High-frequency cutting machine scheme constant value determination method and system, storage medium and computing device

Abstract

The application discloses a high-week machine tripping scheme setting value determination method and system, a storage medium and a computing device. The application considers the new energy grid connection characteristics, constructs a system transient frequency response model after the new energy grid connection under the condition that the new energy does not participate in frequency control and the new energy rotor does not respond to the system frequency change, calculates the maximum value of the system frequency steady-state deviation and the frequency change rate, determines the setting value of the new energy part of the high-week machine tripping scheme of the new energy grid connection system, and determines the setting value of the traditional unit part of the high-week machine tripping scheme of the new energy grid connection system according to a frequency response analysis mathematical model. On the one hand, the system transient frequency response model realizes quantitative analysis on the system frequency stability problem after large-scale new energy grid connection. On the other hand, the setting value of the high-week machine tripping scheme after the regional power grid is isolated after the new energy grid connection is considered. The setting value is calculated, which is of great significance for guiding the reliable operation of an actual power grid.

Description

Technical Field

[0001] The present invention relates to a method, system, storage medium and computing equipment for determining a high-frequency shearing machine scheme constant value, and belongs to the field of power system stability control. Background Art

[0002] The installed capacity of renewable energy is constantly increasing, and the large-scale grid connection of renewable energy has a significant impact on the frequency stability of the power grid. Therefore, how to determine the constant value of the high-frequency shedding scheme after the large-scale grid connection of renewable energy has become an urgent problem to be solved, but there is currently no corresponding method. Summary of the Invention

[0003] The present invention provides a method, system, storage medium and computing device for determining constant values ​​of a high-frequency shearing machine scheme, which solve the problems disclosed in the background technology.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] The method for determining the fixed value of the high-frequency cutting machine scheme includes:

[0006] Considering that renewable energy does not participate in frequency control and renewable energy rotors do not respond to system frequency changes, a transient frequency response model of the system after renewable energy is connected to the grid is constructed based on the proportion of renewable energy in the system.

[0007] According to the system transient frequency response model after the new energy is connected to the grid, the maximum value of the system frequency steady-state deviation and frequency change rate is calculated;

[0008] Determine the setting value of the new energy part of the high-frequency shedding scheme of the new energy grid-connected system based on the maximum value of the system frequency steady-state deviation and frequency change rate;

[0009] Based on the system transient frequency response model before the new energy grid is connected, the setting values ​​of the traditional unit part of the high-frequency shedding scheme of the new energy grid-connected system are determined.

[0010] Considering that renewable energy does not participate in frequency control and renewable energy rotors do not respond to system frequency changes, a transient frequency response model of the system after renewable energy is connected to the grid is constructed based on the proportion of renewable energy in the system, including:

[0011] Under the assumption that renewable energy does not participate in frequency control and the renewable energy rotor does not respond to system frequency changes, the equivalent machine inertia time constant and speed regulator droop coefficient of the renewable energy grid-connected system are determined based on the proportion of renewable energy in the system.

[0012] Based on the system transient frequency response model before the new energy grid is connected, the equivalent machine inertia time constant and the speed regulator droop coefficient of the new energy grid-connected system, the system transient frequency response model after the new energy grid is connected is constructed.

[0013] The formula for the equivalent machine inertia time constant and speed regulator adjustment coefficient of the new energy grid-connected system is:

[0014] H′=(1-α)H

[0015]

[0016] Wherein, H′ is the equivalent machine inertia time constant of the new energy grid-connected system, H is the equivalent machine inertia time constant of the system before the new energy grid-connected, α is the proportion of new energy in the system, R′ is the equivalent machine speed regulator droop coefficient of the new energy grid-connected system, and R is the equivalent machine speed regulator droop coefficient of the system before the new energy grid-connected.

[0017] The system transient frequency response model after the new energy is connected to the grid is:

[0018]

[0019] Among them, α is the proportion of new energy in the system, H is the equivalent machine inertia time constant of the system before the new energy is connected to the grid, R is the equivalent machine speed regulator droop coefficient of the system before the new energy is connected to the grid, Δω is the system frequency deviation in the frequency domain, ΔP G is the mechanical power change of the system equivalent machine under the action of the speed regulator, ΔP d is the instantaneous power disturbance of the system described by a step function, G s (s) is the transfer function, K m is a constant coefficient, F H is the output power ratio of high-pressure boiler in the system equivalent unit, T R is the steam turbine reheater time constant of the system equivalent machine, and s is the frequency domain time variable of Laplace transform.

