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RSS2023 Vol. 10, No. 2
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2023, 10(2): 1-10.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.001
Abstract:
Introduction The research and development of offshore floating photovoltaic complies with the needs of national energy strategic development, caters to the background of industry development led by science and technology, and helps the development of emerging economic industrial chain. This paper aims to deeply explore the main components and core technologies of offshore floating photovoltaic system, and provide a theoretical basis for the development of offshore floating photovoltaic in China. Method Based on the existing research on offshore floating photovoltaic at home and abroad, this paper refined the relevant construction technology of flexible photovoltaic, verified the commercial feasibility of offshore floating photovoltaic development, introduced the configuration and composition of large-scale offshore floating photovoltaic (LOFPV) system, expounded the hydrodynamic design theory and method basis of flexible membrane structure and mooring system, and showed the typical engineering practice of offshore floating photovoltaic. Result Offshore flexible membrane-based floating photovoltaic has many advantages, such as lightweight, miniaturization, high power exchange efficiency and flexible configuration. In addition, the membrane structure is foldable, convenient for transportation, and convenient for installation, and the overall structure has no complex connector, so the system has high reliability and is convenient for operation and maintenance. Relevant achievements of this paper will provide great reference value for the development of China's offshore floating photovoltaic technology. Conclusion The functionality and reliability of flexible membrane-based floating photovoltaic construction technology are explained, and this flexible membrane structure will definitely be an important application type of offshore floating photovoltaic in the future.
2023, 10(2): 11-17.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.002
Abstract:
Introduction There is no study on the integration of the seawater pump-storage and offshore PV at present time in Guangdong Province. The basic conditions are available for the development of offshore PV and seawater pump-storage near sea shore while the sea can be used as the lower reservoir. So it is necessary to study and explore the integration of offshore PV and seawater pump-storage given that studies are done for the difficulties of seawater pump-storage and the development on the key technologies. Method The technical configuration was presented for the independent PV power station based on the past experience from PV projects. Software was used to simulate the PV power station. And an evaluation on economic performance was done for the independent PV power station. The technical configuration was presented for the independent seawater pump-storage power station based on the past experience from pump-storage projects. And an evaluation on economic performance was done for the seawater pump-storage power station. After consideration of the integration of offshore PV and seawater pump storage, the evaluation on economic performance for the integration of pump-storage & PV project was also made. Result The principle technical configuration is provided for the PV & pump-storage integration project. The economic performance with different capacity percentage for the pump-storage & PV integration project is evaluated. Conclusion The integration of PV & pump-storage in Guangdong Province area is a relatively feasible choice based on the actual conditions. This method can solve the unbalance and instability of PV power source with a certain capacity of pump-storage. And it also has a certain economic feasibility. This will be conducive to the "3060 Dual Carbon Goals", and provide market players access to invest in, build and operate power source projects. When the integration project reaches a positive income and a certain investment return rate, it will greatly promote the implementation and scale up of other integration projects.
2023, 10(2): 18-25.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.003
Abstract:
Introduction Energy storage is the basic condition for the development of new energy and the realization of carbon neutrality, where the pumped hydro storage is the most important energy storage method. However, pumped hydro storage depends on geographical conditions and needs to occupy a lot of natural resources, and excellent site resources are very limited. In order to alleviate the contradiction between the demand for pumped hydro storage plant site resources and the scarcity of natural resources, a compressed air energy storage system coupled with pumped hydro storage is proposed and analyzed from the perspective of research idea, conceptual scheme and engineering feasibility so as to provide innovative solutions for the development of the pumped hydro storage industry. Method By focusing on the improvement of the energy storage density, with the reduction of the reservoir capacity and height difference as the breakthrough point, the method of water drainage with compressed air was adopted. The pump turbine was replaced with compressor and expander, and the upper reservoir was changed into a pressure vessel with closed structure. When storing energy, air compressed by the compressor to high pressure and then filled into the lower reservoir to push the water from the lower reservoir to the upper reservoir. When releasing energy, the water returned from the upper reservoir to the lower reservoir, and the compressed air in the lower reservoir was pushed out and released by the expander. This could increase the energy conversion quantity of pumped hydro storage by several times under the same conditions. In order to demonstrate the energy storage effect of the compressed air energy storage power plant coupled with pumped hydro storage, a height difference of 300 m was set between the upper and lower reservoirs, and the thermodynamic analysis and energy storage efficiency calculation of the conceptual scheme of 40 MW/200 MWh were carried out according to the two sets of equipment parameters with low performance and high performance. Result The results show that the energy storage efficiency is 65.68% under the condition of low performance parameters and 70.81% under the condition of high performance parameters; the energy density is 1.67 kWh/m3. Conclusion The compressed air energy storage system coupled with pumped hydro storage can greatly reduce the reservoir capacity or height difference, significantly reduce the site demand and enable the areas with limited development of pumped hydro storage to have development conditions. Besides, the key equipment are mature, and the unit cost is close to that of the conventional pumped hydro storage. Therefore, this kind of compressed air energy storage system is technically and economically feasible.
