Table of Content

05 April 2019, Volume 52 Issue 4

Previous Issue    Next Issue

Study on the Development of Renewable Energy During “Post-Subsidy Period” in China

ZHANG Yunzhou, LIU Jun, ZHANG Jinfang, WANG Caixia

2019, 52(4):  1-7.  DOI: 10.11930/j.issn.1004-9649.201811125

Asbtract ( )   PDF (4686KB) ( )  

References | Related Articles | Metrics

In recent years, the global levelized cost of energy (LCOE) of wind and PV power generation has been decreasing, which improves the economy of renewable energy power generation and provides effective support for alleviating the subsidy dilemma. The development of renewable energy has entered the "post-subsidy era". The paper analyzes the prospect of renewable energy development in China in the mid-and long-term according to the national energy transformation development goals, studies the variation tendency of renewable energy generation cost, and puts forward the key issues that should be paid attention to in the "post-subsidy era". The key measures are analyzed to improve the renewable energy carrying-capacity of power system. In the end, related suggestions are proposed to guarantee the scientific and healthy development of renewable energy.

Frequency Regulation Challenge of Power Electronics Dominated Power Systems and Its New Multi-level Coordinated Control Framework

LU Zongxiang, YE Yida, GUO Li, XIE Zhenjian, LIU Guojing, QIAO Ying

2019, 52(4):  8-17,110.  DOI: 10.11930/j.issn.1004-9649.201903121

Asbtract ( )   PDF (6633KB) ( )  

References | Related Articles | Metrics

The widely-used converters in the source, grid, and demand sides have advanced the electronics domination process of power systems. With the increasing of net load, and the decreasing of synchronous inertia and power balance capability, the risk of frequency stability has emerged. One the one hand, future power system must keep power balance with less synchronous generation capacity; on the other hand, due to absence of output responding to system frequency, and input uncontrollability, and also due to the heterogeneous controllers, converters could hardly be adapted for frequency regulation framework of the traditional synchronous system. Based on designing the voltage resource converter (VSG), the paper proposes a novel multi-level coordinated control framework of power electronics dominated power systems. In the converter level, the coupling relationship of output power and system frequency is rebuilt by simulating the inertial response and primary frequency control. In the equipment level, virtual parameters are grid-friendly optimized to coordinate the energy from internal storage and from input in order to reduce the risk of secondary frequency drip. In the multiple-converters level, devices are cooperated that improves the frequency dynamics and that provide frequency restoration. In the system level, the inter-area frequency regulation is supported again across DC-line-isolated synchronous systems on the basis of droop control of VSC-HVDC stations.

Quantitative Analysis of China's Electrification Process Based on the 3E Optimization Model

ZHENG Kuan, ZHANG Jinfang, LIU Jun, FENG Junshu, FU Guanjun, LI Jiangtao

2019, 52(4):  18-24.  DOI: 10.11930/j.issn.1004-9649.201809047

Asbtract ( )   PDF (4939KB) ( )  

References | Related Articles | Metrics

The electrification of energy production and consumption, which can not only realize the efficient transformation of massive new energy, but also promote the improvement of the overall level of energy efficiency, is a strategic choice of global energy transformation. The paper clarifies the role of electrification in promoting energy transformation, and analyzes the basic conditions for continuous upgrading of electrification level in China. Based on a study of the international trend of future global electrification process, the paper also proposes the strategic path of China's re-electrification by using the model of energy and electricity planning and the model of energy consumption prediction, which can provide a decision supports for accelerating energy transformation and efficiently promoting the development of electrification in China

Operation Evaluation Method of High Proportion Renewable Energy Power System Based on Exchange Convolution

WU Shaolei, FENG Yu, WU Kai, LU Wei, ZHAO Cheng, LUO Cheng

2019, 52(4):  25-31.  DOI: 10.11930/j.issn.1004-9649.201801015

Asbtract ( )   PDF (4742KB) ( )  