[0020] The formula for calculating the steady-state deviation of the system frequency is:

[0021]

[0022] Where Δf ∞ is the system frequency steady-state deviation, f N is the grid reference frequency, α is the proportion of renewable energy in the system, R is the equivalent speed regulator droop coefficient of the system before renewable energy is connected to the grid, K m is a constant coefficient, D is the equivalent damping coefficient of the equivalent machine before the new energy grid is connected, ΔP L is the instantaneous power disturbance of the system before the new energy is connected to the grid, S B is the total system capacity.

[0023] The formula for calculating the maximum frequency change rate is:

[0024]

[0025] Among them, ROCOFmax is the maximum value of the frequency change rate, f N is the grid reference frequency, α is the proportion of new energy in the system, S B is the total system capacity, ΔP L is the instantaneous power disturbance of the system, and H is the equivalent machine inertia time constant of the system before the new energy is connected to the grid.

[0026] The setting values ​​of the new energy part of the high-frequency shedding scheme of the new energy grid-connected system include the number of rounds of the new energy part of the high-frequency shedding, the frequency setting value of each round, and the shedding amount;

[0027] The setting values ​​of the traditional unit part of the high-cycle shedding scheme of the new energy grid-connected system include the first-round action threshold value, the shedding amount in each round and the termination round action threshold value.

[0028] High frequency cutting machine program constant value determination system, including:

[0029] The model building module constructs a transient frequency response model of the system after the new energy is connected to the grid, taking into account that new energy does not participate in frequency control and the new energy rotor does not respond to system frequency changes.

[0030] The calculation module calculates the maximum value of the system frequency steady-state deviation and frequency change rate based on the system transient frequency response model after the new energy is connected to the grid;

[0031] The module for determining the setting value of the new energy part determines the setting value of the new energy part of the high-frequency shedding scheme of the new energy grid-connected system based on the maximum value of the system frequency steady-state deviation and the frequency change rate;

[0032] The module for determining the setting values ​​of the traditional units determines the setting values ​​of the traditional units of the high-frequency shedding scheme of the new energy grid-connected system based on the system transient frequency response model before the new energy grid-connected system.

[0033] A computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform a method for determining a setting value of a high-frequency shear engine scheme.

[0034] A computing device includes one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing a method for determining a setting value of a high-frequency shear machine scheme.

[0035] The beneficial effects achieved by the present invention are as follows: the present invention takes into account the characteristics of new energy grid connection, and considers that new energy does not participate in frequency control and new energy rotors do not respond to system frequency changes, constructs a system transient frequency response model after new energy grid connection, calculates the maximum value of the system frequency steady-state deviation and the frequency change rate, determines the setting value of the new energy part of the high-cycle shedding scheme of the new energy grid connection system, and determines the setting value of the traditional unit part of the high-cycle shedding scheme of the new energy grid connection system according to the frequency response analytical mathematical model. On the one hand, the system transient frequency response model is used to realize the quantitative analysis of the system frequency stability problem after large-scale new energy grid connection, and on the other hand, it realizes the calculation of the setting value of the high-cycle shedding scheme after the regional power grid is isolated after the new energy grid connection, which is of great significance for guiding the reliable operation of the actual power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a flow chart of the method of the present invention;

[0037] Figure 2 It is a transient frequency response model containing only traditional unit systems;

[0038] Figure 3 It is the transient frequency response model of the new energy grid-connected system;

[0039] Figure 4 This is a diagram showing the frequency variation of a small system;

[0040] Figure 5 The simulation calculation curve for a 6% reduction in small system load. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0042] like Figure 1 As shown, the method for determining the constant value of the high-frequency cutting machine scheme includes the following steps:

[0043] Step 1: Considering that renewable energy does not participate in frequency control and renewable energy rotors do not respond to system frequency changes, a transient frequency response model of the system after renewable energy is connected to the grid is constructed based on the proportion of renewable energy in the system.

