Email alert
RSS2019 Vol. 6, No. 3
Display Method:
2019, 6(3): 1-5.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.001
Abstract:
[Introduction] Energy storage is an important component and key supporting technology of Energy Internet. It can provide various services such as peak shaving and frequency modulation. It is an important means to enhance the flexibility, economy and safety of traditional power system. [Method] This paper reviewed the characteristics of the existing main energy storage technologies, and analyzed the functions and requirements of energy storage at power supply side, user side and grid side. According to the status quo of application, the key issues of safety, economy and business model of energy storage are pointed out. [Result] The results show that the energy storage operation simulation, multiple combination utilization, combination of concentration and dispersion should be strengthened from the perspective of energy storage application. [Conclusion] This work provides some guidance for further study on the application research and development of energy storage technology.
2019, 6(3): 6-16.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.002
Abstract:
[Introduction] The selection of types and sites of underground repository for compressed air storage is one of the most important issues of large scale compressed air energy storage (CAES) plant planning. [Method] The advantages and disadvantages of 4 types of underground repository for compressed air storage were concluded based on comparison of analyzing literatures published domestic and oversea. The geology characteristics and distribution region of the suitable hard stratum for construction of underground rock cavern were also analyzed. The technology feasibility of rock cavern for compressed air storage was validated by the in-situ experiment results obtained from the first pilot repository for CAES in China. Sites planning method of underground repository for large scale CAES plant was studied taking Guangdong province for example. [Result] Rock caverns built in salt and hard rock stratum are the most feasible types of the underground cavern for CAES plant and hard rock stratum widely exists in most windy and solar energy abundant aera in China. [Conclusion] Wide distribution of the suitiable stratum for underground cavern construction in intermittent energy generation area solves the difficult problem of site selection for large scale CAES plant. Experiment data indicates that good quality of the rock mass is helpful for the solution of key problems such stability and sealing of underground cavern. All in all, it is feasiblity in technology at the present stage in China.
2019, 6(3): 17-26.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.003
Abstract:
[Introduction] In recent years, the attention paid to the development of energy storage technology and energy storage industry has continued to heat up. [Method] Review of compressed air energy storage technology (CAES) progress and its commercial application scenarios have been summarized in this paper. CAES research teams and their technical characteristics were summarized, which reflected the development direction of CAES technology. Meanwhile, the configuration parameters and operation experience of two commercial CAES power stations (Huntorf station and Alabama station) were introduced. The demonstration progress of various new CAES technologies was also reviewed. These review on CAES technologies, commercial power stations and demonstration stations can provide reference for the development of domestic CAES technology and the development of energy storage industry promoted by national ministries in China. At the end of this paper, the adaptability and application potential of CAES technology were analyzed from three aspects: electricity generation side energy storage, grid side energy storage and user side energy storage. [Result] The two CAES power stations in Germany and the United States have tested the long-term reliability of CAES power plants. The CAES demonstration projects with capacity from 500 kW to 10 MW have been built in China. It indicates that this energy storage technology has achieved breakthroughs from the theoretical research stage to the demonstration verification stage in China. [Conclusion] In the current policy environment, the user-side peak-to-valley electricity price policy is a typical boundary condition for energy storage application scenarios, which can be considered in the application of CAES technology.
2019, 6(3): 32-39.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.006
Abstract:
[Introduction] Economic development and environmental protection are in the focus of attention of specialists in various disciplines regarding the future development of society. On the globe energy chessboard, all kinds of questions, such as energy strategy, direction of energy development, low carbon and energy saving solutions, become quite confusing and challenging to professionals in the China energy and power industry. [Method] This paper introduced the engery policies and trends of our country, and explained that the energy revolution is a policy-oriented and goal-driven process. Based on the current international and domestic situation regarding resources and environment, this paper sorted out the development direction of energy power: to improve energy efficiency and to adjust energy structure, by the means of clarifying the concepts of some main indicators, such as energy intensity , climate intensity of energy use and energy technology efficiency, and providing the quantitative analysis and comparison for energy structure. Meanwhile, for the problem of low carbon and emission reduction, which is inseparable from the energy development, the quantitative analysis and application prospect are discussed from the two aspects of emission reduction and centralized treatment after emission. [Result] As a result, this paper demonstrates that the key to successful energy developemnt lies in scientific and technological innovation and adjustment of energy structure so as to enhance energy efficiency, develope renewable energy, and accelerate the transformation from traditional energy to clean energy. [Conclusion] This work provides readers with a clear and basic understanding of energy trends for low carbon economy and sustainable social development. China is in the process of changing from fossil fuel-driven economic development model to sustainable development model.