References | Related Articles | Metrics

With the large-scale construction of renewable energy, it is urgent to assess the power system with high proportion of new energy and determine its operation mode. It is of great significance to study the operation evaluation of power system with high proportion of new energy. In view of the present evaluation methods that have not fully considered the peak shaving potential of generator units, the method of exchange convolution is proposed. On the basis of the probability production simulation that is based on presently widely used equivalent electricity function method and equivalent electricity frequency method, the load duration curve and equivalent load frequency curve are firstly established, and the pre-probability production simulation is carried out; and then, the high-frequency starting units are determined according to the pre- probability production simulation results; finally the convolution is exchanged based on the exchange convolution method. A case study is made on a practical power system, which verifies the effectiveness of the proposed method. Compared with the traditional method, the method proposed in this paper can give full play to the peak potential of the system and improve the effectiveness of the evaluation.

Optimization of Wind and Solar Power Capacity Proportion Integrated in Multi-terminal VSC-HVDC System with a Pumped Storage Power Station

LI Pai, HUANG Yuehui, WANG Yuefeng, LI Shuiwang

2019, 52(4):  32-40.  DOI: 10.11930/j.issn.1004-9649.201802009

Asbtract ( )   PDF (5017KB) ( )  

References | Related Articles | Metrics

In order to fully utilize the complementary characteristics between wind and solar power sources and reduce the fluctuations of renewable energy power generation, it is necessary to coordinately optimize the wind and solar power capacity proportion integrated in the multi-terminal voltage sourced converter high voltage direct current (VSC-HVDC) system. A method based on time sequence simulation is proposed to optimize the wind and solar power capacity proportion integrated in the multi-terminal VSC-HVDC system with a pumped storage power station. An optimization model is built aiming at maximizing the renewable energy power generation, which takes into account such constraint conditions as the operation modes of the VSC-HVDC system, the curtailment ratio of renewable energy, the system peak shaving demand and the operation limit of the pumped storage power stations. The annual outputs of the renewable energy are incorporated as inputs, the time sequence simulation is carried out to optimize the capacity proportion of wind and solar power. The proposed method is tested on a four-terminal VSC-HVDC system with a pumped storage power station. The testing results show that the proposed method can obtain the optimal wind and solar power capacity proportion integrated in the VSC-HVDC system, consequently realizing the objective of maximal utilization of renewable energy. The case study verifies the effectiveness and applicability of the proposed method, and can provide a useful guidance on planning renewable energy and the VSC-HVDC system.

Study on Power Optimization of the Trans-Regional UHVDC Delivery Channels in Promoting Renewable Energy Accommodation Capacity

DONG Cun, LIANG Zhifeng, LI Xiaofei, WANG Yuefeng, BAI Jie, WANG Shuai

2019, 52(4):  41-50.  DOI: 10.11930/j.issn.1004-9649.201806111

Asbtract ( )   PDF (5251KB) ( )  

References | Related Articles | Metrics

With the operation of trans-regional UHVDC transmission channels, the outbound delivery capacity of the "Three-North" (i.e., Northeast China, Northwest China and North China) regions has been increasing year by year. However, the problem of wind power and photovoltaic power curtailment has not been fundamentally solved. Based on the actual situation of power grid operation, the coordinated optimization of multi-region UHVDC outbound deliver power is studied to promote renewable energy accommodation of multiple regions. Firstly, the distribution characteristics of renewable energy power curtailment in typical areas are analyzed, and the complementarity of renewable energy generation power among different regions is studied. Secondly, an analytical model of renewable energy accommodation capacity is established with consideration of the power optimization of trans-regional UHVDC transmission channels. Finally, the effects of power complementation of trans-regional UHVDC transmission channels are predicted in promoting accommodation of renewable energy for multiple regions. The case study results show that the proposed optimization method for UHVDC operation can effectively improve the renewable energy accommodation capacity of the entire power system.

