Frequency stability evaluation method, device, terminal and medium for new energy receiving system

Abstract

The present application discloses a frequency stability assessment method, device, terminal, and medium for a new energy receiving system. The technical solution provided by the present application is based on the receiving system and adopts a sequential production simulation and frequency regulation margin index. First, based on the unit data and interconnection line power transmission data of the new energy direct current receiving system, a sequential production simulation model of the new energy direct current receiving system is constructed and an operation simulation is performed to obtain the total output data of the new energy direct current receiving system within a preset time period. Then, combined with the total startup capacity of the new energy direct current receiving system and the maximum backup coefficient of each type of unit, the frequency regulation backup power of the new energy direct current receiving system is determined, and then the frequency regulation margin coefficient of the receiving system is obtained to measure the frequency stability of the new energy receiving system. This method is more suitable for direct current systems with a high proportion of new energy, and can more efficiently and comprehensively identify the frequency stability risks of the new energy direct current receiving system.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a method, device, terminal and medium for evaluating the frequency stability of a new energy receiving system. Background Art

[0002] With the construction of new power systems, new energy has become the main power source to meet the growth in load. The northwest thermal wind and solar bases and the southwest hydro wind and solar bases are fed into the central and eastern load centers such as Central China, East China, and the southern regions through multiple DC transmission lines. DC transmission has become the main body of cross-regional resource optimization allocation.

[0003] At present, a high-proportion new energy DC transmission system will be formed under the large-scale base development model represented by the hydropower base in southeastern Tibet. Its output power is dominated by the output characteristics of photovoltaic and wind power generation, and the system operation is mainly based on seasonal characteristics. However, with the access of the DC system dominated by high-proportion new energy, the traditional frequency stability verification method based on typical seasonal scenarios is difficult to adapt to the current new energy DC system environment, which is likely to lead to further increase in frequency stability risks and frequent mismatch between DC operation and receiving-end load. Summary of the Invention

[0004] The present application provides a method, device, terminal and medium for evaluating the frequency stability of a new energy receiving system, which are used to solve the technical problem of poor security in traditional frequency stability calibration methods based on typical seasonal scenarios.

[0005] To solve the above technical problems, the first aspect of the present application provides a method for evaluating the frequency stability of a new energy receiving system, comprising:

[0006] Based on the unit data of the new energy DC receiving system and the power transmission data of the tie line, a time-series production simulation model of the new energy DC receiving system is constructed;

[0007] Performing an operation simulation based on the time-series production simulation model to obtain total output data of the new energy DC receiving system;

[0008] Determining the frequency regulation reserve power of the new energy DC receiving system based on the total output data and in combination with the total operating capacity of the new energy DC receiving system and the maximum reserve coefficient of each type of unit;

[0009] A frequency regulation margin coefficient is obtained according to the ratio of the frequency regulation standby power to the operating power of the new energy DC receiving system, so as to determine a frequency stability assessment result of the new energy receiving system according to a comparison result of the frequency regulation margin coefficient with a preset margin coefficient threshold.

[0010] Preferably, the time series production simulation model specifically includes: an objective function and production simulation constraints;

[0011] The production simulation constraints include: power load balance constraint, positive reserve capacity constraint, unit output range constraint, unit ramp rate constraint, continuous start and stop time constraint, daily start and stop number constraint, three-stage output constraint of the hydropower unit, pumped storage charging power constraint of the hydropower unit and pumped storage charge state constraint of the hydropower unit.

[0012] Preferably, the objective function is specifically:

[0013]

[0014] In the formula, i represents the unit number, I represents the total number of units in the province, t represents the time period number, and T represents the total number of time periods considered. i,t represents the output of unit i in period t, C i,t (P i,t ), They represent the operating cost, startup cost, and shutdown cost of unit i in period t, respectively. represents the power curtailment penalty of unit i in period t, represents the abandoned power of unit i in period t, Respectively represent the load shedding value and load relaxation in time period t, They represent the load shedding penalty and load relaxation penalty in time period t respectively.