[0044] Step 2: Calculate the maximum value of the system frequency steady-state deviation and frequency change rate based on the system transient frequency response model after the new energy is connected to the grid;

[0045] Step 3: Determine the setting value of the new energy part of the high-frequency shedding scheme of the new energy grid-connected system based on the maximum value of the system frequency steady-state deviation and the frequency change rate;

[0046] Step 4: Determine the setting values ​​of the traditional units in the high-frequency shedding scheme of the new energy grid-connected system based on the system transient frequency response model before the new energy grid-connected system is connected.

[0047] The above method takes into account the characteristics of new energy grid connection. Considering that new energy does not participate in frequency control and new energy rotors do not respond to system frequency changes, a system transient frequency response model after new energy grid connection is constructed, the maximum value of the system frequency steady-state deviation and the frequency change rate are calculated, and the setting value of the new energy part of the high-cycle shedding scheme of the new energy grid connection system is determined. According to the frequency response analytical mathematical model, the setting value of the traditional unit part of the high-cycle shedding scheme of the new energy grid connection system is determined. On the one hand, through the system transient frequency response model, a quantitative analysis of the system frequency stability problem after large-scale new energy grid connection is realized. On the other hand, it realizes the calculation of the setting value of the high-cycle shedding scheme after the regional power grid is isolated after the new energy grid connection, which is of great significance for guiding the reliable operation of the actual power grid.

[0048] The system containing only traditional units (generator sets) is analyzed as follows:

[0049] The physical definition expression of the inertia time constant of a traditional generator set is:

[0050]

[0051] Among them, T j Indicates the inertia time constant of the generator set, Ω * =Ω / Ω0, Ω(rad / s) represents the mechanical angular velocity of the generator rotor, Ω0(rad / s) represents the rated speed of the rotor; ΔM * Indicates the per-unit value of the unbalance torque acting on the rotor shaft.

[0052] The generator rotor motion equation can be:

[0053]

[0054] Where δ represents the angle between the generator’s q-axis and the reference phasor U, ω represents the electrical angular velocity of the generator rotor, and ω0 represents the synchronous angular velocity of the reference phasor.

[0055] Further we can get:

[0056]

[0057] Considering the large inertia of the generator, the change of the mechanical angle Ω is generally not too large, and it is approximately considered that the per-unit value of the generator torque is equal to the per-unit value of the power, that is,

[0058]

[0059] Further we can get:

[0060]

[0061] Among them, P T* Indicates the per-unit mechanical power of the generator set prime mover, P E* Indicates the per-unit value of the electromagnetic power of the generator set.

[0062] From ω=2πf, we can get:

[0063]

[0064] Where f is the frequency, f * is the per-unit frequency value.

[0065] Therefore, the analytical mathematical model of the frequency response of the power imbalance caused by the fault in the power grid with only traditional units can be obtained as follows: f0 is the frequency reference value.

[0066] For a system containing only traditional units, when active load disturbance occurs in the system, its transient frequency response model is as follows: Figure 2 As shown in the figure, ΔP L is the instantaneous power disturbance of the system before the new energy is connected to the grid, s is the frequency domain time variable of Laplace transform, ΔP a is the unbalanced power borne by the equivalent machine in the system, ΔP G is the mechanical power change of the system equivalent machine under the action of the speed regulator, H is the inertia time constant of the equivalent machine of the system before the new energy grid is connected, reflecting the overall inertia level of the system, R is the droop coefficient of the speed regulator of the equivalent machine of the system before the new energy grid is connected, K m is a constant coefficient, which is determined by the relationship between the power factor and the standby coefficient of the equivalent machine in the system, and is usually taken as 1. D is the equivalent damping coefficient of the equivalent machine in the system before the new energy grid is connected, reflecting the damping characteristics of the system. Δω is the system frequency deviation in the frequency domain, and F H is the output power ratio of high-pressure boiler in the system equivalent unit, T R is the steam turbine reheater time constant of the system equivalent machine.

