A method for extracting operation mode of high proportion of renewable energy power grid

Abstract

The application provides a kind of operation mode extraction method for high proportion renewable energy power grid, the method comprises: obtaining power system historical operation data, and the historical operation data is sorted in time section sequence;Typical operation scene extraction condition is set, and the extraction condition includes system power result index condition, system reliability index condition and system production emission index condition;According to the extraction condition, the historical operation data is matched, and the historical operation data satisfying the extraction condition is screened out to form an operation mode set.The method is matched with power grid data by setting extraction condition, wherein the extraction condition includes system power result index condition, system reliability index condition and system production emission index condition, and the design fully considers the influence of high proportion renewable energy access on power grid.

Description

Technical fields:

[0001] This invention relates to a method for extracting the operating mode of a power grid with a high proportion of renewable energy, belonging to the field of power systems. Background technology:

[0002] In traditional power systems, the system operation mode is relatively simple and fixed, resulting in relatively stable operation. However, in traditional power systems where the proportion of renewable energy integration is still low, the stability of system operation is mainly affected by load changes and seasonal variations in hydropower output. Therefore, past extraction and characteristic analysis of power system operation modes often relied on pre-set typical scenarios—such as valley load days, peak load days, and days with high and low hydropower generation—essentially "high in winter, low in winter; high in summer, low in summer; abundant water, low water," and was performed manually. Subsequently, the economic, safety, and stability assessment indicators of the operation modes extracted based on different typical scenarios were used to analyze system operation defects and output corresponding planning and adjustment schemes. This extraction method relies heavily on the rationality of traditional typical day and scenario settings and the experience of researchers. In the relatively simple power system operation scenarios of the past, it was able to effectively complete the task of extracting typical power system operation modes. However, with the continuous increase in the proportion of renewable energy in the power system, the increasing complexity of the power grid structure, and the expansion of inter-regional and inter-provincial power grid interconnection, the current extraction of operation modes for future high-proportion renewable energy grid integration will face the following three problems:

[0003] First, the operation of a high-proportion renewable energy grid will be more complex and variable compared to a traditional power system. In the past, typical daily and scenario indicators were singular, relying more on extreme scenarios such as seasonal load demand and hydropower output. However, with the integration of a high proportion of renewable energy, the factors affecting system stability increase, especially considering that solar and wind power, which are heavily influenced by seasonality, will gradually become the mainstay of domestic power supply in the future. In this context, the extraction of operation modes needs to consider not only the impact of load and hydropower output, but also the seasonal distribution of solar and wind resources, as well as the additional regulation capabilities brought about by the rapid development of other energy storage components.

[0004] Second, the extraction of past operating modes mainly relied on screening grid data based on pre-defined typical days and scenarios based on decades of operating mode analysis experience. These pre-defined typical day and scenario schemes are relatively mature and fixed, offering little freedom in selecting operating modes according to target conditions. However, the operating modes of high-proportion renewable energy grids are complex and variable. Typical scenarios fixed based on traditional operating mode analysis experience are no longer sufficient to meet the planning and operational needs of future high-proportion renewable energy grids. Summary of the Invention:

[0005] To address the problems existing in the prior art, this invention provides a method for extracting the operation mode of a high-proportion renewable energy power grid. This method can match historical power grid operation data on a time-by-time basis according to manually set extraction conditions consisting of power output result indicators, system reliability indicators, and system production and emission indicators, thereby outputting the required power grid operation mode. This method is more scientific, reasonable, and efficient.

[0006] The technical solution of the present invention is as follows:

[0007] A method for extracting operating modes for power grids with a high proportion of renewable energy, the method comprising:

[0008] Acquire historical operating data of the power system and sort the historical operating data in chronological order.

[0009] Set extraction conditions for typical operating scenarios, including system power consumption result index conditions, system reliability index conditions, and system production emission index conditions;

[0010] Historical operation data is matched according to the extraction conditions, and historical operation data that meets the extraction conditions are selected to form a set of operation modes.

[0011] Furthermore, the matching of the historical operating data according to the extraction conditions includes the following steps: calculating the system power consumption result index, system reliability index, and system production emission index for the historical operating data on a time-by-time basis, and determining whether the calculation results meet the set system power consumption result index conditions, system reliability index conditions, and system production emission index conditions.