2023, 10(2): 26-31.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.004
Abstract:
Introduction The world′s first 300 MW compressed air energy storage (CAES) power station is in Yingcheng City, Hubei Province, China. The station uses the existing underground salt cavern which is the best of its tight sealing and high capacity as gas storage, The parameters of the underground salt cavern, such as the underground salt cavity volume, shape, and depth, are crucial for the construction feasibility of the CAES power station. Method Based on the Yingcheng CAES power station project practice, this paper analyzed and summarized the many key problems and processing techniques of the high precision 3D seismic geophysical exploration methods in detecting deep salt cavity shapes. Result For the purpose of proving the occurrence characteristics of existing underground salt cavity, the 3D seismic geophysical exploration observation system shall be designed to meet the high resolution requirements, and the CDP gridding shall have an accuracy of at least 5 m×5 m, in order to make sure the fold number of the target area is more than 30 times. It is indispensable to improve the salt cavern 3D seismic data quality by conducting static correction and pre-stack denoising. Consistency processing technique is used and accurate velocity field is constructed according to different excitation and receiving conditions to realize precise depth homing. We find the track integral attribute, reflection strength attribute and sweetness attribute have an obvious advantage in identifying salt cavern space distribution, while edge detection attribute has a strong indication on cavity border depiction and connectivity. Conclusion Through research on key techniques of data processing and interpretation in geophysical exploration, the salt cavity parameters such as volume, shape, and depth are clearly detected to provide detailed and reliable data support for the salt cavern project. Research on the key problems and techniques of the 3D seismic geophysical exploration for the salt cavern can provide reference to the construction of large-scale CAES power stations of underground salt cavern type.
2023, 10(2): 32-38.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.005
Abstract:
Introduction The compressed air energy storage power station lacks corresponding codes as technical support in the design of main power House. There are some controversial and inapplicable provisions in the Code for design of compressed air station, which is difficult to meet the needs of the current large-scale development of compressed air storage power station. The paper aims to solve these critical problems in the implementation of the codes and to find better design schemes for the main power House. Method The explosion risks of the air energy storage compressor were analyzed, an economic comparison between the combined power House design and the separate power House design was made, and the storage volume of compressed air in the compressor room was sorted out and summarized. Result The results show that the air energy storage compressor has no chemical explosion hazard, and no physical explosion hazard on the premise that the equipment′s quality meets the standard. Combined power House design can save a lot of investment compared with separate power House design. The storage volume of compressed air in the compressor room is smaller than that of the main power House. Conclusion From the perspective of process flow, system integration, overall economy, convenient operation and maintenance, combined power House design is recommended for the main power House of a large-scale compressed air energy storage power station. According to the process layout and maintenance operation requirements, large platform structure is also recommended. A class-A fire door can be set up when the compressor power House is adjacent to other rooms, and the door buckets together with other protective measures should be set up.
