Method, device and equipment for analyzing maximum feed-in power of power electronic power supply and medium

Abstract

The invention discloses a power electronic power supply maximum feed-in power analysis method, device and equipment and a medium, and relates to the field of electrical engineering, and the method comprises the steps: obtaining an operation parameter, an equivalent damping coefficient and load power of a start-up unit; the operation parameters, the equivalent damping coefficient and the load power serve as working condition parameters of the frequency response model; optimizing startup under the operation constraint condition of the power system and the startup unit, and calculating the initial feed-in power of the power electronic power supply with safe non-test rate frequency; taking a minimum equivalent inertia constant as a target function, increasing the target function to optimize a startup mode, updating the frequency response model based on the startup mode obtained by optimizing the startup mode, outputting a frequency index by the updated frequency response model, and performing frequency safety check on the frequency index; and updating the upper and lower limits of the dichotomy according to a frequency safety checking result, and converting the initial feed-in power by using the dichotomy to iteratively solve the maximum feed-in power of the power electronic power supply considering the frequency safety.

Description

Technical Field

[0001] The present invention relates to the field of electrical engineering, and more specifically, to a method, device, equipment and medium for analyzing the maximum feeding power of a power electronic power supply. Background Art

[0002] With the gradual increase in the proportion of power electronic power supplies, the power system shows obvious characteristics of "hollowing out" of conventional power supplies, the system inertia continues to decrease, the anti-disturbance power gradually weakens, and the system frequency faces the risk of instability. Therefore, there is an urgent need to propose an evaluation method for the maximum feeding power of power electronic power supplies considering inertia and frequency safety, so as to reasonably plan the feeding power of power electronic power supplies in the power grid and reduce the risk of frequency instability.

[0003] However, at present, the maximum feeding power of power electronic power supplies is mostly evaluated and calculated by replacing synchronous machines with power electronic power supplies. The optimization of the starting mode is not considered, the model built is too simplified, and the accuracy of frequency indicators is not high, resulting in the inability to accurately determine the feeding limit of power electronic power supplies in the power system by using the existing analysis method for the maximum feeding power of power electronic power supplies. Summary of the Invention

[0004] The purpose of the present invention is to provide a method, device, equipment and medium for analyzing the maximum feeding power of a power electronic power supply. The present invention solves the problem that the existing analysis method for the maximum feeding power cannot accurately determine the feeding limit of power electronic power supplies in the power system.

[0005] In the first aspect of the present invention, a method for analyzing the maximum feeding power of a power electronic power supply is provided. The method includes:

[0006] Obtain the operating parameters of all startable units in the power system, the equivalent damping coefficient of the power system, and the load power;

[0007] Take the operating parameters, equivalent damping coefficient, and load power as the operating condition parameters of a pre-constructed frequency response model, where the frequency response model is the equivalent rotor motion equation of the unit;

[0008] Optimize the starting under the operating constraints of the power system and startable units, and calculate the initial feeding power of the power electronic power supply without considering frequency safety; where the operating constraints include active power balance constraint, inertia constraint, unit output limit constraint, unit primary frequency regulation reserve constraint, fault reserve constraint, and maximum frequency change rate constraint;

[0009] Take minimizing the equivalent inertia constant of the power system as the objective function, increase the objective function to optimize the starting mode, update the frequency response model based on the starting mode obtained by optimizing the starting mode, output frequency indicators from the updated frequency response model, and perform frequency safety verification on the frequency indicators;

[0010] Update the upper and lower limits of the bisection method according to the frequency safety check result, and use the bisection method to transform the initial feeding power to iteratively solve the maximum feeding power of the power electronic power supply considering frequency safety.

[0011] In one implementation, the pre-constructed frequency response model includes: constructing the frequency response model of each unit according to the operating parameters of all startable units, with the benchmark of the frequency response model being the load power, and the equivalent inertia constant of the power system being determined according to the start-up mode.

