Table of Content

05 February 2021, Volume 54 Issue 2

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Development Trends and Key Issues of China's Integrated Energy Services

ZHANG Yunzhou, DAI Hongcai, WU Xiaoyu, CHEN Rui, ZHANG Ning

2021, 54(2):  1-10.  DOI: 10.11930/j.issn.1004-9649.202012040

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With the profound changes in China’s macro-economy and the deepening evolution of the new round energy transition, especially the gradual implementation of the carbon peak targets by 2030 and the carbon neutrality vision by 2060 in China, the development of China’s integrated energy services is facing new situations and requirements. Firstly, the future development trend of integrated energy services is studied from the aspects of energy users’ demand, energy technology, energy service model, energy services ecology, and energy policies. Secondly, the key issues for the integrated energy services are analyzed, and the corresponding actions are proposed from the aspects of government, industry and enterprise to promote the high-quality development of China’s integrated energy services.

UHF Partial Discharge Localization Methodology Based on Generalized Regression Neural Network

YU Qichen, LUO Lingen, WU Fan, SHENG Gehao, JIANG Xiuchen

2021, 54(2):  11-17.  DOI: 10.11930/j.issn.1004-9649.202005016

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Partial discharge (PD) detection and localization is an important means for condition monitoring and diagnosis of power equipment. The existing time-difference based ultra-high frequency (UHF) PD localization techniques are limited in application due to their high costs. A novel PD localization method is proposed based on generalized regression neural network (GRNN) and received signal strength indicator (RSSI) fingerprint, which consists of two stages. In the off-line stage of algorithm, a RSSI fingerprint map is built. In the on-line stage, the GRNN is used to calculate the position of the PD source. The field testing shows that the proposed UHF PD localization method has an average localization error of 0.51 m, and a cumulative probability of 81.6% for the localization error of less than 1 m. Compared to the minimum mean square error (MSE) of the Cramér-Rao lower bound (CRLB), which is based on RSSI log normal shadowing model positioning method, the cumulative probability of the GRNN localization error with the mean square error less than 0.6 m² is 66.7%, which is better than CRLB. The proposed method overcomes the shortcomings of low positioning accuracy and high costs of the traditional methods, and has the characteristics of low hardware cost and good environmental adaptability.

Development and Prospect of Structure Health Monitoring Technologies for Bolted Joints of Transmission Towers

ZHANG Wuneng, WANG Yi, ZHANG Liubin, WU Kehua, WANG Xiaochen

2021, 54(2):  18-26.  DOI: 10.11930/j.issn.1004-9649.202005045

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The bolted joints of transmission towers in service are subjected to the environmental random static/dynamic loading, frequently leading to the reduction or loosening of pre-tightening stress, and as a result reducing the total bearing capacities of transmission towers. Therefore, it is of great significance for the safety and reliability of the transmission towers to develop the structure health monitoring (SHM) technology. We make a review on the research progress of several typical SHM technologies for bolted joints, including technologies based on the dynamics theory, guided wave theory, acoustoelasticity effect and computer vision technology. Their basic principles and development status are introduced and discussed. Finally the DHM technologies for the transmission tower bolted joints are summarized and prospected.

Power Sensor-oriented Development and Challenges of Environmental Energy Harvesting Technologies

LI Chunlong, HUANG Hui, LIANG Yun, CHAI Qianyi, ZHAO Ruohan, HU Changyue

2021, 54(2):  27-35.  DOI: 10.11930/j.issn.1004-9649.202005040

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As the basic component of the energy Internet sensing layer, power sensor has attracted attentions from practitioners with focus on its power supply stability. Environmental energy harvesting technology makes the power sensor have self-powered capability and long-term maintenance-free advantages, and its application in power sensors has thus attracted more and more attentions. A review is made of the application status of environmental energy harvesting technologies in the field of electric power, as well as the characteristics of new energy harvesting technologies such as temperature difference, vibration, wind-induced vibration, etc.. Based on the application requirements of power sensors, the development trend of environmental energy harvesting technologies is predicted for their application in electric power industry, which can be summarized as diversification of energy harvesting methods, miniaturization of energy harvesting devices, integration of energy harvesting devices and sensors. In addition, a systematic analysis is made on the technical challenges, reliability challenges and application adaptation challenges in application of the energy harvesting technologies to the power sensor field.