[0015] Preferably, the operation simulation based on the time-series production simulation model to obtain the total output data of the new energy DC receiving system specifically includes:

[0016] An operation simulation is performed based on the time-series production simulation model, and output data of various units in the new energy DC receiving system at different time periods are counted to obtain total output data of the new energy DC receiving system based on the output data.

[0017] Preferably, performing operation simulation based on the time-series production simulation model, and collecting output data of various units in the new energy DC receiving system at different time periods, and obtaining total output data of the new energy DC receiving system based on the output data specifically includes:

[0018] An operation simulation is performed based on the time-series production simulation model, and combined with preset partition information, output data of various types of units in the same partition of the new energy DC receiving system at different time periods are counted, and the total output data of the new energy DC receiving system is obtained by accumulating the output data of each partition.

[0019] Preferably, determining the frequency regulation standby power of the new energy DC receiving system based on the total output data and in combination with the total startup capacity and maximum standby coefficient of the new energy DC receiving system specifically includes:

[0020] Based on the total output data, combined with the total startup capacity and the maximum reserve coefficient of the new energy DC receiving system, the difference between the total startup capacity and the total output data, and the product value of the total startup capacity and the maximum reserve coefficient are calculated, and the smaller value of the difference and the product value is used as the frequency regulation reserve power of the new energy DC receiving system.

[0021] Preferably, the calculation formula for the frequency modulation standby power is:

[0022] P R (t)=∑ k min(λ k S k,t, S k,t -P total,k,t )

[0023] Where, P R (t) is the frequency regulation standby power of the new energy DC receiving system in period t, λ k is the maximum reserve factor of the k-th type unit, S k,t is the total operating capacity of the k-th type unit in period t, P total,k,t is the total output data of the k-th unit in period t.

[0024] At the same time, the second aspect of the present application provides a frequency stability evaluation device for a new energy receiving system, comprising:

[0025] A receiving system simulation model building unit, configured to build a time-series production simulation model of the new energy DC receiving system based on the unit data and the tie-line power transmission data of the new energy DC receiving system;

[0026] a total output data acquisition unit, configured to perform operation simulation based on the time-series production simulation model to obtain total output data of the new energy DC receiving system;

[0027] a frequency regulation standby power calculation unit, configured to determine the frequency regulation standby power of the new energy DC receiving system based on the total output data, in combination with the total operating capacity of the new energy DC receiving system and the maximum standby coefficient of each type of unit;

[0028] The frequency stability risk identification unit is used to obtain a frequency regulation margin coefficient based on the ratio of the frequency regulation standby power to the operating power of the renewable energy DC receiving system, so as to determine a frequency stability assessment result of the renewable energy receiving system based on a comparison result of the frequency regulation margin coefficient with a preset margin coefficient threshold.

[0029] A third aspect of the present application provides a new energy receiving system frequency stability assessment terminal, comprising: a memory and a processor;

[0030] The memory is used to store program codes corresponding to a frequency stability evaluation method for a new energy receiving terminal system as provided in the first aspect of the present application;

[0031] The processor is configured to execute the program code.

[0032] The fourth aspect of the present application provides a computer-readable storage medium, which stores program code corresponding to a new energy receiving system frequency stability evaluation method provided in the first aspect of the present application.

[0033] It can be seen from the above technical solutions that this application has the following advantages:

[0034] The technical solution provided in this application adopts a frequency stability assessment method based on time-series production simulation and frequency regulation margin indicators. First, based on the unit data and interconnection line power transmission data of the new energy DC receiving system, a time-series production simulation model of the new energy DC receiving system is constructed and an operation simulation is performed to obtain the total output data of the new energy DC receiving system within a preset time period. Based on the total output data, combined with the total start-up capacity of the new energy DC receiving system and the maximum reserve factors of various types of units, the frequency regulation reserve power of the new energy DC receiving system is determined. Based on the ratio of the frequency regulation reserve power to the operating power of the new energy DC receiving system, the frequency regulation margin factor of the receiving system is obtained to measure the frequency stability of the new energy DC receiving system. Compared with traditional methods, the method provided in this application is more suitable for DC systems with a high proportion of new energy, and can more efficiently and comprehensively identify frequency stability risks of new energy DC receiving systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0036] Figure 1 This is a flow chart of an embodiment of a method for evaluating frequency stability of a new energy receiving system provided in this application.