[0012] In one implementation, increase the objective function to optimize the start-up mode, specifically:

[0013] The increase amount of the objective function to minimize the equivalent inertia constant is expressed by the following formula:

[0014] ΔH n =H n -H n-1 =k·error n-1 ;

[0015] error=Δf nadir -Δf limit ; In the formula, H n is the equivalent inertia constant of the power system when optimizing the start-up by increasing the equivalent inertia constant for the nth time; k is the proportionality coefficient; error is the difference between the lowest frequency point Δf nadir and the lower limit of the lowest frequency point Δf limit ;

[0016] In the formula, is the lower limit of the inertia constraint when optimizing the start-up by increasing the equivalent inertia constant for the nth time;

[0017] Optimize the start-up mode by updating the lower limit of the inertia constraint.

[0018] In one implementation, the frequency index includes the deviation of the lowest frequency point and the frequency change rate at 200 ms;

[0019] The process of frequency safety check is: if the deviation of the lowest frequency point is less than or equal to the constraint value of the deviation of the lowest frequency point, and the frequency change rate at 200 ms is less than or equal to the constraint value of the frequency change rate at 200 ms, then the frequency safety check passes.

[0020] In one implementation, update the upper and lower limits of the bisection method according to the frequency safety check result, specifically:

[0021] If the frequency safety check passes and the difference between the lower limit and the upper limit of the bisection method is less than or equal to the threshold, the maximum feeding power of the power electronic power supply can be determined;

[0022] If the frequency safety check passes and the difference between the lower and upper limits of the bisection method is greater than the threshold, update the lower limit of the bisection method;

[0023] If the frequency safety check fails and the difference between the lower and upper limits of the bisection method is less than or equal to the threshold, the maximum feed-in power of the power electronic power supply is zero;

[0024] If the frequency safety check fails and the difference between the lower and upper limits of the bisection method is greater than the threshold, update the upper limit of the bisection method.

[0025] In one implementation, the initial feed-in power is transformed using the bisection method, including: determining the feed-in power P of the power electronic power supply for the next iteration by updating the upper and lower limits of the bisection method PEP as: where a and b are the lower and upper limits of the bisection method respectively.

[0026] In one implementation, the maximum feed-in power of the power electronic power supply considering frequency safety is solved iteratively. Specifically: optimize the startup by increasing the objective function, then update the frequency response model simulation to obtain the frequency index and perform frequency check, update the upper and lower limits of the bisection method according to the frequency check result, and thus determine the feed-in power of the power electronic power supply when optimizing the startup by increasing the equivalent inertia constant next time until the iteration is completed to obtain the maximum feed-in power of the power electronic power supply.

[0027] In the second aspect of the present invention, a device for analyzing the maximum feed-in power of a power electronic power supply is provided. The device includes:

[0028] A parameter acquisition module for acquiring the operating parameters of all startable units in the power system, the equivalent damping coefficient of the power system, and the load power;

[0029] A parameter input module for using the operating parameters, the equivalent damping coefficient, and the load power as the operating condition parameters of a pre-constructed frequency response model, where the frequency response model is the equivalent rotor motion equation of the unit;

[0030] A power calculation module for optimizing the startup under the operating constraint conditions of the power system and the startable units, and calculating the initial feed-in power of the power electronic power supply without considering frequency safety; where the operating constraint conditions include active power balance constraint, inertia constraint, unit output limit constraint, unit primary frequency regulation reserve constraint, fault reserve constraint, and maximum frequency change rate constraint;

[0031] A frequency check module for taking the minimization of the equivalent inertia constant of the power system as the objective function, increasing the objective function to optimize the startup mode, updating the frequency response model based on the startup mode obtained by optimizing the startup mode, outputting the frequency index from the updated frequency response model, and performing frequency safety check on the frequency index;

[0032] The maximum feed-in power analysis module is used to update the upper and lower limits of the bisection method according to the frequency security check result, and transform the initial feed-in power by using the bisection method to iteratively solve the maximum feed-in power of the power electronic power supply considering frequency security.

[0033] In the third aspect of the present invention, a computer device is provided, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method for analyzing the maximum feed-in power of the power electronic power supply provided in the first aspect of the present invention are implemented.