Design of a Multifunctional Distribution Room State Monitoring Sensor

ZHANG Min, FANG Jian, WANG Hongbin, LUO Linhuan, HAO Fangzhou, YANG Fan, LIN Xiang

2021, 54(2):  36-43.  DOI: 10.11930/j.issn.1004-9649.202006097

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A multifunctional sensor which can monitor a variety of gases, temperature and humidity in real time is designed to improve the environmental monitoring and operation management level of the distribution room. A detail introduction is made to the sensor’s schematic, hardware circuit design, software design and functional parameters. The sensor uses the STM32L151RDT6 microprocessor as the main control chip, and the advanced spectrum and electrochemical technology as the principle to detect a variety of gases at the same time. Based on ZigBee's wireless transmission module and 485 wired network, the data transmission and communication between the sensor and the monitoring center are realized. The operation state of the distribution room can be judged and forewarned through the upper computer. Performance testing results show that the designed KIS-GTH5A multi-functional sensor has a detection accuracy of ±3%FS for gas, ±0.5 ℃for temperature and±3%RH for humidity. Therefore the designed sensor has the advantages of high performance, small volume and low power consumption, and meets the requirements for gas, temperature and humidity detector in distribution room.

Partial Discharge Pattern Recognition of Switchgear Based on Residual Convolutional Neural Network

HUANG Xueyou, XIONG Jun, ZHANG Yu, LIU Hui, CHEN Lu, MENG Xianglin, JIANG Xiuchen

2021, 54(2):  44-51.  DOI: 10.11930/j.issn.1004-9649.202006061

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The traditional switchgear partial discharge pattern recognition methods lack certain generalization performance and have low recognition accuracy, so it is hard to apply them in practical engineering. A method for switchgear partial discharge pattern recognition based on residual convolutional neural network is proposed. A residual module is added to the network to solve the degradation problem after accuracy saturation caused by the deepening of network layer number, and the shallow and deep feature fusion learning of switchgear partial discharge data is integrated to achieve the pattern recognition. Based on the partial discharge simulation experiments of different insulation defect categories of switchgears and the field testing of distribution stations, a sample database of switchgear partial discharge data is constructed, and experimental analysis is conducted. The experimental results show that the recognition correct rate of the proposed method reaches 96.06%, at least 20.22% higher than that of the traditional recognition methods, and the recognition rate can be improved more with the increase of the number of samples in the training set. Through integrated use of the feature layer fusion module and residual module, the proposed model is significantly improved in the generalization performance and is more suitable for practical engineering.

Partial Discharge Localization Method Based on UHF Wireless Sensor Array in Air-insulated Substation

YAN Shuai, LI Pengyu, WANG Gaojie, LI Qiang, WU Fan, LUO Lingen

2021, 54(2):  52-57,65.  DOI: 10.11930/j.issn.1004-9649.202006006

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To achieve comprehensive insulation deterioration monitoring of power equipment and fault early-warning of air-insulated substations, we propose a data-driven partial discharge (PD) source localization methodology based on received signal strength indicator (RSSI) and Gaussian process classification (GPC). Compared to the existing ultra-high frequency (UHF) time-difference-based technique, the proposed method needs only to record the RSSI measurements, while needs not require time synchronization between UHF sensors, which provides a low-cost solution with high adaptability. Meanwhile, to mitigate the multipathing and shadowing effects in modeling the UHF signal attenuation, it is proposed to use the GPC algorithm to learn the UHF signal features under different transmission paths so as to generate decision-making regions for identifying the RSSI values that are consistent with the signal attenuation model, and as a result, the localization accuracy is improved. The field test is performed and the results show that the proposed method has a mean PD source localization error of 2.51 meters, which is sufficient to identify the power equipment with insulation deterioration in a substation for fault early-warning.