[0037] Figure 2 Schematic diagram of the seasonal characteristics of the frequency regulation margin of the Kunliulong interlock in an example of a frequency stability assessment method for a new energy receiving system provided in this application.

[0038] Figure 3 This is a schematic diagram of the intraday characteristics of the frequency regulation margin of the Kunliulong interlock in an example of a frequency stability assessment method for a new energy receiving system provided in this application.

[0039] Figure 4 A schematic diagram of the seasonal characteristics of the frequency regulation margin of the southeastern Tibet interlock in an example of a frequency stability assessment method for a new energy receiving end system provided in this application.

[0040] Figure 5 This is a schematic diagram of the intraday characteristics of the frequency regulation margin of the Southeast Tibet Interlock in an example of a frequency stability assessment method for a new energy receiving end system provided in this application.

[0041] Figure 6 This is a structural diagram of an embodiment of a frequency stability assessment device for a new energy receiving system provided in this application.

[0042] Figure 7 This is a structural diagram of an embodiment of a frequency stability assessment terminal for a new energy receiving system provided in this application. DETAILED DESCRIPTION

[0043] In view of the current situation where the mismatch between DC operation and receiving-end load becomes normalized after the existing technology is connected to the DC system dominated by a high proportion of renewable energy, such as the situation where DC still maintains large-scale feed-in when the receiving-end load is small, research has found that the frequency stability risk level depends on the multi-time scale coupling characteristics of DC power transmission, load level, and renewable energy penetration rate. With frequent switching within the day, the high-risk period will also be greatly expanded on the annual scale, making it difficult for traditional frequency stability verification methods based on typical seasonal scenarios to adapt to the current power grid environment that contains a large number of high-proportion renewable energy DC systems.

[0044] The embodiments of the present application provide a method, device, terminal and medium for evaluating the frequency stability of a new energy receiving system, which are used to solve the technical problem of poor security in traditional frequency stability verification methods based on typical seasonal scenarios.

[0045] In order to make the purpose, features, and advantages of the invention of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described below are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0046] First, a detailed description of an embodiment of a frequency stability evaluation method for a new energy receiving terminal system provided by this application is as follows:

[0047] See also Figure 1 This embodiment provides a method for evaluating the frequency stability of a new energy receiving terminal system, including:

[0048] Step 101: Based on the unit data and the interconnection line power transmission data of the new energy DC receiving system, a time sequence production simulation model of the new energy DC receiving system is constructed.

[0049] It should be noted that the method provided in this embodiment first constructs a time-series production simulation model of the new energy DC receiving system based on relevant data of the new energy DC receiving system. The production simulation in this embodiment is essentially a unit combination problem, with the goals of minimizing the economic cost of system operation, balancing power and electricity, and absorbing clean energy. Its objective function is as follows:

[0050]

[0051] In the formula, i represents the unit number, I represents the total number of units in the province, t represents the time period number, and T represents the total number of time periods considered. i，t represents the output of unit i in period t, C i，t (P i，t ), They represent the operating cost, startup cost, and shutdown cost of unit i in time period t, respectively, and are used to quantify the economic cost of operation. represents the power curtailment penalty of unit i in period t, It represents the abandoned power of unit i in period t, which is only valid for hydropower, wind power and photovoltaic units. Other types of units have Ensure maximum absorption of new energy; Respectively represent the load shedding value and load relaxation in time period t, They represent the load shedding penalty and load relaxation penalty in time period t, respectively, to ensure power balance.