[0034] In the fourth aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for analyzing the maximum feed-in power of the power electronic power supply provided in the first aspect of the present invention are implemented.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] In a method, device, equipment and medium for analyzing the maximum feed-in power of a power electronic power supply provided by the present invention, first obtain the rotational kinetic energy, governor-prime mover parameters, maximum active power of all startable units in the power system, the equivalent damping coefficient of the power system and the total load power, construct a frequency response model, and then optimize the start-up considering the active power balance constraint, inertia constraint, unit output limit constraint, unit primary frequency regulation reserve constraint, fault reserve constraint and maximum frequency change rate constraint, and evaluate the initial feed-in power of the power electronic power supply when the power system does not consider frequency security, that is, the expected value of the feed-in power of the power electronic power supply; based on the initial feed-in power, with the goal of minimizing the equivalent inertia constant of the power system as the objective function, increase the equivalent inertia constant to optimize the start-up, update the frequency response model according to the start-up method obtained by the optimized start-up, so as to simulate the frequency index and conduct frequency security check; finally, update the upper and lower limits of the bisection method according to the frequency check result, and transform the initial feed-in power of the power electronic power supply by using the bisection method to iteratively solve the maximum feed-in power of the power electronic power supply considering frequency security. The above method, compared with the method provided by the related technology, considers the start-up optimization and simulates and checks the frequency index, and can more accurately analyze the maximum feed-in power of the power electronic power supply when ensuring frequency security. Description of the Drawings

[0037] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings:

[0038] Figure 1 It is a schematic flowchart of the method for analyzing the maximum feed-in power of the power electronic power supply provided by the embodiment of the present invention;

[0039] Figure 2 A schematic flowchart of the maximum power feed-in analysis of a power electronic power supply considering inertia and frequency security constraints provided by an embodiment of the present invention;

[0040] Figure 3 A schematic structural diagram of a frequency response model provided by an embodiment of the present invention;

[0041] Figure 4 A schematic diagram of the inertia iteration process corresponding to the maximum power feed-in of a power electronic power supply provided by an embodiment of the present invention;

[0042] Figure 5 A principle block diagram of a maximum power feed-in analysis device for a power electronic power supply provided by an embodiment of the present invention;

[0043] Figure 6 A schematic structural diagram of a computer device provided by an embodiment of the present invention. Specific embodiments

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments and drawings. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0045] It should be noted that the term "including" or "may include" that can be used in various embodiments of the present application indicates the existence of the claimed functions, operations, or elements, and does not limit the addition of one or more functions, operations, or elements. In addition, as used in various embodiments of the present application, the terms "including", "having", and their cognates are only intended to represent specific features, numbers, steps, operations, elements, components, or combinations of the foregoing items, and should not be construed as first excluding the existence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components, or combinations of the foregoing items.

[0046] In various embodiments of the present application, the expression "or" or "at least one of B or / and C" includes any combination or all combinations of the listed words. For example, the expression "B or C" or "at least one of B or / and C" may include B, may include C, or may include both B and C.

[0047] It should be understood that terms such as "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0048] Please refer to Figure 1 , Figure 1 which is a schematic flowchart of the method for analyzing the maximum feed-in power of the power electronic power supply provided by the embodiment of the present invention. As Figure 1 shown, the method includes:

[0049] S101, obtaining the operating parameters of all startable units in the power system, the equivalent damping coefficient of the power system, and the load power.

[0050] In this embodiment, the unit refers to a steam turbine and a water turbine. It should be noted that the steam turbine and the water turbine are units of conventional technologies in the power system. The operating parameters of the startable units include the governor-prime mover parameters of the units, the rotational kinetic energy, and the maximum active power.

[0051] Specifically, as Figure 2 shown, S201, reading all the basic information of the units in the power system, the equivalent damping coefficient of the system, and the total load power.

[0052] S102, using the operating parameters, the equivalent damping coefficient, and the load power as the operating condition parameters of a pre-constructed frequency response model, where the frequency response model is the equivalent rotor motion equation of the unit.

[0053] In this embodiment, the pre-constructed frequency response model includes: constructing the frequency response model of each unit according to the operating parameters of all startable units, with the benchmark of the frequency response model being the load power, and the equivalent inertia constant of the power system being determined according to the start-up mode.