[0067] according to Figure 2 The system transient frequency response model can be established:

[0068]

[0069] Where ΔP d is the instantaneous power disturbance of the system described by a step function, S B is the total system capacity, G s (s) is the transfer function;

[0070] The system frequency deviation can be further obtained

[0071] Considering the power system's ability to accommodate renewable energy sources such as wind power, new energy and traditional units balance the load power. Because renewable energy lacks inertial response and primary frequency regulation, system frequency disturbances do not alter output. Assuming a system originally consisting of n traditional units incorporates m renewable energy sources, such as wind turbines, the proportion of renewable energy in the power system is defined as the ratio of grid-connected renewable energy capacity to the system's total installed capacity, which can be expressed as:

[0072]

[0073] Among them, α is the proportion of new energy in the system, S j is the rated capacity of the jth renewable energy source, S i is the rated capacity of the i-th traditional unit.

[0074] The integration of new energy sources into the grid leads to the expansion of the system scale. To maintain the disturbance scale unchanged before and after the integration of new energy sources into the grid, we can obtain:

[0075]

[0076] Where ΔP′ L It is the load disturbance power of the system after the new energy is connected to the grid;

[0077] Further introducing α, we can get:

[0078]

[0079] Considering that renewable energy does not participate in frequency control and renewable energy rotors do not respond to system frequency changes, a transient frequency response model of the system after renewable energy is connected to the grid is constructed based on the proportion of renewable energy in the system. The specific process may include:

[0080] 1) Considering that new energy does not participate in frequency control and the new energy rotor does not respond to system frequency changes, the equivalent machine inertia time constant and speed regulator droop coefficient of the new energy grid-connected system are determined according to the proportion of new energy in the system.

[0081]

[0082] Where H' is the equivalent machine inertia time constant of the renewable energy grid-connected system, and R' is the equivalent machine speed regulator droop coefficient of the renewable energy grid-connected system. As can be seen from the formula, the integration of renewable energy that does not participate in frequency control will reduce the system's equivalent machine inertia time constant and equivalent machine speed regulator droop coefficient by an amount equal to the proportion of renewable energy in the grid.

[0083] 2) According to the system transient frequency response model before the new energy is connected to the grid (i.e. Figure 2), the equivalent machine inertia time constant and speed regulator droop coefficient of the new energy grid-connected system can be used to construct the system transient frequency response model after the new energy grid is connected.

[0084] The transient frequency response model of the system after the new energy is connected to the grid is shown in Figure 3 , which can be expressed as:

[0085]

[0086] Based on the typical parameters of the power system, a small system simulation calculation model is built. Based on the transient frequency response equation of the power system after the grid connection of new energy, the frequency deviation of the system under different operating conditions with different proportions of new energy is calculated.

[0087] Take wind power as an example: when the proportion of wind power is 20%, the system frequency deviation is 0.18Hz. When the proportion of wind power increases to 30%, the system steady-state frequency deviation is 0.23Hz due to the weakening of the primary frequency regulation capability of the system unit capacity. BPA software is used to build a small system simulation calculation model, and the frequency change law of the small system under different working conditions of wind power proportion is compared. Figure 4 shown.

[0088] from Figure 4 It can be seen that the system frequency drop amplitude and steady-state frequency deviation both increase with the increase in the proportion of wind power, and the steady-state frequency deviation can reflect the system's primary frequency regulation capability. Based on this, it can be concluded that the grid connection of wind turbines that do not participate in frequency control will weaken the power system's primary frequency regulation capability and increase the system's steady-state frequency deviation. As the proportion of wind power increases, the power system's primary frequency regulation capability decreases and the steady-state frequency deviation increases. When the wind power proportion is 20%, the system frequency deviation does not exceed 0.2Hz (the upper limit of the steady-state frequency deviation). When the wind power proportion increases to 30%, due to the weakening of the system's primary frequency regulation capability per unit capacity, the system's steady-state frequency deviation exceeds 0.2Hz, which is consistent with the calculation results of this method.