2019, 6(3): 40-47.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.007
Abstract:
[Introduction] The paper aims to reduce the intermittent, random, uncontrollable effects of DERs capacity represented by wind and solar energy, and to participate in the competition in the power market, a community-based energy Internet model is proposed. [Method] Considering a community-based energy Internet model consisting of a virtual power plant (VPP) cluster consisting of a wind farm, a photovoltaic power station, and a load, interconnecting a single VPP, and based on the balance of supply and demand within a single VPP, the surplus power game sharing through VPP clusters, and finally trading with the electricity market to achieve reverse sales. [Results] The results we obtained demonstrate that the goal of maximizing the benefits of community-based energy Internet, and adding demand response (DR) to achieve the purpose of saving electricity for users. [Conclusion] This work through the community energy Internet demonstration project, the VPP operation strategy model is proposed, and the feasibility of verifying the power generation strategy in different scenarios is established through the established benefits, which indicates the direction for the construction and transaction of the community energy Internet.
2019, 6(3): 48-53.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.008
Abstract:
[Introduction] With the increasing maturity of distributed energy storage technology, distributed energy storage systems have received extensive attention in the industry, and various demonstration projects have been put into operation. However, the comprehensive benefits of user-side distributed energy storage projects often involve multiple parties such as investors, operators, users and regulatory parts, and are closely related to the user's load characteristics and energy storage system operation strategy, scientific and reasonable and convenient. The comprehensive benefit assessment method has become a key technical issue for a wide range of distributed energy storage projects. [Method] According to the equipment and assets of distributed energy storage projects, this paper combined the user load curve to divide multiple typical operation scenarios, so as to map the cost, function, benefit and related parties of various project assets in different scenarios. Its comprehensive efficiency and benefits were analyzed according to the internal operation mechanism of the project and the external market mechanism. [Results] Using this method, a more quantitative and objective comprehensive benefit evaluation can be carried out for a wider range of distributed energy storage projects. [Conclusion] Based on practical engineering examples, the proposed method is accurate and effective, and provides method support for project investment operation mode and technical solution decision-making.
2019, 6(3): 54-58.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.009
Abstract:
[Introduction] Base on the wind power, photovoltaic, small hydropower, coal-bed methane power generation and other intermittent energy with volatility and randomness, large-scale intermittent energy will bring great influence on the power grid′s safe and stable operation and control after connected to the power grid, and the traditional power grid operation control system can′t completely adapt to the operation control for large-scale intermittent power. In order to realize the operation control of the intermittent energy, it is necessary to study the intermittent energy control system. [Method] In the paper, designed the system architecture, key application technology of multi-energy joint operation control system base on the characteristics of intermittent power, provided technology support for the control of the intermittent power. [Result] Multi-energy joint operation control system has realized the intermittent power to participate in power grid operation control, and improved the ability to deal with the intermittent power fluctuation. [Conclusion] The system has been applied in Guizhou power grid, and has been proved the feasibility of control of the intermittent power.
2019, 6(3): 59-63.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.010
Abstract:
[Introduction] To supply energy for industrial users in an economical and efficient way, an energy supply unit model in distributed energy system (DES) is established based on coupling characteristics of electric and thermal loads, and optimal operation strategy is proposed. [Method] Taking an industrial park in Guangzhou as the research object, combined with the actual load data, the optimum parameters were reasonably determined, annual power generation, gas consumption and energy efficiency were calculated, and the impact of load increment was studied. [Result] The results show that the start-up thermal load of unit has a great influence on the annual power generation of DES. With the optimized operation strategy, the annual power generation can be increased by 18.7%, and the self-power supply ratio of the park can be increased. The energy efficiency is more than 85%. [Conclusion] The optimal operation strategy is correct and effective. It can be applied to the optimization of thermo-electric coupled DES, effectively enhance the energy supply of DES with high energy efficiency.