[0054] Secondly, the structural schematic diagram of the frequency response model is as Figure 3 shown. Figure 3 Among them, 'GI', 'GJ', 'GK', 'GA', 'GM' are electronic governor models, 'GS', 'GL', 'GW' are hydraulic governor models, 'TA', 'TB', 'TC', 'TW', 'TV' are prime mover models; H is the equivalent inertia constant; D is the equivalent damping coefficient; ΔP d is the active power disturbance. The frequency response model retains the complete and detailed governor-prime mover model of each unit, so it can maintain the high precision of the results. Optionally, the governor-prime mover model in the frequency response model includes, but is not limited to, the above governor-prime mover models.

[0055] S103. Optimize the unit startup under the operating constraints of the power system and the units that can be started, and calculate the initial feeding power of the power electronic power supply without considering frequency security. Among them, the operating constraints include active power balance constraint, inertia constraint, unit output limit constraint, primary frequency regulation reserve constraint of the unit, fault reserve constraint, and maximum frequency change rate constraint.

[0056] In this embodiment, in S202, set a pre-fault, and perform an initial feeding power optimization evaluation to obtain the maximum feeding power expectation value P PEPmax and the corresponding unit startup mode.

[0057] The initial feeding power optimization is as follows: taking the maximum feeding power P of the power electronic power supply PEP as the objective function: max P PEP (1). Consider constraints such as active power balance constraint, inertia constraint, unit output limit constraint, primary frequency regulation reserve constraint of the unit, fault reserve constraint, and maximum frequency change rate.

[0058] 1) Active power balance constraint

[0059] Active power balance means that at any moment, the sum of the active power generated by all generators in the power system and the DC feeding power must be equal to the sum of the active power consumed by all loads and transmission lines. During the process of optimizing the unit startup mode, the active power balance constraint can be regarded as the sum of the active power of the generators after optimization plus the feeding power of the power electronic power supply equals the sum of the active power of the generators before optimization, that is: P NSP +∑P Gi x i =P G0 (2), where P Gi is the active power of the i-th generator; P G0 is the sum of the original active power of the generators; x i is the startup state of the i-th generator (0 means shutdown, 1 means startup).

[0060] 2) Inertia constraint

[0061] The system equivalent inertia constant is expressed by Equation (4) and should be less than or equal to the system equivalent inertia constant H when all units are started max .

[0062] H≤H max (3)

[0063]

[0064] where E ki is the rotational kinetic energy of the i-th unit; S BASEis the system reference power, which is set as the total load power of the system.

[0065] 3) Generator output limit constraint

[0066] The generator output limit constraint means that the active power generated by the generator is not less than its minimum stable output and not greater than its maximum active power:

[0067] In the formula, are the minimum stable output and the maximum active power of the generator respectively.

[0068] 4) Primary frequency regulation reserve constraint of the generator

[0069] According to the grid operation criteria, the primary frequency regulation reserve capacity of the generator set is set to be not less than 6% of the rated capacity of the generator set:

[0070]

[0071] 5) Fault reserve constraint

[0072] The primary frequency regulation reserve capacity of the system should be not less than the active power disturbance amount:

[0073]

[0074] In the formula, ΔP d is the active power disturbance amount of the system.

[0075] 6) Maximum frequency change rate constraint

[0076] The maximum frequency change rate should be less than or equal to the maximum frequency change rate limit:

[0077] RoCoF max ≤RoCoF limit (8)

[0078] In the formula, RoCoF max is the maximum frequency change rate at the initial moment of the disturbance, which can be expressed by formula (11); RoCoF limit is the maximum frequency change rate limit.

[0079] S104, with the objective of minimizing the equivalent inertia constant of the power system, increasing the objective function to optimize the unit startup mode, updating the frequency response model based on the startup mode obtained from the optimized startup mode, outputting the frequency index by the updated frequency response model, and performing frequency safety check on the frequency index.

[0080] In this embodiment, in S203, the frequency security index is obtained by updating the starting method simulation, specifically: a corresponding frequency response model is built according to the starting method optimized by the initial feed-in power / inertia, and the frequency security index, that is, the deviation Δf of the lowest frequency point, is obtained by simulation. nadir and the rate of change of frequency RoCoF at 200 ms 200ms .