[0089] When renewable energy sources are not involved in frequency regulation, the interaction mechanisms between photovoltaics, energy storage, and the AC system are similar. In summary, when renewable energy sources are not involved in the power system frequency response, increasing α will change the system's equivalent inertia time constant and the governor droop coefficient. A decrease in the equivalent inertia time constant will weaken the system's dynamic response capability to provide active power support during the rapid inertia response phase. A proportional decrease in the inverse of the governor droop coefficient will affect the system's ability to provide further power support and regulate dynamic frequency during the primary frequency regulation phase. Consequently, the power system's ability to recover from frequency disturbances is weakened.

[0090] According to the above model, the frequency domain expression of the system frequency deviation after per-unit calibration can be further obtained:

[0091]

[0092] Further according to Laplace's final value theorem, the expression of the system frequency steady-state deviation is obtained:

[0093]

[0094] Where Δf ∞ is the system frequency steady-state deviation, f N The grid reference frequency can be used to calculate the system frequency steady-state deviation.

[0095] According to the above formula, when new energy does not participate in system frequency modulation, the frequency steady-state deviation and stable operating frequency of the system after disturbance are mainly related to D, R, K m , load change level (i.e. ) and α are related.

[0096] Further according to Δf ∞ The maximum expression of the frequency change rate can be obtained:

[0097]

[0098] Among them, ROCOF max The maximum value of the frequency change rate can be calculated using this formula.

[0099] According to the above formula, when renewable energy does not participate in system frequency regulation, the maximum frequency change rate after a disturbance is mainly related to α, the load change level, and H. An increase in the proportion of renewable energy carried by the system, α, will also lead to an increase in the system's steady-state frequency deviation and maximum frequency change rate, which will have an adverse impact on the system's frequency stability.

[0100] According to the maximum value of the system frequency steady-state deviation and frequency change rate, the setting value of the new energy part of the high-cycle shedding scheme of the new energy grid-connected system can be determined, specifically including the number of rounds of the new energy part of the high-cycle shedding scheme, the frequency setting value of each round and the shedding amount.

[0101] For example: For Shanxi's actual power grid operation in 2022, the connection of new energy to the grid will have an adverse impact on the stability of the system frequency. Based on the above analysis and calculation, a high-frequency generator cutting plan is formulated: first, a new energy cutting strategy is adopted, 50% of the new energy units are cut off at 50.3Hz, and the remaining 50% of the new energy units are cut off at 50.4Hz.

[0102] According to the system transient frequency response model before the new energy grid is connected, the setting value of the traditional unit part of the high-cycle shedding scheme of the new energy grid-connected system is determined, and the first-round action threshold value, each-round shedding amount and the termination round action threshold value of the high-cycle shedding scheme of the traditional unit are specifically determined.

[0103] The principle for setting the threshold value of the first round of high-frequency shedding scheme for traditional units is based on the maximum frequency change value at the generator end after a three-phase short circuit fault;

[0104] according to It can be seen that the threshold value of the first round of action is 50.6Hz.

[0105]

[0106] The principle for setting the termination wheel threshold value of the high-frequency shedding scheme of traditional units is: based on the last round of system frequency change value; the termination wheel threshold value is not greater than 51.3Hz.

[0107] Considering a post-fault system active power surplus of 1.0Pn, and four high-frequency generator shedding rounds, we estimate the system frequency deviation after the first three rounds of generator shedding using the above formula to determine the threshold for the fourth round. For the first round of generator shedding, we consider a system active power surplus of 1.0, a system equivalent of 20, a generator shedding time of 0.25s, and a system frequency deviation of 0.625Hz. For the second round of generator shedding, we consider a system active power surplus of 0.75, a system equivalent of 17.5, a generator shedding time of 0.25s, and a system frequency deviation of 0.5357Hz. For the third round of generator shedding, we consider a system active power surplus of 0.5, a system equivalent of 15, a generator shedding time of 0.1s, and a system frequency deviation of 0.1667Hz. For the fourth round of generator shedding, we consider a system active power surplus of 0.25, a system equivalent of 12.5, a generator shedding time of 0.1s, and a system frequency deviation of 0.1Hz. Considering that the OPC protection value of the generator set is 51.5Hz, therefore, considering a certain margin, the threshold value of the fourth round of generator cutting plan should not be greater than 51.3Hz.