2019, 6(3): 64-69.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.011
Abstract:
[Introduction] In order to improve the operational flexibility of the gas turbine combined cycle unit, ensure better economic performance of the unit, and avoid the gas turbine working in the inefficient operation area, this paper analyzes and studies the inlet air cooling system of the gas turbine. [Method] The performance change and its influencing factors and the efficiency sensitivity analysis of gas turbine combined cycle unit were studied according to the thermal balance simulation results of considering inlet air cooling or not, based on the GT-Pro/GT-Master software platform. [Result] The analysis results show that the output and efficiency of the gas turbine are greatly improved after using the inlet cooling system, and the output of the combined cycle unit is also increased while the efficiency is slightly reduced. [Conclusion] Therefore, for the combined cycle unit, if the unit is supposed to generate more power, the inlet air cooling system should be used; if the total annual output of the unit is fixed and the annual utilization hours are relatively small, the inlet air cooling system should not be used.
2019, 6(3): 70-74.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.012
Abstract:
[Introduction] The paper aims to improve the efficiency and accuracy of integrated energy system planning, this paper develops and studies the park integrated energy system analysis platform. [Method] Based on the construction of integrated energy system in parks including building parks and industrial parks, this paper made a theoretical study on the overall scheme design method of integrated energy system in parks, the influencing factors and analysis methods of comprehensive energy project benefited in parks, and the platform construction of integrated intelligent energy management platform, then put forward corresponding platforms based on the theoretical research results. The idea of tool development and platform tools was used to assist the planning and design of integrated energy system and the analysis of investment and operation benefits. [Result] The platform research results show that the integrated energy scheme can be automatically generated and the accuracy and efficiency can be improved. [Conclusion] The research results of the project are expected to provide some reference and guidance for the construction and operation of comprehensive energy projects in the following parks.
2019, 6(3): 75-80.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.013
Abstract:
[Objective] Energy Internet is a complex system that optimizes energy efficiency, load and power grids to achieve optimal energy efficiency. The evaluation index system and comprehensive evaluation of planning schemes are key issues that must be solved in the park′s energy internet planning. [Method] Based on the role of energy internet, an evaluation index system for energy internet planning was conducted and the definition and calculation method of each index in the system was performed. Furthermore, a quantitatively evaluates method based on the analytic hierarchy process was proposed in this paper and the application of the indicator system and evaluation method was analyzed. [Results] By the method proposed, a more quantitative and objective comprehensive benefit assessment can be conducted for energy Internet projects in various parks. [Conclusions] The analysis of the example shows that the proposed method is accurate and effective, which provides method support for project investment operation mode and technical solution decision-making.
2019, 6(3): 81-86.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.014
Abstract:
[Introduction] In order to analyze the influence of excess air coefficient on the combustion stability of the furnace under the ultra-low load operation conditions of the thermal power unit, the unit is better guided to participate in peak shaving. [Method] In this paper, through in-depth analysis of boiler operation and heat transfer mechanism in the furnace, the combustion temperature of the furnace was characterized by the outlet temperature of the furnace, and as the index of combustion stability, the furnace exit smoke temperature model was built in MATLAB/SIMULINK. Taking a 300 MW thermal power generating unit as an example, the paper first selected several typical operating conditions. Then the similarity solving method was used to calculate the furnace exit smoke temperature and compare with the design data given by the boiler manufacturer. Finally the test calculation method was basically correct and then substituted into ultra-low load operation parameters which calculated the furnace exit smoke temperature corresponding to different excess air coefficients under deep peaking conditions. [Result] The simulation results show that the model calculates the furnace temperature and the design data given by the boiler manufacturer. The calculation error is less than ±15°C, and the calculation method is basically correct. It can be applied to the calculation of ultra-low load conditions. [Conclusion] As the load is reduced, the optimum excess air ratio that maximizes the flue gas temperature at the exit of the furnace is gradually increased. Therefore, under the condition of ultra-low load operation, the excess air coefficient can be appropriately increased within a certain range to increase the flue temperature of the furnace outlet, thereby improving the stability of the combustion of the boiler, and when the excess air ratio is less than 2.0, the value is higher, the temperature is higher.