[0081] In S204, the process of frequency security check is as follows: if the deviation of the lowest frequency point is less than or equal to the constraint value of the deviation of the lowest frequency point, and the rate of change of frequency at 200 ms is less than or equal to the constraint value of the rate of change of frequency at 200 ms, then the frequency security check passes.

[0082] Among them, the frequency security index check refers to judging whether the following formulas (10) and (11) are established.

[0083] Δf nadir ≥Δf UFLS (10)

[0084]

[0085] In the formula, Δf UFLS is the starting value of the under-frequency load shedding protection; RoCoF 200ms is the rate of change of frequency at 200 ms; is the limit value of the rate of change of frequency at 200 ms.

[0086] In some embodiments, the upper and lower limits of the bisection method are updated according to the frequency security check result, specifically: if the frequency security check passes and the difference between the lower limit and the upper limit of the bisection method is less than or equal to the threshold value, then the maximum feed-in power of the power electronic power supply can be determined; if the frequency security check passes and the difference between the lower limit and the upper limit of the bisection method is greater than the threshold value, then the upper limit of the bisection method is updated; if the frequency security check fails and the difference between the lower limit and the upper limit of the bisection method is less than or equal to the threshold value, then the maximum feed-in power of the power electronic power supply is zero; if the frequency security check fails and the difference between the lower limit and the upper limit of the bisection method is greater than the threshold value, then the lower limit of the bisection method is updated.

[0087] Specifically, if both formulas (10) and (11) are established, then the expected value P of the maximum feed-in power PEPmax is the maximum feed-in power of the power electronic power supply under the pre-fault condition of the system; if formulas (10) and (11) do not hold simultaneously, and the expected value P of the maximum feed-in power of the power electronic power supply PEP is less than 200 MW (200 MW is the accuracy of the evaluation result and can be set by oneself), then the evaluation ends and it is considered that the maximum feed-in power of the power electronic power supply under the pre-fault condition is 0; if formulas (10) and (11) do not hold simultaneously, and the expected value P of the maximum feed-in power of the power electronic power supply PEPIf it is not less than 200 MW, then perform S205.

[0088] S205, update H min , perform inertia optimization.

[0089] The inertia optimization is as follows: Take the minimum equivalent inertia constant as the objective function: minH(12).

[0090] Optimize the startup by increasing H. Equation (3) needs to be changed to Equation (13), and the other constraint conditions are the same as those for the initial feed-in power optimization.

[0091] H min ≤H≤H max (13)

[0092] H min =H + ΔH(14)

[0093] ΔH = k·error(15)

[0094] In the formula, H min is the lower limit of the equivalent inertia constant; ΔH is the increment of the equivalent inertia constant, which is determined by the following formula:

[0095] ΔH = k·error(16)

[0096] error = Δf nadir -Δf UFLS (17)

[0097] In the formula, k is the proportionality coefficient, which is set by itself. If there is a solution to the inertia optimization, return the determination steps of the startup mode; if there is no solution, it means that the frequency indexes obtained by simulating all startup modes corresponding to the current feed-in power expectation do not meet the frequency safety constraints. Then, based on the bisection method, iteratively reduce the feed-in power expectation, and re-optimize and evaluate until it is satisfied.

[0098] S105, update the upper and lower limits of the bisection method according to the frequency safety check result, and use the bisection method to transform the initial feed-in power to iteratively solve the maximum feed-in power of the power electronic power supply considering frequency safety.

[0099] In this embodiment, S206, iteratively reduce the feed-in power expectation based on the bisection method. Specifically: Let the initial lower and upper limits of the bisection method be a and b, and the initial values of a and b are 0 and the maximum feed-in power expectation P PEPmax , then the feed-in power expectation corresponding to the first bisection method iteration The feed-in power expectation corresponding to the nth bisection method iteration

[0100] Correspondingly, the maximum feeding power of the power electronic power supply considering frequency security is obtained by iterative solution, specifically: optimizing the startup by increasing the objective function, then updating the frequency response model to simulate and obtain the frequency index and conduct frequency check, updating the upper and lower limits of the bisection method according to the frequency check result, thereby determining the feeding power of the power electronic power supply when optimizing the startup by increasing the equivalent inertia constant next time until the iteration is completed to obtain the maximum feeding power of the power electronic power supply.