[0052] Then there are the various constraints related to the objective function, including:

[0053] The transmission plan of the DC tie lines and each AC tie line within the receiving end is embedded in the provincial load balance constraint to form a power load balance constraint. This allows the impact of the intra-day and seasonal multi-timescale coupling characteristics of DC to be reflected in the unit combination results of the receiving end power grid, as shown in the following figure:

[0054]

[0055] Where j represents the tie line number, J represents the total number of tie lines, and T j，t represents the planned power of tie line j in period t (input is positive, output is negative), L t represents the provincial load during time period t.

[0056] Considering the overall positive reserve capacity constraints of the province, we have:

[0057]

[0058] Where, α i，t represents the start and stop status of unit i in period t, α i，t =0 means the unit is in shutdown state, α i，t =1 indicates the unit is in operation. is the maximum output of unit i in time period t, where wind power and photovoltaic units take their respective generating capacities, and hydropower units take their maximum output after considering the expected hydropower output. represents the system positive spare capacity requirement at time period t.

[0059] On this basis, consider the unit-level constraints. The unit output should be within its maximum / minimum output range, that is:

[0060]

[0061] Where, are the minimum output and maximum output of unit i in time period t respectively.

[0062] When the unit is climbing up or down a slope, it must meet the climbing rate requirements, which can be expressed mathematically as follows:

[0063]

[0064] Where ΔP i U Indicates the maximum ramp rate of unit i, ΔP i D Indicates the maximum ramp rate of unit i.

[0065] In terms of start and stop time, the unit must meet the minimum continuous start and stop time constraints, namely:

[0066]

[0067] Where, T U 、T D Indicates the minimum continuous start time and minimum continuous stop time of the unit. Indicates the continuous start-up time and continuous shutdown time of unit i in period t, which can be obtained by the state variable α i，t express:

[0068]

[0069] During the day, the number of starts and stops must also be met:

[0070]

[0071] Where η i，t , γ i，t is the switching variable for starting and stopping, η i，t Describes whether unit i switches to the startup state in period t, and γ i，t Describes whether unit i switches to the shutdown state in time period t.

[0072] In particular, the hydropower station needs to meet the three-stage monthly output constraint, which can be expressed as:

[0073]

[0074] Among them, hh represents the hydropower station number, h represents the unit number in the hydropower station, and IH represents the total number of units in the hydropower station. h，t 、 They respectively represent the output and abandoned power of the hth unit in the hhth hydropower station. It represents the monthly expected output, average output and forced output of the hh-th hydropower station.

[0075] Finally, pumped storage must meet the charging power constraint and the state of charge constraint. The charging power constraint can be expressed as:

[0076]

[0077] The above formula are the minimum and maximum charging powers of pumped storage i in time period t, respectively; is a 0 / 1 variable representing the charging state of the pumped storage.

[0078] The state of charge constraints are:

[0079]

[0080] The above formula They represent the charging and discharging efficiency of pumped storage i respectively; represents the state of charge of pumped storage i in time period t; They represent the upper and lower limits of the state of charge of pumped storage i respectively.

[0081] Step 102: Perform an operation simulation based on the time-series production simulation model to obtain total output data of the new energy DC receiving system.

[0082] It should be noted that the operation simulation is performed based on the time series production simulation model. Let k represent the type of coal-fired power, gas-fired power and hydropower units, and the set of unit numbers contained in each type is G k , statistics the output data of various units in the new energy DC receiving system at different time periods, then the total output of the k-th unit in time period t is P k,t =∑i P i,t ,i∈G k According to the given planned total power of the tie line and the initial output of the new energy units, the total output data of the new energy DC receiving system can be obtained by solving the time-series production simulation model composed of equations (1) to (11).

[0083] More specifically, the total output data of the new energy DC receiving system obtained by performing operation simulation based on the time-series production simulation model in step 102 specifically includes:

[0084] Based on the time-series production simulation model, operation simulation is performed to count the output data of various units in the new energy DC receiving system at different time periods, and based on the output data, the total output data of the new energy DC receiving system is obtained.

[0085] Alternatively, based on the above detailed steps, further partition information, such as administrative district information or power network partition information, is added to form the following more preferred total output data acquisition steps, as follows:

[0086] Based on the time-series production simulation model, operation simulation is performed. Combined with the preset partition information, the output data of various units in the same partition of the new energy DC receiving system at different time periods are counted. The total output data of the new energy DC receiving system is obtained by summing up the output data of each partition.