[0012] Furthermore, the operational data includes time-of-use loads at each node in the power system, node load shedding costs, time-of-use transmission power of each tie line, tie line capacity, impedance, time-of-use power generation of each power unit, unit capacity, unit type, unit region, time-of-use charging / discharging of each energy storage unit, energy storage capacity, conversion efficiency, power flow of each line equipment / section, transmission capacity positive and negative limits, as well as unit start-up and shutdown costs, operating costs, fuel consumption rate, fuel consumption cost, and carbon emissions.

[0013] Furthermore, the system power output indicators include system load, tie-line power ratio, power generation ratio, energy storage charging and discharging ratio, and renewable energy curtailment rate ratio; the system reliability indicators include equipment load rate, system load shedding rate, and load shedding cost; and the system production emission indicators include energy production cost, carbon emissions, and carbon emission intensity.

[0014] Furthermore, the formula for calculating the system load is as follows:

[0015]

[0016] In the formula, Load Sys Load Ni These are the load values ​​of the system and the Ni-th node in the system at a certain time section, respectively.

[0017] The formula for calculating the percentage of power on the tie line is as follows:

[0018]

[0019] In the formula, QT Li , ε Li These represent the transmitted power value of the Li-th tie line at a certain time section and its proportion of the transmitted power of all tie lines in the system.

[0020] The formula for calculating the proportion of power generation from the aforementioned power source is:

[0021]

[0022]

[0023]

[0024]

[0025] In the formula, P pi Let μ be the output of the pi-th non-renewable power unit at a certain time segment; pi Let μ be the output percentage of the pi-th non-renewable power unit at a certain time segment; k P represents the output percentage of all non-renewable power sources of type k at a given time interval; Sys P Classic_k These are the sum of the output of all non-renewable power sources in the system at a certain time segment, and the sum of the output of all non-renewable power sources of power type k at a certain time segment, respectively.

[0026] The formula for calculating the proportion of energy storage charge and discharge is as follows:

[0027]

[0028]

[0029] In the formula, Char Sys DiscC Sys CharC Ci DiscC Ci These are the energy storage charging output and discharging output of the entire system and the Ci-th energy storage unit at a certain time segment, respectively.

[0030] The formula for calculating the proportion of new energy curtailment rate is as follows:

[0031] P ri_abandon =P ri_predict -P ri

[0032]

[0033]

[0034] In the formula, P ri_abandon P ri_predict P ri These represent the curtailed output, predicted output, and actual output of the ri-th renewable energy unit at a certain time segment; P ri_j and α j These represent the output value and curtailment rate of a renewable energy unit of type j at a certain time section.

[0035] Furthermore, the formula for calculating the equipment load rate is as follows:

[0036]

[0037]

[0038] In the formula, PLine Ti PLine′ Ti Let be the power flow and transmission capacity of the Ti-th line / main transformer at a certain time segment, and β be the transmission capacity of the line. Ti ,β sys These are the single-device load rate and the system average load rate of the Ti-th line / main transformer at a certain time segment, respectively.

[0039] The formula for calculating the system load shedding rate is:

[0040] Load Cut =Load Sys -P Sys

[0041]

[0042] In the formula, Load Cut γ represents the load shedding amount at a certain time point of the system; γ is the load shedding rate at a certain time point of the system, which represents the proportion of the load shedding amount in the system load.

[0043] The formula for calculating the load shedding cost is as follows:

[0044] Load Cut_Ni =Load Ni -∑{′node′=Ni}P pi

[0045] -∑{′node′

[0046] =Ni}P ri -∑{′node′=Ni}DisC Ci +∑{′node′=Ni}Char Ci

[0047]

[0048] In the formula, Cost CutLoad The total load shedding cost of the system at a certain time segment, Load Cut_Ni and Price Cut_Ni Let P represent the load shedding quantity and load shedding cost at a certain time section of the Ni-th node, respectively; where ∑{′node′=Ni}P pi ,∑{′node′=Ni}P ri ,∑{′node′=Ni}Char Ci ,∑{′node′=Ni}DisC Ci These represent the sum of output values ​​of all non-renewable energy generation units, renewable energy generation units, energy storage unit charging output, and energy storage unit discharging output at a certain time section belonging to the Ni-th node.