[0101] S207. Perform initial inertia optimization to obtain the corresponding startup mode. Among them, the initial inertia optimization is as follows: taking the minimum equivalent inertia constant as the objective function: minH(18), and the constraint conditions are the same as those for the initial feeding power optimization.

[0102] S208. Build the corresponding frequency response model according to the startup mode obtained by the initial inertia / inertia optimization, and update the startup mode to simulate and obtain the frequency security index: the deviation of the lowest frequency point Δf nadir and the rate of change of frequency RoCoF at 200 ms 200ms .

[0103] S209. Conduct frequency security index check to determine whether the above formulas (10) and (11) hold. If both formulas (10) and (11) hold and b - a ≤ 200, then the maximum feeding power of the power electronic power supply is If both formulas (10) and (11) hold, but b - a > 200, then update and perform S111; if both formulas (10) and (11) do not hold and b - a ≤ 200, then it can be considered that the maximum feeding power of the power electronic power supply is 0; if both formulas (10) and (11) do not hold and b - a > 200, then perform S210 to update H min , and perform inertia optimization.

[0104] Among them, the basic steps of inertia optimization are the same as the content of S205 described above. If there is a solution to the inertia optimization, return to S208; if there is no solution, then update and perform S211.

[0105] S211. Update the expected value of the feeding power based on the bisection method, specifically: update the expected value of the feeding power Return and perform S207. According to the embodiment of the present application, the obtained maximum feeding power P of the power electronic power supply NSP The determination result is shown in Table 1, and the corresponding inertia iteration process is as Figure 4 shown, and the corresponding startup mode is shown in Table 2, where 1 represents startup and 0 represents shutdown.

[0106] In one embodiment, transforming the initial feeding power by the bisection method includes: determining the feeding power P of the power electronic power supply for the next iteration by updating the upper and lower limits of the bisection method PEPfor: Among them, a and b are the upper and lower limits of the dichotomy respectively.

[0107] Table 1 Determination results of the maximum feed-in power of the power electronic power supply

[0108]

[0109]

[0110] The power electronic power supply limit penetration rate is the ratio of the maximum power electronic power supply input power to the total system load power. The total system load power is 21438MW; Δf UFLS Set to -0.5Hz.

[0111] Table 2 Maximum feed-in power of power electronic power supply Corresponding startup mode Anticipated fault 1200MW

[0112] 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 1 1 1 0 0 1 1 1 1 1 0 0 0 0 1 0 1 1 1 0

[0113] Expected failure 1400MW

[0114] 1 1 1 0 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 0 1 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 1 0 1 1 1 1

[0115] Expected failure 1600MW

[0116] 0 1 1 0 0 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 0 1 1 1 1 1 1 0 1 1 1 1 0 0 0 1 1 0 1 1 1 1 1 1

[0117] It can be seen that the maximum feed-in power of the power electronic power supply considering inertia and frequency safety constraints provided in this embodiment can be accurately obtained.

[0118] Please refer to Figure 5 , Figure 5 The principle block diagram of the maximum feed-in power analysis device for a power electronic power supply provided by an embodiment of the present invention is as follows: Figure 5 As shown, the device comprises:

[0119] The parameter acquisition module 510 is used to obtain the operating parameters of all start-up units in the power system and the equivalent damping coefficient and load power of the power system;

[0120] A parameter input module 520 is used to use the operating parameters, equivalent damping coefficient and load power as operating parameters of a pre-built frequency response model, wherein the frequency response model is an equivalent rotor motion equation of the unit;

[0121] A power calculation module 530 is configured to optimize unit starting under the operating constraints of a power system and startable units, and calculate the initial feeding power of a power electronic power supply without considering frequency security. The operating constraints include active power balance constraints, inertia constraints, unit output limit constraints, primary frequency regulation reserve constraints of units, fault reserve constraints, and maximum frequency change rate constraints.

[0122] A frequency verification module 540 is configured to use the minimization of the equivalent inertia constant of the power system as an objective function, increase the objective function to optimize the unit starting mode, update the frequency response model based on the unit starting mode obtained by optimizing the unit starting mode, output frequency indexes from the updated frequency response model, and perform frequency security verification on the frequency indexes.

