Issue Ebookcover story
List of IssuesDocument Types
- Abstract：The wind power is a kind of clean and sustainable energy which has been developed rapidly in China in recent years. Doubly-fed induction generator (DFIG) have been widely applied for wind power generations for its flexible controllability. However, due to the special structure of the DFIG, grid-connected DFIG wind farms may cause sub-synchronous oscillation(SSO) in power systems. This paper introduces the mechanism of SSO caused by grid-connected DFIG wind farms. Moreover, a systematic review of researches on the three types of SSOs based on the complex torque coefficient method is presented in the paper. In addition, the extension form and application area the complex torque coefficient method is explored. Furthermore, based on the development trend of wind power generations and the characteristics of the complex torque coefficient method, the research prospects are discussed.Keywords：grid-connected doubly-fed induction generator (DFIG) wind farms;sub-synchronous oscillation (SSO);complex torque coefficient method;sub-synchronous resonance(SSR);sub-synchronous torsional interaction (SSTI);sub-synchronous control interaction (SSCI)14|105|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：The new generation of artificial intelligence driven by big data has shifted from traditional knowledge representation to deep and autonomous learning. It no longer requires too much human intervention and shows a smarter side. In recent years, deep learning (DL) has become the hotspot of artificial intelligence. This paper focuses on the characteristics, principles and the current application status of DL in the power system. It also analyzes the research trends and problems in the application process of the new generation artificial intelligence, and provides solutions based on distributed machine learning and incremental learning methods. This paper is written for providing references for researchers involved in the field.Keywords：power system;artificial intelligence;deep learning;big data38|2245|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：Urban distribution network is an important link for users, and it is of great social and economic significance to carry out scientific evaluation on power supply capacity of urban distribution network. Firstly, this paper summarizes the concept of power supply capacity of urban distribution network, traditional evaluation method and evaluation model. Secondly, the urban distribution network power supply capability evaluation steps are divided into three parts:building urban distribution network, power supply capability evaluation index system of evaluation index weights and evaluation method, and summary analysis are carried on each steps and content. Finally, the application prospect and research direction of power supply capacity assessment of urban distribution network are pointed out.Keywords：urban distribution network;power supply;evaluation methods43|2022|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：An active distribution network (ADN) planning and design architecture was developed. The content requirements of AND planning were given from the aspects of power grid status, load forecasting and power balance. Based on the probabilistic output interval of distributed generation, the formulation method of network load coordination plan was studied. Finally, the electrical calibration method of AND was presented to verify the reasonableness of the formulation of the plan.Keywords：distributed generator(DG);active distribution network(ADN);network planning15|1365|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：Power information systems are important for the operation of power systems. When part of the power information system fails, the loads will be redistributed. Due to network congestions, cascading failures may occur, and additional devices or sub-systems would fail. In this paper, power information system was abstracted to a complex network. The traditional load-capacity model was improved to satisfy the characteristics of power information systems. The improved model also reflects the distribution of power information system nodes. Moreover, two vulnerability indices were established from the perspective of both topological structure and network properties, and the vulnerability assessment process was proposed. Finally, cascading failure process and the impact of redundancy factor were analyzed in case study. The effectiveness and rationality of this method was verified by the results.Keywords：power information system;load-capacity model;vulnerability assessment;complex network;scale-free network31|86|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：A kind of connection scheme of three-terminal back-to-back (BTB) voltage source converter based HVDC(VSC-HVDC) system in 10 kV distribution network was discussed, which can improve the reliability of power supply and restrain the circulation by the control of VHC-HVDC. With the traditional control strategies, VSC-HVDC system has almost no interia and is hard to be involved in the dynamic regulation of the power system effectively. To improve the stability of the frequency in the receiving system and improve the performance of the system after