[0049] Furthermore, the formula for calculating the energy production cost is as follows:

[0050] Cost pi =Cost pi_start-stop +Cost pi_run +Cost pi_Energy

[0051] Cost ri =Cost ri_run

[0052] Cost Ci =Cost Ci_run

[0053] Cost sys =∑Cost pi +∑Cost ri +∑Cost ci

[0054] In the formula, Cost pi Cost pi_start-stop Cost pi_run Cost pi_Energy These represent the energy production cost, start-up and shutdown cost, operating cost, and fuel consumption cost of the pi-th non-renewable energy unit at a certain time segment; Costri Cost ri_run These represent the energy production cost and operating cost of the ri-th renewable energy unit at a certain time segment; Cost Ci Cost Ci_run These represent the charging / discharging cost and operating cost of the Ci-th energy storage unit at a certain time segment;

[0055] The formula for calculating the carbon emissions is:

[0056]

[0057] In the formula, Enission Sys , σ pi These are the total carbon dioxide emissions at a certain time point of the system and the carbon dioxide emission intensity per unit power generation of the pi-th non-renewable energy unit at a certain time point, respectively, with units of tCO2 / MWh;

[0058] The formula for calculating carbon emission intensity is:

[0059]

[0060] In the formula, δ represents the carbon emission intensity of the system at a certain time section, with units of tCO2 / MWh.

[0061] Compared with the prior art, the present invention has the following advantages:

[0062] This invention provides a method for extracting the operating mode of a grid with a high proportion of renewable energy. In this method, grid data is matched by setting extraction conditions, which include system power output indicators, system reliability indicators, and system production and emission indicators. This design fully considers the impact of high proportion of renewable energy access on the grid.

[0063] The operation mode extraction method of the present invention has a high degree of freedom in setting extraction conditions. Business personnel can select different extraction condition standards according to different objectives. It also supports free combination of different conditions, which can meet the analysis and planning needs of high-proportion renewable energy grid operation modes with complexity and variability. Attached image description:

[0064] Figure 1 A flowchart illustrating the method for extracting operating modes for grids with a high proportion of renewable energy.

[0065] Figure 2 This is a diagram illustrating partial matching results;

[0066] Figure 3 This is a schematic diagram of the power balance results. Detailed implementation method:

[0067] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0068] Example 1:

[0069] The present invention provides a method for extracting the operating mode of a power grid with a high proportion of renewable energy, such as... Figure 1 As shown, the method includes:

[0070] 1) Obtain historical operating data of the power system and sort the historical operating data in chronological order. The operating data includes time-of-use load of each node in the power system, node load shedding cost, time-of-use transmission power of each tie line, tie line capacity, impedance, time-of-use power generation of each power unit, unit capacity, unit type, unit region, time-of-use charging / discharging of each energy storage unit, energy storage capacity, conversion efficiency, power flow of each line equipment / section, transmission capacity positive and negative limits, as well as start-up and shutdown costs, operating costs, fuel consumption rate, fuel consumption cost and carbon emissions of the unit.

[0071] 2) Set extraction conditions for typical operating scenarios. These conditions include system power output indicators, system reliability indicators, and system production and emission indicators. System power output indicators include system load, tie-line power ratio, power generation ratio, energy storage charging / discharging ratio, and renewable energy curtailment rate ratio. System reliability indicators include equipment load rate, system load shedding rate, and load shedding cost. System production and emission indicators include energy production cost, carbon emissions, and carbon emission intensity. These extraction conditions can be adjusted by technical personnel based on actual production planning needs. For example, to meet production planning needs, the threshold for the system load shedding rate in system reliability can be set to 10%, meaning the extraction condition is a system load shedding rate less than or equal to 10%. In scenarios where thermal power units flexibly regulate peak loads, renewable energy units are the main functional components, and a certain renewable energy consumption ratio is met, the threshold for the output ratio of coal-fired and gas-fired units in power generation ratio can be set to 30%, and the threshold for the renewable energy curtailment rate ratio can be set to 10%. Therefore, the extraction condition is a coal-fired and gas-fired unit output ratio less than or equal to 30% and a renewable energy curtailment rate ratio less than or equal to 10%.

[0072] 3) Match historical operation data according to the extraction conditions, filter out historical operation data that meet the extraction conditions, and form a set of operation modes.