2023, 10(2): 39-47.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.006
Abstract:
Introduction The co-combustion of coal and solid waste can not only realize the energy recycling of solid waste, but also is one of the paths to realize carbon emission reduction of coal-fired power generation. Method This paper reviewed the study on co-combustion of coal and solid waste in coal-fired power plants, and mainly introduced the combustion application and technology development of co-combustion of coal and different solid wastes based on the current mainstream power plant boiler as a reactor; Evaluated the development of co-combustion technology of coal and solid waste from the perspectives of fuel economy, fly ash characteristics of mixed fuels, pollutant emissions, and carbon tax; Finally discussed the characteristics of direct and indirect mixing technologies. Result Direct co-combustion of coal and solid waste is required to minimize the impact on boiler operation, especially the emission of gas pollutants, the impact of fly ash on heat transfer surfaces, and the harmless disposal of fly ash. Indirect co-combustion can avoid the influence of mixed fuel combustion on the furnace, but requires high hardware cost investment and more complicated coupling technology. The oxygen-enriched combustion technology still needs to optimize the existing boiler structure to improve the applicability of the technology. Conclusion The direct co-combustion is better than the indirect co-combustion considering the realizability and the cost, and the extensive adaptability of circulating fluidized bed fuel is conducive to the application of direct co-combustion technology of coal and solid waste. With the development of the oxygen- enriched combustion technology based on the circulating fluidized bed, it is more conducive to realize carbon emission reduction in coal-fired power plant.
2023, 10(2): 48-54.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.007
Abstract:
Introduction The strategic goal of "carbon peaking and carbon neutrality" has increased the demand for new energy power grid integration, so it is necessary to improve the flexible operation capacity of coal-fired generating units. Method This paper introduced the flexible transformation technology and common evaluation indicators of existing coal-fired units in detail. Flexibility transformation mainly included condensate throttling technology, coupled biomass co-combustion transformation technology of coal-fired units, flexibility technology of pulverizing system of coal-fired units, etc.; Common evaluation indicators for the flexibility of coal-fired generating units included: the power consumption rate of the generator set plant, the thermal efficiency of the boiler, the standard coal consumption rate of the generator set, etc. On this basis, this paper summarized and analyzed the flexibility transformation technology and evaluation indexes. Result Finally, the paper puts forward seven kinds of the technology development direction and relevant suggestions of coal-fired generating units. Conclusion The structural improvement of original generating units, the introduction of multi-form new energies and the coordinated regulation design of multi-heat storage will be the main direction of subsequent development. It is expected that paper can provide reference for subsequent coal-fired generating units to adapt to "dual carbon" energy planning.
2023, 10(2): 55-61.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.008
Abstract:
Introduction In recent years, natural gas power generation has played an important role in the construction of clean energy system of China. By the end of the "14th Five-year Plan" in 2025, China's gas power installed capacity is expected to hit 150 million kilowatts. Carbon capture, utilization and storage (CCUS) is one of the key paths for gas power to achieve the carbon peaking and carbon neutrality goals. Method To this end, an integrated plant combining 600 MW natural gas combined cycle (NGCC) and CO2 post-combustion capture (PCC) were set up as the simulation object. Result The simulation study shows that the design captures all CO2 flue gas with 90% efficiency, the CO2 compression and purification rate is 99.5%, the total output of gas power generation decreases by about 16.05%, the auxiliary power ratio increases by 5.55%, and the demand for circulating cooling water increases by about 50.52%. Conclusion The economic analysis shows that the static investment cost of the integrated plant is 54.28% higher than that of the single power plant, and the levelized cost of energy (LCOE) increases by 15.96%, which brings great difficulties to the deployment and development of carbon dioxide capture. However, the natural gas price is still the most important factor affecting the operating cost of the power plant.
2023, 10(2): 86-91.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.012
Abstract:
Introduction Before the project implementation, it is required to pre-evaluate the degree of flexible operation of coal-fired power plants, including the prediction of the technical index of boiler minimum combustion stable load rate. Since the existing experience and algorithms cannot meet the flexibility evaluation requirements of power plants, it is necessary to draw up a new semi-empirical calculation curve of the boiler minimum combustion stable load rate in combination with the performance index that the current equipment can achieve. Method Based on the literature data and engineering experience, the parameters with strong correlation with stable combustion index were selected, and statistical and regression methods were used to fit the semi-empirical calculation curve. Result With Vdaf (volatile matter of coal) and φ (total output margin coefficient of the burner) as independent variables, combined with the statistical analysis value of minimum ignition energy, the theoretical index of boiler minimum combustion stable load rate can be obtained. Conclusion The new calculation curve takes the known parameters available from the engineering data and can accurately calculate the theoretical value of boiler minimum combustion stable load rate under different conditions, which is consistent with the actual operation test data and can be used as tool for engineering design.