2019, 6(3): 87-91.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.015
Abstract:
[Introduction] The high exhaust temperature of gas turbine can increase the bottom cycle and generate electricity by using the waste heat of exhaust gas, so as to improve the total energy utilization rate of fuel. In view of its high thermal efficiency, simple system, compact structure, flexible operation and other potential advantages, supercritical CO2 cycle can be combined with gas turbine to form a new type of gas-supercritical CO2 combined cycle. [Method] In order to make full use of the exhaust heat of the gas turbine, a simple regenerative supercritical CO2 cycle was constructed on the basis of a simple regenerative supercritical CO2 cycle, and the thermal efficiency of the PG9351 (FA) gas turbine was calculated and analyzed. At the same time, by adding waste heat utilization device in the system, the residual heat could be used for heating, converting into cold energy or generating electricity. [Result] The results show that for the selected gas turbine, the maximum temperature of supercritical CO2 cycle can reach 600 C, the cycle power generation efficiency is about 32%, the heat recovery temperature is above 170 ℃, the heat recovery accounts for 9% of the exhaust heat of gas turbine, and the combined cycle power generation efficiency is about 54%. [Conclusion] The gas-supercritical CO2 combined cycle power generation system has high thermal efficiency and retains some high-grade waste heat, which can be further used in power plant operation.
2019, 6(3): 92-97.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.016
Abstract:
[Introduction] The study of power grid operation planning plays an important role in power system and has decision-making significance for power distribution, which is a multi-constraint combinatorial optimization problem in fact. Research is mainly focused on the wind power cost calculation model. [Method] In view of various constraint conditions that generation expansion planning need to consider, particle swarm optimization (PSO) was used to solve this kind of objective optimization problem, and the traditional PSO was optimized based on simulated annealing theory. [Result] Numerical examples confirmed the superiority that can be found an optimal power output scheme to satisfy various constraints by comparison with the particle swarm algorithm and genetic algorithm. Finally, the influence on wind power grid connected operation cost under different wind speed were further analyzed. [Conclusion] It is feasible and effective to apply this model to power grid planning and analysis.
2019, 6(3): 98-104.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.017
Abstract:
[Introduction] (The SOH(State of Health) evaluation of lithium-ion batteries is difficult to meet the on-board environment requirements of electric vehicles because of the dispersion of evaluation results was caused by the inconsistent characteristics of batteries. [Method] To solve the problem, the corresponding changes of open circuit voltage curve, pulse voltage response and incremental capacity curve of typical energy storage component NCM battery during life cycle test were analyzed. 6 characteristic variables which were closely related to the battery capacity loss were selected, and a comprehensive SOH evaluation method based on fuzzy logic was proposed. In this method, membership function was used to establish the relationship between SOH evaluation sets and variable indicators, and analytic hierarchy process based on correlation coefficient was used to determine the weights of variable indicators that have an impact on the evaluation results. Finally, the validity of the proposed method was verified by four NCM-21700 batteries that completed the life cycle test. [Result] The results show that the method can effectively reduce the dispersion of SOH evaluation, and the average error is not more than 3% as well as the maximum error is no more than 5%. [Conclusion] This work provides some guidance for further study on state of health evaluation of lithium-ion batteries.
2019, 6(3): 105-112.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.018
Abstract:
[Introduction] In order to evaluate the distribution network more reasonably and objectively. [Method] This paper established a scientific and reasonable evaluation system of distribution network from these five aspects, and extracted the implicit data of distribution network indicators by principal component analysis. The internal relationship made the weight of each index objectively and reasonably calculated. Fuzzy comprehensive evaluation method was applied to evaluate the whole distribution network situation more comprehensively and accurately, in which the interval of actual data scoring results was divided and the evaluation grade standard of quantitative index in the fuzzy comprehensive evaluation method was unified. [Result] So as to solve the problem, fuzzy comprehensive evaluation method can not deal with a large number of quantitative index data, which reduced the computational complexity, while maintaining the accuracy of the evaluation results. [Conclusion] We demonstrate the evaluation of distribution network more real, reasonable and reliable. The example analysis of Jiangxi distribution network shows that the evaluation method is scientific and effective.