Optimal Dispatch Model of Grid-Connected Power Base Considering Photovoltaic Power and Concentrating Solar Power

MIAO Miao, LIU Sai, SHI Tao, GUO Yasen, ZHANG Yiqing, LI Junxian

2019, 52(4):  51-58.  DOI: 10.11930/j.issn.1004-9649.201711223

Asbtract ( )   PDF (5047KB) ( )  

References | Related Articles | Metrics

The construction of solar energy bases is developing from unitary photovoltaic power generation to multi-solar-energy utilization of photovoltaic power and concentrating solar power. By using the large capacity of thermal storage device of the concentrating solar power station and the fast climbing speed of steam turbine units, the grid-connected united power base of photovoltaic power and concentrating solar power will improve significantly in terms of the control and dispatch capability. Based on the operation mechanism, a two-stage optimal dispatch model of photovoltaic and concentrating solar power is established based on improved particle swarm optimization algorithm. The objective of the first stage optimization is to reduce the peak-valley difference of the equivalent load and improve the load curve, and the second stage optimization objective is to minimize the total cost of power generation. The model satisfies the main operation constraints of the photovoltaic power and concentrating solar power stations and the traditional security constraints of unit commitment, which is suitable for grid-connected dispatch operation of the united power base. In the premise of full acceptance of solar power, a ten-machine example system is simulated, and the benefits of the power base are analyzed in terms of the peak-valley difference reduction, the renewable energy consumption and the total cost of power generation. The sensitivity analysis indicates that it is economically significant in planning and construction of the power base to select the appropriate capacity of the steam turbine and the thermal storage device.

Study on Icing and Contamination Flashover Characteristics and Critical Flashover Current of Composite Insulators

WU Gaolin, ZHOU Qing, XIAO Qianbo, HU Jianlin, BI Maoqiang

2019, 52(4):  59-65.  DOI: 10.11930/j.issn.1004-9649.201801061

Asbtract ( )   PDF (3850KB) ( )  

References | Related Articles | Metrics

The electrical characteristics of the insulators are one of the key parameters for the design of the external insulation of the transmission lines. Insulator critical flashover current plays an important role in condition assessment and flashover warning for insulators. In this paper, the artificial pollution test and artificial icing test of the FXBW-110/100 composite insulators are carried out in the artificial climate chamber. The test results show that the contamination flashover voltage and icing flashover voltage of composite insulator decrease with the increase of salt density on the surface of the insulator, which can be fitted as the exponential expression. The fitting parameters of the exponential expression under contamination condition with and without ice are almost same. Therefore, the icing condition can be considered as a special form of pollution condition. The flashover voltage of the insulators with icing is lower than that of the insulators without icing under the same pollution conditions. The flashover voltage decreases with the increasing of the thickness of icing layer on the insulator. The critical flashover current of icing and contamination composite insulators increases with the increase of SDD. The relationship can be fitted as exponential expression under the same pollution conditions, the critical flashover current(Ic) of ice covered insulators is larger than that without icing.

Affecting Factors of Short-Circuit Currents of Busbar at UHV AC Substation

TANG Jinrui, YANG Fanqi, HOU Tingting, HUANG Juanjuan, SHAO Chong, WU Xiaoshan

2019, 52(4):  66-73.  DOI: 10.11930/j.issn.1004-9649.201804062

Asbtract ( )   PDF (3390KB) ( )  

References | Related Articles | Metrics

The affecting factors of short-circuit currents of 1 000 kV and 500 kV bus-bar at UHV AC substation are analyzed based on the components of corresponding self-impedance. And then the proportions of all factors to the short-circuit currents at 1 000 kV bus-bar and 500 kV bus-bar are proposed and determined, including the configuration of 1 000 kV power grid, the main transformer and the configuration of 500 kV power grid. The results indicate that the short-circuit currents of 1 000 kV bus-bar are greatly affected by the configuration of 1 000 kV power grid. The 500 kV power grid and the main transformer have a dominant influence on the short-circuit currents of 500 kV bus-bar at UHV AC substation. The results can provide theoretical support and decision-making reference for the optimization of short-circuit limit.