2023, 10(2): 92-100.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.013
Abstract:
Introduction In order to reduce the initial investment in the gas turbine power plant and ensure the safety of the unit, and obtain the economic subsidy of Guangdong auxiliary services through the black start function, the configuration scheme of using multiple diesel generator units is proposed when expanding the gas turbine, which are used as both the emergency shutdown power supply of 9F unit, and the black start power supply of the original 9E unit. Method In order to achieve technical and economic optimization, a reasonable configuration scheme was given through multi-scheme comparison and demonstration on the configuration of diesel generator units and the auxiliary power wiring. The emergency shutdown control logic and black start control logic of the recommended scheme were also explained. Result The results of the black start test show that all electrical quantities meet the requirements of the specification, and the recommended scheme can meet the black start function and pass the verification of the Grid Company. Conclusion Multiple diesel generator units are used for both black start and emergency functions in the scheme, which provides reference for the future engineering design of black start and emergency power supply in gas turbine power plants.
2023, 10(2): 62-70.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.009
Abstract:
Introduction In the process of building a new power system, renewable energy will maintain a high-speed development trend. Along with large-scale grid connection of renewable energy sources such as wind energy and photovoltaic energy, the randomness and fluctuation of its output will bring challenges to the safe and economical operation of the power system. The new energy storage system will become an indispensable resource subject to flexible regulation for the power system in the future due to its fast response ability and the effect of cutting peak and filling valley as well as the gradual reduction of its cost. Method The energy storage capacity planning was a global problem of the power system. By analyzing the renewable energy consumption rate and frequency modulation adequacy, a provincial power grid energy storage scale analysis method was proposed from the perspectives of peak shaving and frequency modulation based on the target of the lowest total cost of the system. Result Taking the actual parameters of the provincial power grid as an example, the time series production simulation software has been used to analyze the power startup mode, and the impacts of different energy storage scales on the economical efficiency of the whole society have been compared. Conclusion It shows that the consumption of renewable energy can be improved and the cost of the whole society can be reduced by adopting the appropriate scale of energy storage. The effectiveness of the method has been verified. Therefore, this work can provide some guidance for practical application.
2023, 10(2): 71-77.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.010
Abstract:
Introduction The paper proposes an energy consumption calculation method for prefabricated cabin type lithium iron phosphate battery energy storage power station based on the energy loss sources and the detailed classification of equipment attributes in the station. Method From the perspective of an energy storage power station, this paper discussed the main factors to be considered in the energy consumption calculation of prefabricated cabin type lithium iron phosphate battery energy storage power station, and then divided the energy consumption of the energy storage power station into two parts, namely, the energy consumption of the energy storage system and the energy consumption of the auxiliary equipment operation. Besides, it also provided the calculation method for the energy consumption of each part and the selection method of efficiency value respectively. Result Through a practical calculation example, the whole-day energy consumption of a 2 MW/2 MWh energy storage battery prefabrication cabin in a certain operation mode is analyzed and compared with the field test results. The difference between the field test results and the theoretical analysis results is analyzed from the perspective of the heat produced by the energy storage battery and the heat transmitted by the air conditioner, and suggestions are put forward for the energy consumption statistics of the energy storage power station. Conclusion The energy consumption calculation method proposed in the study comprehensively discusses the main factors affecting the energy consumption index of the prefabricated cabin type lithium iron phosphate battery energy storage power station and gives the energy consumption calculation method for the main equipment according to the detailed classification of equipment attributes, which has a good engineering reference value.