2019, 6(3): 113-119.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.019
Abstract:
[Introduction] To fill the shortcomings of traditional on-line power quality monitoring system, such as high deployment cost, large maintenance workload, low coverage and single function, which are highlighted under the higher requirement of information and intellectualization for the rapid development of UHV grid and new energy grid-connected technology. [Method] A method of identifying, extracting and calculating power quality characteristic parameters based on fault recorder data mining was proposed, and a system architecture of non-intrusive power quality monitoring, evaluation and decision support for wide area power grid using existing recorders and dispatching data network was designed. [Result] The results of pilot application show that the power quality indicators monitored by the system are comprehensive, the acquisition accuracy is better than the standard requirements, and the accuracy of event recognition and diagnosis is high. It has obvious advantages in station coverage, capacity of monitoring points, file upload, early warning and information delivery. [Conclusion] The design of the system is feasible and can extend and supplement the existing power quality online monitoring system in wide area power grid with a small input.
2019, 6(3): 120-125.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.020
Abstract:
[Introduction] Through the investigation of the implementation of the "3C Green Power Grid Construction Evaluation Standard" index, the applicability of the index is analyzed, and some suggestions for the revision and perfection of the evaluation index are provided. [Method] Since "3C Green Power Grid Construction Evaluation Standard" was published in 2013, it has effectively guided the construction of many substations, lines and distribution networks of China Southern Power Grid. The investigation included 52 substations in many places, for example, Guangdong, Guangxi, Yunnan, Guizhou, and Hainan province. There were 15 three-level substations, 15 two-level substations, 17 one-level substations, and 5 small extension project. Among them, 3-star projects 15, 2-star projects 15, one-star projects 17, 5 small expansion projects. [Result] The standard plays a positive role in guiding the construction of green power grid. After the completion of the evaluation project, the proposed green grade can be basically realized, which proves that most of the indexes can be implemented. Certainly, there are some problems, for instance, the guidance of indexes needs to be enhanced, and some indexes limits need to be adjusted. The application investigation of green power grid provides a good reference for the revision of the standard. [Conclusion] The next step of standard revision should be carried out from the direction of improving the guidance of the index and combining the technical development with the revision of the limit value of the index.
2019, 6(3): 126-131.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.021
Abstract:
[Introduction] In order to obtain the safe and economic operation plan of microgrid, a mathematical model of optimal economic operation of microgrid based on support vector machine regression theory was proposed. The load forecast of distributed power sources in microgrid was realized, and the distribution was analyzed according to real-time electricity price. The output of the power supply, and the corresponding theoretical basis. [Method] In order to construct the microgrid model as accurately as possible, aiming at the operating cost, environmental protection cost and comprehensive benefits of the system, a mathematical model of optimal economic operation based on common five distributed power sources was constructed, using Yalmip/CPLEX. The model was solved and the real-time output of each distributed power source was obtained. [Result] The calculation results show that the scheduling scheme with the comprehensive benefit can achieve the lowest operating cost of the microgrid, and coordinate the economic and environmental protection of the microgrid. [Conclusion] The model can lay a theoretical foundation for the research on the optimal utilization of microgrid grid-connected resources and the improvement of power supply reliability.
2019, 6(3): 132-138.
doi: 10.16516/j.gedi.issn2095-8676.2019.03.022
Abstract:
[Objective] The large-scale integration of new energy sources has led to an increase in the demand for peaking and frequency regulation of power grid systems. How to improve the market mechanism of power-assisted services has attracted wide attention. Moreover, with the maturity of energy storage battery technology and the advantages of the energy storage system itself, how the economic benefits of energy storage and participation in auxiliary services become a hot spot. [Methods] This paper focused on the development history of China′s power-assisted service market, and combined the data of regional auxiliary service market in the first half of 2018 to analyze the characteristics of auxiliary services in different regions and the trend of auxiliary service market mechanism under the situation of electricity reform; At the same time, it introduced the prospects and subsidy policies of energy storage in the auxiliary service market. [Results] Through the combing of market mechanism and subsidy policy, the huge prospects of energy storage participating in the auxiliary service market were clarified. [Conclusions] The example of thermal power combined with energy storage participating in AGC frequency modulation verified that the energy storage participation auxiliary service has good economics and provides decision support for relevant investors.