[0123] A maximum feeding power analysis module 550 is configured to update the upper and lower limits of the bisection method according to the frequency security verification result, transform the initial feeding power by using the bisection method, and iteratively solve the maximum feeding power of the power electronic power supply considering frequency security.

[0124] Please refer to Figure 6 , Figure 6 FIG. is a schematic structural diagram of a computer device provided by an embodiment of the present application. The computer device 600 includes a processor 610, a memory 620, a communication interface 630, and at least one communication bus for connecting the processor 610, the memory 620, and the communication interface 630. The memory 620 includes, but is not limited to, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (PROM), or a portable read-only memory (CD-ROM). The memory 620 is used for relevant instructions and data.

[0125] The communication interface 630 is used to receive and send data. The processor 610 can be one or more CPUs. When the processor 610 is a single CPU, the CPU can be a single-core CPU or a multi-core CPU. The processor 610 in the computer device 600 is used to read one or more programs 621 stored in the memory 620 and perform the following operations: obtaining the operating parameters of all startable units in the power system, the equivalent damping coefficient of the power system, and the load power; using the operating parameters, the equivalent damping coefficient, and the load power as the operating condition parameters of a pre-constructed frequency response model, where the frequency response model is the equivalent rotor motion equation of the unit; optimizing the startup under the operating constraints of the power system and the startable units, and calculating the initial feeding power of the power electronic power supply without considering frequency safety; where the operating constraints include active power balance constraints, inertia constraints, unit output limit constraints, unit primary frequency regulation reserve constraints, fault reserve constraints, and maximum frequency change rate constraints; taking minimizing the equivalent inertia constant of the power system as the objective function, increasing the objective function to optimize the startup mode, updating the frequency response model based on the startup mode obtained from the optimized startup mode, outputting a frequency index by the updated frequency response model, and performing a frequency safety check on the frequency index; updating the upper and lower limits of the bisection method according to the frequency safety check result, and using the bisection method to transform the initial feeding power to iteratively solve the maximum feeding power of the power electronic power supply considering frequency safety.

[0126] It should be noted that the specific implementation of each operation can be the corresponding description of the method embodiment shown above Figure 1 The computer device 600 can be used to execute a method for analyzing the maximum feeding power of a power electronic power supply in the method embodiment of the present application above, and will not be specifically described here.

[0127] In an embodiment of the present disclosure, a computer-readable storage medium is further provided. The computer-readable storage medium is a memory device in a computer device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. Moreover, one or more instructions suitable for being loaded and executed by a processor are also stored in this storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the method for analyzing the maximum feeding power of a power electronic power supply in the above embodiment. Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0128] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for analyzing the maximum infeed power of a power electronic power supply, characterized in that: Methods include: Obtain the operating parameters of all startable units in the power system and the equivalent damping coefficient and load power of the power system; The operating parameters, equivalent damping coefficient and load power are used as operating parameters of a pre-built frequency response model, wherein the frequency response model is an equivalent rotor motion equation of the unit; Optimize startup under the operating constraints of the power system and the units that can be started, and calculate the initial feed-in power of the power electronic power supply without considering the power frequency safety; wherein the operating constraints include active power balance constraints, inertia constraints, unit output limit constraints, unit primary frequency regulation standby constraints, fault standby constraints, and maximum frequency change rate constraints; Taking minimizing the equivalent inertia constant of the power system as the objective function, increasing the objective function to optimize the startup mode, updating the frequency response model based on the startup mode obtained by optimizing the startup mode, outputting the frequency index from the updated frequency response model, and performing frequency safety check on the frequency index; The upper and lower limits of the binary method are updated according to the frequency safety verification results, and the initial feed-in power is transformed using the binary method to iteratively solve the maximum feed-in power of the power electronic power supply considering frequency safety.

2. A method for analyzing the maximum infeed power of a power electronic power supply according to claim 1, characterized in that: The pre-built frequency response model includes: building a frequency response model of each unit according to the operating parameters of all start-up units, the reference of the frequency response model is the load power, and the equivalent inertia constant of the power system is determined according to the start-up mode.