Experiment on AC Breakdown Characteristics of CF₄/CO₂ Gas Mixture

WANG Xingwei, PENG Yanqing, YUAN Chuanzhen, FU Feifeng, ZHANG Damin

2019, 52(4):  74-79.  DOI: 10.11930/j.issn.1004-9649.201808153

Asbtract ( )   PDF (3847KB) ( )  

References | Related Articles | Metrics

SF₆ is a widely used as gas insulating medium in electrical equipment at present, but its greenhouse effect has a great impact on the environment. Therefore, it is of great significance to study the environmental friendly gas insulating medium which can replace SF₆. CF₄ is a strong electronegative gas with low global warming potential (GWP) index and liquefaction temperature. In this paper, the power frequency breakdown characteristics of CF₄/CO₂ mixture were studied by power frequency breakdown test, and its synergistic effect, GWP value are also analyzed. The results show that the insulation strength of CF₄/CO₂ mixture with 50% CF₄ mixing ratio can reach about 90% of pure CF₄, and the GWP value is low, so it has potential for gas insulation. The synergistic effect of CF₄/CO₂ mixture is between 0.12 and 0.38, showing obvious synergistic effect.

Spatial Load Forecasting Method Based on Support Vector Machine and Internet Information Correction

GUO Yanfei, CHENG Lin, LI Hongtao, RAO Qiang, LIU Manjun

2019, 52(4):  80-88.  DOI: 10.11930/j.issn.1004-9649.201807020

Asbtract ( )   PDF (4669KB) ( )  

References | Related Articles | Metrics

In order to improve the spatial load forecasting accuracy of power system planning, a spatial load forecasting (SLF) method is proposed based on support vector machine (SVM) and Internet information correction. The method can be divided into three steps: firstly, based on k-means clustering analysis, the SVM model is used to get the initial prediction value of the block load; secondly, the deviation between the actual load value and the predicted load value can be calculated based on the historical data of the block load; and thirdly, those uncertain events that causes deviation, including the newly increasing load events in the cells and the mutation of revenue growth rate of the enterprises in the cells, are identified by Internet information that is obtained by search engine. The impact of the uncertain events on spatial load is qualitatively analyzed, and a quantitative impact model is established for classifying the events between these two events and their effects. Based on the model, the initial forecasting value of the load is corrected, and the final forecasting load values of the blocks in the planning area is obtained. A case study of an area in Beijing shows that this method can improve the prediction accuracy and can be used for spatial load forecasting in distribution network and energy Internet planning.

AHP-Based Comprehensive Monitoring Method of Transmission Section

WANG Yang, XU Biao, ZHOU Chaofan, YIN Xianggen, YAN Faqi, SHEN Yuliang

2019, 52(4):  89-95.  DOI: 10.11930/j.issn.1004-9649.201708088

Asbtract ( )   PDF (3576KB) ( )  

References | Related Articles | Metrics

The power transmission section is an important monitoring and analysis object for the safe and stable operation of the power grid and the emergency handling of the faults. Enhancing the monitoring capability of transmission section is helpful to understand the real-time operation of power grid, and effectively improve the early warning ability of power grid security. In order to meet the demand of grid operation dispatching, this paper studies a comprehensive evaluation method of transmission sections based on the analytic hierarchy process (AHP) and proposes the quantitative calculation indicators for the safe operation of the transmission sections; The Delphi method is introduced to make full use of the experience of operation dispatching experts to improve the AHP, so as to reflect the relationship between the multiple indexes and the operation state of the transmission sections, and achieve a comprehensive monitoring of the transmission sections. This method is applied in the control center of a regional power grid, and the results show that this method can effectively improve the monitoring capability of power transmission section.