[0087] It should be noted that, based on the provincial unit, according to the total planned power of the provincial and regional interconnection lines for the whole year and the initial output of new energy units, the matrix P consisting of the K-type units in a single province and the output of all periods in the whole year can be obtained. area , such as:

[0088]

[0089] Assume that the number of provinces covered by the receiving system is N, and the output matrix of the nth province is P area，n , then the output matrix P of the receiving end total have

[0090]

[0091] Step 103: Based on the total output data, combined with the total operating capacity of the new energy DC receiving system and the maximum reserve coefficient of each type of unit, the frequency regulation reserve power of the new energy DC receiving system is determined.

[0092] It should be noted that based on the total output data of the new energy DC receiving system obtained in the previous step, combined with the total operating capacity of the new energy DC receiving system and the maximum reserve coefficient of each type of unit, the frequency regulation reserve power of the new energy DC receiving system is calculated. This frequency regulation reserve power represents the current frequency regulation reserve capacity of the new energy DC receiving system.

[0093] Among them, in the frequency regulation system dominated by synchronous generators, coal-fired power, gas-fired power and hydropower units are the main power sources providing primary frequency regulation backup. Define the maximum backup coefficient λ of the k-th type unit k , the total operating capacity S of the k-th type unit and time period t k，t And the total output P total，k，t Without considering the overload of the unit, the maximum reserve of each type of unit should not exceed the total increase capacity, then the corresponding frequency regulation reserve power P R (t) can be expressed as:

[0094] P R (t)=∑ k min(λ k S k，t , S k，t -P total，k，t ) (14)

[0095] Step 104: A frequency regulation margin coefficient is obtained based on the ratio of the frequency regulation standby power to the operating power of the new energy DC receiving system, and a frequency stability assessment result of the new energy receiving system is determined based on a comparison result of the frequency regulation margin coefficient with a preset margin coefficient threshold.

[0096] Finally, the ratio of the frequency regulation reserve power to the operating power of the renewable energy DC receiving system is calculated to obtain the frequency regulation margin coefficient of the renewable energy receiving system. The frequency regulation margin coefficient of the DC blocking can be expressed as the ratio of the current reserve to the demand, as shown below:

[0097]

[0098] Where, P r (t) is the operating power corresponding to the rth DC block at time t, representing its static frequency regulation demand, η r (t) is the frequency margin coefficient. The smaller the frequency margin, the greater the frequency stability risk. Generally, it is defined by default that there is a frequency stability risk in scenarios where the frequency margin is less than 1.

[0099] Analysis of typical operating scenarios is unable to cover all year-round risks, leading to safety hazards in the operation of new energy DC receiving systems. The method provided in this application generates operating scenarios in a more refined manner. The defined indicators intuitively depict the risk distribution under different fault conditions, enabling efficient and comprehensive identification of all risk scenarios throughout the year.

[0100] In order to more clearly demonstrate the effect of the technical solution of the present application, this embodiment uses the 2025 Southeast Tibet planning data as an example to illustrate the frequency stability evaluation method of the new energy receiving system of the present application. The specific example is as follows:

[0101] Table 1 shows the total planned power of interconnection lines in each province and region throughout the year (in MW).

[0102] Table 1 Total planned power of interconnection lines in each province and region throughout the year

[0103]

[0104] Table 2 shows the annual output of new energy units in each province and region (in MW).

[0105] Table 2 Output of new energy units in various provinces and regions throughout the year

[0106]

[0107] By solving equations (1) to (11), we can obtain the output of each type of unit in each province and region, as shown in equation (12). The output of each type of unit in Guangdong, Guangxi, Guizhou, and Hainan is shown in Tables 3 to 6.