Circuit Breaker Energy Storage State Identification Based on Quick Extraction of Vibration Signal Interval Features

XIA Xiaofei, LU Yufeng, SU Yi, YANG Jian

2021, 54(2):  58-65.  DOI: 10.11930/j.issn.1004-9649.202004012

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The vibration signal based circuit breaker faults diagnosis has the problem of time-consuming in feature extraction and poor real-time, which makes the method inapplicable to on-line monitoring. We therefore proposed a circuit breaker energy storage state identification method based on fast extraction of interval features. Firstly, the starting point of the energy storage state of the circuit breaker was detected by the kurtosis-wavelet modulus maximum value, and the vibration signals were marked through KS test to indicate the significant difference in the envelope amplitude. Then the signal envelope was extracted and used as the feature vector, and the ReliefF-SFS method was used to reduce the dimensionality of features to obtain the optimal feature subset. Finally, the fuzzy C-means clustering (KFCM) was used to pre-classify the features to obtain the optimal hyperplane with the least risk, and a training model was established with support vector machine (SVM) for state identification. The experimental results show that the proposed state identification method only takes 0.2 s to extract features with reliable recognition accuracy, which has important application value in the field of circuit breaker state monitoring.

Capacity Allocation Method for Wind-Solar-Hydro-Storage Complementary System Considering Time and Spatial Transfer Characteristics of Load

WEN Jie, LIU Jichun, WEN Zhengnan, LI Jianhua, LI Chenxin

2021, 54(2):  66-77,97.  DOI: 10.11930/j.issn.1004-9649.202002151

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By taking advantage of the quick regulation ability of cascade hydropower and the flexible conversion of the working conditions between power generation and pumping of the pumping generator units, and on the basis of compensating the fluctuation and uncontrollability of wind and PV output, a wind-solar-hydro-storage complementary system model is established at the source end to enhance the regulation ability of the power generation system. At the same time, considering the market spot electricity price and the time and spatial transfer characteristics of load, a load-side model is established, and a source-grid-load interaction strategy is proposed based on multiple system indicators such as the economy and state evenness of system and the load tracking, with consideration of the randomness of wind/solar power output at source end and the system network constraints. Based on above study results, a multi-objective capacity allocation model of complementary power generation system is built. Finally, through a case simulation, the nonlinear optimization problem is solved by professional optimization software (LINGO), and the allocation capacities of the source end system under different planning years and scenarios are obtained, which has verified the effectiveness of the proposed method in improving the system indicators.

CNN-based Rolling Optimization Strategy for Prosumer Group in Demand Response

ZHANG Xudong, LI Fei, LIU Di, SUN Yi, LI Bin

2021, 54(2):  78-89.  DOI: 10.11930/j.issn.1004-9649.202001039

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With the massive installation of distributed photovoltaics, a large number of prosumers with dual attributes of load and power supply have appeared. In the environment of electric power spot market, the decision mechanism of prosumers and electricity sellers in the price-based demand response are analyzed based on the Stackelberg model, and a convolutional neural networks(CNN)-based prosumer group decision behavior prediction model is proposed to achieve accurate prediction of load adjustment and rebound of prosumers. Furthermore, with full consideration of the impact of the load rebound phenomenon on the price-based demand response, a rolling optimization strategy considering load rebound is proposed to increase the revenue of electricity sellers, reduce the load imbalance of prosumers, and promote the local consumption of distributed photovoltaics. Simulation experiments show that the prediction accuracy of the prosumers decision behavior prediction model proposed in this paper is more than 99%, and the rolling optimization strategy considering the load rebound phenomenon can increase the prosumers’ local consumption rate of renewable energy by more than 5%. At the same time, compared to the time-of-use electricity prices and the real-time electricity prices that do not take load rebound into consideration, the revenue of electricity sellers can increase by 118.8% and 15.1%, respectively.