Study on Control Strategy of Back to Back MMC-HVDC Connecting Chongqing and Hubei Power Grid

FAN Yunlong, REN Jianwen, YE Xiaohui, LI Xia

2019, 52(4):  96-103.  DOI: 10.11930/j.issn.1004-9649.201804111

Asbtract ( )   PDF (4526KB) ( )  

References | Related Articles | Metrics

The construction of back to back MMC-HVDC connecting Chongqing and Hubei Power Grid has put forward higher requirements for the dynamic control capability of large-scale power grids. This paper first introduces the system structure of the project. After studying the basic MMC-HVDC control strategy, considering the demand of the actual project for the control effect on the system operation, this paper proposes a new double-loop control strategy based on the traditional power control, in which the limit of the voltage deviation is added. At the same time, the fault crossing logic of MMC-HVDC under severe AC faults is introduced. The simulation process combining control strategy and MMC-HVDC operating zone is also provided. Finally, The PSD-PSModel is used to simulate the Chongqing-Hubei system. The results verify the effectiveness and correctness of the proposed control strategy for large-scale networked projects.

A Hybrid Transfer Learning/CNN Algorithm for Cable Tunnel Rust Recognition

ZHOU Ziqiang, JI Yang, SU Ye, CAI Junyu

2019, 52(4):  104-110.  DOI: 10.11930/j.issn.1004-9649.201808121

Asbtract ( )   PDF (2364KB) ( )  

References | Related Articles | Metrics

With the continuous development of the power industry, the laying of high-voltage cables and the construction and maintenance of underground cable tunnels have gradually become one of the hot issues in this field. This paper proposes a cable tunnel rust recognition method based on the integration of transfer learning and the classical convolutional neural network (LeNet5), which is able to realize the specific rust recognition of some electrical devices, such as the internal power box, fan and other equipment. The whole recognition process is based on the Tensorflow framework, and is able to solve such problems as insufficient training samples, long training time, and low recognition accuracy. Furthermore, by comparing with four classical target recognition algorithms, the proposed scheme is proved to be superior in terms of training time and recognition accuracy. The entire scheme provides a solid theoretical basis and experimental support for the realization of subsequent cable tunnel inspection robot system.

Obstacle Recognition and Location of Inspection Robot for High-Voltage Transmission Lines

ZHANG Feng, GUO Rui, LU Shibin, LI Zhenyu, YANG Bo, SUN Xiaobin

2019, 52(4):  111-118.  DOI: 10.11930/j.issn.1004-9649.201805103

Asbtract ( )   PDF (2710KB) ( )  

References | Related Articles | Metrics

According to the geometric shape and structural characteristics of the obstacles on the ground wire of high-voltage transmission lines, a method based on monocular visual recognition for the recognition and location of obstacles on multi-sensor high-voltage lines is proposed. Use the camera on the robot body to obtain the image, and then determine the type of the obstacle based on the geometry features of the obstacle. A distance measuring geometric model is established based on the recognized positional relationship between the obstacle feature point and the camera, thereby calculating the distance from the robot to the obstacle. When the robot is very close to obstacles or is passing through obstacles, the camera positioning method is not applicable. In this case, photoelectric sensors and dynamic inclinometers installed on the robot can be used in combination with the robot's running speed and the sensor's acquisition signal. The changes can identify the key points of the obstacle and calculate the specific position that has reached the obstacle.

