) data and measured meteorological data to help for weather classification. This approach reduces the model’s reliance on the accuracy of forecasted meteorological indicators and improve the robustness of the model. Experiments based on data from a PV power station in Jilin demonstrated the rationality of the proposed weather classification method. Combining the PV power probability prediction with the proposed weather classifier resulted in prediction interval coverage probabilities closer to the preassigned confidence level and narrower mean prediction interval width.Keywords：photovoltaic power generation;weather classification;photovoltaic power probability prediction;time series K-means clustering;multi-modal learning;uncertainty;numeric weather prediction100|214|7<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15Research on Dynamic Characteristics of Monopile Offshore Wind Turbine Tower Under Different Wind Speed Conditions AI Introduction
Abstract：Based on the ANSYS finite element software, the NREL 5 MW monopile offshore wind turbine tower system was modeled in 3D. The influence of different wind speeds on the dynamic characteristics of the tower structure was simulated and analyzed under the full consideration of the soil structure coupling effect and the impeller rotation. The six average wind speeds and the corresponding impeller speeds in the interval between the cut-in wind speed of 3 m/s and the cut-out wind speed of 25 m/s were selected as simulation conditions. The analysis results show that, with the increase of wind speed and impeller speed, the modal frequency of the tower structure gradually increases, and the first two modal frequencies change most obviously. Moreover, the peak value of the tower displacement increases as the wind speed and impeller speed increases, but the amplitude decreases. The displacement shows a non-linear growth trend. The equivalent stress value of the tower increases as the wind speed and impeller speed increases, but the change trend is different from the displacement, which is roughly linear. The fatigue life of the tower decreases sharply, but they are far more than the actual working hours, the fatigue damage and safety factor hazard values are mainly distributed at the bottom of the tower and at the single pile, consistent with the maximum equivalent stress distribution position.Keywords：offshore wind turbine;tower;wind speed;blade rotation speed;soil-structure interaction;dynamic characteristics67|264|3<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15Research on an Ultra-Short-Term Wind Speed Prediction Method Based on Improved Combined Neural Networks AI Introduction
Abstract：Ultra-short-term wind speed prediction is the key to ensure the implementation effect of wind turbine pitch angle feedforward control, and has an important impact on improving the environmental adaptability of wind turbines. In order to improve the prediction accuracy, an ultra-short-term wind speed prediction method based on an improved combined neural networks was proposed. In this method, BP neural network and long short-term memory (LSTM) neural network, which are suitable for time series prediction and have strong nonlinear learning ability, are selected for weighted combination to eliminate the large error that may exist in a single neural network. At the same time, to improve the combination effect, the differential evolution (DE) algorithm was used to optimize the combination weight. The method was applied to the ultra-short-term wind speed prediction of a wind farm. Compared with the results of single neural network prediction and equal weight combined neural networks prediction, the effectiveness of the proposed method in improving the prediction accuracy was verified.Keywords：wind power;ultra-short-term wind speed prediction;BP neural network;long short-term memory (LSTM) neural network;differential evolution (DE) algorithm61|216|9<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15
New Energy
Numerical Simulation of Solid Oxide Fuel Cell Tail Gas Catalytic Combustion Based on Three-Way Catalyst AI Introduction
Abstract：As a clean and efficient advanced power generation equipment, the solid oxide fuel cell (SOFC) has the structural advantages of separation of air and fuel gas, which makes it easy to enrich the CO2 in the tail gas of the fuel side. In order to improve the CO2 concentration in SOFC anode tail gas, a steady-state multi-physical coupled model was established for the commercial three-way catalysts, considering the mass transfer, heat transfer, and chemical reaction processes in the catalytic combustion of SOFC anode tail gas. Based on this model, the catalytic combustion characteristics of SOFC anode tail gas were simulated. The effects of different inlet temperature, reaction space velocities and catalyst sizes on combustion temperature, wall temperature, H2 conversion, CO conversion and outlet CO2 concentration were studied, and the change trend of each parameter was obtained. Based on the existing experiments, the outlet CO2 volume fraction could be increased from 94.72% to 95.33% by optimizing the space velocity, and the outlet CO2 concentration could be increased from 94.72% to 95.64% by optimizing the catalyst size. By analyzing the variation characteristics of outlet CO2 concentration under different working conditions in the catalytic combustion of tail gas, the guidance for the commercial three-way catalyst to be used in the catalytic conversion of anode tail gas and CO2 enrichment in the tail gas of SOFC system was provided.Keywords：carbon emission;carbon capture;three-way catalyst;solid oxide fuel cell (SOFC);numerical simulation60|160|1<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15