2023, 10(2): 78-85.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.011
Abstract:
Introduction In order to solve the problem of the short-term heavy load of main transformers in substations caused by the high peak load of the power grid with the relatively reasonable average-load-rate and increasing utilization hours of the substations, delay the construction investment of the power grid and ensure the economic operation of the power grid, a capacity sizing method of energy storage in substations is proposed in this paper, which meets the power supply requirements with N-1 main transformers. Method Firstly, a capacity sizing mathematical model of energy storage was built for peak load shaving of the load operation curve and reducing the maximum load rate of the transformer. Then, the capacity sizing economic objective function of lithium ion electrochemical energy storage was constructed to compare the construction investment of lithium ion electrochemical energy storage and main transformer expansion and analyze the economy of energy storage capacity sizing. Finally, in combination with the actual condition of substations, the energy storage capacity and its feasible construction cost in economy is proposed. Result Through analysis, with the decreasing of unit cost of lithium ion electrochemical energy storage in the future, the energy storage power can be considered in accordance with the substation capacity of 15% and charging and discharging time of 2 hours. When the unit cost of the energy storage system is decreased to about RMB 1 200/ kWh, the economic advantage of energy storage construction is obvious. Conclusion The capacity sizing method of energy storage proposed can solve the problem of short-term heavy load in substations effectively, and has better economy than conventional power transmission and transformation projects.
2023, 10(2): 101-109.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.014
Abstract:
Introduction With the development of domestic renewable energy industry, the recession of governmental subsidies and the implementation of policies such as competitive allocation of resources, Levelized Cost of Energy (LCOE) is gaining more and more attention and application, but its calculation method is inconsistent in domestic energy industry. In this paper, the relationship between Internal Rate of Return (IRR) and LCOE is analyzed to improve understanding of LCOE and standardize its application. Method The characteristics and application scenarios of LCOE and IRR were analyzed, and then their calculation formulas were simplified and transformed to analyze the difference and relation between them in models. Finally through the case analysis of an offshore wind power plant, the actual difference between the results was calculated, and the factors causing the difference and their sensitivities were analyzed. Result From the perspective of results, the simplified calculation models are very similar except for the income tax. According to the case analysis, the factors causing the difference between IRR and LCOE include the VAT deduction, after-tax incentives of VAT and income tax, additional taxes, and financing during the construction period, and influenced different directions to different extent. It can be considered that IRR and LCOE are similar in principle, but they become different under the influence of domestic fiscal policy, tax system and increased boundary conditions. Conclusion It is suggested that LCOE is properly localized and revised by competent departments, industry associations, etc. In combination with environmental impact costs and power system impact costs, the economy of different power generation approaches can be compared, and the rapid comparison of the economy of different schemes can also be achieved in specific projects.
2023, 10(2): 110-118.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.015
Abstract:
Introduction Lightning strike is the primary cause of failures of ±800 kV UHVDC power transmission lines, and the lightning protection assessment of power transmission lines is critical to the safe and stable operation of the system. Method Based on a ±800 kV power transmission line project under construction in China, the conductor and ground wire types were selected according to the design and use conditions of the project, and the typical towers were determined according to the altitude and meteorological area distribution along the line. After comprehensive consideration of the distribution ratio of ground inclination, soil resistivity, thunderstorm days, meteorological zone, etc. of towers along the line, the lightning protection performance of the line was evaluated and specific lightning protection measures were proposed in respect of the lighting characteristics of the project. In addition, the calculation differences between the two methods regarding terrain considerations in the EGM were compared. Result The calculation results show that the comprehensive lightning flashover rate doesn’t meet the requirements of design reference value and mainly protect against shielding failure. Thunderstorm days and the terrain conditions on the positive side of tower are the key factors for lightning protection. Conclusion After adopting the -15° tower protection angle, the line located in lightning areas with C level and above whose positive side ground inclination angle is ≥25° can meet the lightning protection requirements that the lightning flashover rate is not more than 0.10 fl/(100 km·a·40 d). The lightning protection performance and actual operating data of this project and adjacent ±800 kV as-built lines are compared and analyzed, which verifies the rationality of the calculation method and results in this paper.
2023, 10(2): 119-128.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.016
Abstract:
Introduction The existing angle steel transmission tower has been running for many years, and the structural damage leads to the reduction of service performance. At the same time, the design bearing capacity of the old transmission tower ceases to meet the design requirements of the existing specifications. In order to address the insufficient bearing capacity of the old transmission tower, a parallel reinforcement method of angle steel fitted with channel steel is proposed. The bearing capacity of the reinforced structure is obtained through experimental research and finite element analysis (FEM), and the critical buckling load is proposed based on elastic analysis. Method In order to obtain the bearing capacity of members, two groups of axial compression tests on test specimens were set up. Two kinds of finite element numerical simulation include unreinforced angle steel and angle steel fitted with channel steel were conducted under axial compression. According to the failure mode, the calculation formula of buckling load of thin plate based on elastic analysis was deduced. Result The axial compression test results show the bending failure of the unreinforced angle steel specimen and the local buckling failure of the angle steel fitted with channel steel. The results also show that the bearing capacity of the reinforced members could be effectively improved. Conclusion Angle steel fitted with channel steel changes the instability failure state of the original angle steel and improves the bearing capacity of the angle steel. The established FEM can reflect the true failure state of the reinforced members, and the theoretical calculation formula can accurately calculate the axial compression bearing capacity of the reinforced members.