Study on Steam Temperature Regulation Characteristics in Flexible Ultra-supercritical Boiler with Double Reheat Cycle under Wide Loads

XU Wei, ZHANG Jian, FAN Haojie, ZHANG Zhongxiao, SUN Weiting

2019, 52(4):  119-126.  DOI: 10.11930/j.issn.1004-9649.201811131

Asbtract ( )   PDF (4750KB) ( )  

References | Related Articles | Metrics

A cell-divided model of double-reheat boilers for thermodynamic calculation is established, in which the formula of the gas temperature at the furnace outlet is revised by using the convective heat volume of high temperature heating surfaces in the furnace. The model is validated on a domestic 660 MW double-reheat boiler. Based on this model, the impacts of tilting burners, adjustment of gas dampers and gas recirculation on the steam temperatures are studied, and the characteristic curves of the steam temperature change with respect to various regulating methods are obtained. From the results it turned out that the main steam temperature is more sensitive to gas recirculation. For every 1% jump of the recirculation rate, the main steam temperature drops by 0.8 ℃. Besides, the reheat steam temperatures are more sensitive to gas damper adjustment. For every 1% increase of the damper opening in front flue, the primary-reheat steam temperature rises by 1 ℃, while the secondary-reheat steam temperature drops by 1.7 ℃.

Feasibility Study on Combined Application of Ethanolamine and Ammonia in the Secondary Circuit of Nuclear Power Plant

ZHAO Yongfu, JIANG E, GONG Bin, WEN Juhua, TANG Min, YIN Zhaohui, HE Yanchun

2019, 52(4):  127-132.  DOI: 10.11930/j.issn.1004-9649.201810041

Asbtract ( )   PDF (4168KB) ( )  

References | Related Articles | Metrics

The problems from the usage of single alkalinity treatment were analyzed and then the countermeasures and basic standards of combined application of ethanolamine (ETA) and ammonia in the secondary circuit of nuclear power plant (NPP) were put forward in order to further optimize water chemistry condition and reduce chemical operation cost. With various combination ratios of ethanolamine and ammonia, the alkalinity concentration and pH values at different parts of secondary circuit of a typical nuclear power plant were calculated by CHEMWORKS. The optimum concentration ratio and range of ethanolamine and ammonia were filtered and verified by theoretical calculation and autoclave tests. The results show that satisfactory outcome can be attained in practice when the concentrations of ethanolamine and ammonia in the feed-water of secondary circuit meet the following requirements: w_ETA:w_NH3≈4:1, 2×10^-6≤w_ETA≤4×10^-6, 0.5×10^-6≤w_NH3≤1×10^-6.

Study on the Effects of Low Pressure Economizer on Turbine Exhaust Volume

PANG Le, ZHAO Yuzhu, ZHANG Shuai, LI Peng

2019, 52(4):  133-137.  DOI: 10.11930/j.issn.1004-9649.201809062

Asbtract ( )   PDF (4256KB) ( )  

References | Related Articles | Metrics

In order to evaluate the effectiveness of utilizing the heat absorbed by the low-pressure economizer, based on the fundamental principles of the equivalent enthalpy drop method, a general computation model is established for the influence of extraction and injection of the condensate in the low-pressure heating system on the exhaust volume of the steam turbine. Then, a general model is derived to compute the influence of the low-pressure economizer on the steam turbine exhaust volume when operated under various connection modes. Taking a domestic 330 MW unit as an example, using the computation model proposed in this paper, the increments of the steam exhaust volume and exhaust losses under two different operating conditions are obtained respectively, which shows that only about 10% of the thermal energy absorbed in the low-pressure economizer is reused by the steam turbine to produce power, while the rest of the heat eventually becomes part of cold source loss.

The Improvement of Primary Frequency Regulation Functionality and Its Application in a 660 MW Cogeneration Unit

YU Mingshuang, ZHANG Peng, WANG Guocheng

2019, 52(4):  138-143.  DOI: 10.11930/j.issn.1004-9649.201809099

Asbtract ( )   PDF (4536KB) ( )  

References | Related Articles | Metrics

Due to the issues that came up after the commissioning of a 660 MW supercritical cogeneration unit, such as high heating load consumption and frequent frequency fluctuations, the passing rate of primary frequency control compensation only hover around 50% under the original control logic. By means of completing the triggering logic and tuning the initial action value, the action speed of primary frequency compensation is improved. In addition, by working out the sliding pressure curve in heating operation mode, adjusting the dynamic compensations of pressure deviations and heating loads, in combination with the modifications of the flow characteristic curve through steam turbine flow testing, the improvement of primary frequency control logic is accomplished, which makes the target of passing rate of primary frequency control over 85% achieved.