the breakdown, the control strategy of virtual synchronous generator (VSG) in the application of three terminal back-to-back VSC-HVDC under a medium voltage (10 kV) AC distribution network context was proposed. First three terminal back-to-back VSC-HVDC device was added to the 10 kV system to establish the AC/DC hybrid distribution network, and the mathematical model of the converter under the traditional control and VSG control was established. Then the simulation was carried out by using the PSCAD/EMTDC platform, the operating characteristics of disturbance and fault were obtained in two control modes. The results show that the three-terminal back-to-back VSC-HVDC system can effectively participate in the regulation of power grid system using VSG control, and gain the interia to improve the system's performances of transient states, and the reliability of the grid are effectively improved.Keywords：virtual synchronous generator (VSG);interia;back-to-back voltage source converter based HVDC;distribution network56|1855|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
Energy Internet
- Abstract：The electrical energy is converted into mechanical energy in the long term continuous operation of air compressor in thermal power plant. The air is strongly compressed in the process, and the temperature increases greatly, and should be cooled through the cooling system before storage. If this part of the energy is recovered, it can help enterprises to save energy consumption and create good economic, environmental and social effects. In this paper, the scheme of the waste heat utilization of air compressor is designed, and the heat recovery of the compressed air system of six 250kW units in Qing He plant is carried out, the reclaimed heat is used to heat domestic water. The economic analysis is also carried out related to the project. It is shown that the payback period of the project is only about 8 months, and it can save 718 tons of standard coal annually.Keywords：thermal power plant;air compressor;waste heat recovery;economy55|1684|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：Direct at the problem of only one turbine's waste heat can be recovered in typical double-units configuration power plant, the waste heat quantity of the wet cooling unit and the present technologies' ability to recover waste heat were analyzed quantitatively. A heat supply system that absorption heat pumps in series low pressure cylinder with bare-shaft to recovery waste heat from circulating water was presented. And the system to recover waste heat of steam turbine driving feed water pump was also proposed. With the system, all the two units' waste heat could be recovered to supply district heat for the typical double-units configuration power plant.Keywords：heat and power cogeneration;steam turbine;waste heat supply;waste heat of circulating water41|1924|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：The method of urea pyrolysis for ammonia denitrification has been widely used in the denitrification technology of thermal power plants due to the safety of raw materials and the maturing technology. However, crystallization of the pyrolysis furnace occurs frequently. In order to avoid crystallization and environmental events, based on the experience of operation, the judging basis and treatment method of the crystallization of the pyrolysis furnace were introduced. The causes of the crystallization from the point of view of system design and operation adjustment was expounded. The optimization scheme of the system design for the pyrolysis furnace and operation adjustment methods was given. The engineering practice shows that timely and accurate crystallization judgement, effective operation adjustment method and optimized heat release nitrate system can effectively prevent the crystallization of the pyrolysis furnace and eliminate the occurrence of environmental protection events.Keywords：pyrolysis principle;technological process;accident treatment;crystallization reason;optimized scheme;operation adjustment35|2560|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：The structure and layout of flue gas system of coal-fired units not only determine the resistance of the smoke wind system, but also affect the operation state of related equipment. Due to the unreasonable flue structure between induced draft fan and desulfurization tower in a 2×1060 MW unit, one of the two parallel induced draft fans oscillated badly, affected the reliability and economy of the unit. A numerical simulation of the flow field of this part of the flue gas was carried out by the software of fluid dynamics. The problems existing in the flue gas were analyzed, and the optimum plan was proposed to reform the flue in combination with the field conditions. After technological transformation, the flue resistance of this part decreases to 300 Pa, parallel deviation is less than 3%, and the vibration detection value of the fan is reduced from more than 4.6 mm/s to 2.5 mm/s. This creates huge economic benefits for power plants.Keywords：coal-fired power unit;induced draft fan vibration;flue resistance;numerical simulation;flow field optimization54|121|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：The problem of large area damage was analyzed