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- Abstract：Park level clean heating is an urgent problem to be solved in integrated energy service. The multi-pass circulating fluidized bed technology adopts a three-stage furnace structure to form a two-stage material circulation in the furnace, which solves the problem of miniaturization of traditional circulating fluidized bed boilers. The industrial practice has proved that the multi-pass circulating fluidized bed boiler can use biomass, industrial solid waste, coal and other fuels. The thermal efficiencies of various fuels reach 88%~92%, and the emissions of the pollutants meet the required permissible effluent concentrations of the national standards and local standards. The multi-pass circulating fluidized bed technology has the advantages of decentralized energy utilization and simultaneous application of multiple fuels, which can be effectively applied to park level integrated energy service.Keywords：integrated energy service;multi-pass;circulating fluidized bed technology;biomass;industrial solid waste39|213|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：Nowadays more and more distributed photovoltaic is connected to distribution grid. Under the condition, as an effective method of improving grid stability and decreasing electricity cost, the photovoltaic and energy storage system has become an important trend of new energy application. Application of the user-side photovoltaic and energy storage system in the developed countries as Europe, United States and Japan was studied. On the base of the analysis, the important developing condition and technology roadmap of the user-side photovoltaic and energy storage system abroad was summarized. Secondly, some typical domestic photovoltaic and energy storage projects in the business market, industrial park and residential area were introduced. And the development problems of the domestic photovoltaic and energy storage projects were analysed. Finally, according to the analysis of the application experience abroad and the situation of the rapid development of the electric vehicle charge at home, the development suggestions are put forward, which can be used for reference for the healthy development of domestic user side optical storage projects.Keywords：user-side;photovoltaic and energy storage system;distributed photovoltaic;fee-in tariff;ancillary service market56|216|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：Uncertainties in renewable energy and loads bring challenges to the operation of integrated energy system (IES). Firstly, the general model of the industrial park's IES was established based on the linear energy hub. Then a two-stage economic dispatch model of the industrial park's IES based on the affine adjustable robust optimization was constructed. In this model, the on-off state and base power output of units were calculated to satisfy the energy balance regardless of the renewable energy output, and participation factors were obtained to ensure a feasible solution for all scenarios under the uncertainty set of the renewable energy output. Finally, the model was transformed into a mixed integer linear programming (MILP) model. The case study shows that the proposed dispatch method provides a more economical and practical scheme than the classical robust optimization.Keywords：integrated energy system (IES);affine adjustable robust optimization;uncertainty;economic dispatch;energy hub61|240|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：In order to improve the proportion of wind power accommodation, a source-load cooperative dispatch strategy based on genetic algorithm was proposed. The purpose of this dispatch strategy is to alleviate the problem of large-scale wind power curtailment, which is caused by the anti-peak regulation characteristics of wind power. Based on the voluntary participation of users in grid dispatching, the influence mechanism of excitation-type demand response participating in power grid dispatching on wind power consumption was analyzed. The source-load coordination optimization model was established with the goal of minimizing the total cost of the system. On the premise of ensuring the safety and reliability of the system, genetic algorithm was adopted to solve the model, Matlab was used to carry out simulation calculation on the calculation example in this paper. The results show that the proportion of wind power increase by 27.56%, and the total dispatch cost decrease by 4798 RMB, whichverify the effectiveness of the proposed strategy.Keywords：wind power accommodation;source-load cooperative dispatch;demand response;dispatch model;genetic algorithm (GA)67|216|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：With the development of interaction between electricity, natural gas and heat networks, collaborative optimization of integrated energy system has become a new research focus. An improved NSGA-Ⅱ algorithm was proposed to solve the optimization problem of integrated energy system, which contained multiple objectives and nonconvex constraints, a global Pareto set maintenance method was proposed to improve the search efficiency of Pareto-optimal solutions. Dimensional reduction and dynamic adjustment were applied to improve the probability of finding feasible solutions under high-dimension equality constraints. An example was analyzed to prove the validity of the proposed method.Keywords：integrated energy system (IES);improved NSGA-Ⅱ algorithm;genetic algorithm;multi-objective optimal scheduling69|280|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：Ubiquitous power internet of things (UPIoT) is the concrete embodiment of internet of things in the power field. The construction of UPIoT is the key link to promote the three types and two networks, and also a necessary means to achieve the goal of energy transformation. The definition of UPIoT was expounded. From the perspective of power supply companies, based on the actual situation of Beijing economic-technological development area, the implementation strategy of UPIoT was discussed based on regional characteristics and the problems that may be encountered were analyzed. With the in-depth construction of UPIoT, power supply companies can provide diversified services