2023, 10(2): 129-135.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.017
Abstract:
Introduction This paper aims to effectively avoid the design quality problems caused by the difference between domestic and foreign engineering design specifications. The study makes comparative analysis of slenderness ratio of cross bracings for angle steel members of transmission towers according to the current Chinese standard Technical Code for the Design of Tower and Pole Structures of Overhead Transmission Line (DL/T 5486—2020) and the European standard Overhead Electrical Lines Exceeding AC 1 kV (EN—50341—2012). Method An example of the typical arrangement pattern of cross bracings with auxiliary materials in projects was given to calculate the slenderness ratio of the poles according to the two standards. Result The results we obtained demonstrate that when calculating for the two cross bracings subject to same compression, the Chinese standard adopts the calculation of length correction factor to correct the influence of the joint action of the two cross bracings on the buckling strength of the compression member. The European standard adopts the checking calculation of the sum of buckling strength of the two poles which shall be greater than or equal to the algebraic sum of the loads on the two poles to ensure the buckling strength of the member meets the structural requirement. Conclusion In the arrangement pattern of typical cross bracings with auxiliary materials, the calculated buckling strength obtained according to the Chinese standard is less than that obtained according to the European standard under the following three conditions: two poles subject to same compression and equal pressure, two poles subject to same compression and unequal pressure, and two poles with one pole subject to pulling and the other subject to compression.
2023, 10(2): 136-142.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.018
Abstract:
Introduction In view of the digital transformation under the development of big data and the Internet, the application status of digital twin technology in power grid engineering is analyzed. Method The equipment and production data was integrated based on the constructed 3D model which maps the actual project. Therefore, a data link between reality and virtual space was formed, and an intelligent digital twin based power grid operation and maintenance platform was established which matches the needs of power grid operation and maintenance work. Result The platform realizes the deep integration of the station-side data through the invocation, transmission and centralized processing of the data of each subsystem. The function of panoramic information display realizes the visual display of power grid data. The function of intelligent auxiliary monitoring realizes the full-scene equipment monitoring and personnel control. The funtion of intelligent operation and maintenance realizes the reverse intervention guidance by the virtual space to the real project. Conclusion The sensitivity, visiblity and controllability of power grid can be enabled in the digital transformation because of the application of digital twin technology in power grid projects. At the same time, the digital twin technology can also effectively improve the work efficiency and the intelligent integration of system in daily power grid operation and maintenance operations under the new power system.
2023, 10(2): 143-150.
doi: 10.16516/j.gedi.issn2095-8676.2023.02.019
Abstract:
Introduction Nuclear power operation data is characterized by high dimension and large volume, and the complexity of the internal system of nuclear power plant makes it difficult to build a corresponding mechanism model. Therefore, it is very difficult to manually screen out relevant parameters from nuclear power data, and the introduction of non-relevant parameters will greatly affect the accuracy of the model. By means of improving the model accuracy, the purpose of accurate modeling can be reached. Method This paper proposed a correlation analysis method based on multi-scale time window. This method extracted state switch points for target parameters, classifies each sensor according to the characteristics of the data recorded by different sensors, and then designs detection windows for different kinds of sensors that meet their characteristics. The state switch detection was carried out in the corresponding time neighborhood of each sensor, and the correlation matching rate between each sensor and the target sensor was calculated to judge the correlation. Result Based on the actual historical operation data of nuclear power plant, the sensor parameters associated with the target sensor are selected successfully by the established correlation matching rate rule. Conclusion The experimental results show that the proposed method can screen out the correlation parameters more accurately. Compared with the commonly used Pearson correlation coefficient, the proposed method is more accurate.