Analysis of Coupling Effect between the Height of SCR Rectifier Grid and the Catalyst Installation Height

GAO Jianqiang, LIANG Shengying, WEI Riguang

2019, 52(4):  144-150.  DOI: 10.11930/j.issn.1004-9649.201807102

Asbtract ( )   PDF (4218KB) ( )  

References | Related Articles | Metrics

The uniform flow field and concentration field in the SCR reactor are essential to achieving high denitrification efficiency. In this paper, by taking the SCR denitration reactor of a 1 000 MW coal-fired unit as the research object, its structure is thoroughly studied. The optimal spacing and height of rectifying grille are then determined from digital simulation, and the coupling effect of the ratio of rectifying grille height to the installation height of the first catalyst layer (denoted as c) on the flow field and concentration field uniformity is further simulated and verified through a series of experiment. The results show that the grid spacing should not be too large or too small, which is recommended at around 0.2 m. When the value of c increases, the velocity deviation of the first layer catalyst will increase. When the value of c is greater than certain threshold, the velocity deviations will jump sharply at all different grid heights. Particularly with the grid height at 0.8 m, the distance between the rectifying grille and the first layer catalyst can be increased correspondingly, and the value of c can be relaxed to 0.8.

Study on the Oxidation Effects of Commercial SCR Catalyst on Elemental Mercury (Hg⁰)

QU Litao, LI Caiting, TAO Li

2019, 52(4):  151-155,160.  DOI: 10.11930/j.issn.1004-9649.201806025

Asbtract ( )   PDF (5332KB) ( )  

References | Related Articles | Metrics

In order to develop a novel integrated catalyst with better joint removal effects on various pollutants such as NO_x and mercury in the flue gas, the oxidation effects of commercial SCR denitration catalyst on elemental mercury (Hg⁰) and its influencing factors were studied in this paper. The oxidation reaction mechanism of Hg⁰ was also explored. The experimental results show that the SCR catalyst has some certain oxidation effects on Hg⁰ in flue gas. However, its maximum oxidation efficiency on Hg⁰ is still below 50% even at the optimum reaction temperature of 250~300 ℃. In the presence of low concentration of NO and 5% O₂, the catalyst has a relatively high oxidation efficiency for Hg⁰. While in the presence of SO₂, the oxidation of Hg⁰ was apparently inhibited, and the toxicity of SO₂ to the catalyst was basically irreversible. Moreover, there exists a competitive relationship between NH₃ and Hg⁰ in the adsorption process. So the presence of NH₃ reduces the oxidation efficiency of Hg⁰ by the catalyst. It also appears that the presence of H₂O has significant negative impact on the oxidation of Hg⁰.

Exploring the Environmental Protection Management of Thermal Power Industry within the Pollution Discharge Permit System

XU Zhen, YANG Guangjun, LING Xiaofeng, WANG Zhigang, ZHOU Ying

2019, 52(4):  156-160.  DOI: 10.11930/j.issn.1004-9649.201810081

Asbtract ( )   PDF (3865KB) ( )  

References | Related Articles | Metrics

As an important initiative to speed up the reform process of ecological civilization system, the pollutant discharge permit system highlights the main responsibilities of pollutant discharge business entities. Having been one of the first few industries to be issued with emission permits, the thermal power industry has been focusing on "emission by license, self-compliance with the law" as the vital principle of daily environmental protection and management. According to the characteristics of thermal power generation, this paper analyzes the typical problems existing in the process of implementing pollutant discharge permit in thermal power plants, and puts forward suggestions from the aspects of completing technical support system as well as the optimization of enterprise mechanism and system.