[0108] The principle for setting the amount of power loss in each round of high-frequency power loss in traditional units is: the change in active power corresponding to a 1Hz change in system frequency;

[0109] From the rotor motion equation we can get:

[0110]

[0111] Among them, P m 、P e are the mechanical power of the generator set and the electromagnetic power of the generator set respectively;

[0112] From ω=2πf, we can get:

[0113]

[0114] Integrating both sides of the equation yields:

[0115]

[0116] We can further get the expression of frequency changing with time:

[0117]

[0118] The response expression of the unit speed governor can be obtained from experience:

[0119]

[0120] Derivative the expression of frequency changing with time, the moment when the derivative is 0 is the maximum value of frequency deviation, as shown in the formula:

[0121]

[0122] in, f max are the per-unit value of the maximum frequency deviation and the maximum frequency deviation respectively.

[0123] In summary, it can be concluded that the system active power changes by 6%, the system frequency changes by 1Hz, and the traditional units are switched off by 6% in each round.

[0124] When a single-machine small system with load is built in BPA, when the load of the small system is reduced by 6%, the simulation calculation curve of the small system frequency deviation change is as follows Figure 5 As shown, it can be seen that when the load is reduced by 6%, the system frequency changes by 1Hz.

[0125] Based on the same calculation scheme, the present invention also discloses a software system of the above method, a high-frequency shearing machine scheme constant value determination system, comprising:

[0126] The model building module constructs a transient frequency response model of the system after the new energy is connected to the grid, taking into account that new energy does not participate in frequency control and the new energy rotor does not respond to system frequency changes.

[0127] The calculation module calculates the maximum value of the system frequency steady-state deviation and frequency change rate based on the system transient frequency response model after the new energy is connected to the grid;

[0128] The module for determining the setting value of the new energy part determines the setting value of the new energy part of the high-frequency shedding scheme of the new energy grid-connected system based on the maximum value of the system frequency steady-state deviation and the frequency change rate;

[0129] The module for determining the setting values ​​of some traditional units determines the setting values ​​of the traditional units of the high-frequency shedding scheme of the new energy grid-connected system based on the system transient frequency response model before the new energy grid-connected system.

[0130] In the above software system, the data processing flow and method of each module are consistent and will not be repeated here.

[0131] Based on the same technical solution, the present invention discloses a computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, which, when executed by a computing device, enable the computing device to execute a method for determining a constant value of a high-frequency shear machine solution.

[0132] Based on the same technical solution, the present invention discloses a computing device comprising one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing a method for determining a constant value of a high-frequency shear machine scheme.

[0133] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0134] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0135] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0136] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0137] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. The method for determining the constant value of the high-frequency cutting machine scheme is characterized by: include: Considering that renewable energy does not participate in frequency control and renewable energy rotors do not respond to system frequency changes, a transient frequency response model of the system after renewable energy is connected to the grid is constructed based on the proportion of renewable energy in the system. According to the system transient frequency response model after the new energy is connected to the grid, the maximum value of the system frequency steady-state deviation and frequency change rate is calculated; Determine the setting value of the new energy part of the high-frequency shedding scheme of the new energy grid-connected system based on the maximum value of the system frequency steady-state deviation and frequency change rate; Based on the system transient frequency response model before the new energy grid is connected, the setting values ​​of the traditional units in the high-frequency shedding scheme of the new energy grid-connected system are determined; The transient frequency response model of the system after the above-mentioned new energy is connected to the grid is: Among them, α is the proportion of new energy in the system, H is the equivalent machine inertia time constant of the system before the new energy is connected to the grid, R is the equivalent machine speed regulator droop coefficient of the system before the new energy is connected to the grid, Δω is the system frequency deviation in the frequency domain, ΔP G is the mechanical power change of the system equivalent machine under the action of the speed regulator, ΔP d is the instantaneous power disturbance of the system described by a step function, G s (s) is the transfer function, K m is a constant coefficient, F H is the output power ratio of high-pressure boiler in the system equivalent unit, T R is the steam turbine reheater time constant of the system equivalent machine, s is the frequency domain time variable of Laplace transform; The formula for calculating the steady-state deviation of the system frequency is: Where Δf ∞ is the system frequency steady-state deviation, f N is the grid reference frequency, D is the equivalent damping coefficient of the equivalent machine before the new energy grid is connected, ΔP L is the instantaneous power disturbance of the system before the new energy is connected to the grid, S B is the total system capacity; The formula for calculating the maximum frequency change rate is: Among them, ROCOF max is the maximum value of the frequency change rate.