3. A method for analyzing the maximum infeed power of a power electronic power supply according to claim 1, characterized in that: Increase the objective function to optimize the startup mode, specifically: The increase in the objective function to minimize the equivalent inertia constant is expressed as follows: ΔH n =H n -H n-1 =k·error n-1 ; error=Δf nadir -Δf limit Where H n The equivalent inertia constant of the power system is optimized for the nth increase in the equivalent inertia constant when starting up; k is the proportional coefficient; error is the lowest frequency point Δf nadir The lower limit of the lowest frequency point Δf limit The difference between In the formula, Optimize the lower limit of the inertia constraint at startup for the nth increase in the equivalent inertia constant; The startup mode is optimized by updating the lower limit of the inertia constraint.

4. A method for analyzing the maximum infeed power of a power electronic power supply according to claim 1, characterized in that: The frequency index includes the frequency minimum point deviation and the frequency change rate at 200ms; The process of frequency safety check is as follows: if the frequency minimum point deviation is less than or equal to the frequency minimum point deviation constraint value, and the frequency change rate at 200ms is less than or equal to the frequency change rate constraint value at 200ms, the frequency safety check passes.

5. A method for analyzing the maximum infeed power of a power electronic power supply according to claim 4, characterized in that: Update the upper and lower limits of the binary method according to the frequency safety check results, specifically: If the frequency safety check passes, and the difference between the lower limit and the upper limit of the dichotomy is less than or equal to the threshold, the maximum feed-in power of the power electronic power supply can be determined; If the frequency safety check passes and the difference between the lower limit and the upper limit of the binary search is greater than the threshold, the lower limit of the binary search is updated; If the frequency safety check fails, and the difference between the lower limit and the upper limit of the dichotomy is less than or equal to the threshold, the maximum feed-in power of the power electronic power supply is zero; If the frequency safety check fails and the difference between the lower limit and the upper limit of the binary search method is greater than the threshold, the upper limit of the binary search method is updated.

6. A method for analyzing the maximum infeed power of a power electronic power supply according to claim 1, characterized in that: The initial feed-in power is transformed by using the binary method, including: determining the feed-in power P of the next iteration of the power electronic power supply by updating the binary method upper and lower limits PEP for: Among them, a and b are the lower and upper limits of the dichotomy respectively.

7. A method for analyzing the maximum feed-in power of a power electronic power supply according to claim 6, characterized in that: The maximum feed-in power of the power electronic power supply considering frequency safety is solved iteratively, specifically: the startup is optimized by increasing the objective function, and then the frequency response model is updated to simulate and obtain the frequency index and perform frequency verification. The upper and lower limits of the dichotomy are updated according to the frequency verification results, thereby determining the next time the equivalent inertia constant is increased to optimize the power electronic power supply startup. Until the iteration is completed, the maximum feed-in power of the power electronic power supply is obtained.

8. A device for analyzing the maximum infeed power of a power electronic power supply, characterized in that: The device includes: A parameter acquisition module is used to obtain the operating parameters of all start-up units in the power system and the equivalent damping coefficient and load power of the power system; A parameter input module, used for taking the operating parameters, equivalent damping coefficient and load power as the operating parameters of the pre-built frequency response model, wherein the frequency response model is the equivalent rotor motion equation of the unit; A power calculation module is used to optimize the startup under the operating constraints of the power system and the units that can be started, and calculate the initial feed-in power of the power electronic power supply without considering the power frequency safety; wherein the operating constraints include active power balance constraints, inertia constraints, unit output limit constraints, unit primary frequency regulation standby constraints, fault standby constraints and maximum frequency change rate constraints; A frequency verification module is used to minimize the equivalent inertia constant of the power system as an objective function, increase the objective function to optimize the startup mode, update the frequency response model based on the startup mode obtained by optimizing the startup mode, output the frequency index from the updated frequency response model, and perform frequency safety verification on the frequency index; The maximum feed-in power analysis module is used to update the upper and lower limits of the binary method according to the frequency safety verification results, and use the binary method to transform the initial feed-in power to iteratively solve the maximum feed-in power of the power electronic power supply considering frequency safety.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method for analyzing the maximum feed-in power of a power electronic power supply according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for analyzing the maximum feed-in power of a power electronic power supply according to any one of claims 1 to 7 are implemented.

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