Global Reserve Optimization Method Considering Resources and Output Characteristics of Renewable Energy

CAI Qian, WANG Jing, GENG Tianxiang, LI Feng, MA Tiandong

2021, 54(2):  90-97.  DOI: 10.11930/j.issn.1004-9649.202004192

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A global reserve optimization technology based on trans-regional UHVDC transmission channels was presented, which takes into account the complementary characteristics and the predicted output characteristics of renewable energy resources. Firstly, the correlation and complementary characteristics of renewable energy resources in China were analyzed, and the feasibility of complementary operation of overall resources in different regions was studied. Then, a real-time reserve optimization technology based on statistical characteristics of renewable energy prediction was proposed, and a trans-regional global reserve optimization technology based on time series production simulation method was established. Finally, taking “Three North” regions as an example, the case study of global reserve optimization considering the complementary characteristics of regional resources was carried out. The case results show that the method proposed in this paper optimizes the startup mode of conventional thermal power units, and can realize the reasonable optimization of real-time reserve, promote the accommodation of renewable energy, and improve the overall operation efficiency of the power grid.

Operation Optimization Method of Energy Storage System with Two-Part Tariff

CHEN Yiwei, QIAN Xiao, TANG Yi, ZHONG Lei, YIN Lu, FU Yanan

2021, 54(2):  98-103,112.  DOI: 10.11930/j.issn.1004-9649.202002059

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With the rising opportunities from the two-part tariff and the development of energy storage, massive economic benefits will become available for customers by installing energy storage system. In order to explore the economic potential of energy storage system, based on the calculation of the lower bound of the maximum load at demand end, this paper proposes an optimal operation model of energy storage system to achieve the maximum benefits. In this model the maximum load demand and energy storage power are chosen as the control variables, and the energy storage system operation and lifespan, variable association, etc. are taken into full consideration as the constraints. With the aids of the proposed auxiliary variables, the nonlinear optimization operation model is transformed into a linear model, which greatly reduces the complexity of solution. Finally, the model has been implemented successfully in Beijing and Shanghai regions to analyze the benefits of energy storage system in the typical scenarios.

Hierarchical and Partitioned Optimal Control of Distribution Networks Considering the Coordination Between Energy Storage and Distributed Generation Systems

ZHANG Ying, KOU Lingfeng, JI Yu, YU Hui, HU Zhuandi, SUN Zhen’ao

2021, 54(2):  104-112.  DOI: 10.11930/j.issn.1004-9649.202001081

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The current distribution network is facing the challenge of large-scale distributed generation and diverse forms of energy storage being integrated into the distribution network, which has brought extreme complexity to the optimal management and control of distribution system. Inspired by the idea of layered optimization and partition coordination, a layered optimization system for distribution networks with regional autonomy and coordination among regions was proposed to achieve the purpose of system optimization after the integration of large-scale distributed generation into the bulk power grid. At the optimal dispatch layer, the dynamic mathematical model is established with the power exchange between each regions and the main power grid as the objective function. Then through the optimization coordinated by each regions, the large-scale distributed energy resources are connected to the grid smoothly and hourly schedules of the inter-region power exchange are obtained. At the control layer within the region, considering the discrepancies between the regulation capabilities of each distributed energy source, the dispatch order from upper layer is revised based on fuzzy control logic in combination with the energy storage system. Additionally the 5min ultra short term dispatch order is also issued for each region. At the unit control layer, real-time control is implemented based on PWM converter. Finally, the correctness and validity of the proposed strategy are verified by virtue of case studies with simulated calculations.

Comparison and Enlightenment of Energy Transition Between Domestic and International

ZHANG Ning, XUE Meimei, WU Xiaoyu, DAI Hongcai, ZHANG Yunzhou, LIU Lin, ZHANG Dong

2021, 54(2):  113-119,155.  DOI: 10.11930/j.issn.1004-9649.202005162

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At present, the global energy transition is in a period of accelerated advancement, and the transition process of various countries also exhibits certain differentiated characteristics. Based on the analysis of the development direction of energy transition, this paper proposes an energy transition evaluation index system covering four dimensions: energy structure, energy efficiency, energy security, and energy price. On this basis, a comparative analysis of the energy transition situation in major countries such as China, the United States, Germany, France, Japan, and South Korea is conducted, and then conclusions and enlightenments for China's energy transition are put forward.