[0108] Table 3 Output of various types of units in Guangdong Province

[0109]

[0110]

[0111] Table 4 Output of various types of units in Guangxi Zhuang Autonomous Region

[0112]

[0113] Table 5 Output of various types of units in Guizhou Province

[0114]

[0115] Table 6 Output of various types of units in Hainan Province

[0116]

[0117] Through formula (13), the output of various types of units in the receiving power grid is obtained as shown in Table 7.

[0118] Table 7 Output of various types of units in the receiving power grid

[0119]

[0120] This patent considers the risk calculation caused by the blocking of the Southeast Tibet DC and Kunliulong DC. The frequency regulation reserve can be obtained through formula (14). Combined with the operating power of the Southeast Tibet DC and Kunliulong DC, the risks under the two types of DC blocking can be obtained through formula (15) as shown in Table 8. In engineering, the maximum reserve coefficient λ of coal-fired power, gas-fired power and hydropower units is k Take 0.06, 0.06 and 0.1 respectively, and the other maximum reserve coefficients are 0.

[0121] Table 8 Frequency regulation reserve, Southeast Tibet DC and Kunliulong DC operating power and frequency regulation margin

[0122]

[0123]

[0124] For intuitive demonstration, we first visualize the frequency regulation margin distribution under the Kunliulong and Southeast Tibet DC interlocking systems from both seasonal and intraday perspectives. The seasonal characteristics of the former are described by the frequency regulation margin curve for an entire year (8760 hours), while the latter is described by the frequency regulation margin curve for 24 moments, each with 365 days.

[0125] in, Figures 2-3 The seasonal and daily frequency regulation margin distribution of the Kunliulong DC interlock is given. The threshold of the frequency regulation margin is set to 1. When the margin is less than 1, there is a risk. Figure 2 As shown in the figure, the number of hours exceeding the limit in the whole year is 509 hours, and the hours in the flood season account for 90%. The frequency regulation margin shortage scenario has typical seasonal characteristics. Figure 3 From the above, the period of obvious over-limit is from 17:00 to 21:00, indicating that the frequency stability risk dominated by Kunliu Long also has daily characteristics; Figures 4-5 The distribution of frequency regulation margin dominated by the Southeast Tibet DC interlock is analyzed. Obviously, the frequency regulation margin has the risk of exceeding the limit throughout the year, and the minimum margin is concentrated in the period around the Spring Festival, which has seasonal characteristics to a certain extent. Figure 5 Judging from the intraday changes, the frequency regulation margin exceeding limit scenario appears at around 9:00 and disappears at around 16:00, with prominent daily characteristics.

[0126] Based on the above analysis, the frequency regulation margin over-limit risk caused by DC blocking at different sending ends shows a coexistence of seasonal and daily characteristics, and both characteristics may dominate. The dominant periods of the Kunliulong and Southeast Tibet DC are basically decoupled. The former's dominant risk period is from 5 pm to 9 pm during the flood season, while the latter's dominant period is from 9 pm to 4 pm throughout the year. The risk situation is closely related to the seasonal characteristics of the load. Further combining the load level and the operating characteristics of the unit, the typical high-risk scenarios of the receiving-end power grid can be divided into three categories:

[0127] 1) During the evening hours (5:00 PM to 9:00 PM) during the flood season, the Southeast Tibet DC link operates at low power, while the Kunming-Liuyang-Longchuan DC link operates at high power. If the large load leads to power shortages, the units' increased capacity will be insufficient, resulting in an overrun of the frequency regulation margin.

[0128] 2) Low-water period daytime (9:00-16:00) waist mode: the overall load level is low, the startup mode is small, the operation scale in southeast Tibet is large, and the frequency regulation margin is low.

[0129] 3) Large mode during the daytime (9:00-16:00) in the flood season: Similar to the Kunliulong DC line, the low frequency margin may be caused by insufficient reserve for unit upgrades.

[0130] From the above analysis, it can be seen that this patent can effectively calculate the frequency regulation margin throughout the year, and thus can intuitively reflect the frequency stability risk distribution under different DC blocking conditions.