when cleaning and dismantling gas-gas heater(GGH) corrugated plate in a factory. The causes of corrugated plate damage were mainly studied from the field soot and operating conditions. The results show that high pressure steam is not suitable for direct soot blowing, and the safe soot blowing method is decompressing high pressure steam into low pressure steam before soot blowing. High pressure steam with pressure higher than 0.8 MPa, and enthalpy value more than 2 978.4 kJ/kg can be used as the corrugated plate soot source. Research findings would play a positive role in maintaining the life of the corrugated plate and provide reference for safe blowing of air preheater and GGH.Keywords：steam parameters;corrugated plate;safety soot blowing;life;enthalpy value29|167|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：This paper presents a power generation system using liquefied natural gas (LNG) cold energy to implement gradient utilization, which is a Rankine's cycle integrated with gas turbine combined cycle. In this system, the heat transfer of evaporator in Rankine's cycle is equal with that of condenser in gas turbine combined cycle. Circulating water system is in closed type and would not be affected by environmental temperature. The system was simulated, and main influence parameters of the system were analyzed. The results show that:the net output power and efficiency of Rankine's cycle are elevated with the decrease of the condensation temperature in Rankine's cycle; with the rise of circulating water temperature, the net output power and efficiency of Rankine's cycle are elevated while the output power of steam turbine decreases, but the both total power output reduces slightly.Keywords：liquefied natural gas (LNG);cold energy;power generation;Rankine's cycle;gas turbine combined cycle34|214|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
Power Generation and Environmental Protection
- Abstract：Due to the randomness, volatility and anti peak characteristics of wind power, a high proportion of wind power penetrating into the power grid will have a great impact on the stability and security of the power system. Therefore, it is necessary to control the active power of the wind farm to reduce the fluctuation and improve the smoothness of the output power. With the increasing installed capacity, a large number of wind curtailment occur, and the control mode of wind farm is changed from the traditional maximum power point tracking (MPPT) mode to the limit power control mode. The necessity of controlling the active power of the wind farm was analyzed, based on the backgrounds of the control requirements of the wind power connected to power grid and curtailment. Starting from the single machine power control and station level power control, taking the station level power control as the emphasis, the research status of active power control of wind power was summarized. The control characteristics and shortcomings of different control methods were summarized, and research directions were prospected.Keywords：wind farm;wind turbine;active power control;maximum power point tracking(MPPT)81|255|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：Aiming at the problems of inefficient manual detection of wind turbine (WT) blades and difficult diagnosis of defects, a method of defects detection for WT blades based on unmanned aerial vehicle (UAV) and image processing is proposed. Through the joint development of Halcon 12 and Visual Studio 2015, the functions of image processing flow, test result output and defects playback are realized, including camera calibration, image processing through fast adaptive weighted median filtering and dynamic threshold segmentation. Through the regional processing to identify defects such as cracks and trachoma, the defects are classified and measured, and the analysis report of WT blades quality can be output to finally realize the automatic detection function of the surface defects of the WT blades. The high accuracy and stability of the algorithm of this method in detecting WT blades surface defects are demonstrated experimentally.Keywords：wind turbine;defects detection;unmanned aerial vehicle;image processing32|635|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
- Abstract：Permanent magnet eddy current heating is a heating form using wind energy. Because of its low requirement on wind quality, relatively simple device structure and high heating efficiency, it is an effective application of distributed energy. Taking the permanent magnetic eddy current heating device as the research object, the input torque of the heating device, which was deduced according to the principle of electromagnetic field, was compared with the input torque of the vertical axis wind turbine. A mathematical model of the relationship between the geometric parameters of different components inside the device was established, and the components of the permanent magnet eddy current heating device were determined, which provides a theoretical basis for the design of a more reasonable permanent magnet eddy current heating device structure.Keywords：eddy current;heating device;mathematical model;parameter design;wind energy41|190|0<HTML><L-PDF> <Meta-XML>Updated：2025-06-06
New and Renewable Energy