2. The method for determining the constant value of a high-frequency shearing machine scheme according to claim 1 is characterized in that: Considering that renewable energy does not participate in frequency control and renewable energy rotors do not respond to system frequency changes, a transient frequency response model of the system after renewable energy is connected to the grid is constructed based on the proportion of renewable energy in the system, including: Under the assumption that renewable energy does not participate in frequency control and the renewable energy rotor does not respond to system frequency changes, the equivalent machine inertia time constant and speed regulator droop coefficient of the renewable energy grid-connected system are determined based on the proportion of renewable energy in the system. According to the system transient frequency response model before the new energy grid is connected, the equivalent machine inertia time constant and the speed regulator droop coefficient of the new energy grid-connected system, the system transient frequency response model after the new energy grid is connected is constructed.

3. The method for determining the constant value of a high-frequency shearing machine scheme according to claim 2, characterized in that: The formula for the equivalent machine inertia time constant and speed regulator adjustment coefficient of the new energy grid-connected system is: H′=(1-α)H Among them, H′ is the inertia time constant of the equivalent machine of the new energy grid-connected system, and R′ is the droop coefficient of the equivalent machine speed regulator of the new energy grid-connected system.

4. The method for determining the constant value of a high-frequency shearing machine scheme according to claim 1 is characterized in that: The setting values ​​of the new energy part of the high-frequency shedding scheme of the new energy grid-connected system include the number of rounds of the new energy part of the high-frequency shedding, the frequency setting value of each round, and the shedding amount; The setting values ​​of the traditional unit part of the high-cycle shedding scheme of the new energy grid-connected system include the first-round action threshold value, the shedding amount in each round and the termination round action threshold value.

5. High frequency cutting machine program constant value determination system, characterized by: include: The model building module constructs a transient frequency response model of the system after the new energy is connected to the grid, taking into account that new energy does not participate in frequency control and the new energy rotor does not respond to system frequency changes. The calculation module calculates the maximum value of the system frequency steady-state deviation and frequency change rate based on the system transient frequency response model after the new energy is connected to the grid; The module for determining the setting value of the new energy part determines the setting value of the new energy part of the high-frequency shedding scheme of the new energy grid-connected system based on the maximum value of the system frequency steady-state deviation and the frequency change rate; The module for determining the setting values ​​of the traditional units in the high-frequency shedding scheme of the new energy grid-connected system is used to determine the setting values ​​of the traditional units in the high-frequency shedding scheme of the new energy grid-connected system based on the system transient frequency response model before the new energy grid-connected system is connected. The transient frequency response model of the system after the above-mentioned new energy is connected to the grid is: Among them, α is the proportion of new energy in the system, H is the equivalent machine inertia time constant of the system before the new energy is connected to the grid, R is the equivalent machine speed regulator droop coefficient of the system before the new energy is connected to the grid, Δω is the system frequency deviation in the frequency domain, ΔP G is the mechanical power change of the system equivalent machine under the action of the speed regulator, ΔP d is the instantaneous power disturbance of the system described by a step function, G s (s) is the transfer function, K m is a constant coefficient, F H is the output power ratio of high-pressure boiler in the system equivalent unit, T R is the steam turbine reheater time constant of the system equivalent machine, s is the frequency domain time variable of Laplace transform; The formula for calculating the steady-state deviation of the system frequency is: Where Δf ∞ is the system frequency steady-state deviation, f N is the grid reference frequency, D is the equivalent damping coefficient of the equivalent machine before the new energy grid is connected, ΔP L is the instantaneous power disturbance of the system before the new energy is connected to the grid, S B is the total system capacity; The formula for calculating the maximum frequency change rate is: Among them, ROCOF max is the maximum value of the frequency change rate.

6. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any one of the methods according to claims 1 to 4 .

7. A computing device, characterized in that include: One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs comprising instructions for performing any of the methods according to claims 1 to 4.

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