[0131] The above is a detailed description of an embodiment of a method for evaluating the frequency stability of a new energy receiving system provided by this application. The following is a detailed description of an embodiment of a device for evaluating the frequency stability of a new energy receiving system provided by this application.

[0132] See also Figure 6 This embodiment provides a frequency stability assessment device for a new energy receiving system, including:

[0133] The receiving system simulation model building unit 201 is used to build a time-series production simulation model of the new energy DC receiving system based on the unit data and the tie line power transmission data of the new energy DC receiving system;

[0134] The total output data acquisition unit 202 is used to perform operation simulation based on the time series production simulation model to obtain the total output data of the new energy DC receiving system;

[0135] The frequency regulation reserve power calculation unit 203 is used to determine the frequency regulation reserve power of the new energy DC receiving system based on the total output data, the total operating capacity of the new energy DC receiving system, and the maximum reserve coefficient of each type of unit;

[0136] The frequency stability risk identification unit 204 is used to obtain a frequency regulation margin coefficient based on the ratio of the frequency regulation standby power to the operating power of the renewable energy DC receiving system, and to determine a frequency stability assessment result of the renewable energy receiving system based on a comparison result of the frequency regulation margin coefficient with a preset margin coefficient threshold.

[0137] In addition to the above-mentioned embodiment of the frequency stability assessment device for a new energy receiving terminal system, the present application also provides a detailed description of an embodiment of a frequency stability assessment terminal for a new energy receiving terminal system and a computer-readable storage medium, as follows:

[0138] See also Figure 7 The present application provides an embodiment of a frequency stability assessment terminal for a new energy receiving system, which includes, but is not limited to, personal computers, industrial computers, servers, and embedded intelligent devices. Its main components include: a memory 33 and a processor 31, which can be connected via a communication bus 34;

[0139] The memory 33 is used to store program codes corresponding to a frequency stability evaluation method for a new energy receiving terminal system provided in the above embodiment;

[0140] The processor 31 is configured to execute program codes to implement a frequency stability evaluation method for a new energy receiving terminal system as provided in the above embodiment through the execution of the program codes.

[0141] In a fourth aspect, the present application provides a computer-readable storage medium, in which a program code corresponding to a frequency stability evaluation method for a new energy receiving system as provided in the above embodiment is stored.

[0142] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the terminals, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0143] In the several embodiments provided in this application, it should be understood that the disclosed terminals, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0144] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0145] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0146] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0147] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0148] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0149] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for evaluating the frequency stability of a new energy receiving system, characterized in that: include: Based on the unit data of the new energy DC receiving system and the power transmission data of the tie line, a time-series production simulation model of the new energy DC receiving system is constructed; Performing an operation simulation based on the time-series production simulation model to obtain total output data of the new energy DC receiving system; Determining the frequency regulation reserve power of the new energy DC receiving system based on the total output data and in combination with the total operating capacity of the new energy DC receiving system and the maximum reserve coefficient of each type of unit; A frequency regulation margin coefficient is obtained based on a ratio of the frequency regulation standby power to the operating power of the new energy DC receiving system, and a frequency stability assessment result of the new energy receiving system is determined based on a comparison result of the frequency regulation margin coefficient with a preset margin coefficient threshold; The time series production simulation model specifically includes: an objective function and production simulation constraints; The production simulation constraints include: power load balance constraint, positive reserve capacity constraint, unit output range constraint, unit ramp rate constraint, continuous start and stop time constraint, daily start and stop number constraint, three-stage output constraint of hydropower unit, pumped storage charging power constraint of the hydropower unit, and pumped storage charge state constraint of the hydropower unit; The objective function is specifically: ； In the formula, i represents the unit number, I represents the total number of units in the province, t represents the time period number, and T represents the total number of time periods considered. Indicates the unit The output in time period t, 、 、 Respectively represent the units Operating costs, startup costs, and downtime costs in period t, Indicates the unit The curtailment penalty in period t is: Indicates the unit The curtailed power in period t, 、 Respectively represent the load shedding value and load relaxation in time period t, 、 They represent the load shedding penalty and load relaxation penalty in time period t respectively.