[0073] Example 2:

[0074] This embodiment, based on Embodiment 1, further designs the following: In this example, based on the dual-carbon planning target, the carbon emission amount and carbon emission intensity in the system production emission indicators are set at 1 billion tCO2 and 0.5 tCO2 / MWh, respectively. The corresponding extraction conditions are: hourly carbon emissions less than or equal to 114,100 tCO2, and daily peak carbon emission intensity less than or equal to 0.5 tCO2 / MWh. Based on the above extraction conditions, the system power output result indicators, system reliability indicators, and system production emission indicators are calculated for historical operating data on a time-series basis. The calculation results are then determined to meet the set conditions for the system power output result indicators, system reliability indicators, and system production emission indicators. The results are shown in Table 1, which presents some time sections.

[0075] The time segment with a match check of 1 represents the execution mode that hits the set extraction conditions. `Emis_sys` and `Emi_intensity` are the corresponding extraction condition metrics, and the rest are other metrics. Only a portion of the results are shown here. Business personnel can check whether there are any anomalies in the system's basic data and whether there are any weaknesses in reliability, stability, etc., under the execution mode that hits the extraction conditions, and then conduct corresponding analysis and research.

[0076] Table 1

[0077]

[0078]

[0079] Example 3:

[0080] This embodiment, based on Embodiment 1, further designs the following: This example specifically designs the calculation formulas for the system power output result index conditions, system reliability index conditions, and system production emission index conditions. Specifically, the calculation formula for the system load in the system power output result index conditions is:

[0081]

[0082] In the formula, Load Sys Load Ni These are the load values ​​of the system and the Ni-th node in the system at a certain time section, respectively.

[0083] The formula for calculating the percentage of tie-line power in the system power result indicators is as follows:

[0084]

[0085] In the formula, QT Li , ε LiThese represent the transmitted power value of the Li-th tie line at a certain time section and its proportion of the transmitted power of all tie lines in the system.

[0086] The formula for calculating the proportion of power generation in the system power output result index is as follows:

[0087]

[0088]

[0089]

[0090]

[0091] In the formula, P pi Let μ be the output of the pi-th non-renewable power unit at a certain time segment; pi Let μ be the output percentage of the pi-th non-renewable power unit at a certain time segment; k P represents the output percentage of all non-renewable power sources of type k at a given time interval; Sys P Classic_k These are the sum of the output of all non-renewable power sources in the system at a certain time segment, and the sum of the output of all non-renewable power sources of power type k at a certain time segment, respectively.

[0092] The formula for calculating the proportion of energy storage charging and discharging in the system power result index is as follows:

[0093]

[0094]

[0095] In the formula, Char Sys DiscC Sys CharC Ci DiscC Ci These are the energy storage charging output and discharging output of the entire system and the Ci-th energy storage unit at a certain time segment, respectively.

[0096] The formula for calculating the renewable energy curtailment rate in the system power output results indicators is as follows:

[0097] P ri_abandon =P ri_predict -P ri

[0098]

[0099]

[0100] In the formula, P ri_abandon P ri_predict Pri These represent the curtailed output, predicted output, and actual output of the ri-th renewable energy unit at a certain time segment; P ri_j and α j These represent the output value and curtailment rate of a renewable energy unit of type j at a certain time section.

[0101] The formula for calculating the equipment load rate in the system reliability index is:

[0102]

[0103]

[0104] In the formula, PLine Ti PLine′ Ti Let be the power flow and transmission capacity of the Ti-th line / main transformer at a certain time segment, and β be the transmission capacity of the line. Ti ,β sys These are the single-device load rate and the system average load rate of the Ti-th line / main transformer at a certain time segment, respectively.

[0105] The formula for calculating the system load shedding rate in the system reliability index is:

[0106] Load Cut =Load Sys -P Sys

[0107]

[0108] In the formula, Load Cut γ represents the load shedding amount at a certain time point of the system; γ is the load shedding rate at a certain time point of the system, which represents the proportion of the load shedding amount in the system load.