for power customers and improve customer satisfaction. Local power supply companies can carry out more electricity-related businesses by relying on the UPIoT. The security, practicability and effectiveness of UPIoT are the primary issues facing the development.Keywords：ubiquitous power internet of things (UPIoT);smart grid;load control51|307|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：With the deepening of power system reform, power customers have acquired the ability to participate in power trading with emerging technologies such as distributed generation, energy storage systems and electric vehicles. However, the operation and control methods of traditional power systems are difficult to adapt to the demand of open electricity market in the new era. The strategy of ubiquitous power internet of things (UPIoT) proposed by State Grid Co., Ltd. can realize the interconnection of all aspects in power system, overall state perception and optimal control, which is an effective technical support for building an open electricity market. The challenges faced by the development of power systems in the new era and the necessity of constructing UPIoT were analyzed. The typical application of UPIoT in the open electricity market was researched. Finally, the key technologies of UPIoT for the electricity market were discussed, which provide reference for constructing modern open electricity market.Keywords：ubiquitous power internet of things (UPIoT);electricity market;optimal control;renewable energy47|475|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：Based on social and economic development, environmental protection needs, industrial policy guidance and other factors, smart energy will bring a new round of tremendous changes to the traditional energy structure. The rapid development of modern information communications technology (ICT) provides strong technical support for the transformation and upgrading of traditional energy to smart energy. The whole smart energy system will be guided by innovative scenario demand, supported by the deep support of cross-border scientific and technological forces, and drive the structural upgrading of the whole energy and related industrial chain. An ICT framework of energy system suitable for smart energy application scenario was proposed, which combined cloud computing, big data, internet of things (IoT), mobile communication, artificial intelligence, blockchain and other emerging technologies to enable traditional energy system. It runs through the bottom to the top of energy system, and realizes the comprehensive integration of energy flow, information flow and value flow of intelligent energy system.Keywords：internet of things (IoT);artificial intelligence;smart energy;block chain;information communications technology (ICT);cloud computing;big data55|311|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
Key Technologies for Ubiquitous Power Internet of Things and Integrated Energy Systems
- Abstract：Under the condition of three-phase unbalanced load in micro-grid, three-phase four-leg inverter can solve the unbalanced three-phase output voltage because of unbalanced load. Nevertheless, in the dq0 synchronous reference frame, the output voltage and current of three-phase four-leg inverter are coupled with each other. If the load is unbalanced and the open-loop control is directly used in the dq0 synchronous reference frame, the output voltage is still unbalanced because of double frequency disturbance caused by unbalanced load. To solve these problems, this paper established the mathematical model of three-phase four-leg inverter, derived the open-loop transfer function of the controlled plant and deeply analyzed the mechanism of unbalanced output voltage of three-phase four-leg inverters. In addition, according to the system model information, a second-order active disturbance rejection controller (ADRC) controller was designed to decouple the voltage and current in dq axis, and it could reduce the number of originals measured. Proportional resonant controller was introduced to eliminate the disturbance caused by 100 Hz. Finally, the effectiveness of the solution was verified by Matlab/Simulink.Keywords：micro-grid;three-phase four-leg inverter;unbalanced voltage;dq axis decoupling;active disturbance rejection controller (ADRC);proportional resonant controller53|400|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：With the introduction of the ubiquitous power Internet of Things, power system analysis based on data mining will play an increasingly important role in the construction of the energy internet. The boundary problem of critical transient stability is one of the core issues in evaluating the transient stability of power systems. At present, in the transient stability assessment, it is often impossible to give an accurate judgment on the critical state of the grid, so that there is a fuzzy area in the safety assessment. From the perspective of data analysis, the related research on the feature extraction of critical transient stability boundary of power system was carried out. Based on the transient stability single machine model and energy function, the boundary phenomenon of critical transient stability of power system was characterized. Then, based on the BPA automatic simulation program, the transient stable data sample generation problem was solved. Finally, the selection of the input characteristics of the "source-network" and the correlation analysis of the input features were completed, and the verification was completed by the IEEE-39 node system.Keywords：power system;critical transient stability;boundary phenomena;data analysis;input feature selection44|268|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：In practical engineering application, it is necessary to judge the stability of direct current distributed power system (DCDPS) by using stability criteria, so as to adopt appropriate control strategies. Therefore, stability criteria of DCDPS are generally interested by scholars at home and abroad. The basic idea and characteristics of stability criteria based on equivalent source converter (subsystem) and equivalent load converter (subsystem), a bus voltage-controlled converter and a bus current-controlled converter, passivity