The Role and Function of East China Grid in the Unified Electricity Market of China

ZENG Dejun, YANG Libing, LI Xiaogang

2021, 54(2):  120-126.  DOI: 10.11930/j.issn.1004-9649.202009011

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In order to play the role of the East China Grid in the unified electricity market system of China, and to promote the integration of electricity resources in Yangtze River delta, this paper analyzes the role and function of the East China Grid in the unified electricity market of China. It is pointed out that the inter-province market in East China Grid is an integral part of national inter-province market, and the East China Grid is the most important vehicle for realizing the integration of electricity resources in Yangtze River delta. The experience of the inter-province market in the East China Grid can provide a reference for building the China’ unified electricity market. Finally the path for building the inter-province market in the East China Grid is given.

Simulation of Operational Performance of PV Systems in Distribution Network

HE Yupeng, WANG Jie, DONG Yinghua, GU Zeyu, XUE Yulong, DING Aifei, LI Yingfeng

2021, 54(2):  127-132.  DOI: 10.11930/j.issn.1004-9649.202004197

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A simulation analysis is performed on the operational performance of distributed PV systems connected to distribution networks. Firstly, the topology of distributed PV system is analyzed. And then the operational model of PV module and PV inverter is established according to the operational mechanism of key components of PV system, and the shadow occlusion model of PV modules is established according to the I-V characteristics of PV modules. Finally, combined with the field test results, the operational model parameters for the PV system are determined. The operational performance of the distributed PV system can be evaluated with the structure and PV modules of PV system.

6 kV/180 ℃ High Temperature Reverse Bias Test Equipment for High Voltage and High Power Devices

DENG Erping, MENG Heli, WANG Yanhao, ZHAO Zhibin, HUANG Yongzhang

2021, 54(2):  133-139.  DOI: 10.11930/j.issn.1004-9649.201906002

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High Temperature Reverse Bias (HTRB) test is an important part in reliability tests on IGBTs. The accuracy and function of the test equipment determine the accuracy of the performance monitoring of the tested device. To Meet the requirements of space, accuracy and reliability for test equipment, HTRB test equipment with voltage level of 6 kV and ambient temperature of 180 ℃ was independently built for high voltage and high power devices. Further, the test equipment integrates some functions such as automatic measurement of temperature-drain current relationship curve and high-frequency acquisition of failure data, which can better monitor the state of the tested device for reliability evaluation and failure analysis. For the purpose of testing the function and reliability of the test device and getting the relationship curve of leakage current–temperature and aging time–leakage current, some commercial IGBT devices were tested with the equipment. Leakage current–temperature curve is an exponential function and aging time–leakage current curve is increasing slowly. This equipment realizes the test requirement of high voltage and high power devices, suiting for different packages of IGBTs.

Fault Path Direct-Current Resistance Based Off-Line Single-Phase-To-Ground Fault Location

LI Fuzhi, ZHENG Weibin, ZHANG Wenhai, ZHANG Zhiyong, LIN Defeng, ZHANG Xubo, ZHANG Rongjian

2021, 54(2):  140-146.  DOI: 10.11930/j.issn.1004-9649.201903072

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In order to figure out the off-line transmission line fault location, a new fault location method based on fault path direct current resistance measurement is proposed. Firstly, an off-line fault detection and diagnosis method based on three-phase insulation resistance measurement is proposed, including fault type and fault phase diagnosis. Then the single-phase-to-ground fault location method is proposed which occurred the most frequently. In the proposed methods, the ground resistance and three phase direct-current resistance between two substations are measured firstly. Then considering the effect of fault resistance, the KVL is used to form two independent equations which contain two unknown numbers, fault resistance and fault distance. Then fault distance and fault resistance can be figured out by solving equation set. The proposed method is verified in the PSCAD/EMTDC by simulation. The correctness and accuracy of the proposed fault location method are verified. Also it is verified in the field test. It is helpful for clearing the fault for newly-built lines and overhaul lines. It is very important to ensure that transmission lines are put into operation on time.