[0109] The formula for calculating load shedding cost in the system reliability index is:

[0110] Load Cut_Ni =Load Ni -∑{′node′=Ni}P pi

[0111] -∑{′node′

[0112] =Ni}P ri -∑{′node′=Ni}DisC ci +∑{′node′=Ni}Char ci

[0113]

[0114] In the formula, Cost CutLoadThe total load shedding cost of the system at a certain time segment, Load Cut_Ni and Price Cut_Ni Let P represent the load shedding quantity and load shedding cost at a certain time section of the Ni-th node, respectively; where ∑{′node′=Ni}P pi ,∑{′node′=Ni}P ri ,∑{′node′=Ni}Char Ci ,∑{′node′=Ni}DisC Ci These represent the sum of output values ​​of all non-renewable energy generation units, renewable energy generation units, energy storage unit charging output, and energy storage unit discharging output at a certain time section belonging to the Ni-th node.

[0115] The formula for calculating energy production costs in the system's production emission indicators is as follows:

[0116] Cost pi =Cost pi_start-stop +Cost pi_run +Cost pi_Energy

[0117] Cost ri =Cost ri_run

[0118] Cost Ci =Cost Ci_run

[0119] Cost sys =∑Cost pi +∑Cost ri +∑Cost Ci

[0120] In the formula, Cost pi Cost pi_start-stop Cost pi_run Cost pi_Energy These represent the energy production cost, start-up and shutdown cost, operating cost, and fuel consumption cost of the pi-th non-renewable energy unit at a certain time segment; Cost ri Cost ri_run These represent the energy production cost and operating cost of the ri-th renewable energy unit at a certain time segment; Cost Ci Cost Ci_run These represent the charging / discharging cost and operating cost of the Ci-th energy storage unit at a certain time segment;

[0121] The formula for calculating carbon emissions in the system's production emission indicators is as follows:

[0122]

[0123] In the formula, Emission Sys , σ pi These are the total carbon dioxide emissions at a certain time point of the system and the carbon dioxide emission intensity per unit power generation of the pi-th non-renewable energy unit at a certain time point, respectively, with units of tCO2 / MWh;

[0124] The formula for calculating carbon emission intensity in the system's production emission indicators is as follows:

[0125]

[0126] In the formula, δ represents the carbon emission intensity of the system at a certain time section, with units of tCO2 / MWh.

[0127] Application Examples:

[0128] This example uses the extraction method of this invention to extract the operating mode of historical operating data. The historical operating data is the historical operating simulation data of Jiangsu Province from January 1, 2022 to December 31, 2022. The operating data is divided into hourly time segments, and there are a total of 8760 segments in the historical operating simulation data. The extraction conditions set according to the actual production targets A and B are shown in Table 2. The extraction conditions of the typical operating scenario set according to the actual production target A in Table 2 include: the system load shedding rate is less than or equal to 10%. The extraction conditions of the typical operating scenario set according to the actual production target B include: the new energy curtailment rate is less than or equal to 10%, and the output of coal-fired and gas-fired units is less than or equal to 30%.

[0129] Table 2

[0130] A System load shedding rate <= 10% B Coal-fired and gas-fired power generation output <= 30% && renewable energy curtailment rate <= 10%

[0131] Partial matching results as follows Figure 2 As shown, out of the 8760 hours (time segments) throughout the year, 2606 time segments were matched, accounting for approximately 30% of the total, mainly concentrated in the operating period from June to December. The power balance results of the matched time segments were analyzed, as follows... Figure 3 As shown, the overall power output of the system is mainly from new energy sources, with zero peak-shaving dispatch of thermal power (coal and gas).

[0132] Based on the above embodiments, the system operation mode under different extraction conditions at different time segments can be analyzed and studied. For example, for stability analysis, data such as the fluctuation rate of the load curve and the peak-valley range of the load can be viewed, and corresponding optimizations can be made in the planning scheme accordingly. For example, measures such as increasing the peak-shaving capacity of thermal power plants can be taken to optimize the system operation mode during periods of high load fluctuation.