Energy Storage
A Wireless Multi-Objective Power Sharing Method for Energy Storage System in DC Micro-Grid Considering Oscillatory-Type Power AI Introduction
Abstract：As the construction of new power systems, DC microgrids will become an important part of the distribution network. As AC load connecting to DC microgrids, the oscillating power will enter the DC system, which affects the power distribution of energy storage system. To solve this issue, the comprehensive principle of power distribution of distributed energy storage system was given, and a wireless power sharing method was proposed. This method takes the charge state as the “information carrier”, each energy storage unit can realize state of charge (SOC) balancing and oscillating power sharing at same time. In addition, from the perspective of equivalent output impedance, this paper gived a detailed analysis and discussion on the distribution effect of different control algorithms, which showed the proposed control algorithm could meet the requirements of the comprehensive principle. Finally, the effectiveness of the proposed distributed energy storage control strategy was validated by experiments.Keywords：new power system;DC micro-grid;oscillatory-type power;power sharing;state of charge (SOC) balancing48|94|10<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15Risk Prediction Method of Low Frequency Oscillation in Maintenance Power Network Based on Long Short Term Memory Neural Network AI Introduction
Abstract：With the expansion of power grid scale and the increase of power components, the maintenance methods of power system become more and more complex. It is difficult to evaluate the low-frequency oscillation risk of power grid under massive maintenance only by traditional methods. To solve this problem, a risk prediction method of low-frequency oscillation in maintenance power network based on long short term memory (LSTM) neural network was proposed. Firstly, the unified coding method of power system maintenance mode was proposed, so that the computer can quickly and accurately identify the operation state of power grid under various maintenance modes. Then, based on the historical data measured in real time by phasor measurement unit (PMU), the number of low-frequency oscillation of power grid under different maintenance modes was predicted by using LSTM neural network, so as to evaluate the risk of low-frequency oscillation of power grid under maintenance. Finally, a regional power grid in central China was taken as an example to verify the accuracy and rapidity of the proposed method.Keywords：power system;maintenance method;computer coding;low frequency oscillation;risk prediction;long short term memory (LSTM)69|85|4<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15Application of Practical Data Synchronization Technology in Multi Person Cooperation Mechanism of New Distribution System Planning AI Introduction
Abstract：With the development of energy internet,it is necessary to lay the foundation for the integration of data between different energy departments,which can also adapt to the development trend of the internet. The key to the synchronization of heterogeneous databases lies in the capture of data changes at the source,the identification of data operations at the destination,and the synchronization of data at the destination. In the aspect of source side change data capture, the amount of transmitted data was greatly reduced by the source side change data based on the creation of temporary table. In terms of data operation identification,the source side used combined coding to uniformly identify and update data, and the destination side analyzed it by itself,so as to avoid the confusion of interpretation. In order to save the parsing time of a large number of similar statements,the storage procedures of various data operations were formulated in advance at the destination to realize the convenient writing of synchronous data. The practical data synchronization technology was applied to the multi person cooperation mechanism of energy internet planning of Zhuzhou new distribution system,which successfully improves the efficiency,effectiveness and feasibility of the method. The proposed technology of practical data synchronization can not only accurately capture the changed data at the source with the least system overhead,but also make the data at the destination write more quickly.Keywords：new distribution system;heterogeneous database;combined coding;stored procedure;multi person cooperation;trigger;change table26|77|2<HTML><L-PDF> <WORD> <Meta-XML>Updated：2025-06-15
Smart Grid