2. A frequency stability evaluation method for a new energy receiving system according to claim 1, characterized in that: The operation simulation based on the time-series production simulation model is performed to obtain the total output data of the new energy DC receiving system, specifically including: An operation simulation is performed based on the time-series production simulation model, and output data of various units in the new energy DC receiving system at different time periods are counted to obtain total output data of the new energy DC receiving system based on the output data.

3. The method for evaluating frequency stability of a new energy receiving system according to claim 2, wherein: The operation simulation is performed based on the time-series production simulation model, and output data of various units in the new energy DC receiving system at different time periods are counted to obtain total output data of the new energy DC receiving system based on the output data. Specifically, the process includes: An operation simulation is performed based on the time-series production simulation model, and combined with preset partition information, output data of various types of units in the same partition of the new energy DC receiving system at different time periods are counted, and the total output data of the new energy DC receiving system is obtained by accumulating the output data of each partition.

4. The method for evaluating frequency stability of a new energy receiving system according to claim 2, wherein: Determining the frequency regulation standby power of the new energy DC receiving system based on the total output data and in combination with the total startup capacity and the maximum standby coefficient of the new energy DC receiving system specifically includes: Based on the total output data, combined with the total startup capacity and the maximum reserve coefficient of the new energy DC receiving system, the difference between the total startup capacity and the total output data, and the product value of the total startup capacity and the maximum reserve coefficient are calculated, and the smaller value of the difference and the product value is used as the frequency regulation reserve power of the new energy DC receiving system.

5. A frequency stability evaluation method for a new energy receiving system according to claim 4, characterized in that: The calculation formula of the frequency modulation standby power is: ； Where, is the frequency regulation standby power of the new energy DC receiving system in period t, is the maximum reserve factor of the kth type unit, is the total operating capacity of the k-th type unit in period t, is the total output data of the k-th unit in period t.

6. A frequency stability evaluation device for a new energy receiving system, characterized in that: include: A receiving system simulation model building unit, configured to build a time-series production simulation model of the new energy DC receiving system based on the unit data and the tie-line power transmission data of the new energy DC receiving system; a total output data acquisition unit, configured to perform operation simulation based on the time-series production simulation model to obtain total output data of the new energy DC receiving system; a frequency regulation standby power calculation unit, configured to determine the frequency regulation standby power of the new energy DC receiving system based on the total output data, in combination with the total operating capacity of the new energy DC receiving system and the maximum standby coefficient of each type of unit; a frequency stability risk identification unit, configured to obtain a frequency regulation margin coefficient based on a ratio of the frequency regulation standby power to the operating power of the renewable energy DC receiving system, and determine a frequency stability assessment result of the renewable energy receiving system based on a comparison result of the frequency regulation margin coefficient with a preset margin coefficient threshold; The time series production simulation model specifically includes: an objective function and production simulation constraints; The production simulation constraints include: power load balance constraint, positive reserve capacity constraint, unit output range constraint, unit ramp rate constraint, continuous start and stop time constraint, daily start and stop number constraint, three-stage output constraint of hydropower unit, pumped storage charging power constraint of the hydropower unit, and pumped storage charge state constraint of the hydropower unit; The objective function is specifically: ； In the formula, i represents the unit number, I represents the total number of units in the province, t represents the time period number, and T represents the total number of time periods considered. Indicates the unit The output in time period t, 、 、 Respectively represent the units Operating costs, startup costs, and downtime costs in period t, Indicates the unit The curtailment penalty in period t is: Indicates the unit The curtailed power in period t, 、 Respectively represent the load shedding value and load relaxation in time period t, 、 They represent the load shedding penalty and load relaxation penalty in time period t respectively.

7. A new energy receiving system frequency stability assessment terminal, characterized in that: include: memory and processor; The memory is used to store a program code corresponding to the frequency stability evaluation method for a new energy receiving system according to any one of claims 1 to 5; The processor is configured to execute the program code.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores program code corresponding to the frequency stability evaluation method for a new energy receiving system according to any one of claims 1 to 5.

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