Defect Detection of Power Equipment by Infrared Image

HUANG Ruiyong, DAI Meisheng, ZHENG Yuebin, HUANG Qinqin, KANG Liye, GOU Xiantai, ZHOU Weichao

2021, 54(2):  147-155.  DOI: 10.11930/j.issn.1004-9649.202004116

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The infrared image collected by the robot during inspection is hard to reflect the texture information of the equipment target. The artificial methods or traditional machine learning methods cannot accurately identify and classify the defects of power equipment, and other environmental factors may easily lead to false judgment. In this paper, the algorithm model of CenterNet combined with structured positioning is adopted. Through collecting field infrared image data samples, the algorithm model is trained and verified to identify and position different substation equipment and its components with high accuracy from complex infrared images. According to the surface temperature range of equipment components and the type of substation equipment, the infrared image is combined with relevant temperature specifications to realize the defect detection of power equipment. The experimental results show that this method improves the accuracy of infrared image for detecting the defects of power equipment, and provides a new idea for infrared image used for intelligent detection of power equipment.

Insulator Defect Detection Based on EfficientDet and Binocular Camera

LIU Yifan, WANG Shuqing, QING Yihui, WANG Chenxi, LAN Tianze, YAO Ruotian

2021, 54(2):  156-163,196.  DOI: 10.11930/j.issn.1004-9649.202006315

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Insulator is an important component of transmission lines. The defective insulator will cause hidden dangers to the lines. Image detection technology can improve the efficiency of insulator defect detection and greatly reduce the maintenance cost. However, the existing insulator defect detection technology has the disadvantages of low accuracy and long detection time. Aiming at this problem, an insulator defect detection method is proposed based on EfficientDet and binocular camera. Firstly, a data collection method is designed for binocular camera to solve the problem of insufficient open source data set; Secondly, the problem of excessive resources occupied by EfficientDet is solved by a labeled classification first algorithm; Finally, the proposed algorithm is compared with three conventional algorithms. It is found that the mAP of the proposed algorithm is 50.04, which is superior to other three algorithms. The accuracy rate of insulator and defect identification and positioning is more than 95% and 90%, respectively, which shows the proposed algorithm’s good efficiency and practicability.

Economic and Environmental Dispatch of Combined Heat and Power System Based on Improved MOBCC Algorithm

LU Zhigang, QI Shengjing, CAI Yao, MA Yuwei

2021, 54(2):  164-174.  DOI: 10.11930/j.issn.1004-9649.202002162

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Combined heat and power has become an important part of the integrated energy system owing to its advantages in energy conservation and emission reduction. For the economic and environmental dispatch problem of combined heat and power system, the improved MOBCC algorithm based on Pareto dominance is applied, which has excellent performance in the aspects of convergence, diversity of solution set and time efficiency. In addition, the constraint conditions are taken care by virtue of the constraint violation index. The multi-objective decision-making method based on the relationship between the objective satisfaction and the objective weight is applied to select the best compromise solution. The case study shows that by setting proper objective weights, both the economic and environmental objectives are taken into account in the combined heat and power system operation such that the optimal operation of combined heat and power system can be achieved. Meanwhile, the effectiveness of the improved MOBCC algorithm is also verified.

The Impacts of Key Technology Development on the Natural Monopoly Attributes of Distribution Network

YANG Su, WU Zechen, WANG Donghui, HU Yuan

2021, 54(2):  175-181.  DOI: 10.11930/j.issn.1004-9649.202004056

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The technical and economic characteristics of each section in power industry are essential to the power system reform. With the development of distribution technology and the application of intelligent distribution technology, the technical characteristics of the distribution network have changed significantly. In order to explore the impacts of technological developments on the natural attributes of the distribution network, this paper delves into the natural monopoly attributes of the distribution network, including the sub-additivity of costs, scale economy and scope economy. On this basis, this paper analyzes the impacts of the distribution network intelligence and automation technology on the scale economy and scope economy of the distribution network, which can provide decision-making reference for the reform measures of electric grid section as well as the incremental distribution network reform.