Claims

1. A method for extracting operating modes for power grids with a high proportion of renewable energy, characterized in that: The method includes: Acquire historical operating data of the power system and sort the historical operating data in chronological order. Set extraction conditions for typical operating scenarios, including system power consumption result index conditions, system reliability index conditions, and system production emission index conditions; Historical operation data is matched according to the extraction conditions, and historical operation data that meets the extraction conditions are filtered out to form a set of operation modes; The process of matching the historical operating data according to the extraction conditions includes the following steps: calculating the system power consumption result index, system reliability index, and system production emission index for the historical operating data on a time-by-time basis, and determining whether the calculation results meet the set system power consumption result index conditions, system reliability index conditions, and system production emission index conditions. The system power output indicators include system load, tie-line power ratio, power generation ratio, energy storage charging and discharging ratio, and renewable energy curtailment rate ratio; the system reliability indicators include equipment load rate, system load shedding rate, and load shedding cost; the system production emission indicators include energy production cost, carbon emissions, and carbon emission intensity.

2. The method for extracting operating modes for high-proportion renewable energy grids according to claim 1, characterized in that: The operational data includes time-of-use loads at each node in the power system, node load shedding costs, time-of-use transmission power on each tie line, tie line capacity, impedance, time-of-use power generation of each power unit, unit capacity, unit type, unit location, time-of-use charging / discharging capacity, energy storage capacity, conversion efficiency of each energy storage unit, power flow of each line equipment / section, transmission capacity positive and negative limits, as well as unit start-up and shutdown costs, operating costs, fuel consumption rate, fuel consumption cost, and carbon emissions.

3. The method for extracting operating modes for high-proportion renewable energy grids according to claim 2, characterized in that: The formula for calculating the system load is: ； In the formula, , They are respectively the system, the first in the system The load values ​​of i nodes at a certain time section; The formula for calculating the percentage of power on the tie line is as follows: ； In the formula, , These represent the transmitted power value of the Li-th tie line at a certain time section and its proportion of the transmitted power of all tie lines in the system. The formula for calculating the proportion of power generation from the aforementioned power source is: ； ； ； ； In the formula, For the first The output of a non-renewable power unit at a certain time segment; For the first The output percentage of a non-renewable power unit at a certain time segment; The output percentage of all non-renewable power sources of power type k at a certain time section; , These are the sum of the output of all non-renewable power sources in the system at a certain time segment, and the sum of the output of all non-renewable power sources of power type k at a certain time segment, respectively. The formula for calculating the proportion of energy storage charge and discharge is as follows: ； ； In the formula, , , , The entire system, the first Energy storage charging output and discharging output of i energy storage units at a certain time section; The formula for calculating the proportion of new energy curtailment rate is as follows: ； ； ； In the formula, , , The first The curtailed output, predicted output, and actual output of i renewable energy units at a certain time segment; and These represent the output value and curtailment rate of a renewable energy unit of type j at a certain time section.

4. The method for extracting operating modes for high-proportion renewable energy grids according to claim 3, characterized in that: The formula for calculating the equipment load rate is: ； ； In the formula, , The first The power flow and transmission capacity of i lines / main transformers at a certain time segment, and , The first The load rate of a single device and the average load rate of the system at a certain time section for each i-line / main transformer; The formula for calculating the system load shedding rate is: ； ； In the formula, This represents the load shear rate at a certain time point in the system. The load shedding rate is the percentage of the load shedding in the system load at a certain time point. The formula for calculating the load shedding cost is as follows: ； ； In the formula, The total load shedding cost of the system at a certain time segment. and The first The load shedding amount and load shedding cost of i nodes at a certain time section; where , , , They belong to the first The sum of the output of all non-renewable energy units, the sum of the output of renewable energy units, the sum of the charging output of energy storage units, and the sum of the discharging output of energy storage units at a certain time section of node i.

5. The method for extracting operating modes for high-proportion renewable energy grids according to claim 4, characterized in that: The formula for calculating the energy production cost is as follows: ； ； ； ； In the formula, , , , The first Energy production cost, start-up and shutdown cost, operating cost and fuel consumption cost of a non-renewable energy unit at a certain time segment; , The first Energy production cost and operating cost of a renewable energy unit at a certain time segment; , The first The charging and discharging costs and operating costs of an energy storage unit at a certain time segment; The formula for calculating the carbon emissions is: ； In the formula, , These represent the total carbon dioxide emissions at a certain time point of the system and the first... The carbon dioxide emission intensity per unit of electricity generated by a non-renewable energy unit at a certain time segment, expressed in tCO2 / MWh; The formula for calculating carbon emission intensity is: ； In the formula, The carbon emission intensity of the system at a certain time point is expressed in tCO2 / MWh.

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