and large disturbance signal were analyzed. Based on the above analysis, the advantages and defects of the stability criteria were pointed out. The research trends of the stability criteria for DCDPS were put forward, and a new method of stability criteria was proposed by combining passivity-based stability criterion and other stability criteria.Keywords：direct current distributed power system (DCDPS);stability criteria;source converter;load converter;minor loop gain;passivity;large disturbance105|671|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：A method based on sparse component analysis-variational modal decomposition (SCA-VMD) was proposed to separate transformer operation sound signal and reduce noise. The under-determined blind source separation based on sparse characteristics can realize the effective separation of source signals when the number of observed signals is less than the number of unknown source signals, and the variational modal decomposition (VMD) can decompose a multi-component signal into multiple single-component signals at one time. The two-channel observation signals were used as input, the transformer operation acoustic signals were separated by SCA, the separated signals were decomposed into four-layer intrinsic mode function(IMF) components by VMD, the high frequency components and low frequency components were denoised by the method of threshold filtering, and the denoising signals were reconstructed by the new IMF components. The results of simulation and experiment show that this method can effectively separate and de-noising the operating sound signal of transformer.Keywords：transformer;noise reduction;variationalmodal decomposition (VMD);threshold filtering41|44|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
Energy Internet
- Abstract：Organic Rankine cycle (ORC) is the main way to generate electricity by using medium-low temperature (< 150℃) geothermal heat. In actual operation, zeotropic mixture tends to condense to the subcooling state. This paper analyzed the effect of subcooling on thermal performance of ORCs using zeotropic mixture as working fluid. The mathematics model of the ORC and the ORC with internal heat exchanger (IHE) were established, and then the evaporation pressure was optimized to maximize the net power output. Moreover, the system exergy analysis was also conducted. The results show that the condensation subcooling affects the temperature profile match between the working fluid and the heat sink. Limited by the pinch point temperature difference, the condensation pressure rises with the subcooling increasing. The subcooling also changes the heat allocation between the preheater and evaporator, the optimal evaporation pressure also increases as the subcooling increases. When the subcooling is 2℃, the net power output can be reduced by 4.36% for isobutene/isopentane (0.4:0.6) which is the most affected by the subcooling. The IHE recovers the waste heat of expander exhaust to preheat the working fluid, as a result, the net power output of the subcooled ORC system can be increased by 0.55%. The subcooling causes a significant increase in the condenser exergy destruction that can be reduced by 24.7% using the recuperative ORC system.Keywords：geothermal power generation;organic Rankine cycle (ORC);zeotropic mixture;subcooling;internal heat exchanger (IHE);thermal performance41|62|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：Mass unbalance is one of the most common faults of fans in thermal power plants. Sometimes, even the vibration of fans caused by other faults can be doubled by the exciting force caused by mass unbalance. Therefore, it is very important to improve the accuracy of dynamic balance. The frequency, amplitude and phase characteristics of unbalanced faults were discussed in order to judge the unbalanced faults accurately. Then, two common field treatment methods of unbalanced faults were introduced, and empirical formulas were provided. Finally, the basic process of field dynamic balancing of large-scale fan was explained through two cases of field dynamic balancing. It shows that the same influence coefficient will greatly improve the efficiency of dynamic balancing of similar equipment. The research results provide a reference for the fault analysis and treatment of fan imbalance in thermal power plantKeywords：fan;fault diagnosis;dynamic balance;influence coefficient61|362|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：A compressor rotor crack accident occurred in 13E2 gas turbine used for combined cycle in Shenzhen Nantian Power Plant. To accurately predict the fatigue life of similar units, based on elastic-plastic theory, considering the influence of temperature field and centrifugal force on fatigue life of compressor compressor rotor, the finite element thermo-solid coupling numerical simulation model of the compressor rotor of the gas turbine was established. Based on the low cycle fatigue theory, it is calculated that the fatigue life of the gas turbine compressor rotor is 5333 times, and the actual fatigue life of the compressor rotor of the gas turbine in the power plant is 4435 times. The calculation error is within 20%. This method can be used to estimate the rotor life of gas turbine accurately.Keywords：turbine;rotor;low cycle fatigue;numerical simulation32|320|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
- Abstract：Biomass direct-fired power plant is a clean and concentrated way to utilize bioenergy. Reducing the flue gas temperature and making full use of the waste heat of the power plant will effectively improve the utilication efficiency of bioenergy or open up a new economic growth point for the power plant. Based on the characteristics of biomass direct-fired power plants in rural areas, the possibilitie of applying waste heat of flue gas from power plants to agriculture was discussed. The results show that it would promote farmers' income and protect ecological environment by applying waste heat from biomass direct-fired plants to domestic heating, planting, breeding and other agricultural fields.Keywords：biomass direct-fired power plant;waste heat utilization;agriculture31|260|0<HTML><L-PDF> <Meta-XML>Updated：2025-07-04
Power Generation and Enbironmental Protection