Spatio-Temporal Variation Characteristics of Fugitive Particulate Matter Emissions from the Coal Storage Yard of Coal-Fired Power Plants in Beijing-Tianjin-Hebei and Surrounding Areas under Different Regulatory Scenarios

WU Jiayu, MO Hua, HU Yun, ZHU Jie, SHUAI Wei, ZHANG Qing, JIANG An

2021, 54(2):  182-189.  DOI: 10.11930/j.issn.1004-9649.202009115

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In order to support the in-depth control of fugitive particulate matter emissions in the coal yard of coal-fired power plants in Beijing-Tianjin-Hebei and surrounding areas, by taking the data collected from the year of 2017 as the baseline and the total suspended particulate (TSP) as the research objective, the temporal and spatial variation characteristics of fugitive particulate matter emissions from the coal yard of coal-fired power plants are explored. Based on relevant policies, two scenarios with different approaches are designed and their control effects are analyzed respectively, i.e., porous fences reconstruction and fully enclosed reconstruction. The results show that in 2017, there were 3 044.41 tons of fugitive particulate matter emitted from the coal yards in the above areas. Winter and spring seasons (from January to May) are the critical time period for the control of fugitive particulate matter emissions. With the approach of total enclosure reconstruction, the fugitive particulate matter emissions can be reduced by 98.33% from coal yards. From the perspective of improving the local environmental quality, emission control of the fugitive particulate matter in coal yards is more cost-effective than that of “colored plume” reduction. At last, it is suggested to attach significance to the control of fugitive particulate matter emission in the coal yard of regional coal-fired power plants. Also by seizing the critical period of environmental management, the fully enclosed reconstruction of coal yard should be carried out in an orderly and step-by-step manner.

Comparative Analysis of PM₁₀/PM_2.5 Laboratory Sampling for Ultra-low Emission of Coal-Fired Power Plants

HUI Lifeng

2021, 54(2):  190-196.  DOI: 10.11930/j.issn.1004-9649.202006319

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In the ultra-low emission facilities of coal-fired power plants, in order to explore the cause of different PM₁₀/PM_2.5 measurement results from the particle samplers adopted with different principles, the correlation and stability of the sampling results of the cyclone separator and virtual impactor were tested and compared. In addition, the influence of humidity on the two sampling methods was verified and analyzed, which were all based on particle sampling experiment verification simulation system and automatic filter membrane batch weighing system in the mass concentration environment of 0~6 mg/m³. The results show that the test results of the two sampling methods of cyclone separator and virtual impactor are highly correlated. The stability and reproducibility of the cyclone separator in dry environment is better than that of the virtual impactor. However, the humidity shows stronger effect on the cyclone separator than the virtual impactor. Particularly in the case of PM₁₀/PM_2.5 detection in ultra-low emission power plants, appropriate sampling methods should be selected in consideration of environmental differences.

Research on the Quality and Characteristics of Carriers for Resource Reuse of Waste Flue Gas Denitration Catalyst

HUA Chenfei, ZHU Lin, YAO Jie, ZHUANG Ke

2021, 54(2):  197-204.  DOI: 10.11930/j.issn.1004-9649.202009139

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In this study, three resource-recycled titanium-based carriers and one fresh titanium-based carrier were selected and analyzed to study the differences between these two types of carriers by virtue of laser particle size analyzer, X-ray fluorescence (XRF) analyzer, inductive coupled plasma (ICP) emission spectrometer, BET testing method and mercury intrusion porosimeter, etc. Furthermore, the above four carriers were used as raw materials to prepare finished catalyst products through active component loading and extrusion molding. Then the main components and trace element contents, specific surface area, mechanical strength, denitration efficiency and activity were tested respectively in the finished catalysts. The results show that, compared with fresh titanium-based carriers, the resource-recycled titanium-based carriers have more uneven particle size distribution, smaller specific surface area, less specific pore volume, and higher contents of toxic elements, which will affect the qualities of the corresponding finished catalysts, and eventually result in low denitration efficiency and activity.