Research on Co-removal and Emission of Trace Elements in the Coal-Fired Power Plant

CHE Kai, ZHENG Qingyu, HAN Zhongge, CHEN Chongming, YU Jinxing

2019, 52(4):  161-166.  DOI: 10.11930/j.issn.1004-9649.201805230

Asbtract ( )   PDF (4232KB) ( )  

References | Related Articles | Metrics

In order to study the distribution and enrichment of the trace elements in the emissions from power plants and the synergistic removal of the trace elements from conventional pollutant purification facilities(SCR, ESP, WFGD, WESP), the concentration of the trace elements (Be, Cr, Mn, Co, Ni, As, Se, Cd, Sb, Pb, Hg) in the emissions of smoke and air pollutant control devices are tested by using US EPA Method 29 in a 350 MW coal-fired power unit. The results show that the trace elements that are mainly distributed in the fly ash and the gypsum takes 54.51%~97.58% and 1.61%~38.08% respectively of the total amount of emitted trace elements, while much less are distributed in the bottom ash and the chimney inlet flue gas. The overall removal rate through air pollutant control devices is 91.98%~99.98%. The concentration of trace elements in the stack is 0.02~9.23 μg/m³, and the concentration values of Mn, As, Se, Pb concentrations are much higher than the ones that are required for the new coal-fired unit trace elements emission quality standards issued by EPA.

An Overview of Energy Storage Applications in Power Systems with High Penetration Renewable Energy Resources

ZHAO Jian, WANG Yifan, XIE Hua, ZHOU Ning, SUN Qian

2019, 52(4):  167-177.  DOI: 10.11930/j.issn.1004-9649.201801166

Asbtract ( )   PDF (6917KB) ( )  

References | Related Articles | Metrics

Due to its intermittency and power fluctuations, the large-scale renewable energy resources, may cause negative impacts on power quality, security and stability, etc. when integrated into the power grid. An effective solution is thus provided by virtue of the energy storage technology for power systems with high penetration renewable energy resources. In this paper, after combing through the existing types and typical applications of energy storages, the basic models containing energy storage part and electricity conversion part are summarized, and the control strategies are given from single point control to multiple points coordination control. Then the application scenarios of energy storages in power systems are analyzed including power fluctuation stabilization, peak load shifting, transmission capacity improvement, power quality improvement, frequency modulation and system operation safety enhancement, and so on. In addition, the development trend of large-scale application of energy storage is explored in the aspects of the device development, planning optimization, operation control and business mode. Furthermore, the positive role of energy storages in energy internet is discussed.

Wind Power Curtailment Index and Sequence Model for Power Systems

WANG Lili, QI Yongzhi, HUANG Yuehui, ZHANG Nan, WANG Yuefeng, WANG Weisheng, LIU Chun, LI Min, DU Chengrui, WANG Jinlong

2019, 52(4):  178-184.  DOI: 10.11930/j.issn.1004-9649.201707067

Asbtract ( )   PDF (6536KB) ( )  

References | Related Articles | Metrics

With the rapid increase of wind power curtailment, the wind power curtailment issue becomes a serious problem. In this paper, the evaluation indexes of the wind power curtailment sequence of power system are put forward: the distribution of the wind curtailment period, wind curtailment continuous duration and wind continuous curtailment generation. A method of wind curtailment sequence model based on the time sequence production simulation is proposed. Wind curtailment sequence is calculated based on the renewable energy time sequence production simulation which maximizes the integration of renewable energy. The simulation results show the validity of the wind curtailment model method based on the time sequence production simulation by comparing the actual sequence and simulated sequence characteristic of the wind curtailment. At the same time, under the circumstance of high proportion of wind power, the ratio of long wind curtailment continuous duration increase significantly and the wind power curtailment problem becomes more serious.